Woodfinishers Weblog

Wood finishing forum for professional finishers

Back painting glass using the CIC Mustang adhesion promoter

Adhesion promoters are a very useful tool to have in your belt as a finisher, as you will see in this very informative video by master finisher and good friend Thomas Craven, of Thomas Craven studios in Van Nuys California.

Back painting glass is what we are doing here, the other uses for this product are where you have to paint  rubber or plastic, this product was originally designed for painting plastic bumpers  and parts for the automotive industry ( Rubber bumpers on cars, 30 years ago that was a joke). Another use is painting over plastic laminates. I had a customer that bought some very expensive custom cabinet doors from Italy, they were a laminate that had a custom wave C-N-Ced in to the door, the customer made a mistake and got the wrong color,  we used the adhesion promoter on these and fixed the color.

Tom is using the CIC mustang adhesion promoter to back paint glass that is going to be used as a black splash, this is a cool little technique and is very popular. It has high tech ultra modern look and is easy to do, getting the paint to stick to the Glass is the tricky part.

An adhesion promoter is in essence a spray on glue that bonds to the glass and then bonds to your paint and thereby promoting adhesion, Simple Right?    yes and no.

There are a few key application points that Tom goes over in the video that are very Key, two light  (underline) coats. this is not a coating in itself you just want enough to get so stick.

NEXT POINT, you apply  your paint while the adhesion promoter is still tackie. don’t let it dry and then paint over it you have defeated the purpose.

The CIC mustang is a great product as it sprays out very light and doesn’t clump or clog, when looking at the glass you wouldn’t know that there was anything other than the color coat, and guess what you can get that product and other fine CIC products on my web site at http://www.annexpaint.com. if  you have questions you are welcome to write to me at info@annexpaint.com.

and here’s the video:

 

best,

Greg Saunders

 

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February 2, 2015 Posted by | Conversion varnish, Spray techniques, Tips and Tricks | , , , , , , | Leave a comment

Painting speaker cabinets Flat Black with pinnacle polyprimer and CIC conversion varnish

Thomas Craven of Thomas Craven studios, ( http://www.tcwoodfinishers.com/index.html) has done a phenomenal short video series on refinishing a pair of Vandersteen speakers.

He has 6 short videos in all which are very concise and to the point, clearly covering the points of proper prep and application for doing a professional paint Job.

After proper preparation they applied 4 coats of pinnacle polyprimer from Ellis paint. applied in two applications, sanding in-between coats. This gave him and exceptionally hard finish that was very smooth,

Probably one of the most common mistakes of beginning finishers and professionals alike is applying too much paint too quickly, for the sake of speed they whammer on two heavy coats and walk away only to have it bubble or crack on them later. When the first coat doesn’t have a chance to dry properly and then is covered over by successive coats the later layers will dry quicker and harden, then when the earliest layer finally dries a week or two later it will shrink, the later coats already dry and unable to contract will be pulled together and will crack.

The best practice is sneak up on a high build by successive light to medium coats

The videos are all linked together, there are two introductory videos which go over the project and the prep following that you have two more short videos of the spray applications

After that they applied the polyprimer they applied a flat Clear Conversion Varnish. Conversion varnish is a catalyzed coating which is very hard and durable. CIC coatings is the brand of Conversion varnish being used, I’m very fond of this this particular product as it has been specially formulated to be applied right out of the can with out thinning or retarding, it lays out incredibly smooth and dries quickly.

These products can be obtained through my store Annex Paint in Reseda California If you have any questions about these products feel free to contact me.

Greg Saunders 818-439-9297

If you are interested in having a specialty coating on your furniture contact Thomas Craven at the above web site.

June 14, 2014 Posted by | Conversion varnish, Tips and Tricks, Uncategorized, Wood finishing | , , , , , , , , , | Leave a comment

Sucess story using the Rexcell water based conversion varnish

Walnut Kitchen Island finished with W/B Conversion Varnish

 This is a story from  a gentleman who is a retired air force officer whose hobby is cabinet and furniture building, As you’ll see he is an incredible cabinet builder.

 As his shop is in his garage with limmetted space and no spray booth Dennis was interested in water born products but needed something that was super tough. I suggested the Rexcell  Water based Conversion varnish. As you will see it turn out stunningly beautiful.

Fore note: this product is no longer manufactured by Rexcell but is now being manufactured to spec by another American manufacturing company, the product is as good or better than before, It has been referred to as three different manufactures Renner, Rexcell and now CIC. It is all the same product, a water born Conversion Varnish.

Here’s is the Story Dirrect from Dennis : 

FIRST EXPERIENCE WITH WATER BASED FINISH

 I have been building wooden furniture and cabinets as a hobbyist for over forty years. Over this period I have sprayed, brushed and wiped on all the standard finishes that hobbyist woodworkers usually use. Because I’m in my upper sixties in age, I have looked upon the new water based finishes for wood with skepticism. I recently finished a kitchen island for my daughter’s new kitchen. It’s a walnut cabinet with a maple butcher block top. It measures 50 inches long by 30 inches wide by 36 inches high. And, I sprayed a water based conversion coating (called water based lacquer) for the protective finish. This was my first experience with a water based coating and I’m extremely pleased with the way it turned out. I chose it for it’s touted durability which was demonstrated to me by Greg Saunders, a sales representative for the Annex Company of Reseda, California. Greg showed me samples, coated with the product I used, that he placed in his home shower for approximately two months and the durability was impressive. ( You can see this test in another post on the Blog)

 The material I used is made by the Rexcel Company, and is a water based conversion varnish, meaning that it is tough enough for counter tops and moisture resistant for high moisture areas)

I used a Goldenstar HVLP air spray gun (Advertised as being especially for water based finishes)

( This is an inexpensive but quality spray gun that Annex paint sells)

Fluid orifice: 1.7mm (this size is recommended for this water based product)

Pressure required: 15-50 psi (I used 30 psi)

 I was spraying in 90 degree summer weather and therefore added 3 percent of regular lacquer retarder. Greg, the sales rep, said I could thin the product with water by about 10 percent but I used it full strength and it seemed to spray very well. I am used to spraying regular nitro cellulose lacquer and I used the very same technique with this water based lacquer. It appears milky in color when it first goes on but otherwise it sprays on like regular lacquer. You have to use the same caution on vertical surfaces as with regular lacquer. A good technique is to use a big piece of brown cardboard to adjust your spray volume and pattern before tackling your project.

 I sprayed three coats and sanded lightly between coats. I probably could have gotten by with only two coats. Remember, each coat of this water based finish lies on top of the previous coat. It doesn’t melt into the previous coat as with regular lacquer. As with regular lacquer, this product dries quickly and can be sanded within 20 minutes and recoated. It was hot and dry when I sprayed so weather conditions might alter the drying times. After the third coat, it was a bit too glossy for my preference so I waxed with a steel wool pad which resulted in a soft sheen that I was looking for. I’m totally happy with the way it turned out.

 I kept a bucket of water and a rag nearby while I was spraying. A couple of times when I got runs, I immediately wiped it off, let it dry, sanded lightly, and recoated. I really enjoyed the water clean up – of the runs and the clean-up of the spray equipment. A word here about clean-up – and this attests to the durability — if you wait until this finish dries, you can’t clean up with water – it takes acetone. I sprayed the first coat with my regular glasses on (plastic lenses). I got overspray on my glasses and I still haven’t gotten it off. However, acetone on my plastic lenses would probably not be smart.

 I made a silverware tray at the last-minute for one of the cabinet drawers and I brushed on two coats of finish with a foam brush. That went on very nicely too. Will I continue to use water based finishes? — definitely yes, especially for kitchen and bathroom furniture. Will I use it for living room furniture? – the jury is out, but I’m hoping to.   

Here is another picture of Dennis’ work. For note this stunningly beautiful Kitchen Island was built by Dennis for his daughter who recently returned from active service in the Military in Iraq.

Walnut cabinet finished with Rexcell water based conversion Varnish

 For his privacy, I have left out Dennis’s contact informations, However, you are welcome to comment on his work and ask any questions on this blog. If you are intersted in contacting Denis for custom work please send me an e-mail and I’ll foreward it on to him.

 As always if you have finnishing qustions you can leave me a comment here on the Blog or write to me dirrectly at : greg@annexpaint.com

February 12, 2010 Posted by | CIC Centurion, water based Conversion Varnish, Conversion varnish, Tips and Tricks, Water based Lacquers | , , , , , , | 2 Comments

Is Rexcel Water based conversion coating flammable ?

I had a contractor ask  me the question is the conversion coating flammable as he was going to finish a wine cellar in a basement where there was a gas burning furnace. Normally when spraying lacquers on a job site you want to make sure that all open flames are extinguished Vapors sometimes being heaver then air can sprayed along the ground to a gas burning water heater and go boom –not good. Matt the contractor wanted to find a water based material that would not have this problem and was interested in the Rexcel conversion coating  the following is my response …

“The materials are not flammable However, they are potentially combustible, you should always spray in an area that is properly ventilated and I would, if at all possible turn off the furnace while spraying. Inert dust, such as saw dust or even flower can become explosive all by itself if there is a sufficient quantity of in suspended in the air. Like wise with a sealed room full of over spray and vapor.

The Rexcel conversion coating is water based but it does have volatile chemicals in it.  If for some reason you can’t turn off the furnace then ventilate the room so that your fumes are being sucked out of the room and not into the furnace.”

All that being said I doubt you would have a problem, but I don’t want to be the on that gets you blown up. What I have done personally in the past when confronted with such situations is to erect a temporary spay booth around the work with Plastic and 2X2s or something similar. Tape it to the ceiling and floor, Home depot sells zippers that you can tape on to the plastic and use as an entry and exit.  Then I would duct in (either with plastic or flex dusting you can also find at home depot) and air supply and an exhaust, I have built some pretty spiffy spray booths in some real swanky homes where the customers did not want to spell lacquers. You can put a A/C air filter on the exhaust side to catch particles before it goes out a window.   

 Let me know if that is helpful.

Greg Saunders

ANNEX PAINT

November 12, 2009 Posted by | CIC Centurion, water based Conversion Varnish, Conversion varnish, Tips and Tricks, Water based Lacquers | , , , , , | 1 Comment

What is the best finish for my Kitchen?

Since I have had this blog up I have had numerous calls and emails from homeowners and professionals alike asking what is the best finish for my kitchen?  Some go on to say things like my contractor wants to put Valspar luster lac on but my architect tells me that we should use polyurethane and my neighbor say use water base. What do I do?

 The simple answer is have all these people give you samples of the finish not only should you ask for a sample but have them do a sample on the same wood and materials that  you are going to have in your kitchen: alder, cherry, maple or what ever. Then have them use a door or a cabinet from your kitchen. If you have to pay a little for it you should.  A real good finishing job is expensive and worth it using multiple steps in the finishing process you can gain a depth and clarity that you don’t with the lower quality finishing.

By survey, a well painted room or a high quality cabinet finishing job will make a room “feel different” the untrained person coming into the room will feel more comfortable and will prefer the room with the higher quality finish to the room with the lesser quality finish. The technology behind this is the fact that consciously or not a person does perceive imperfections and they will make you feel to one degree or another uncomfortable. The same thing is true when you go into a room that is off square and a room that is perfectly square even when the rooms are identical in every other aspect by test, most people will “like” the square room better. Not all things are square, nor do you always want square. The point being that people can perceive the difference in quality and workmanship, when the difference is not as obvious. Ever notice the phenomena of seeing two similar looking products you pick up the more expensive one? 

 I’ve digressed; a good finish is worth the extra cost. That being said, what are the differences and the pros and cons of each.

 Nitro-cellulous lacquer– The easiest to apply; it gives a great look and feel. All regular lacquers will yellow over time, some faster than others. Valspar has been notorious for that. Regular lacquer is relatively soft and will not hold up to moisture. But feel great and therefor it is not good for kitchens and bathrooms. Lacquer finishes are easy to repair as each successive coat of lacquer melts into itself.

 Pre-Catalyzed lacqueror Pre-Cat lacquer, designed about 50 years ago as a material that would hold up to moisture environments better, the kitchen and bath rooms. Pre-cats   have an acid catalyst in the mix that makes it a lot harder and yet it is still relatively easy to work with.  Pre-Cats are what you should have in your kitchen but they have a tendency to crack if applied too heavily and they are not impervious to moisture. You have to wipe up spills and not let the dish water sit in the crevices and cracks of a cabinet door.  Give that door a year with a daily dose of water sitting on it not cleaned up and the coating is going to fail.  You do have to clean up after your spills. If you don’t like that Idea, hire a maid or go with stainless steel. The Pre-Cat lacquer brand I like the best is Gemini. It is thick and yet can be sprayed directly out of the can dries quickly and looks great. 

 Water based lacquers– they have come a long way. They have had a tendency to have a “plasticie” look as the materials lay on top of the wood rather than soaking in to the wood as a lacquer does. One person I know refers to water base materials as nothing but watered down Elmer’s glue. 20 yeas ago that was about what a water based finish looked like.

 Times have changed and the water bases of today are far superior to what they were. Old time finishers who haven’t taken the time to train themselves on how to properly apply the materials still cling to their earlier fixed Ideas on the matter. The truth is that properly applied a water based finish can look just as good as a lacquer finish and is twice as durable as lacquer when it comes to moisture. The trick is in knowing how to apply it and letting the water based materials fully cure. Cure is different than dry. The materials will dry in a few minutes and then take a week or two to fully cure. The other up-side to water based materials are that you are releasing toxins in to the atmosphere don’t however think that water based materials are with out carcinogens. There are lots of nasty chemicals in water based paints they are just not being released into the atmosphere as are the lacquer products. Personally I have a few water based materials that have proven them selves; the Gemini brand “Titanium” and more recently the Italian brand Renner. The Renner is hands down the best water based material I have found to date.  Like a Lamborghini however, it’s pricy at $210 for five gallons as apposed to the $170 a five for Gemini Water based lacquers.

 Conversion Varnish, this is tough stuff and is the product that I would recommend for table tops and high wear areas. It is tougher to work with and is rougher on both the personnel spraying it and the equipment it requires a higher skill set to use and it more difficult to repair. There are high end finishers that do all there work in Conversion Varnish as they want the toughest finish they can provide. It does have great moisture resistant qualities however it is not designed for out side use. The brand I sell and have had good results with is again the Gemini brand. (I have had others  I  stocked and had troubles with. Suffice to say I no longer carry those brands). The Conversion I sell is about $50 to $60 dollars a gallon. And comes with the catalyst you have to add

 Water based conversion coating; This is a new product to the market that I’m beginning to really like. It combines the best of both worlds.  There aren’t many companies that make it. Rexcel is the brand I have, American made and comparable to the solvent base stuff. You can see other articles in this Blog about it.  Very tough and moisture resistant (see the earlier article I wrote where I have pictures of the panels coated with the Rexcel in my shower stall getting the extreme moisture test. The panels have been in there for over two months with two or more showers happening a day and there is no signs of failure in the coating. This particular product needs no further catalysing which makes it very painter friendly.

 Polyurethanes, Water based and other wise, these are the toughest finish that you can get and the most expensive. One part polyurethanes or single stage that have not catalyst aren’t really worth the effort of buying. Most polyurethanes come with a catalyst you have to add before applying similar to epoxy glue, there is a part A and a part B. you have to get the ratios right or it either won’t dry or will dry and crack. They generally sit on top of the wood as a coating and so give it that plastic film look. It’s tough to glaze in-between coats and which is the technique that gives you that depth and quality. There are some really good finishers that can pull the off but normally for the expense that is not something you need for your house or kitchen. This is the product I recommend for commercial applications that is getting high wear and constant abuse. Additionally If you want shinny you can buff and polish polyurethane to a high gloss that is mirror smooth. 

 To give you an idea, polyurethanes are the coatings you put on your floor, that’s the toughness you get from a poly. If you want a high build thick film that you can see this would be the product to use as you can lay it on thick unlike Lacquers.  There are water based polys and solvents based, I carry both.  I wouldn’t recommend doing you kitchen cabinets in polyurethane, that being said I have some very high end finishers who have perfected the skill sets and can product incredible products with polyurethanes. These finishing procedures come with a cost. “Thomas Craven Finishing Company” are at the top of their league for high end work. 

 So what should you have your kitchen done with. Get the samples and look at them. see the look that you like and then decide what you are willing to pay for it. If you are a Hollywood celebrity, have lots of parties and don’t clean, go with the polyurethane. If you are a regular family and are looking to cover you new custom cabinets with something that will preserve them for a long time to come use a Pre Cat lacquer or the water based conversion coating or perhaps the conversion varnish depending on what looks the best for you.

 Either way get your finisher to provide you with samples so you can see the difference yourself. Finishers are usually creatures of habit and like to do what they have done and feel safe with. Often an old school finisher will tell you something is bad because he has no clue how to use it and doesn’t want to learn.

 I enjoy your comments suggestions and opinions.

 Greg Saunders

Annex Paint
greg@annexpaint.com

May 3, 2009 Posted by | polyurethane, Water based Lacquers, Wood finishing | , , , , , , , , , | 32 Comments

Questions about about what wood finishing product to use and where

I thought I would post an Email that was sent to me with a very valid question. Water Based polyurethanes versus Solvent conversion Varnish. Which is harder which is better?

 

Hello,

 I am in the process of building some pantry cabinets for my shore house.  I want to achieve a nice solid white finish. What would you recommend. I was thinking a white tinted conversion varnish applied w/ a hvlp conversion gun. Any other suggestions. I just need it to be more durable than paint. My other option was to paint then apply a waterborne polyurethane coating.

MR B.

Here is my response and answer to the question

 

Hi Mr. B,

 

You have several options. But what I would recommend is the water born poly or similar product. The conversion vanish is great stuff but is very tough on both the people who spray it and your equipment. The acid catalysis is rough on a body, if you do use it get a spray suit with a hood and wear a respirator. It does produce an incredible finish and fast. On the up side to the conversion varnish it is slightly clearer, but you are not doing a clear over a wood stain so that wouldn’t be a significant issue.

 

The down sides to the waterborne poly is it is a little trickier to spray and requires a larger tip size usually 1.7mm or bigger and you may need to experiment around first to get it to lay down smoothly, you may require a certain amount of retarder so that it will lay out smoothly, 3% is all you would want to add after that it will take forever to dry and will compromise the hardness. Once you have your solution dialed in its pretty simple.

 

I would get a good white primer on first otherwise you will be putting on more coats of the poly that you really need and they are harder to sand. Ellis 1262 water based white primer is a great one. Ellis is however a La company I don’t know where you are. Dunn Edwards and Sherman Williams both make decent primers; a good primer will save you time and money. Get the surface as smooth as you can with the primer then two top coats and you are done.

 

Don’t get a water based poly from Home depot or Lowes the “Minwax” polyurethane they sell isn’t that good and doesn’t do that well. I would get something used by professionals, Renner is what I sell  and I love the stuff this is an Italian manufactured material. Of course there are others that are very good as well. “General Finishes” have a few.

 

I have an incredible product that I really like that is somewhere in-between a water based poly and a Conversion varnish. It is manufactured especially for us by a company called Rexcel I have mention of it on my Blog. If you go to the Blog you can see the Rexcel listings I have there as well as the test I am running with the material. I have three panels I shot my self that are in my shower getting wet daily. So far they have been there a month and show no signs of water damage.  

 

 

  Anyway, that product is interior/exterior and harder than hell, you can also buff it to a mirror finish and is only about 54 bucks a gallon if you are interested in having some shipped. We can do that.  We have it white I believe, the one thing about white is there are several whites so you might want to do some testing first. You can also send us a color sample and we can match it. If you do that you have to provide a board with the color of your choosing that is at least 6”X6” that way we’ll have some thing to work with.

 

 

 Let me know what you decide and how it all comes out. If you are interested send some pictures with a little write up and I’ll post it on the Blog.  There is currently one posting from a guy that did his own kitchen with a water base lacquer and it turned out great. You should read that one as well as there are a few tips in there that are Key. One of which is the fact that all water base materials take longer to dry and longer to Cure. You have to let them cure for a few weeks before they get really hard. You can install them after a day or two but be very gentle with it for at least a week. The Conversion Varnish goes hard with a chemical reaction and will continue to cure for days and weeks but will get harder faster than the water based materials that cure at the rate of water evaporating. That by the way is determined by temperature and relative humidity. You can force dry then with heat and air flow but don’t cook them.

 

 

You got me on a roll here, did I answer your sufficiently?

 

Greg Saunders

ANNEX PAINT

818-439-9297

 

 

 

 

March 7, 2009 Posted by | Conversion varnish, polyurethane, Tips and Tricks, Water based Lacquers, Wood finishing | , , , , , , , | 1 Comment

Test Results for the Water based conversion varnish

In the earlier post I hadn’t really done much  with the water based conversion varnish now that a few months have passed I have some more results to post and some pictures.

I really like this stuff and have begun to sell it in quantities. First thing you should know is that it is now not Renner But Rexcel, has made it all along however we were buying it though Renner; In a mutual agreement with Renner USA we are now buying it direct from the factory which is right here in the USA, Texas as a matter of fact.

This is a single part material that you can catalyze for additional hardness, although I have found that it is not necessary, When you do add the hardener you are not giving it a pot life, normally when you have a product you have to add a catalyst to, you have only a certain amount of time to use the material before it becomes hard, with this you don’t have that problem.  Add the cross linker  ( that is what you call a catalyst for a water based product) today and if you don’t use all the materials today  it won’t go bad on you just add more cross linker tomorrow.

Ok, it goes on smooth, I had some trouble with orange peel but that sorted out easily with the proper application of water-based retarder and then it dries quickly. The day I sprayed  the panels you are about to see it was raining out side and I was spraying  under a canopy that was wide open on two sides. I wasn’t getting rained on but I wasn’t inside by any means.  I had no troubles with Blushing and it dried reasonably quickly which was surprising for a water based product on a cold and rainy day.

Several days later I demonstrated this material to a party rental place that normally uses solvent Conversion Varnish and it went on very smoothly with out retarder needed, The finish looked great and was very hard but the one issue I had was that the sheen died down after drying fully this was dark black mix on party chairs.

Ok I tell people about the materials that I recommend and why I recommend them I don’t say things about materials that have haven’t observed.  I have found  the hard way that it is a year or two down the line where you find out what holds up and what doesn’t.

So here is the test that I am conducting:

I have two  coats of the Rexcel conversion coating on three pieces  of crown molding. As you can see here.

rexol-coating-on-molding-feb19th1

They were sprayed out in January by myself. I have let them cure for a few weeks and now have placed them in my shower to accelerate the wet /dry cycle that cabinets go through.

 

Here is a close up of the back of one of the panels: as you can see this panel was given the two coats and no cross linker.

The Back of the Panel

The Back of the Panel

 Now, here is the test: in the next picture you will see these three panels in my shower, two of them are in the back of the shower and the third one is up in the front of the shower. The panels in the back are going to simulate the normal amount of water that  kitchen  cabinets get in front of the sink. A light mist of water twice a day that is not cleaned off.
The third panels is in the front of the shower and is going to get a hosing daily, twice daily. My wife and I use this shower daily.
Yup, this is my Shower

Yup, this is my Shower

Here is the final picture of the panel that is going to get a soaking daily, we’ll see how long it takes for these panels to show water damage.
panel in the front f the shower

panel in the front of the shower

So far after three days in the shower they are showing no signs of wear or water damage. if they did at this point  that would be extremely discouraging and I probably wouldn’t carry the product. 
Some one told me they did a similar test, but like the Kitchen Cabinet Manufactures Association, they smeared different household products on their panels and found that of all things, tooth paste took off the coating.  So at some later point we’ll try some tooth past and see what that does to our Rexcel coating.
If you have questions and or need help with a particular coating send me an e-mail and I’ll see what we can do to point you in the right direction. I would love to hear back from any of the readers.
until the next time,
Greg Saunders
Annex Paint

February 19, 2009 Posted by | CIC Centurion, water based Conversion Varnish, Conversion varnish, Uncategorized, Water based Lacquers | , , , | Leave a comment

Water based Conversion Varnish

RENNER logo

RENNER logo

RENNER, an Italian manufacturer of water based lacquers and polyurethanes.  has just come out with a Water-based conversion varnish that is a single stage material. Interesting. theoretically it’s tougher than an pre-Catalyzed Lacquer and not as expensive as a polyurethane I have been given a small amount of the material to test out If you are interested in trying someand are in the LA SO Cal area send me a line and I’ll see if I can’t get you some to try. So far I have been very impressed with the performance of the Renner line of products and would like to hear back from others who have used the material Your Successes and your failures I want to her  it all, Thanks

Greg

ANNEX PAINT
7450 Reseda Blvd.
Reseda,California
 818-344-3000

September 28, 2008 Posted by | CIC Centurion, water based Conversion Varnish, Conversion varnish, Wood finishing | , , , | 1 Comment

Spray Finishing Basics

 Thomas Craven is one of the Best finishers in the La area that I have come across, I have worked with him for several years now and his finishes are High quality and consistently above manufacturing specification. Over the years we have put on several different wood finisihing seminars. For the classes he has delivered we have used the following expertise he wrote for the class. I liked it so much, I asked for and got Thomas’s  permission to publish it on our BLog — 

 

I welcome your comments and suggestions and I would like any feed back as to how this information was of use to you. as well I welcome your questions  on the matter.

 

 If you would like to contact Thomas Craven directly you will find His shop address at the bottom of the article along with his web site address and Email information.

 

Enjoy,

 Greg

 

Spray Finishing Basics

by

Thomas Craven

 

All spray systems attempt to achieve one thing, that is atomization. Atomization from the dictionary is to, “reduce to minute particles or to a fine spray”. Whether you chose conventional, HVLP, or airless spray equipment, they all achieve the same thing; that is atomization. A satisfactory finish is produced when the spray material is atomized to the point that the material will flow onto the surface and become a uniform and even coating.

 

Viscosity and pressurization are the two main factors that effect proper atomization. 

 

I looked up the definition of viscosity in the dictionary and found it to be just as hard to understand as the name itself. So I will tell you my definition of viscosity as it relates to spray finishing. Are you ready for it; it’s how thin the material is! Correct atomization occurs when the material being sprayed is just viscous or thin enough that the pressurization provided by the spray equipment in use can break up or vaporize the particles to produce a satisfactory coating. You only thin the material down enough so that your spray equipment will atomize the material while producing a coating that flows out onto the surface. Thinning the material too much will leave a coating that is spotty and runs down vertical surfaces. A coating too thick that is drying to fast will give you dry, rough areas and orange peel.

 

Now that we have our material correctly thinned how do we then atomize it? By pressurization. It is the air under pressure coming out of the front of an air gun that breaks up

 the material. Or in the case of airless spray equipment, it is the pressurization of the material itself in the spray line that is then forced out the front of the gun through a very small orifice or spray tip that causes atomization at the front of the gun.  

 

Spray Equipment

 

Conventional– High-Pressure, Low-Volume air spraying is out dated technology. Rarely in use in California any more. Produces a lot of overspray and hence wasted material. Material is presented at the front of the gun where air ports in the air cap at the front of the gun introduce a low volume but high pressure, (40 – 60 psi.), stream of air into the material to break it up and create a variable fan pattern.

  

HVLP– High-Volume, Low-Pressure, is the standard equipment in use today in California. It atomizes the material in the same manner as the conventional gun, by introducing a stream of air into the material that is presented to the front of the gun. However HVLP guns use a larger volume of air at a lower pressure typically 10-20 psi. Reversing the relationship between pressure and volume. This system decreases voluminous overspray and saves materials.

 

Compressors and Filters. Both of these spray systems need compressed air to operate. This air should be filtered as the action of compressing the air heats it up. While in the tank and hose, this air cools down. The moisture in the air then condenses in the tank and lines. In addition compressors will inject oil and other contaminants into the air supply. An oil and water separator / filter mounted close to the end of the airline is recommended. The compressor should be installed outside the building whenever possible. Remember it will be drawing air from the surrounding area you install it in and blowing it on your work. 

 

Spray cups / guns and spray pots.

 

A siphon cup gun has a one-quart cup attached to the bottom of the gun. When you pull the trigger on the gun, air is released out of the air ports in the cap at the front of the gun. This air stream siphons / pulls material out of the cup. The vent hole at the top of the cup must remain free and clear to allow air to enter the cup so that the siphoning action can take place.

 

A gravity feed cup gun is a new innovation in cup / gun design. The cup is mounted above the gun so that the force of gravity is used to bring the material down and present it at the front of the gun. You must keep the vent hole at the top of the cup free and clear to allow the material to drain into the gun. It is superior to the siphon feed cup gun design. Both siphon and gravity feed cup guns are best used for small amounts of material. Sample work, shading and toning procedures, etc.

 

A spray pot is a two-gallon or sometimes five-gallon pot or bucket that has a pressure regulator attached to the top of it. The regulator allows air to free flow through to the gun to atomize the material, but it also pressurizes the material in the pot. Instead of passively siphoning or allowing gravity to feed the material to the front of the gun, the spray pot will deliver material under pressure to the front of the gun for atomization to take place. This will allow greater production as less air is needed to atomize more material. In addition greater capacity is provided by the two or five gallon quantity of material in the pot.

 

Airless spray machines use a hydraulic pump to pressurize the material that is sucked up in a pick up tube from a five-gallon bucket. The material travels in a ½” diameter spray line that are available in fifty foot lengths. The material is forced out the front of the gun through a very small orifice or spray tip. This spray tip atomizes the material and shapes it into a spray fan of preset widths 3 to 21 inches wide.

 

 

The big advantages to airless spraying are,1. Dispensing with the need for compressed air to atomize the material. You get straight material coming out of the gun without the cold, damp, dirty air that is delivered by most compressors. 2. A uniform spray pattern delivering a consistent amount of material all the time. This spray pattern does not require constant adjustment like the conventional and HVLP guns do. 3. It is a closed airtight system so that you may leave material in the spray rig and bucket for extended periods of time. 4. Only one material line too the gun allowing for more mobility. Excellent choice for high production shops.

 

Spray Techniques

 

Spray finishing skills take a lot of raw gun time to be proficient at. You can speed this process up with proper training and coaching. A very simple concept I express to my spray man trainees is; Spray until the surface just gets wet, no more and no less. If you spray too dry, the material won’t flow and will be rough. If you spray too wet, it will and run and fall down vertical surfaces or pool and puddle. Your goal is to get the material to flow and become one even uniform coating with no orange peel, dry spots, runs etc.

 

Always start from the up wind end of the work and spray away from you towards the face of the booth. You don’t want to spray into the airflow of the spray booth as this will leave overspray on previously finished parts and the spray man too. Shoot all edges first and try to shoot your best surfaces last. Cabinet boxes should be shot from top down, working from inside out and horizontal bottoms last.

 

Lapping the material. The general rule of thumb is to overlap your spray pattern by 50 %. This is not set in stone. It can vary depending on the speed you are moving your spray hand. Just remember the basic principal. Spray until the surface just gets wet, no more and no less. Be sure to overlap the leading and trailing edge of a panel to apply a uniform coating to the edge.

 

Six to eight inches away? Again this is a rule of thumb that is not written in stone. Hold the gun the distance from the surface that produces a coating that is just wet.

 

Watch the material coming out the front of the gun. Don’t watch the gun or the surface you are spraying. Keep your eye focused on the material flowing out the front of the gun. This technique gives you a better perspective on how much material is being deposited on the surface.

 

Samples

 

To live or die by your sample? Variations between samples and finished product are to be expected in natural materials that are assembled and finished by hand. This is a concept that your clients need to understand. It should presented in an educational manner so as not to offend or lead the client to believe you will not try your hardest to achieve the look represented by the approved sample. Variations in color and sheen of finish occur do to variations in natural wood colors, variations in porosity of different wood species, changing lighting conditions, etc. You should express to your customer that every effort will be made to achieve the overall effect depicted by the approved sample. This effort is what differentiates between custom finishing and factory produced assembly line finishes.

 

Stain Finishes

 

Surface Prep – Filling nail holes and minor defects with solvent-based filler is the first surface prep step. You want to leave as little putty on the surface as possible as the filler is hard to sand. The entire surface should now be sanded with 180 grit sandpaper to remove residual putty, dirt, pencil marks, fingerprints etc. I recommend no fill paper as opposed to garnet. If your milling department is leaving too many saw and milling marks in the material, it should be improved. The milling department should be providing the finish shop with stain ready material.

 

Stain Types and Their Uses. The two types of stain we will discuss today are oil based and water based stains. The basic difference between the two will be in appearance and safety. Water based stains and their related finishes are generally milkier or waxy looking compared to oil based stains. However the water-based stains are safer to handle and are more environmentally friendly, as they have no harsh solvents or oil in them. Oil based stains and their related solvent borne finishing systems will produce very transparent and clear stain finishes. Stain rags should be soaked in water in a closed container and disposed of according local regulations.

 

Out Of the Can or Custom Mixed? Use out of the can stains provided by your supplier when ever possible to save time and maintain uniformity between samples and finished product. Mixing stains between stock out of the can stains to achieve a specific color is the next step in providing a custom color for your client. If you desire to take the next step in providing your clients with truly custom colors, you can dive into the world of custom mixing concentrated pigments into the appropriate stain bases. This process requires an understanding of color theory and how the basic ingredients relate to each other.

 

To stain or to glaze? That is the question. Stain open grained woods like oak, birch and ash to achieve a more natural and transparent look. Glaze closed grained woods such as maple, cherry, pine and fir to prevent blotching and promote color consistency.

 

Water based stains on raw wood tend to be blotchy and raise the grain. It is recommended to either glaze the stain over the sealed surface or spray shade the stain on the raw surface with the spray gun and leave it alone; that is no wiping.

 

Glaze is stain medium that is hand applied, “glazed”, (with brushes or rags), over and in between finish coats. This is what differentiates the glazed, finish from a stain that is applied to the raw wood. This finish is typically applied to softwoods or closed grained woods such as, pine, fir, maple and cherry wood. “Glazing the wood”, provides maximum color control and prevents blotching. In addition glazing naturally highlights all details and distressing and creates that warmly aged patina exhibited by fine old furnishings and cabinetry.

 

Sealing – A sanding sealer is usually the same material as the finish with the addition of a sanding paste added to it. It is a slippery soap like substance that allows for easy sanding of the surface in preparation for the topcoat. Some finish coatings like polyurethane will seal themselves with a thin first application. (Demonstrations)

 

Prep for Top coating– Sand with 220 or 320 grit sandpaper. Rub with red scotch brite.  

 

 

 

Top Coating – We will discuss three types of finish today. Lacquer, conversion varnish and water borne lacquer.

 

Solvent based lacquershave been the standard of the furniture and cabinet finishing industry for years due to their excellent clarity, ease of use and versatility. In California they are slowly being phased out as the SCAQMD has deemed them to have too many polluting compounds in them, (volatile organic compound or voc). In addition as they have decreased the voc’s in these products they have become harder to use and not as durable.

 

Conversion varnishis the finish that I am most excited about recently. It is essentially a catalyzed varnish that offers the ease of use of lacquer while eliminating the number of coats applied to achieve the same film depth and appearance of lacquer. My standard eight-coat lacquer finishing process has been reduced to four coats of conversion varnish. In addition as this is a catalyzed finish it offers superior wear and tear and durability. This product sprays and dries almost like a lacquer but has the build and full-finished look of varnish. It is voc compliant.

 

Water borne lacquer is the finish that we will be demonstrating today as it is the material that is used on a daily basis here at the Closet Factory. The paint industry has been continuously improving this product since the late eighties when the SQACMD pronounced that they would be slowly phasing out heavily voc laden finishes i.e. solvent borne lacquer. Many furniture manufactures and other heavy users of solvent based finishes relocated to Mexico and other U.S. states with less regulation during that time. Today some shops are returning and new shops are opening due to improvements made to these waterborne finishing systems. This is a superior product compared to what was available ten years ago and will continue to improve. The advantages of this product are, its very low voc content allowing shops in California to use this material virtually on an unlimited basis. The use of synthetic acrylic resins in this material yield a very durable non-yellowing finish product. In addition due to the minimal evaporative solvents in this material you need less applied coats to achieve an acceptable finish as compared to solvent borne lacquer. The primary disadvantage to this material is the drying time that is still slow compared to faster solvent borne finishing systems. The higher the humidity the slower the drying time. This slow drying time can be improved with warmer, dryer air ventilated through the shop. Heat lamps can be used for work that needs to be finished very quickly. Another disadvantage is the slightly milky or waxy appearance of the final finish detracting from finish clarity.

 

Paint Finishes

 

Essentially all of the information provided pertaining to stain finishes as far as surface prep, priming, (which is basically the same step as sealing), prep for top coating and top coating are the same for painting. The materials are essentially the same with the addition of titanium dioxide and pigments to provide the color and hue.

 

 

Touchup

 

For holes, scratches and minor defects, I use colored wax sticks and putties that are available from furniture finishing suppliers. For larger repairs it may be less expensive to simply replace the part instead of spending hours on repair and touchup that may never be acceptable to the client anyway.

 

Minor color touchups can be performed with colored dye stain markers available from furniture finishing suppliers and art stores. My most often-used touchup marker is a black Sharpie pen. Dab the pen onto the area to be touched up and quickly rub it out with your finger to blend into the surrounding surface before it dries. For touchups that require more than what a marking pen can provide; I use straight concentrated Universal Tint Colorants, (UTC). The dry powder touchup kits that are available are great but they are expensive. I use the UTC stain pigments because I stock them any way for the custom mixing I do. In addition they are ready to apply straight out of the can, thinned with a little paint thinner or naphtha if necessary. 

 

Feather outthe area to be touched up with 220 or 320 grit sandpaper. If you leave a sharp, distinct line between the raw wood area and the adjacent stain it will be very difficult to blend that new touchup into the existing stain color. To feather the area you must sand the affected area until the underlying raw wood color graduates slowly from the raw wood color into the fully stained surrounding area.

 

Start applying colorthat is lighter than the surrounding color. Pad or stipple the color onto the effected area. Simply brushing color evenly onto the surface is usually ineffective as it appears like a paint smear. Padding and stippling the color on diffuses the color onto the surface. You want a slightly busy application that will blend the touchup into the surrounding area. Allow to dry for a little while then apply a couple of coats of finish. Apply your final color to blend in with the surrounding area again padding and stippling as necessary for texture. Apply finish. Rub out and polish to remove overspray and blend finish.

 

Standard rub out materialsare 0000 steel wool with a good quality furniture cream or polish. A lot of polish and light rubbing is usually enough. If the 0000 steel wool produces a sheen that is to shinny try 00 wool; be careful not to rub too hard or you may remove your touchup. Buff with a clean rag. 

 

Reference Materials / Trade Magazines

 

Professional Refinishing is a new free trade magazine. I have been impressed with the quality of the articles. (818) 715-9776 / www.prorefinishing.com

 

PWC / Painting and Wallcovering Contractor is another free trade magazine that has good articles once in awhile. (314) 961-6644 / www.paintstore.com

 

Finishes and Finishing Techniques and More Finishes and Finishing Techniques are two books that are compilations of articles published in Fine Woodworking, another trade magazine with some great articles in it. ©

 

Thomas Cravens Shop address

15746 Arminta Street · Van Nuys, CA 91406

Cell # (805) 341-7713 · Fax # (818) 908-8061

Email: ThomasCraven@msn.com

Web Site: TCWoodFinishers.com

© November 2008 by Thomas Craven ©

 

 

this materil is copy write protected, please feel free to print  and use the data contained here in If you intened to re publish this material please contact Mr. Craven and gain his specific permission.

September 28, 2008 Posted by | Conversion varnish, Wood finishing | , , , , , , , , , , , | Leave a comment