Woodfinishers Weblog

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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