Woodfinishers Weblog

Wood finishing forum for professional finishers

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

 

 

 

 

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