# Someone who knows conversion varnish please help



## Amateur Spray guy (Jul 24, 2018)

Hi I’m Peter. I’m 19. My brother asked me to come work at the small workshop he also works at. Their last spray guy passed away a few weeks before I started there so they really want me to take his place. I’ve only been spraying for two months. I’m not sure why but every once in a while on a project I get a series of bubbles coming up it almost looks like when gun wash has touched finish in a mixing container and it gets lifted off the surface ya know? But I clean the hell out of my gun fully before every spray. And since the first occurance I’ve made sure to be as meticulous as possible as soon as they go into the booth. Yet it still happens. I use an hvlp gun and a giant compressor we use products by acroma pro. I spray as evenly as I can and don’t have problems anymore with orange peel or wrinkling I just don’t know what to do it’s so annoying because I feel I’m ruining these beautiful creations my brother makes. Someone told me not to put links because most people won’t look at them but I don’t know how to do it otherwise. Please look at the pictures


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## Toolman50 (Mar 22, 2015)

What if you flash sand the spots with 320 sp and re-spray?


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## difalkner (Nov 27, 2011)

Peter, is this new wood or reclaimed? Are there any silicone products around? This isn't really like fisheye, more like something began a stripping process or reacted with the finish. Are you wiping the wood down with Naphtha or thinner before spraying and, if so, is your rag clean?

That's exactly what a finish looks like when you start putting stripper on it so it's a bit odd.

David


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## Steve Neul (Sep 2, 2011)

It looks like a chemical reaction to a substance on the wood. If you are spraying the conversion varnish too soon after staining the wood that is a possibility. If there was anything wrong with the conversion varnish it would be all over, not just in spots.


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## Amateur Spray guy (Jul 24, 2018)

Sanding it with a scuff pad and re shooting it is how I’ve fixed it in the past I just don’t want that extra step. I stained them in the morning however and then sprayed it about 3 hours later. How long should you wait between staining and spraying? Also please dumb down the wood working terms this is all very new to me. My brother gave me the basics of wood finishing because he’s only been doing it for 6 months himself and doesn’t really know all the variables to it as well. Any books you guys can recommend on spraying finish? That’s what I’m saying it looks like gun cleaner was sprayed on but that’s not possible so I’m just lost


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## Steve Neul (Sep 2, 2011)

Amateur Spray guy said:


> Sanding it with a scuff pad and re shooting it is how I’ve fixed it in the past I just don’t want that extra step. I stained them in the morning however and then sprayed it about 3 hours later. How long should you wait between staining and spraying? Also please dumb down the wood working terms this is all very new to me. My brother gave me the basics of wood finishing because he’s only been doing it for 6 months himself and doesn’t really know all the variables to it as well. Any books you guys can recommend on spraying finish? That’s what I’m saying it looks like gun cleaner was sprayed on but that’s not possible so I’m just lost


These questions are difficult to answer. If you follow the instructions on some stains it says let the stain sit there 10-15 minutes before wiping it off. What this does is have the stain deeply penetrate into the wood where it oozes stain out for many hours. The linseed oil in stains often causes chemical reactions with a lot of different finishes. In reality the wood will accept all the stain it needs in moments and if you wipe it off immediately then three hours drying time should be sufficient. Even if you apply the stain with one hand and wipe it off with the other if the temperature where you are is low or the humidity is high or both the stain could take overnight drying before it's safe to topcoat. 

A fix in this situation isn't likely. The finish is lifting right off the wood. You would somehow need to get it off without affecting the stain to fix it by recoating it. It's not like lacquer where you can melt the previous coat with solvents. Once conversion varnish is dry that's what you got.


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## difalkner (Nov 27, 2011)

You mentioned the other guy doing the spraying and that he wasn't very organized. So I wonder, did he have the same issues with this finish or did it lay down for him as it should?

David


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## woodnthings (Jan 24, 2009)

*It's either of 3 things ...*

It's either a chemical that's gotten into or on the wood from your shop or where is was sourced.

It's possible the lines and compressor are contaminated with oil or moisture. Install a dryer and vapor filter at the end of the line as close to the gun as possible. A "giant" compressor sounds like it may have some maintenance issues...? Spray some clean white butcher paper to see if there is any discoloration with clear solvents in the same environment as you normally use.... temperature, fans running etc.


It could be the chemicals and ratios you are using are not appropriate or compatible with one another. Your spray pressure may be too high.


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## Steve Neul (Sep 2, 2011)

Here is another possibility. Can you find instructions with the conversion varnish you are using? Look specifically about drying time with it and if it says something like recoat within a couple of hours or wait seven days. Some finishes have a recoat window which you can't allow it to completely dry before putting another coat over the top. If you let it completely dry the solvents in the second coat will lift the first coat as though you put paint stripper on it. 

If you have exceeded the recoat window it's going to be more difficult to fix those spots than to take it off and start over. You would at least have to sand the white off. Then you would have to let it dry a lot longer than the drying time says. At that point it would be more susceptible to lifting than before so you would have to go back with very light coats until you have it covered and then spray a full coat.


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## difalkner (Nov 27, 2011)

On the topic of pressure, you mentioned in the other thread that you're spraying at 60 lbs. I spray lacquer with my HVLP gun at about 28 lbs. Is there a reason why you're using so much pressure?

David


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## woodnthings (Jan 24, 2009)

*I said the same thing ...*

In your "please help" thread I posted the same advice, that 60 lbs seemed excessive. Usually HVLP guns use 30 psi or less. Try spraying some samples using the very same wood and mixtures ratios, but cut the pressure in half. Spray overlapping wet coats and for that you will need excellent overhead lighting. Good lighting is the key to getting a nice finish in my experience. :wink:


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## Walrus Oil (Aug 4, 2018)

I have used conversion varnish on table tops in the past. When we tried drying each coat outdoors with a lot of humidity we noticed bubbles...and had to sand them out and add more coats. I understand the stuff is super toxic but for best results in our experience we would cure them in a VERY WELL ventilated room with a dehumidifier running. Obviously I would do a moisture reading on the wood too before doing anything, make sure its been kiln dried.


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## ColorStylist (Jul 19, 2014)

What wipe stain is he using under the conversion varnish? What varnish do you use? Do you notice on certain wood substrates only?

Sounds like you would be better off after staining to wait till the next day before shooting the varnish to make sure the wipe stain is completely dry. After a wipe stain id applied, Most bigger furniture factories for instance run their wood through ovens at 120 degrees for 10-15 minutes and still may notice some wipe stain bleed back, especially in very pourus woods. 

You also can try and wipe down the doors again before you spray them with a clean wiping rag and then spray them just to make sure they are dry.


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