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Just Jennifer - The Paint
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Discussion Starter · #1 ·
"Almost all aerosol furniture polishes and some non-aerosols contain silicone. Also, some hand lotions, cosmetics and even deck stains contain silicone.
I doubt there’s any problem in finishing more frustrating than fish eye. The problem usually appears as moon-like craters in the first coat of finish seconds after application, but it can also appear as ridges (sometimes called “crawling”), and it can hold off showing itself until the second or third coat. Fish eye is almost always caused by silicone that has managed to get into the wood. To test for silicone contaminate, paint the surface with an application of mineral spirits, it should start to crawl immediately."
FIX:
"If you suspect silicone contamination before you apply a finish, take one or more of the following preventive steps.
Add silicone to your finish. This lowers the surface tension, or slickness, of the finish to match that of the wood surface, so the finish then flows out level. Once you’ve added silicone to one coat of finish, you have to add it to each additional coat.
Silicone intended for this purpose is sold under a number of trade names, including Fish-Eye Destroyer, Fish-Eye Flo Out, Sil Flo and Smoothie. You can add the silicone directly to any solvent lacquer and stir it in, but you will need to thin it a little with mineral spirits before adding it to varnish or polyurethane. For water-based finishes you will need to get a special emulsified silicone from the finish manufacturer.
Add one-to-two full eyedroppers to a quart of finish. This will make the finish feel a little slicker and it may raise the gloss slightly. You could decide to add silicone to a finish on purpose when you want it to have these characteristics.
Keep in mind that adding silicone to your finish will contaminate your spray gun and require you to clean it extra well to remove all the oil. But contrary to popular myth, you can completely remove all the silicone from the spray gun by spraying solvent through it. I’ve done it countless times.
You should work with a good exhaust to keep over-spray and bounce-back from contaminating other objects in your shop.
Seal the silicone in the wood with a sprayed coat of shellac. The alcohol in the shellac isn’t a solvent for the oil. If you’re spraying lacquer over the shellac, avoid really wet coats because the lacquer thinner in the finish could dissolve through the shellac.
Remove the silicone from the wood in the same way you would remove any oil. Wash the wood with a solvent such as mineral spirits or naphtha. This type of cleaning is only partially effective, however, because the solvent just thins the oil. It doesn’t pull the oil out of the pores. So the trick is to continually change to clean cloths so you don’t just move the oil around; you pick it up and remove it. The more times you wash the wood in this manner, the more you will reduce the oil left in the pores until finally there is not enough to cause a problem." By Bob Flexner
Brown Water Liquid Rectangle Fluid
 

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Just Jennifer - The Paint
Joined
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261 Posts
Discussion Starter · #3 · (Edited)
Fisheyes are a nightmare. I've only had them a couple times.
I run up against them OFTEN in furniture refinishing. People love furniture sprays and that silicone leaches right through the finish, so, even, fully striped and sanded, they appear. I find I need to sand pretty deeply to resolve the issue. The mineral spirits test was a brilliant and learned very late! Paint the surface with an application of mineral spirits, it should start to crawl immediately if the surface is contaminated. One problem I suspect with this test is it might drive the silicone deeper into the wood and would only be of value if you wanted to use silicone to cure the problem. Of course, the mineral spirits should be allowed to dry completely before the finish is applied. I never really found the "washing" worked very well. I just sanded deeply and changed the papers OFTEN while I was doing that. Yes, Fish Eyes are a real monster! Addiing silicone to the finish material works BUT it also keeps kicking the can, on down the road. Not something I ever wanted to do. Not to mention, I do not want ANY silicone in my working environment, that s**t can really get around! There are companies that will permanently ban you from their premises if they ever catch you bring the substance on their site!
 
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