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Coping with an Anti-Silicone Snafu
Question
Forum Responses
From contributor B: This is one of the reasons our shop only uses products from one company (ML Campbell in our case but I don't know if it's available where you are located if you're not in Uncle Sam's backyard). I've had this problem, often called "fish-eye" while refinishing the occasional item for a customer. We rarely do refinish jobs specifically for this reason. I have to add a product that ML Campbell makes called "Fish Eye Eliminator". One squirt to a quart of finish does the trick. Use it in every coat. It seems to cause the lacquer to cure more slowly. From the original questioner: We take money from Uncle Sam but don’t buy stuff from him. I am in Israel - we have European stuff, some from Italy. I will try something, I am doing a test piece and I will check it out. From contributor D: If you do sand you should wash your surface with TSP (tri-sodium phosphate) and water. If TSP is not available for you then spray the surfaces with a water mix of dissolved oxalic acid. Use a garden bug spraying container or a deck sprayer to spray this. This then needs to be rinsed off, preferably using a pressure washer set at between 500 psi - 700 psi. This pressure is enough to rinse the product off the wood without the water soaking into the wood too much (if at all) and also without so much pressure that the high pressure stream destroys the wood. That gets rid of most of the source of silicones and contamination. Then I would spray on a thinned coat of dewaxed shellac just to make sure that everything is sealed in. The thin shellac coating will be your barrier coat. Scuff lightly with 320 on that and continue as normal. If none of those chemicals are available to you then a good washing and rinsing of the surface with xylene will help. Then do the shellac barrier coat (light applications to seal in the contamination and not have it float to your surface).
From the original questioner: Thank you all. I have a piece I am testing. From contributor E: If you can get the current finish to sand flat you can use shellac as a separation coat to seal what is already on the table. Then you can spray several very light coats of finish. Let them dry for extra time between coats and then finish, but don’t get any of the following coats too thick in one spraying or you could be back to square one. From the original questioner: I did a test today, because the silicone is on the topcoat only from an anti-silicone material I added. So I did a test on a sample piece. I did dilute my base coat 1:6 to thinner and sprayed it in light coats, and for 5-6 times while waiting in between to dry, and then scuff sanded it and sprayed a real good coat of the base coat and then sand and topcoat and it got out good. I will check it out on the big door and hope it will be ok. Would you like to add information to this article? Interested in writing or submitting an article? Have a question about this article? Have you reviewed the related Knowledge Base areas below? 
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