HELP! I think I have fisheye!

[David Eisan]

Dear All,

I put these tables away last year because I was getting tired of messing with the finish. Not once, but twice I cut through the top coat and colour coat down to raw wood when trying to cut back the finish flat. I kept getting little craters in the finish that needed to be sanded out. The table top is red oak with ebony inlay, the colour layer is a water based aniline dye and the top coat is gloss oil based poly, brushed on.

I put another coat of finish on tonight and I got the little craters again. I am very close to setting fire to these table tops and building new ones. I have never had this happen to *any* finish before and I didn't do anything different with this finish than any other finish I have applied.

As I brush the finish on, I can watch it climb away from certain spots on the table and form little craters, no matter how many times I brush the finish out, always in the same places.

http://members.rogers.com/moreweb/images/fisheye.jpg

Can this be fixed?

Thanks,

David.

Every neighbourhood has one, in mine, I'm him.

[Bob Lasley]

David,

I'm not even close to a finishing guru, but I think you may have something on the surface, such as silicone, that is keeping the poly from adhering where the fisheyes are occuring. You might try giving it a light sanding and then putting a coat of dewaxed shellac on. Then you can go back with the poly. The shellac will act as a barrier to whatever is keeping the poly from sticking in those spots.

Hopefully the experts will chime in and give you better advice.

Good luck,
Bob

[Bobby Hatfield]

David you need what they call fish eye medicine, in the older auto painting business, when they were spraying a lot of oil base enamel and the old nitrocellulose lacquer. I buy mine at the auto parts store where they sell auto painting supplies. The auto body and paint business has changed so much the last few years I'm not sure who would stock what you need. Try a local body shop if you can't find it at your supplier.

[Jim Becker]

I agree with Bob on this, you probably have some form of persistent contamination on these table tops. While silicone is the most obvious (and something you NEVER want anywhere near your shop) there are undoubtedly other things that can cause this.

Bob's suggestion for a barrier coat is a good possibility and worth trying. Please note that you must use de-waxed shellac for this. Unfortunately, polyurethane is one of the worst products for adhesion over certain things (including itself), so you need to take special care.

If that fails, I suggest you chemically strip the tops back to "no finish" and start over. Or switch to a different clear finish. Poly is the most overused and over-hyped product out there and you have lots of alternative choices, including two other types of oil-based varnish that do not contain the urethane resins.

There are also some finishing professionals that spend time in a finishing forum at another Internet discussion site sponsored by one of the woodworking magazines that might be a good resource to tap on this...I'm not sure what the rules are about mentioning that kind of thing are here, but Jim Kull, Paul S and Steve Mickley undoubtedly will know much better than I about this kind of problem!