Fish-Eye Problem in Re-Finish Following Water Damage

The story starts with water damage to a conference table caused by leaks during a re-roof of the building, and just gets better from there. August 22, 2013

Question (WOODWEB Member) :
Hi all. Looking for a solution to a finishing issue. A conference table we built for a customer was water damaged during re-roofing. The MDF cherry veneer panel swelled and delaminated. We extracted the damaged panel and fit a new one. The 4" solid cherry perimeter and 3/4" solid birch inlay were scraped and sanded to bare wood. The cherry portions were stained with SW BAC stain and the whole thing sprayed with Chemcraft conversion poly sealer. The issue is there were craters in the finish on the refinished cherry and all along the old glue joints, presumably from polish or oils that migrated into the joints. Re-stripped the perimeter and inlay, treating with Wil-bond deglosser prior to each step or change in sanding grit. Re-stained and sealed with the same result. Any suggestions at this point before we end up rebuilding the whole table from scratch?

Forum Responses
(Finishing Forum)
From contributor P:
Sanding does not get rid of silicone contamination. It just spreads it around. I've had some success using automotive wax and silicone remover. Apply it half a dozen times, wiping and discarding rags frequently. Then seal with dewaxed shellac after staining. You can always use fisheye eliminator (aka "Smoothie"). I don't want that stuff in my shop. I hate refinishing enough to recommend remaking the top from scratch as a solution, especially if the client is paying.

From the original questioner:
Contributor P, I share your sentiments on refinishing; huge cans of worms. The customer is a friend of the business, so cost containment is a factor. Is the automotive silicone remover much different than the Wil-bond de-glosser we used? And if it is, is it effective on the already stained and sealed (1 coat) portions, or are we taking this back down to wood and starting over? Please say over the current finish.

From contributor P:
Not familiar with Wilbond, but I seriously doubt that's the right product to get rid of silicone. The product I used is called Pre-Kleano, and I purchased it many years ago at an automotive paint shop. Its specific purpose is to remove wax and silicone before refinishing.

You should not have to strip down to bare wood. Just keep in mind that you should not sand after applying the silicone remover, as that will expose any silicone trapped in the finish. I'd also lay down a few coats of sealer before sanding for the same reason.

From the original questioner:
Thanks. I can come down from the ledge for now.

From contributor B:
I'm not familiar with your sealer but have you considered either a vinyl sealer (if compatible) or a dewaxed shellac to seal in the contamination? Otherwise multiple super thin coats of your sealer (a technique I've used) with just the minimum of sanding or better would be synthetic steel wool before attempting a wet coat.

From Paul Snyder, forum technical advisor:
Identifying, repairing, and avoiding fish eye is a pretty common discussion on this forum. There's information in the Knowledge Base which you can access in a search at the top right of the forum.

From contributor D:
This isn't typical fish-eye. Here is the follow up to what's been tried. Cleaned affected area with Wil-bond and applied sealer coat. Repeated 2 more times. Small improvements but not perfect. Wiped the sealer coat with DX330/Acryli-Clean, sanded, re-wiped and top-coated with conv. poly. Dried about 1 1/2 hour. Repeated the wipe, sand, wipe steps and applied second top coat. Resulted in dramatic crackling anywhere it was wiped with DX330. Not sure why on this coat and not the previous (dry time?) Will sand out crackle and go back to Wil-Bond. On the advice of my finishing supplier, didn't use dewaxed shellac or vinyl sealer because of compatibility concerns.

From contributor P:
Why did you seal before using the DX330? The whole purpose of that product is to get rid of as much of the silicone as possible before applying any more coats. A crater or fisheye is an area where the finish has crawled away from the silicone contamination. Because of that, the silicone is still exposed at the bottom of the crater.

Also, you should sand the cratered finish flat first, then apply the DX330, then seal. I would definitely wait a few hours before sealing to let the solvents from the DX330 flash off and allow the surface to recover from any softening caused by the DX330.

I suspect using the DX330 on a newly applied coat of finish was the cause of the crackling. Applying it after sealing is unnecessary.

From the original questioner:
I was using Wil-bond to mitigate the silicon before each sealer coat. Specifically, wipe with Wil-bond, sand flat, re-wipe with Wil-bond, seal. I switched to DX330 hoping for better results, as there was still some cratering after using Wil-bond.

I suspect you are right about the crackling. I just rushed the finish coat.