Re-Coating a Scratched Conversion-Varnish Table Top

Conversion varnishes take time to fully harden, and a customer used this one too soon. Luckily, repair is feasible: in this thread, finishers provide advice on sanding and re-coating. July 24, 2005

I recently made a curly maple tabletop with a very bright stain/dye color (yellow/orange) and coated it with MLC Krystal. The top is full of small very shallow hairline scratches. I have a full coat on this (4-5 mil), so I am reluctant to put on another coat.

Is there a way to buff/polish out the scratches? It has a dull sheen to it. If I sand it with 320 grit paper, would it be safe to put on another coat of CV? Any suggestions on how to get rid of the scratches would be appreciated.

Also, I did another smaller top and this one was wrapped for two weeks before putting it into use and this one is scratch-less, so I know that the finish at least is capable of not being scratch prone.

Forum Responses
(Finishing Forum)
From contributor D:
Sand the finish to lose some dry mil thickness. Then lay down a thin coat of new topcoat. I would suggest selling a table pad with every table project which you do. I use McKay table pads. The pads add to my bottom line and they are the bumper that you should buy when you purchase a truck. You are doing your customers a service when you sell them table pads.

From contributor O:
Beware of thinning your topcoat too much as you may not get the luster you thought you would get. I've had reps tell me that Krystal can be thinned almost indefinitely if you wanted to use it as a washcoat, but to maintain your intended luster you should do samples if you are going to thin it more than 30%.

In addition to this you should still shoot a full wet coat so be careful if you're thinning with a fast solvent. We just resolved a similar problem by shooting Krystal satin thinned 30% with the MLC reducer sprayed at 4-5 mils wet. Don't expect the wet Krystal to burn up your sanding scratches up either - remember you're going over Krystal. Keep to 320 with the grain and only the trained eye will see the scratches in the right light.

From contributor T:
It all depends on how much you spray per coat and how much you sand between coats. The only way to find out is to measure it digitally, but I'm sure you're safe. Just sand back with 400 or higher grit you prefer and re-spray it lightly.

From contributor S:
It’s not an issue really. The table tops are flat, so a nice six inch random orbit sander with P400 on it will level everything out and remove a couple of mills of build, and frankly the final product will look much better than when you first delivered it.