Refinishing table with Mahogany Veneer

[Geoff Harris]

Hi, I was over at my mums the other day and she has been refinishing a table that has a Mahogany Veneer. She is not happy with the results she got so far. What has been done was: it was stripped with chemicals, stained and then sprayed with several coats from a poly spray can.

The grain is very pronounced at this point and she doesn't like it. At present the finish looks matte even though she's used a gloss finish. What she wanted was a smoother glossy finish.

I've never tried finishing an open grained wood before but I understand some sort of grain filler can be applied before the poly. I've also read that by continuing to add layers and sanding down may eventually fill the pores.

I am looking for some good advice on how to rescue this. It's a nice table if the finish can be restored. So is there some grain filler that can be applied over poly? Should she continue applying coats and sanding or restrip the surface and start again with a filler? Or is there something else to try?

Geoff.

[Carl Eyman]

I have finished a fair amount of mahogany and prefer a "piano" finish. I doubt if any pore filler will stick to the polye that is on there. Any fillers I've ever used or read instructions for tell you to use then earlier in the process. Multiple coat build up will take a bunch of coats. spray can polye builds up very slowly;so it'd be even more than with a spray gun. Beside polyeurethane is a tough surface to sand; so it would be doubly tough to build up. That is, you have to put on a lot of coats because each is so thin, and you have to do a lot of sanding because it is so hard to sand.

If a good waterborne finish like Fuhr's #355 will stick over polye, you might build up with it and then rub it down with Abralon discs and a ROS. You'll need to assure yourself whatever topcoat you put over the polye will stay there. Asking the manufacturer would be the best way, I guess.

I don't have spray equipment. When I absolutely must have a piece sprayed I use a local auto body shop to do it for me.

[Jim Becker]

You can use a barrier coat of de-waxed shellac over the existing polyurethane varnish so you can use a grain filler before re-finishing.

[Steve Schoene]

A coat or two from a spray can on bare mahogany isn't much finish--fortunately. If the wood still looks like the finish has basically all soaked in, you can probably still apply a pore filler to level the pores. It should be tinted to the color you want. Often a just shade darker for the pores looks nice on mahogany.

You can fill the pores with multiple coats of the top coat, but with spray can finishes you should wait until I can buy some of the maker's stock because you will be buying the finish by the case.

Better to use a full strength brushed on finish such as Behlen Rockhard and expect to put on 6-8 coats, sanding using a sanding block pretty heavily between coats with 320 grit paper, perhaps 220 grit once you are confident of not sanding through the stain. Gradually, the "shiny pits" will become smaller and smaller. While you may have to put on lots of coats, the final finish will not be excessively thick, but with the pores filled with the transparent finish you would have a very nice look.

[Steve Schoene]

Once the poly has cured, I don't think it will inhibit the pore filler from adhering, especially if there is a light scuff sanding first. But by adding the shellac coat you may make it more difficult for the pore filler to adhere because it will have smoothed more of the interiors of the pores giving less grab within the pores. Probably should give the poly a week before the pore filler.