Fixing a finish

[Bubba Wood]

So my neighbor asks me to look at his kids desk to see if I know how to fix it. He had a 10 gal aquarium on it for about a year with a towel between the tank and the desk top. There are black spots and streaks in the top where moisture was trapped.

The top is MDF core red oak veneer with what looks like about a 1/64" thick veneer. There is no stain on the wood, just a clear coat which I will assume is either an acrylic or poly product. There are a few areas where the finish has lifted and flaked off around the black stains and the grain has lifted a little bit. There may even be a few small areas of delamination.

All the neighbor wants is for the staining to be gone. I don't know if the stain is mold, mildew or something else. The wife tried some mildew product on it with no success. That may of been what caused some of the grain to raise.

Has anyone seen this before and know a good method to correct the problem. I'm looking for ways to remove the stain. It seems to be a surface stain or growth, I was able to scratch some of it off with a finger nail but other areas did nothing when scratched.

My first thought was to try a weak bleach solution.

Thanks Larry

[Locutus]

Sand down the top and refinish.

[Andy]

This was my first thought, but I'd guess that any staining (whether mold or other discoloration) would penetrate at least 1/64". Sand lightly so you don't go through the veneer! I'd try bleach, as that should kill and remove anything fungal (mold/mildew). Can't hurt, and even if it does, you're not out too much as the top is already discolored. I wouldn't use a large volume of bleach or anything water-based, as that could swell/disintegrate the MDF. I'd plan on replacing or refacing the top (1/4" red oak ply isn't too expensive, and could be glued right on top of the old surface, and then maybe the whole top could be edge-banded?). That way, if none of the stain removal or sanding procedures work, you won't be too disappointed, and you can just move on to the new surface. Good luck, Andy

[remove]

I'd try some wood bleach (check out the info at the following link)

that doesn't work - the black stain may go all the way through the veneer, - then you could replace the top or just re-veneer over the existing top.

HTH Bill

[Tim W]

[...].

Some stains in some woods can be easily removed with a mild acid. This is a trick which will save you a lot of grief if you ever have wooden kitchen worktops which are very easily marked by iron pans or cans:

Saturate a piece of paper towel with lemon juice, lay it on the wood, cover with cling film or a polythene bag to stop it drying out, leave it overnight. In the morning, the stain will be gone.

Tim w

[marks542004]

I would also try a bleach solution , again on a paper towel or damp sponge .

If its a kids work desk I wouldnt worry too much about it , cover it with a desk blotter or something.

[Juvenal]

[...]

Oxalic acid bleach is usually used to remove black stains from oak. Available at any hardware store.

Try stripping the finish, let dry, bleach with oxalic acid solution, let dry, sand ever so gently by hand with 150 or 180, stain and finish.

-- Timothy Juvenal

[Bubba Wood]

Looks like the Oxalic Acid bleach is the way to go. I know it is a water based stain in oak. This piece of furniture will not stand for much sanding, and since it is a MDF veneer with a breadboard border of solid oak with a full radius bullnose re covering is not an option. Thanks for all the suggestions.

Larry

[Old guy]

I think you could recover it.

I've seen several tables in restaurants that have a bullnose solid wood edge, that have a sheet of Formica just applied to the top. It is held back from the edge a uniform distance, and looks good. Yes there is a 1/16" height difference between it and the perimeter of the edge, but it has never caused me any problems (and I am a klutz.)

It is a fix, not a restoration, but I think a field of solid color matte laminate framed in the existing oak edges would look OK, and when the next aquarium is placed on it, there won't be any problems.

Good luck, whatever you do. Hope the neighbor helps you with YOUR next project.

Old Guy