help with refinishing oak table

[David Huston]

I have been struggling with refinishing a dining room table of mine for a few weeks. Table had a big black water stain that I removed with oxalic acid. The stain is as light as I think I can get it. I still can tell where it was but I have been looking at it every night for several days. The problem is that now when I sprayed my first coat of em6000 the spots where the acid was turns pink. It doesn't seem to be drying pink but it is drying like the finish soaked completely. I am also getting alot of pinholes. I will sand back the first coat and turn down the air on my gun (Fuji mini mite 3). Please help me fix this problem. I was thinking about spraying more coats to see if it evens out but don't want to have to restrip this table again. It has been taking up my garage for too long!

320003

[Kent A Bathurst]

Eeek!

What about a sealcoat of shellac first?

[David Huston]

It didn't dry that pink shade but it is definitely lighter than the rest of the table. I am thinking the acid has just bleached the wood. Will a semi transparent stain even this out? I am so frustrated with this project!!

[Conrad Fiore]

I would say strip, sand and bleach the entire surface to get all the wood the same color (or lack there of).

Question to the OP is do you find the color of the bleached wood acceptable? If so you can then proceed with your finish coats. If not, then you will have to color before finish. Coloring can be done with dye, stain or shellac. But I would suggest that you get the entire surface the same lack of color before going any further. Matching a section, especially as large as the one you have would be difficult even for a professional refinisher.
Pinholing and bridging is common with a waterborne on oak. Kent makes a good suggestion of first sealing the surface with a dewaxed shellac.

[David Huston]

The weird thing (to me at least) is that when sanded you can't tell where the lighter wood is. Even when I wipe down with mineral spirits you can't see it. Is there a possibility that there may be some acid in the wood that is reacting with the waterborne topcoat?

[Conrad Fiore]

Did you neutralize the wood after bleaching? You should have if you didn't. Wipe the surface with a solution of two tablespoons of either baking soda or borax in one quart of water. I would think that the product has a notation for neutralizing after use.

[Mel Fulks]

Well,...I saw this coming. Once the table is deemed ready for sale the garage will be full of finishing materials. The buyer will paint it purple. Sincere wishes for a speedy project end.

[David Huston]

No I didn't neutralize the acid. The container just said to wash three time with distilled water. When I use the baking soda and water should I let it dry on the wood or just wipe it over the affected area?

[Art Mann]

I suspect you are going to have to remove quite a lot of surface material, perhaps with a belt sander, before you can expect to have the entire top finish uniformly. Whatever you did with part of the surface with oxalic acid, you will never be able to match with other treatments or colorants in such a way that the difference won't show. Just my rather pessimistic opinion.

[David Huston]

Here is a pic of the table sanded to 220. Half has been wiped with mineral spirits. You can not tell where to acid was. I am going to try a coat of rattle can shellac before I bleach the whole table. The table is 8 ft long with two 20 leafs. I am afraid of making

320045

it worse and I don't know if I have enough acid left for the whole thing.

[David Huston]

Here it is after one side sprayed with clear shellac. Can't see the bleached area at all. Going to let dry overnight. Sand lightly with 400 grit and spray with the em6000 tomorrow. Crossing my fingers this works out and I don't have to strip/sand this thing again!!

320049

[David Huston]

Everything seems to have worked out. Pretty sure it was the un-neutralized acid that was reacting with the em6000. Two light coats of shellac and three coats of em6000 and it is looking good. One more question, I have some aquacoat grain filler can I use this between coats of the em6000 to fill in some rough areas of grain?

Here is a pic of the table right after the third coat is sprayed.



320068

[David Huston]

Everything was going good but now I have some scratches under the last topcoat. I got some debris on one coat and I think I may have gotten something under the sanding pad. Didn't notice them and sprayed two more coats before I saw them. Is the only way to remove them is sanding back the last two coats? Should I use my ROS to do this? I was thinking about using 180 then 220 and then following that up with 320 then 400 by hand. Does that sound reasonable? I could just leave it as is because they aren't that noticeable and I am just going to try and sell the table as it is too big for our dining room but I hate knowing I could fix it and not doing so. Thanks for all the help so far.

[Prashun Patel]

Personally, I would switch to a satin top coat. It will be far more forgiving of scratches both pre-sale and post-sale.

If you really want to stay with gloss, and if you are sure it's scratches or dust in the top coat, then I would just sand with 400 or 600 to level it out. 180 or 220 can work, but it just may be a little aggressive and therefore will require you to use a more deft hand.

If your scratches or swirls are in the WOOD, then if you want it perfect, you'll have to sand back to the wood (unless you switch to satin topcoat, which IMHO will hide most of your sanding prep sins).