Refinishing advice/opinions

[FritzCat]

I'm in the midst of refinishing my '66 Joe Maphis. There were tons of cracks in the lacquer, and in stripping the finish I found the spruce top was stained from sweat, beer, or whatever else leaked through the cracks. My question is, is there some way of removing these stains? I've tried teak brightener (oxalic acid) and it didn't do a thing. Is there any other sort of bleaching agent you'd recommend? I'm reluctant to use anything that would screw with the plastic binding. Alternatively I could just lacquer over the stains, they do have an interesting pattern to them. Or I could paint it a different color. What do you guys think? Here's some pics of it's current state (the staining is much darker when the wood is wet)
(Click for big)

[GattonFan]

Yes, there are numerous brands of wood bleach available that you can use - are you going with a translucent finish, or a solid color?
Dennis

[FritzCat]

I'll be using clear lacquer. My local hardware store didn't have anything but oxalic acid, so I tried household bleach, which reduced the staining by about 50%! I think another application or two will do it.

[zarfnober]

The problem with using BLEACH on wood is that it does the same thing to wood as it does to fabric. Leave a tshirt in bleach and it eventually disappears. Bleach will basically eat at the surface of the wood and may cause premature failure of the finish. Oxalic acid is much safer and doesn't eat at the surface. You want to find a way to nuteuralise(did I spell that wrong?) the wood before you put any coats of paint or primer on it after cleaning with bleach.

I use oxalic acid all the time when I'm cleaning/restoring wood decks and it works great. the ones I did with bleach(3 or 4) had a high finish failure rate. Good luck on your project,

Rocco

[FritzCat]

Thanks Rocco, I wouldn't have thought to neutralize the bleach. I did wipe/rub the surface down with water after each application of bleach, but I'll also wipe down with hydrogen peroxide (as a neutralizer) and again with water before I use any finishing materials. Thanks again!

[zarfnober]

Didn't know peroxide would nuteuralise the bleach, good idea. Give it a good amount of time to dry between each application and wipe down, it will help to bleed out any excess chemicals in the wood, then give it your finish sanding. The nice thing about oxalic acid is that it is made from wood by-products(so I'm told) and helps draw out molds, etc from the wood without damage to the surface. It will however, lift any "dead" wood fiber. This is the graying you see on outdoor decks and cedar fences. OA also nuteuralises stripping agents like sodium and potassium hydroxide and will bring natural color back to weathered wood.

Proper prep will make your finish look better and last longer, take your time and it will turn out great. You'll be glad you did. Post photos when done.

Rocco

[oipunkguy]

fritz, there's a couple different things you can try. use a good liquid stripper (not a semi-paste) and rub it out with "0000" steel wool. Just be careful with the binding. The stripper will eat the binding, but if you don't use too much stripper and control it correctly, then no worries. make sure you are using heavy duty rubber gloves and have lots of paper towels handy. if you get any drips on the bindings, wipe it up right away, and you should be okay.
you can also use acetone as well. I've gotten stubborn stains out with acetone when stripper didn't work out, and you may need to go with a courser steel wool if "0000" is too fine. again watch the binding with the acetone as well.

clorox bleach can help, but just be careful not to leave it on the wood for any length of time. in extreme cases the bleach will even chew up the wood fibers. I wouldn't leave it on for more then 5 minutes at one time. but the stripper of acetone will not harm the wood in any way.

if this all fails, let it completely dry, and try lightly sanding the body again and see where you are. sometimes it can take several times to of doing these processes over and over again to get where you need to be, but it'll come out. good luck, if you have any questions about this process, just PM me, I'm on all the time.

[woodchuck30]

I was going to sugest lac thinner, but it souns like you got it under control.