Question Regarding Stripping/Refinishing

5-string Dan · #1 02-23-2009, 12:59 PM

Hello All,
This is my first post / question.
I've read many posts regarding the finishing process, but my issue is related to the preparing of the wood.
I currently am working on a multi-laminate Washburn which was finished with either clear poly or lacquer - straight from Vietnam.

The original finish had several flaws which were screaming to be corrected. So....
I've spent 20 + hours stripping with chemicals, and then more chemicals, and then finally attacked the body with brute force. Two "Mouse" sanders, belt sanding, and many hours of block sanding later, I have a bare body/one piece neck with one additional problem:
"There is still poly or lacquer deep in the grain in some areas which shows up white"
I've tried pore filling, and staining but the residue remains.
I've been told that I must "keep on sanding" until I get below the grain which is holding in the old finish.
Any words of wisdom are greatly welcome!

ttmnky · #2 02-23-2009, 01:10 PM

I think that if you're going to do a solid colour over the top, you don't need to sand to the grain. I didn't in my refin.

Of course, my refin was less than stellar.

But from my understanding, you only need to rough up the first coat if you're planning on just shooting the entire body a solid colour.

5-string Dan · #3 02-23-2009, 01:21 PM

My intentions are to re-finish using Tru-oil. I'm after a natural looking and feeling rig.
The woods are beautiful multi-laminate, not to be covered up. I've tried to do some wet sanding with the wipe on varnish to either cover up or dislodge the sediment in the grain, but only marginal success. By examining under 12x magnification, I can see clearly that some of the residue in deep down, and some is flush with the surface.
I've even "picked" out some of the residue in the grain with a fine point exacto, but obviously that's not an option, merely a test to see what's happening.
So far I've stripped it down three times:
1) The orginal strip down
2) Removing the (2) Tru-oil wet sanded coats
3) Removing the oil based grain filler - (I should have tried it in only a small area)
I'm running out of ideas at this point. Perhaps just continuing to go "Midevil" is the only course to pursue?

62bass · #4 02-23-2009, 01:48 PM

If you plan on an oil finish and want it to look right your only choice is to sand right down through the grain filler which is probably an epoxy or polyester. It's a lot of hard work. I went through the same thing when I refinished my old ash bodied P bass. Stripper wouldn't touch it. The heat gun stripped the finish but wouldn't lift all the grain filler so I sanded and sanded. It took 2 afternoons of hard work before I was ready to stain and refinish.

One tip-get yourself some 36 grit ceramic belt sander belts. They last longer before the abrasive dulls and they won't tear. You can cut them into convenient sizes and use double sided tape to stick them to a piece of 1 1/2" dowel and a length of 2" plastic drain pipe so you can get into the inside curves with some force as well as a piece on a flat block. It'll save you a lot of work. Then work your way up the grits to 320 before the true oil.

Beej · #5 02-23-2009, 01:58 PM

Got any pics?

When refinishing old oak veneered furniture that has been painted, I have tediously picked out all of the old paint stuck in the grain. I've done it this way to avoid the chance of sanding through the veneer. The picking will remove all of the old colour after which you can pore fill and refinish nicely. Its time consuming but yields great results...

5-string Dan · #6 02-23-2009, 02:14 PM

It's nice to hear a little feedback regarding my "issue" with this project. I'm not a wood worker by trade....electronics is my main gig. I was afraid that going after the wood in terms of depth was going to be the word. Although 36 grit sounds a bit heavy, but I guess taking off sheer volume is what it's all about at this point.
Here's a couple pictures that show the problem at hand.

Again, thanks for your input!

62bass · #7 02-23-2009, 05:33 PM

Quote:

Originally Posted by 5-string Dan

It's nice to hear a little feedback regarding my "issue" with this project. I'm not a wood worker by trade....electronics is my main gig. I was afraid that going after the wood in terms of depth was going to be the word. Although 36 grit sounds a bit heavy, but I guess taking off sheer volume is what it's all about at this point.
Here's a couple pictures that show the problem at hand.

Again, thanks for your input!

Sure, 36 grit is coarse. You could start with 80 grit and sand twice as long. In the end, you still have to work your way up to a fine grit.

I recommend the ceramic sanding belts because they don't tear, the abrasive doesn't rub off easily and they stay sharp longer. Saves on buying sandpaper.

Beej · #8 02-23-2009, 11:19 PM

Quote:

Originally Posted by 5-string Dan

It's nice to hear a little feedback regarding my "issue" with this project. I'm not a wood worker by trade....electronics is my main gig. I was afraid that going after the wood in terms of depth was going to be the word. Although 36 grit sounds a bit heavy, but I guess taking off sheer volume is what it's all about at this point.
Here's a couple pictures that show the problem at hand.

Again, thanks for your input!

Looking at those pics, if it were me, I'd definitely be picking out the white bits and the pore filling afterwards. There doesn't appear to be too much still stuck in the pores. If you sand it down too much, you'll need to shim your bridge or it may be too low...

5-string Dan · #9 02-25-2009, 09:23 AM

I believe I'm going to split the difference and go with a high quality abrasive
3M Al Oxide Open Coat and give it the business starting at 80 grit.
I just happened upon a DVD "Woodfinishing Basics" and this guy sands in a diagonal pattern to knock down the grain, then switches directions up through the grits.
The idea of picking out the residue makes my head spin, so I believe I'll give this a shot.
I had to special order the paper, so hopefully I get it before the weekend.
I'll let you know how it goes.

Thanks

poomwah · #10 02-25-2009, 01:01 PM

so asian poly is really that hard to remove :[ THAT is definitely a disappointment :[ I think I may just scuff and repaint the ones I was going to do rather than try to strip and stain them :[

62bass · #11 02-25-2009, 01:08 PM

Quote:

Originally Posted by poomwah

so asian poly is really that hard to remove :[ THAT is definitely a disappointment :[ I think I may just scuff and repaint the ones I was going to do rather than try to strip and stain them :[

Yes, it really is tough stuff. Forget about using the cheap garnet sandpaper with this.

I usually use a heat gun to get off the worst, then switch to sandpaper. But there are times when a heat gun shouldn't be used and even sandpaper is dangerous, like when dealing with a thin veneer top.