Official Luthiers Forum!

I'm seeing spots that look like bare wood underneath my epoxy filler. I'm assuming this is from glue drips from gluing the bindings on. Anyway, I'm looking for suggestions on what to do. I'm assuming I should sand off the epoxy and sand down the wood in the areas of the spots. But I sanded down the body pretty well before I applied the filler, so I want to make sure that will take care of the problem if I'm going to have to go to the trouble. Is this easily fixable? I'm probably not going to hear anything that will make me happy, but I thought I'd put some feelers out there just in case.

If it's glue drips it's an easy enough fix.

If it were me, I'd sand back the whole body. Sand out the glue drips, then put a wash coat of Z-Poxy using 50/50 with alcohol.

Mat

Yeah, good advice guys. I sanded the body down this morning and refilled. Everything is looking pretty good now. So, I now have a question regarding a wash coat. I have the last zpoxy coat sanded down nicely. On my previous builds I used a coat of sanding sealer as a wash coat between filler and lacquer. I'm assuming this isn't necessary now, correct? Matthew, you said to do a wash coat of alcohol and zpoxy. Is any of this even necessary if it looks like I've gotten all of the little cracks filled well? Or should I just go straight to lacquering? Sorry for all the questions. Applying a finish just gets my mind all squirmy and I don't wanna make a mistake!

You don't need a wash coat. I like to leave a thin coat of zpoxy on the body after filling (just because I like the way it 'pops' the grain). Sometimes after sanding the zpoxy level you may get some areas which have sanded back to bare wood - this will show up under finish. To avoid this, I like to sand back to bare wood and then put a thin wash coat over the body - but it's just personal ways of doing things.

I also put a wash coat of shellac on top of this as some have said that their 'might' be some adhesion problems with the EM6000 that I'm using.

Good luck

Mat

So.....pore fill with z-poxy once (maybe twice) and sand back to the wood followed by a 50/50 wash coat.

My question is: Once the pores are filled how worried are we about scratches prior to the sandback? What grits do you use prior to the wash coat? Orbital or hand sand with the grain?

I'm thinking that it's right there...prior to the washcoat...that you can put in scratches that won't show up until WAY later. Maybe I'm wrong?

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Does this sound reasonable, Todd?

1. Shellac wash coat(s) - clear
2. Z-poxy - fill (maybe twice)
3. Z-poxy - 50/50 wash coat
4. Shellac - or vinyl sealer
5. EM 6000 top coats (I dunno....3-5 coats)

??

I'm trying a number of different approaches but I think the template above would work.

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

I'm not Todd....and I use West System Epoxy instead of Z-poxy, but I believe you'll be better off putting the Z-poxy on the bare wood, without the shellac wash coat. Epoxy doesn't adhere well to shellac, and you'd probably pull alot of it out of the pores while sanding.
I'd go
1. Z-poxy fill, how ever many coats are needed. Usually 1 or 2 with West Systems, depending on wood.
2. Z-poxy wash coat. (I don't do this, but it's popular)
3. Shellac, I believe shellac would be better than vinyl sealer under waterbased finish. Shellac adheres fine to epoxy, but I don't think epoxy adheres to shellac very good. (it doesn't make sense to me)
4. EM-6000, I don't use it, but I suspect more than 3 to 5 coats will be needed. When finishing I check the thickness with a micrometer behind the soundhole, at the center seam, and rosette. That way I can check the exact same place everytime. With most finishes I want ~.005" to .006" before buffing.

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/