Official Luthiers Forum!

Hello all, I've got a question about a wood product. My current build has a walnut burl veneer over the face. I would like to try to avoid spraying the burl with 10+ coats of sealer before I begin getting an even surface (This burl veneer absorbs finish like a freaking Sham-Wow). I am considering using a putty before I start finishing to get a smooth surface right off the bat (this product in particular http://www.stewmac.com/shop/Finishing_s ... iller.html). My worry is that using this product will take away from the crazy grain and wild figure of the wood because the putty will OBVIOUSLY not share a grain pattern with the burl. Is this product safe to use, are there any other products the I should be aware of? -Alex

Hi, Alex,
I can't respond about that specific product. However, I've used wood pore filler, colored with my own recipe, on walnut burl lots of times. I have a hunch that with any similar product, you just need to carefully wipe and sand off all surface residue, leaving the filler only in the pores, and then you should be okay. You'll just have to make your best guess about the color you want and then experiment on some scraps. Benjamin Moore wood pore filler mixed with my own artists oil colors and a little walnut oil stain winds up looking a LOT better than these photos would indicate.
Patrick

I think the pictures look pretty darn good! Nice headstock too!

I forgot to add that I have used TimberMate on a walnut headstock. Worked fine. Some people have complained that it makes the wood look "cloudy" but I did not experience that.

_________________
http://www.CostaGuitars.com
PMoMC

do you give the guitar a coat or two of finish before applying the filler, or do you just apply straight to the wood

I use Deft Brushing lacquer as a finish so before I pore fill, I put a wash coat or two of the lacquer diluted 50% with lacquer thinner(what else?). The wood was prepped with 220 grit paper prior to the wash coat. Once that dries, it is pretty flat since it is so thin, I don't have to level sand, so I go to town with the filler. Timbermate dries really fast and smells like kerosene or some type of petroleum product so I do this away from my kids. Anyway, smoosh it into the pores like any other type of filler and then sand with 220 or 320 to get rid of the excess and leave it only in the pores. Thats it. I did two fast coats on some walnut. I had filled the rest of the body using Todd Stock's epoxy method and used Z-poxy. I forgot to do the headstock since the neck was not done yet! I did not want to wait to get some lacquer on the guitar so I used the Timbermate. I have no complaints with how the headstock looks. I will try to remember to post pics later tonight. I do not have any at work.

_________________
http://www.CostaGuitars.com
PMoMC

Do you know its safe to use water based filler over the base coat of diluted lacquer?

I used the Mahogany tinted Timbermate on a Mahogany Uke and had to darken it with Brown Mahogany Transtint dye to match. It darkens when you put on a top coat but for this project it was lighter than I wanted under Tru-Oil. Test your finishing schedule on scrap!

Hi, Alex,
I'm not sure if you're asking me, but I'll chime back in. The guitar in the photos was stained and filled at the same time, with the pore filler, walnut oil stain, and a dab of artist's oil paint (cadmium red light--a little goes a long way). No sealer on the instrument prior to filling--EXCEPT on the spruce. That got two sprayed coats of shellac to protect it in case I slopped my filler. The filler is mixed to a consistency about like cold cream or liquid mustard and then rubbed on with a cloth. I go in swirls to rub it down into the pores. In a few minutes it starts to look dull, and you need to wipe off all the residue vigorously, because it's starting to harden up. In the process, a little is often pulled up out of the pores. After drying a day, buff off any remaining surface residue with 0000 steel wool. Repeat, as necessary, to fill any remaining pores. Some artist oil colors have a slow drying time, so if you use them, you should wait several days before clear finishing. In my case, I waited from one Sunday to the next weekend, because I was only working on weekends. Buff any touch ups with the steel wool. Then sweep, wipe, vacuum, air blast, etc. etc. all steel wool fibers off the instrument. Then you may seal again with shellac or go straight to your finish. I used Target Oxford Ultima waterborne lacquer on my guitar. Target finishes are compatible with the oil based filler as long as the filler is DRY AND HARDENED.

Now, let me say one more thing. This system fills and levels the pores, so they are opaque, and you won't see down into them. But the effect is NOT cloudy. Cloudiness hiding grain and figure would only happen if you don't buff off all the surface residue. That's an easy mistake to make. When buffing or sanding the fill job, work under strong light and check your progress with naphtha. If the wood's natural luster doesn't show, you've still got residue on your surface and it will, indeed, look cloudy. My dark stain/red highlight recipe enhances highlights in the figure and provides contrasting darks in the pores. When a gloss finish goes over the top, it has its own depth and luster. I love it, and that's why I keep using it.

Having said all that, many builders here really like filling with clear epoxy, and I admire the results they usually get with it. But I like to put color tints into the walnut to warm it up.

Patrick

I'm with Patrick. Epoxy fill (Zpoxy if available) and I don't try to match the color of the wood, but go a bit darker or sometimes even black. I will then scrape and sand, use a WB Shellac as a buffer coat before building coats of WB Laquer (EM6000).

Danny

If this is for me, I would say yes. I did a test of Timbermate using the same process, I.e. diluted lacquer, Timbermate, more full strength lacquer.6 months later and no issues. I think IIRC, Timbermate claims to be compatible with any finishing system.

_________________
http://www.CostaGuitars.com
PMoMC

Thanks for all the wonderful advice! I have one more question. What what grit should I sand the burl with prior to finishing. 400 sounds about right but Im not sure.

I sand thin veneer with 400 prior to filling. This is because most veneer sheets have a tell-tale line or two, cause by the knife that sliced them off the log or the burl. After I fill, I use 0000 steel wool, as stated previously. But lots of these other guys sand after filling with EXCELLENT results. I think sanding would be imperative if you fill with epoxy. So listen to them, too, and then do some experimenting before you work on your actual instrument. See what works best for YOU.
Good luck with it. You're obviously approaching this with caution and patience. I'm sure it'll be just fine!

Patrick