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How to pop the grain on walnut

Posted: Fri Jun 08, 2018 11:14 am
by Christ Kacoyannakis
I am working on my first electric build, a carved top, set neck guitar. The top is curly crotch walnut, and is a fantastic piece of wood. I know on curly maple, you can use some dark brown or black dye on the raw wood, and then sand it back to accentuate the curly grain. My understanding of how this works is that the dye goes deeper into the end grain of the curl structure, and not as much into the face grain of the curl structure, and when you sand it back you only sand through the face level dye, thus popping the curl.

I plan on trying this on some scraps from my top, but I am not sure it would work, so I would like to see if people have other suggestions. I asked this question on a luthier Facebook page of which I am a member, and a lot of people just said to use tung oil or something similar. I know this is going to look great under a clear finish, but I am also looking to give it that little extra punch to really bring out the beautiful grain of this wood. Any ideas would be greatly appreciated. Thanks. Here is a picture of the top.
walnut.jpg

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 12:37 pm
by Bryan Bear
I'm not an expert at finishing by any means so. . .

I know a lot of people like the black stain and sand back on curly maple but to my eye it looks less 3 dimensional than just finish alone. It seems like you are trading depth for contrast. Again just my opinion.

What are you going to fill the pores with? What are you planning to top coat with?

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 1:48 pm
by Aaron Helt
Fill the pores with epoxy. You'll have plenty of pop.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 2:13 pm
by Christ Kacoyannakis
I am strictly water based finished in my shop. I will be using an Aqua Coat grain filler, and am trying a new water based lacquer, Brite-Tone. The Aqua Coat is supposed to help pop the grain. I'll do a bunch of samples to see what looks best.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 2:57 pm
by Bryan Bear
I was going to suggest what Aaron said and say make sure you leave a thin layer on the wood rather than sanding back to bare wood with filled pores, but I wasn't sure what the rest of the finish would be. I don't know how Aqua Coat looks but maybe do a test sample with epoxy too to see which you like the look of better.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 3:11 pm
by Brian Evans
Brite-Tone is excellent, a very clear, very hard finish designed for instruments. It is post-catalyzing, so it definitely does a chemical cure and cross-linking after several days, so try to get your coats on with a day or less of dry time. It won't "burn in" after it cross-links. It builds fast, so they recommend 6 coats, three in the first day, three in the second day, but I did around 10 coats. It turned out a bit thick looking, but I was worried about sanding back and polishing, which went pretty well. I sprayed it without thinning, they have a special thinner but I think Gordon has thinned with distilled water. They recommend spraying directly on wood, but they do have their own sanding sealer and pore filler products so it should be fine with pore-filler, which gets sanded back to around 99% wood anyway.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 3:34 pm
by Steve Sawyer
Christ - don't do anything with that beautiful cap other than finish. I would assume you've already done so, but wipe that down with with alcohol, mineral spirits or naphtha (or even water if you don't mind re-sanding to remove the raised grain) and you'll have a good idea of what the results will look like. To clarify, the rule-of-thumb is that stain pops grain (the pigment gets into the pores of the wood), and dye pops figure (it's differentially absorbed by end-grain and long-grain as you describe). Thus dye works really well on pale woods like maple as you get good contrast between the two grain orientations. I think any attempt to "pop" the figure in that cap with dye is going to just muddy it up. Test by all means, but I'm thinking that you will end up just using a clear finish, whatever your choice is.

Lordy, that is one beautiful piece of wood!!

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 4:21 pm
by Simon Magennis
That piece is spectacular. I don't think it needs any special treatment at all to look incredible. I have no experience with an finish except shellac as I only make classicals. It would look spectular with a shellac finish so I guess plain old nitro or whatever else is used to day will make it looks great.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 10:06 pm
by Bob Howell
I have always heard the best way to pop the grain is to put an oil based finish on first, then a clear finish. I have followed that for years successfully for years.

Just a dilute coat of linseed oil would work and I think just about anything will be compatible on top. I've not heard of a problem, but maybe someone has.

Re: How to pop the grain on walnut

Posted: Fri Jun 08, 2018 10:26 pm
by Rick Milliken
+1 for Steve’s approach, only clear.

I’ve not done it on an instrument yet, but I like the look of black walnut with a coat or two of garnet or even dark garnet shellac. It adds a “warmth” that I like. It also seems to help with any of the green or grey tones that sometimes show up in walnut.

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 3:09 am
by Peter Wilcox
Here's the way I did it a few years ago. Basically, applying the first coat of finish (or epoxy for pore filling), then sanding back to the wood and up through 1200 grit, and then finishing as usual. The first coat stays in the end grain portions of the figure, and sanding to an almost polished surface limits the subsequent penetration of the finish into the face grain which then remains lighter in color, thus increasing the contrast in the figure. No dye.

http://www.mimf.com/phpbb/viewtopic.php?f=13&t=3531

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 7:43 am
by Clay Schaeffer
One way to intensify the color is to use a clear "drying oil" (Danish oil - Watco, etc.) on the bare wood as a base coat. Let it dry and cure for a couple of weeks before applying your top coat. I have done that with solvent based finishes, so you should test on scrap to see if waterbournes behave the same.
Walnut is fairly close grained, so I usually self seal with the finish- no pore filling (again I use solvent based that burns in to itself).

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 11:45 am
by Christ Kacoyannakis
Thanks for all the tips. I have got a bunch of scraps so I will do some tests and see what I like best.

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 11:46 am
by Steve Sawyer
Peter Wilcox wrote:Here's the way I did it a few years ago. Basically, applying the first coat of finish (or epoxy for pore filling), then sanding back to the wood and up through 1200 grit, and then finishing as usual. The first coat stays in the end grain portions of the figure, and sanding to an almost polished surface limits the subsequent penetration of the finish into the face grain which then remains lighter in color, thus increasing the contrast in the figure. No dye.
Peter - that's brilliant. Read through the thread you linked to. My next project will probably be a short-scale bass, and I'm on a hunt for a spectacular hunk of wood to use for the body. Hadn't considered walnut, but you've definitely put this species on the short list in my quest.

Do you have any pictures of the end result? Interestedin seeing how close the final results came to the effect you were aiming for.

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 3:06 pm
by Peter Wilcox
Steve - it's hard to know what effect the process has on the figure, as there's no control done without it. Here's another pic of one of the guitars in the other thread
walnut-tele2.jpg
and another one done later from the same tree:
walnut-top.jpg
I'm satisfied with the results, but don't know if they're better than just a regular lacquer finish. I still have 2 tops cut from the same piece of wood that I may get to if I ever get off my maple kick.

Re: How to pop the grain on walnut

Posted: Sat Jun 09, 2018 6:55 pm
by Steve Sawyer
Peter - sorry - I missed the second page of that thread. My eyes say that your technique works quite well. In looking at the results in that thread (the Tele on the left) compared with the "partially flashed" example you started in your OP, I wouldn't want to have to live on the difference. Much more contrast in the figure than the one that was still uniformly wet.

Re: How to pop the grain on walnut

Posted: Tue Jun 12, 2018 1:01 pm
by Rodger Knox
In my opinion, the best way to accentuate the figure is to sand the surface very smooth, at least 600 grit and maybe even 1000. That may cause adhesion problems with many finishes, but it works nicely with TruOil, which is my first choice of finishes.