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I haven't used spalted maple for a top, but I use it for rosettes & peghead plates on occasion.
The stuff I used was very porous & soft in spots. Not suitable for anything structural.
I saturate the pieces with thin CA or epoxy before I machine it. Cutting tools (chisels, planes, scrapers) tend to tear the soft surface if it's not treated with something. It sands well. but the softer places sand away more quickly than the firmer areas.
That's only my experience & your wood may not be as fragile as the stuff I used.
That sure is one PRETTY piece of wood!
There is a product called Git-Rot sold at marine supply stores which might work really well. It is a very thin epoxy (IIRC) that penetrates deeply into rotted wood & hardens it.
That's gonna make a spectacular guitar!

Filippo, I know you asked for people with specific experience with spalted maple. While I don't have that, if it were me, I would route the contours in 1/16" successions and sand to your final contour.

They did a few of those while I was at PRS. They do look cool, but I remember that the guys hated working on them. I believe they flooded coated them with epoxy prior to sanding to help keep them from breaking up while being sanded.

Best,
Trev

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http://www.PeakeGuitars.com

That is a beautiful piece of wood. I bet that will look amazing when finished.

As said, very porous and friable. Be carefull when working it. I don't suggest to use router on it. I sand behind Daniel: It sands really easily so cut it near the final shape and sand the over... Need lot of porefilling, obviously. And it looks AWESOME!

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Francis Richer, Montréal
Les Guitares F&M Guitars

Sanding, and I harden the surface with CA glue prior to and after finishing.

It SUCKS to work on.

I have built a few LP style guitars out of it and it is hard in some spots and soft in others, when you sand it it is very hard to keep it even the soft spots want to sand faster and tend to divot.

It looks cool under finish, but it is no fun to work with.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Yep, flood the heck out of it with epoxy...!

I know it's not supposed to be the easiest stuff...but man, it sure does look cool!

Best,
Trev

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http://www.PeakeGuitars.com

In addition to the above comments concerning the soft/hard problems....

I've worked with spalted maple as a woodworker doing flat work and bowls before, and the thing I didn't like more than any other attribute was the odor/moldy smell. Obviously, spalted is the first leg towards decomposition, which is probably a smell that isn't the best thing to be breathing into your lungs. At a minimum, I'd wear a good dust mask at all times.

Interesting a lot of you are saying to use epoxy. I didn't find that to be particularly helpful. I had a really punky piece that I used once that I dumped literally a whole 16 oz bottle of Starbond into (you need goggles and a respirator for this), and I have also tried epoxy (West 105/206), thinking both would give a bit more consistancy of the material and make them easier to work.

I found that the superglue just made it "gunky" to sand and left the surface kind of blotchy. Once the finish epoxy coat was on you really couldn't tell but I don't think it made working the material any easier. As for the epoxy to firm up the soft parts, I really didn't think it penetrated deep enough for a carved top.

I have one more I am finishing up now, but after that I am going to leave the spalted tops for flat topped electrics.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

The two cents that I am going to throw in here:

Last time I did one, I was having a very hard time getting the epoxy (West Systems) to penetrate as deeply as I needed to carve, so I smeared it, carved it, smeared it, carved it, etc...working each carving session until the wood did not feel consistent. The results were decent. Time consuming, but decent.

Stephen

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www.ziegenfussguitars.com

I wonder if soaking spalted wood in polyethylene glycol would help???

Lookin' good Fillipo.

Has anyone ever tried the process that Larry Davis uses to permeate wood with plastic resin for the purpose of making super hard knife handles? I couldn't find his website but here's a link to his patent claims. http://www.patentstorm.us/patents/5744210/claims.html

Thanks for the tracings Fillipo...and Chris!

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JJ
Napa, CA
http://www.DonohueGuitars.com

Thanks, I just applied it with a hard piece of rubber and "squeegeed" it in. I think you are right, thinner would work better. The CA was a bust though, I wouldn't recommend that.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I've built a few electrics with it and always used shellac as i was working it down. It did a good job of soaking in.The key is to pick good stable spalted maple. If it sets too long before milling, it gets too soft to work well.It has to be milled just at the proper time when the mold sets in to be good.