Baked Spruce Top?

[soundofpi]

Hello,
I am interested in real-world experience from players of guitars with "baked" spruce tops. This is a new (to me) technique of pre-aging the wood. I've heard that it produces a good sound, but is it structurally sound? Any particular grievances or raves about this treated wood?

[KevinLPederson]

I've heard of people doing this in an effort to further dry the wood out. I see it working to dry the wood out further. If you leave bread in the oven and the temp low you can cook the moisture out of the bread leaving "rusk".

Yes it would further dry it. To what end? I don't know right now. Wood is hygroscopic which means it absorbs moisture from the air (or the opposite). So once you took it out, you'd have to prepare it with shellac. I think you'd have to keep shellacking it where you cut or sanded through the end of the build. And this only slows down the moisture exchange. Once you got your final finish on it, this would seal the wood and keep that moisture out. You'd want to shellac the inside of the top. I'd like to try it someday on a proto.

Let's here what some others say.

Kevin.

[jeff crisp]

http://dogwoodguitars.com/baking-tops/

[KevinLPederson]

Thanks for that link Jeff. I don't see it doing anymore than relieving the wood of any remaining moisture content. Which would allow the wood to be more responsive and sonorous. Seems beneficial.

Kevin.

[Mbroady]

Originally Posted by soundofpi

Hello,
I am interested in real-world experience from players of guitars with "baked" spruce tops. This is a new (to me) technique of pre-aging the wood. I've heard that it produces a good sound, but is it structurally sound? Any particular grievances or raves about this treated wood?

More then one way to skin a cat - or in this case age wood.
cool info about another process, Used on violins

http://www.sciencedaily.com/releases...0914111418.htm

Sounds like the same process used on Stonebrige guitars.

[Jim.S]

There is some evidence that high temperature kiln drying of softwoods (like for building) can lower the strength. Most soundboard wood though is likely to have been air and or slow kiln dried before someone gets it in their oven and that may make a difference. One benefit of the oven might be that after woods have been brought down to very low in moisture content they may become more hydrophobic post drying so that in the future they will take on less moisture than without the drying providing better stability. This may only be relevant or necessary for some species though.

Jim

[KevinLPederson]

Originally Posted by Mbroady

More then one way to skin a cat - or in this case age wood.
cool info about another process, Used on violins

http://www.sciencedaily.com/releases...0914111418.htm

Sounds like the same process used on Stonebrige guitars.

Interesting article. Treated with a fungus.

There could be a lot to say about the area where the tree was grown and the seasons it was grown in. It seems logical that this would affect the wood/cell structures densities.

Interesting stuff if nothing else.

Thanks.

Kevin.

[Mbroady]

Originally Posted by KevinLPederson

Interesting article. Treated with a fungus.

There could be a lot to say about the area where the tree was grown and the seasons it was grown in. It seems logical that this would affect the wood/cell structures densities.

Interesting stuff if nothing else.

Thanks.

Kevin.

IT will be interesting to see how these fungus and/or heat treated tone woods hold up 20, 30, 60, years from now.

[redir]

Sounds like good marketing to me. Dogwood may be on to something in an attempt to get the wood as dry as possible as a starting point. But still whether there is too much moisture in the wood or too little, wood being hygroscopic, will reach an equilibrium in a controlled shop after a few weeks/months anyway.

I have not tried it myself so I can't speak from experience but I'm not sure how you could even conduct a controlled test for such a hypothesis.

[fazool]

In my engineering/manufacturing role we don't deal with organic living things like trees and wood. But, we continually artificially age things to accelerate the effects of aging (for testing or whatever).

The aging acceleration process always include thermal cycling (baking) as well as other environmental changes.

So, none of this translates except to say - we bake things all the time to dry them out and accelerate the aging effects.

Another interesting work is in torrefaction/torrefication which is a specific process of artificially baking under vacuum/pressure changes.

[Ned Milburn]

I have heard various theories about Stradavarius (sp??) woods being buried or dunked in water, and that fungus has been detected, etc etc etc... There were even "blind" surveys done by professional violinists comparing Stradavari and modern violins that showed no preference at all for the Stradavari.

Also, good to remember that shellac is not a complete moisture barrier, and it will only slow the movement of moisture through it to the wood. I am no chemist, but I expect many (most??//all??) finishes are similar. Proof of this is the whitening of various finishes including shellac and many lacquers when exposed to water, or a combination of water and heat.

I think the most important thing to remember is that good wood, cut & dried well, and used well, will sound good in an instrument. "Bad" wood, or poorly cut wood, can still make a fine sounding instrument but will certainly fall short of good wood cut well. And good wood, even cut well, but used poorly will make an instrument that does not live up to its potential.

[arie]

suppose we bake our tops to accelerate the aging and crystallization process of the wood thereby possibly placing the guitar into it's tonal "midlife". what about the first half? i suppose some people want to cut to the chase and experience the sound of a vintage guitar right now but maybe others want to watch the instrument develop it's voice in it's own time?.

not all vintage guitars sound good by the way. i've played plenty of 1890's to 1920's relics that sounded like crap but they took a long time to get that way (one would hope).

here's a past thread about this:
http://www.acousticguitarforum.com/f...d.php?t=164612

also i think somogyi had something to say about baking tonewood in relation to it's tonal lifespan. can't seem to find the article though...

[Mbroady]

Originally Posted by arie

suppose we bake our tops to accelerate the aging and crystallization process of the wood thereby possibly placing the guitar into it's tonal "midlife". what about the first half? i suppose some people want to cut to the chase and experience the sound of a vintage guitar right now but maybe others want to watch the instrument develop it's voice in it's own time?.

not all vintage guitars sound good by the way. i've played plenty of 1890's to 1920's relics that sounded like crap but they took a long time to get that way (one would hope).

here's a past thread about this:
http://www.acousticguitarforum.com/f...d.php?t=164612

also i think somogyi had something to say about baking tonewood in relation to it's tonal lifespan. can't seem to find the article though...

There is something to be said about being part of the process - hearing your guitar mature. When I picked up my Stonebridge d22sm-A (A for aged top) I was the first one to play it out of the box. knocked my socks off from day one.

When I picked up a D-18 it sounded good but it definitely did not have the same "out of the box" mojo. Over the last couple of months it has started to shine/open up. Very cool to hear this happening. (my first new Martin)

[KevinLPederson]

I am not sure how this would affect the cell structure. But like I said, its mostly "drying" the wood more. Getting that last little bit of moisture baked off. Does this manipulate the cell structure? It probably does. If you over bake a cookie it is crisp and falls apart...its dried out and brittle. But a piece of spruce structure is obviously different than a cookie. So I just see it as relieving the moisture. So the wood is lighter, just by grams and getting the moisture out of the cell structure will leave it more sonorous. I don't think its a "magical" thing - its actually scientific. If drying the wood further is better than this would be a good thing.

As far as "tonal mid-life" and the "first part" I'd look at it as just starting out more sonorous for the first part of its "life". I don't think we are "aging" it faster...just "maturing" it sooner haha...

My 1.5 cents worth of splitting hairs.

Fun to talk about.

Kevin.

[printer2]

I baked the top of my current build, not to push it along the maturity cycle but because it is said the wood is more stable with humidity changes. Being cedar it also smelled up the house in a nice way.