Baking Tops - Luthier Tips du Jour Mailbag
In this episode, Robbie O’Brien discusses torrefaction and its use in guitar building.
Video Transcription
[on-screen text reads: Luthier Tips du Jour Mailbag]
Mailbag question: Can you shed some light on the subject of baking your guitar top before you build with it?
Robert O'Brien: Today's Tips du Jour Mailbag questioning comes to us from Australia. "Dear Robert, I recently read somewhere about baking the top of the guitar before using it to build with. Can you shed any light on this subject?" Mike in Australia.
Mike, the technical term for that is torrefaction. In other words, you're baking your top. Basically, what you're doing is introducing heat but without the oxygen. And what this does is dry the wood out, changes the cellular structure, removes the moisture and the resins, and dries it out, almost like aging it 20 or 30 years. Martin guitars and Taylor guitars use this process, torrefaction, on some of their instruments. And recently I spoke with Eric Sakimoto of Taylor Guitars about this very subject. And it was very interesting what he told me. So, let me let you listen in on our conversation.
Something else that you've touched on in your demonstration this morning is baking the top. And the technical term is?
Eric Sakimoto: Torrefaction.
Robert: Torrefaction.
Eric: Yep. It's gaining a lot of popularity and-
Robert: What exactly does that do to the-
Eric: ... been doing it, and Martin does. What it does to the soundboard?
Robert: In layman's terms.
Eric: Yeah.
Robert: I'm sure there's a very technical description for it.
Eric: A lot of people like acoustic guitars to be opened up and worked at already. When you get a new guitar, it's a little tight. You have to play the guitar and let the whole body and the wood vibrate to open up and loosen the volume and all that stuff. But torrefaction, what it is, it's baking the wood under high heat but with no oxygen. If you add the oxygen there, you'll pretty much burn it.
Robert: Right.
Eric: You also add a lot out of pressure on there. And what that does is it ages the spruce. So, it already... When you put it on a guitar, it already has that broken in vintage sound that you get, that you want out of spruce.
Robert: So, basically you're speeding up the drying process?
Eric: Yep. It's like taking a guitar that's 25, 30 years and putting it on a new guitar.
Robert: All right.
Eric: Now when you look at it, it's dark. When you look at spruce, it has a really white look to it, and then over time it gets that dark look. And that's what you get when it comes out.
Robert: You get that immediately from the torrefaction process-
Eric: Immediately. Yeah. It's really dark too. It's not like putting a guitar out in the sun and allowing it to tan a little bit.
Robert: Right.
Eric: It's even darker than that.
Robert: It's really dark. Interesting.
Eric: You can almost tell that's been through that torrefaction process.
Robert: All right. Thank you very much Eric. I appreciate your time.
Eric: You're welcome. Thanks for having me.
Robert: All right, thank you.
Eric: Yeah.
Robert: So, Mike in Australia, I hope you were able to understand Eric's explanation of torrefaction. I don't think I would try this at home boys and girls, this is a pretty advanced technique and you might wind up with an expensive piece of firewood. So, I hope this has answered your question, Mike, and shed a little bit more light on the subject. And happy building.
[on-screen text reads: More Luthier Tips and online courses available at www.obrienguitars.com. Private and small group guitar building and finishing instruction available.]
