3- and 4-piece top questions

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Eric Knapp
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3- and 4-piece top questions

Post by Eric Knapp »

Hello, I am wondering about a good approach to arranging wood when making 3 or 4 piece tops. I have this cutoff from building my workbench. It is old-growth Douglas-Fir from a Wisconsin barn. The tree this came from was probably there when the first settlers came to the area. The barn it was part of stood for over 150 years. It’s sitting on my bench made from it and other beams.
B0C50529-C461-429C-BB24-08A7456D849A.jpeg

The grain is so tight, and the wood so old, that I wanted to see if it could make guitar tops. The grain runs 45º so cutting it like this results in quarter-sawn pieces.
DCB5FFD3-9BB5-4C03-BC27-3D8FAF886D0E.jpeg

I cut slices like this. This is half of the cutoff.
A8E595D6-577A-4F8E-AFDA-1BECCFDB92D3.jpeg

I can get 4” and 5” widths from the slices which could make 3 or 4 piece tops potentially.
4B2308D6-9728-499B-BD41-236A8365B131.jpeg

The grain is very tight and the slices are very stiff. They really shine after a little planing.
EE3698B4-6868-494E-BF85-4C2314D09B12.jpeg

How do you recommend arranging the wood for a top? Would book-matching still make sense? If making furniture I would have them all aligned sequentially with the same face out. That would facilitate surfacing with smoothing planes easier. Is there some common wisdom for this?

Thanks,

-Eric
Alan Carruth
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Re: 3- and 4-piece top questions

Post by Alan Carruth »

The object with book matching is to get the best grain in the center of the top. Usually the tightest grain is toward the outside of the tree (which is mostly a cosmetic issue), and the cut tends to be better quartered there as well, so the book match is made on the 'bark' side. The major reason to avoid that with a two-piece top is when the tree grew with increasing twist as it aged. With a 'bark' match there will be a lot of run out along the center joint, while the 'heart' side will have little or none. That's not really an issue here, I think.

If you 'sequence match' these you're going to end up with wider sections along one side of the top, and narrower on the other. You could justify it with some sort of BS about narrow sections favoring the bass (or treble; since it's BS it's your call), but it makes more sense to me to keep things pretty symmetric. Book match the two widest pieces in the center, and trim them to the same width, Then start adding on pieces along the outside, matching them in the same way.
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Bryan Bear
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Re: 3- and 4-piece top questions

Post by Bryan Bear »

I would listen to Alan if I were asking this question. one thing I will add for discussion is that you really don't know if there is any runnout n the pieces. This board may or may not have had runnout in it. If you bookmatch the center seam, you may have color variation under finish as the grain reverses. People are kind of used to seeing this. If you also bookmatch the wings, you may have two other lines of color shift that would look off to most. I would consider this as I was picking and orienting the wing pieces.
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Eric Knapp
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Re: 3- and 4-piece top questions

Post by Eric Knapp »

Alan Carruth wrote: Fri May 13, 2022 2:14 pm If you 'sequence match' these you're going to end up with wider sections along one side of the top, and narrower on the other. You could justify it with some sort of BS about narrow sections favoring the bass (or treble; since it's BS it's your call), but it makes more sense to me to keep things pretty symmetric.
I make things just for me, I don’t have to justify anything to anyone. :D
Alan Carruth wrote: Fri May 13, 2022 2:14 pm Book match the two widest pieces in the center, and trim them to the same width, Then start adding on pieces along the outside, matching them in the same way.
This is good advice. I put an OM pattern on the wood and it looks like I will have two 5” pieces in the middle with some ears.

Thanks,

-Eric
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Eric Knapp
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Re: 3- and 4-piece top questions

Post by Eric Knapp »

Bryan Bear wrote: Fri May 13, 2022 2:43 pm I would listen to Alan if I were asking this question. one thing I will add for discussion is that you really don't know if there is any runnout in the pieces. This board may or may not have had runnout in it.
The beam does not show any runout. I used most of this beam in my bench and I could plane it from either direction on all faces with no problem.
Bryan Bear wrote: Fri May 13, 2022 2:43 pm If you bookmatch the center seam, you may have color variation under finish as the grain reverses. People are kind of used to seeing this. If you also bookmatch the wings, you may have two other lines of color shift that would look off to most. I would consider this as I was picking and orienting the wing pieces.
I think I’ll bookmatch the center section and add sections to the outside with grain that matches as well as I can. The wood has such tight grain that a good joint will be hard to see.

Thanks,

-Eric
Chris Reed
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Re: 3- and 4-piece top questions

Post by Chris Reed »

From your description I don't think it matters, structurally, how you arrange the slices.

So I'd go for the best- looking arrangement. I'd guess that would be some kind of bookmatch, but maybe not - I built a uke with a koa top from two boards that were rejected by a professional builder (flaws which I could cut away as I was building a smaller instrument). They might have come from the same billet, but definitely didn't make a bookmatch. I simply made the best-looking join, and some 8 years later I can't find it (it wasn't on the centreline).

One suggestion, once you have a potential line-up, is to splash on some white spirit (mineral spirit in the US, I think) to see how the colour will change under finish. It would be sad to match up the grain lines beautifully, only to find that the final colours were very different!
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