MIMF

Not sure where to post this.

I resawed this and glued it about a year ago, and it's been stacked between some other pieces. It originally had a finer, shorter crack that I thought I might be able to fill with CA and sawdust, but it now has grown and is through to the other side (1/4") in places. I hate to waste this, and I know it won't be invisible, but what might be a way to make it the least noticeable if I decide to use it?

Filling a crack like that will stick out and just be a disaster waiting to happen. I've used a trick with ripping the board following the crack from one end of the board to the other end with a band saw. I then clamped the 2 pieces back together and repeated, following the same kerf until the ragged edge of the crack is gone and the 2 pieces mate up. This leaves a joint that is difficult to see if you have clean edges and releases the tension in the wood that caused the crack. Use a zero clearance insert in the band saw and a sharp blade.

Another option is to do the above but laminate a thin piece of contrasting wood or inlay in the joint to get your width back and a reason to charge more for the guitar.

I would try re hydrating the piece to see if it will close. Good chance it will. If it closes you can glue it and clamp it closed and let it dry. Water will evaporate much more quickly than the original tree juices did, so it might be workable in a few weeks. If it open up again then cut it through the crack and glue it back together. Yes, you can still use that piece of wood.

Slip the piece into a plastic bag along with a few damp paper towels and close the bag. Check it in a few days and re wet the towels if needed.

Is this, perhaps, an opportunity for a design feature? I can't quite tell, but if there is a similar crack appearing on the other side, then a contrasting infill of crushed stone (for example - there are many options there) might work.
Is it thick enough to be used for a chambered body, and an f-hole placed over the crack?
Or go PRS dragon-style with some fancy inlay to accentuate the quilt?

Adam

Thanks for your excellent suggestions. It's in a garbage bag with wet, old socks now, and even after a few hours the crack appears to be getting narrower. If that turns out to be insufficient, I will try the bandsaw fix. If still inadequate, looks like a snake inlay might be the ticket, though I don't relish the thought of all that work.

I'm also thinking of parting the current center seam and regluing the outer edges in the center - I think I might like that bookmatched figure better than the current one, and if worse comes to worst, I can hide most of the defect with a pick guard.

Yes, it will be a top for a chambered solid body - maybe I could figure some arrangement of F type holes to hide some of it.

Anyway, thanks for the advice, and anyone feel free to add more.

It may just close up without rewetting but I like Mr Lewis's dampening idea. I try closing up cracks like that in my milling machine vise which is quite persuasive. I'd also bleach the wood in the crack to avoid a dark glue line.
You will probably want to cleat the back side of the crack or put a thin layer of parchment as insurance.

Maybe I wasn't clear but I mean damp, not wet. The reason is the wood needs water vapor, a gas, not water liquid. It will take longer to swell the wood but is much less risky to the wood. Also it will be easier to glue if it isn't wet.

It will probably work better if left with the crack clamped closed for drying for a week or more before gluing. You want it to dry well. This is a good place to use hot hide glue as it will show less than other glues. If the crack doesn't fully close then go with your other ideas.

When I rehydrate a guitar to close a crack it usually takes a few days to a week to get it closed. At that point it needs to be glued and cleated, but you can't glue wet wood with the glues I use.

Michael, I'm not sure where the line between damp and wet is. In any case, the socks are not oozing water, and are several inches away from the wood, hydrating the air trapped inside the bag.

Unfortunately, though the crack is slightly narrower, it is not making significant progress toward closing. I'll wait a few days, then I might try to clamp it closed and glue once it has dried. However, this will probably re-introduce the stresses that caused the crack in the first place, so maybe one of the alternative options will be a better course to take.

I have a friend who likes to rehydrate bowed double bass bridges by simmering them for an hour or two to completely saturate them. It works well on a small pieces that have lots of endgrain. You hang them on a string from the ceiling and they tend to dry completely flat.

Peter, it sounds like you are doing well. Solid wood will take a while, maybe a week or more.

One thing to remember is wood can and will take a 'set' as it dries, which is why guitar wood is stickered and stacked and weighted to dry. If allowed to cup and curl it will, but if kept flat it will dry that way unless there is significant internal stress in it. It would just take longer for it to settle.