Filling it with glue may not stop the propagation of the crack or even the appearance of another. Get it repaired properly!
Hi,
What needs to be done is to pull the sleeve in the head, close the crack, glue, re-bore the head, and re-glue the sleeve in the head. Otherwise it will never stay closed, even if you have a repairer put ugly pins in the crack!
Hmm, probably easier said than done! How would you take out the lining tube (without pulling hard)? Then, would sand paper suffice to sand out the bore, or would I need a certain tool/lathe - which I don’t have…?
Thanks Jon C.
While removing the slide, closing the crack, reboring and refitting the slide may be the “correct” way to do it and I’ve done this, you can glue such a crack and it may well hold indefinitely. I’ve successfully glued several that are still closed after several years. I think it depends on where how and why it has cracked in the first place as to whether it’s a good idea to try gluing it or not.
If you want to try here’s one method for fairly narrow cracks:
Flush out the crack with acetone. Then with a very slightly oily finger oil the outside of the flute to help stop excess glue from sticking to the wood. Get some sandpaper about 240 grit and a piece of similarly colored wood to what you’re repairing (or darker is OK on cocus which has dark lines already) and create some wood dust which you fill the crack with. Then get super low viscosity “super glue” (cyanoacrylate) ie very thin runny stuff and run some into the crack. It’ll get sucked down into the sanding dust (and run every where else you don’t want it if you’re not very careful). Carefully scrape off the excess. Repeat if necessary. Correctly done this can create an almost invisible repair. Badly done and you can ruin the thing you’re trying to fix.
Cheers
Graeme
Hi,
Yes it is a little tricky, without the proper equipment. Maybe Groxburgh’s option might be best…
Jon
I’ve just done one last night! The only “special” equipment I used was my paint-stripper hot air gun to heat up the liner in the cracked head to melt the old shellac and general gunk holding it in. (Don’t get the gun too near the wood and point it so the hot air goes throught the liner tube from the male tuning slide end to avoid scorching the wood.) I then used a pair of those rubber “chain wrench” type grippers to twist and pull the liner out of the wooden tube (carefully! - it’s all rather hot!). Then clean everything up, run superglue into the crack and clamp shut with cable-ties. When glue set, clean up surface and use sandpaper on dowel and/or a medium size half-round engineering file to re-ream bore until (cleaned up) liner tube can be reintroduced as a snug but not tight fit. (Be careful not to “hour-glass” the wooden tube bore). Then glue the liner tube back in (Jon’s recommendation of Gorilla glue is ideal - thanks Jon!) being careful to align the embouchure cut outs correctly and not to have an excess of glue where you can’t remove it at the tuning slide end in the recess for the barrel nose of the tuning slide! I spread the glue with a brush in the wooden tube, then introduce the liner from the lower (tuning slide) end to achieve this. You will need to clean up the crack line of excess glue on the outer surface. If there is still a hollow there after or a very visible glue line because the crack could not be fully pulled close, scratch out a little of the glue in the top of the crack and use wood-dust (saved from filing out the bore! - and better filed than sand-papered anyway - then there’s no sand in it!) and superglue as Graeme describes to top-dress it. The one I’ve just done didn’t need top-dressing as it has closed up very nicely, and apart from the glue being a little shiny, just looks like a grain line.
I also recently dealt with the other circumstance mentioned, where the head (on a Boehm style lined wooden head on a late Rudall Carte cylindrical 8-keyer in this instance) had one full length crack and a shorter one over the tuning slide (French type) which were not standing open and could be easily pressed together to virtual invisibility by hand, so clearly the wood had not shrunk significantly and wasn’t under pressure from the liner. They were stable and not likely to deteriorate further, but they were causing some air leakage so needed fixing. I removed the ferrule rings at each end, gently levered the cracks a little open with the point of a knife, ran in superglue and cable-tie compressed, then cleaned up with acetone when the glue was set. They have closed up nicely, didn’t need filling or top dressing, are barely visible and should be OK hence forth. I wouldn’t, however be inclined to do a fill-and-glue on an open-standing crack or one clearly under pressure if pressed closed, nor on one through the embouchure. Better to do the full reconstruction job then.