I have always used cross-grain soundhole patches to avoid cracks developing in the end grain exposed by the soundhole. I presently use hickory veneer because it is strong and I have a big roll of it.
Bob
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| Author: | Daniel Minard [ Thu Jan 20, 2011 2:54 pm ] |
| Post subject: | Soundhole re-enforcement. |
I have been adding a cross grain soundhole re-enforcement patch on my recent (steel string) guitars. I'm wondering if adding braces at the edges of the patch is overkill. Any comments? |
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| Author: | Howard Klepper [ Thu Jan 20, 2011 6:55 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
IMO soundhole braces serve two functions: to keep the rosette from breaking out, and to keep the soundhole area from distorting. A thin reinforcement patch does the former, but not much of the latter. |
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| Author: | Ti-Roux [ Fri Jan 21, 2011 1:09 am ] |
| Post subject: | Re: Soundhole re-enforcement. |
I think it's overkill. This area is already really stiff, and the patch is there to protect the rosette area. You don't need to put too much useless stress in this part of the top. You can even put a patch that is not cross-grain. Francis |
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| Author: | Laurent Brondel [ Fri Jan 21, 2011 6:44 am ] |
| Post subject: | Re: Soundhole re-enforcement. |
IMHO a cross grain patch does little. I glue a .090" patch and use subtantial soundhole braces mortised under the UTB. As Todd points out, a lot of steel strings tend to sink around the soundhole. |
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| Author: | Daniel Minard [ Fri Jan 21, 2011 1:55 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
Thanks guys. I really appreciate the input. Looks like patch & braces from here on. Sounds good to me, being a "belt & suspenders" kind of guy. I often end up putting a pickup in my guitars & the bass side soundhole brace gets in the way of some on-board controls. I was hoping a substantial patch (I've been using .110" thick Sitka) would eliminate the problem. |
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| Author: | Alan Carruth [ Fri Jan 21, 2011 2:28 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
I got tired of replacing tops after a couple of mine got dropped and had the necks shift inward (I get tired of warrenty work in a hurry). I went to using an 'A' brace setup, with 1/4" square braces on either side of the soundhole that inlet into the upper arms of the X braces, and run through the shoulder brace to inlet into the neck block. Since then I haven't had any necks shift, despite a couple of instruments coming in for really big dings in the back of the neck after misadventures. This also stiffens up the soundhole edge, and seems to help stabilize the setup. Ken Bonfield, who spends a lot of time on the road with my guitars, says that they seem to move a little bit after the first big seasonal change when he gets them, after which they stay put, and I think a lot of that is the 'A' brace. |
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| Author: | Daniel Minard [ Fri Jan 21, 2011 8:53 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
Thanks for adding your experience here Alan. I use a heel block extension which is butted & glued to the UTB. Adding an "A" brace seems like a very good idea. It's a step I've been considering for a while now. I too have seen some pretty funny shaped soundholes in older guitars that are in for repair. Not an easy fix. A few grams of prevention might go a long way here. Do your braces taper at the ends, or stay the full 1/4" square the full length? |
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| Author: | unkabob [ Fri Jan 21, 2011 9:51 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
I have always used cross-grain soundhole patches to avoid cracks developing in the end grain exposed by the soundhole. I presently use hickory veneer because it is strong and I have a big roll of it. Bob
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| Author: | bluescreek [ Sat Jan 22, 2011 8:15 am ] |
| Post subject: | Re: Soundhole re-enforcement. |
I am a traditionalist in my building and do things very Martinish . I do know that the A frame is one of the most efficient load carriers for the upper bout area . Martin incorporated that design into the Mortise and tenon . Agree that cross grain may help with the rosette but it is an anti split support but not structural . Laurents look good with a heavier brace appearance . |
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| Author: | Laurent Brondel [ Sat Jan 22, 2011 11:14 am ] |
| Post subject: | Re: Soundhole re-enforcement. |
Not sure what you mean by plate vs. beam Filippo, but my soundhole reinforcement is along the grain. In my (simple) mind it makes up for the "missing" soundhole wood. I do not use the excellent A-frame, but an inverted Spanish foot, which does the same thing. I also use an extra wide UTB (5/8") which does a better job than a thinner/taller one to counter act rotational forces on the upper bout. |
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| Author: | bluescreek [ Sat Jan 22, 2011 5:28 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
I can't say for sure but I have seen sound hole reinforcement that looked like an 1/8 inch thick disk and glued onto the top under the rosette . |
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| Author: | muthrs [ Sat Jan 22, 2011 6:54 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
I believe in real soundhole braces. I use an A-frame similar to Al. Mine are 3/8" tall by 1/4" wide, tucked into the head block and half lap jointed as they pass through the upper face brace. Then they are triangulated in profile as they become soundhole braces. Not sure if I'm being clear here. I also use a laminated upper face brace and a spanish foot on the the head block. |
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| Author: | woody b [ Sat Jan 22, 2011 7:24 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
bluescreek wrote: I can't say for sure but I have seen sound hole reinforcement that looked like an 1/8 inch thick disk and glued onto the top under the rosette . Lowden??? (I think) I use soundhole braces similar to Laurents. |
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| Author: | Alan Carruth [ Sat Jan 22, 2011 7:32 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
Lately I've been tapering the lower ends of the A braces, where they inlet into the upper arms of the X. On the last few guitars I've also incorporated a spruce soundhole reinforcement, about 2.5mm thick, with the grain running about 5 degrees out of line with the top grain. That little change in alignment adds a lot of splitting resistance without introducing much stress from differential expansion. I have to say I have not suddenly 'got religion': I got a stack of soundboard cutoffs from Carleen Hutchin's estate, and that looked like a good use for them. She got the wood from Martin, back in the '70s, when the Catgut folks were researching a synthetic substitute for spruce. Martin and Ovation supplied them with some tops to measure up, so they'd know what they wanted to make. |
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| Author: | Jim Kirby [ Sun Jan 23, 2011 8:18 am ] |
| Post subject: | Re: Soundhole re-enforcement. |
bluescreek wrote: I can't say for sure but I have seen sound hole reinforcement that looked like an 1/8 inch thick disk and glued onto the top under the rosette . That's pretty standard in a number of more modern classical designs. One guitar in the shop that I am neglecting to work on right now is derived from Greg Byers' double fan lattice design and has just exactly that, trimmed to fit between the upper and lower transverse braces. But steel string guitars could do with more support than this. |
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| Author: | Daniel Minard [ Sun Jan 23, 2011 2:31 pm ] |
| Post subject: | Re: Soundhole re-enforcement. |
Great info guys... Thanks! Dan |
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