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Soundhole reinforcement
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=49844
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Author:  SnowManSnow [ Sun Oct 22, 2017 7:15 pm ]
Post subject:  Soundhole reinforcement

So here’s an idea that is, I’m SURE, more complicated than it is worth.

I’ve seen some folks reinforce the soundhole area with a solid ring on the inside. Some do the traditional thin “braces” on 3 sides and I’ve even seen some attach binding to the inside of the ring to seal off the end grain.

So I wonder... has anyone done like an “insert”?
What I mean is a round reinforcement that will be under the soundhole, but also has a raised lip that inserts into the sound hole and comes flush with the top.

I’ll include a REAL bad drawing to farther complicate things here :)

Check out this art!
Image


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Author:  Jonny [ Sun Oct 22, 2017 7:20 pm ]
Post subject:  Re: Soundhole reinforcement

You mean a 4" sound hole flange ?

Author:  Clay S. [ Sun Oct 22, 2017 7:43 pm ]
Post subject:  Re: Soundhole reinforcement

I think Ovation did something similar, only in plastic, and on the outside of the guitar (plastic rosette).

You would probably be better off doing the "doughnut" reinforcement and then binding the sound hole. That way there is no end grain exposed.

Author:  Mark Mc [ Sun Oct 22, 2017 8:05 pm ]
Post subject:  Re: Soundhole reinforcement

I agree with what Clay just said. It is a good idea to have soundhole reinforcement. It can also look really nice to have a soundhole binding, say in the same timber as your other bindings. You could achieve both things with one piece of timber, as you have suggested. However, I think it could be a real hassle to engineer that with a perfect fit. I usually do the donut in off-cuts of the soundboard (softwood, light). Then you will have a thickness of about 5-6mm at the cut edge of the soundhole and it is pretty easy to bend a piece of your binding into a circle and fit that to cover the end grain. It has the advantage of usually being a hardwood, for better protection of the edge of the hole. If you can do that with one piece I will be really impressed, so take some photos to show us.......

Author:  SnowManSnow [ Sun Oct 22, 2017 8:29 pm ]
Post subject:  Re: Soundhole reinforcement

Mark Mc wrote:
I agree with what Clay just said. It is a good idea to have soundhole reinforcement. It can also look really nice to have a soundhole binding, say in the same timber as your other bindings. You could achieve both things with one piece of timber, as you have suggested. However, I think it could be a real hassle to engineer that with a perfect fit. I usually do the donut in off-cuts of the soundboard (softwood, light). Then you will have a thickness of about 5-6mm at the cut edge of the soundhole and it is pretty easy to bend a piece of your binding into a circle and fit that to cover the end grain. It has the advantage of usually being a hardwood, for better protection of the edge of the hole. If you can do that with one piece I will be really impressed, so take some photos to show us.......

Even if I could i would still have end grain exposed:/ I do like the binding idea, but haven’t tried it.
I suppose all I really need is a 4” hot pipe to bend around


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Author:  SteveSmith [ Sun Oct 22, 2017 9:16 pm ]
Post subject:  Re: Soundhole reinforcement

SnowManSnow wrote:
Mark Mc wrote:
I agree with what Clay just said. It is a good idea to have soundhole reinforcement. It can also look really nice to have a soundhole binding, say in the same timber as your other bindings. You could achieve both things with one piece of timber, as you have suggested. However, I think it could be a real hassle to engineer that with a perfect fit. I usually do the donut in off-cuts of the soundboard (softwood, light). Then you will have a thickness of about 5-6mm at the cut edge of the soundhole and it is pretty easy to bend a piece of your binding into a circle and fit that to cover the end grain. It has the advantage of usually being a hardwood, for better protection of the edge of the hole. If you can do that with one piece I will be really impressed, so take some photos to show us.......

Even if I could i would still have end grain exposed:/ I do like the binding idea, but haven’t tried it.
I suppose all I really need is a 4” hot pipe to bend around


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Just use the regular bending iron. I've done several. The hardest part is to bend the binding without breaking it.

Author:  Mark Mc [ Sun Oct 22, 2017 9:24 pm ]
Post subject:  Re: Soundhole reinforcement

It is a fairly tight bend, but no worst than many cutaways. Thin the binding strip down a bit. Super-soft can help. Use a metal backing slat. But it is no different from hand bending a normal binding. I do them on a normal bending iron - no need for a special tool for this job.

I think I remember seeing a YouTube video by Nigel Forster, which you could search for. He made it look easy so I tried it, and I only snapped 2 or 3 before I got it right (so maybe don't do it with your valuable BRW bindings for the first attempt).
Here is the video from Nigel:
https://www.youtube.com/watch?v=9f_t-wGo30o&sns=em

Author:  J De Rocher [ Mon Oct 23, 2017 12:13 am ]
Post subject:  Re: Soundhole reinforcement

Are you envisioning the insert being made from a single piece of wood? What wood would the insert be made of?

It wouldn't be hard to make an insert like that that fits nicely from one piece of wood using a router in a circle cutter base. If it was made from spruce though, I think it might look a bit odd to have a narrow ring of spruce around the soundhole opening with a different grain than the surrounding top wood.

Author:  Hesh [ Mon Oct 23, 2017 4:31 am ]
Post subject:  Re: Soundhole reinforcement

Back in the day the G*bson MK series was state of the art with unique bracing and the design resulted from a collaboration between Kasha and Richard Schneider. They had a genuine, imitation pl*stic.... sound hole..... thing..... that I believe was supposed to project like a trumpet.

Like many things in the guitar world it didn't work as envisioned, the guitars are widely considered to be pieces of crap.... and although they have their following it's just one more example of why attempting to reinvent the wheel before understanding more completely traditional guitar design tends to be a rather futile pursuit. Resistance is futile.....;). There are very good reasons why sound holes look like they do these days.

Don't mean to be a buzz kill but there is very little that has not been done prior in the guitar world.

Image

We have a collector who is a client and we work on several of the MKs from time to time. One of his still has vomit chunks and bong water stains from when he went to Michigan State University. Provenance..... they say.... :? :roll: [xx(] :D The only thing I hate worse than a guitar with vomit in the sound hole is a Rikinbacker 12 string. I just doubled my pricing to set up the Rik 12's because they make me want to puke every time I have to work on them. What were they thinking....;)

Author:  Bob Shanklin [ Mon Oct 23, 2017 4:11 pm ]
Post subject:  Re: Soundhole reinforcement

If you decide to bind the sound hole, make yourself a Soundhole Binding Clamp from a piece of 3.5" plastic drain pipe and a few wedges. The clamp will hold the binding tight in the sound hole.


download/file.php?mode=view&id=57491&sid=f5f8ec0aa4c028243737da4137e0a2d3http://www.luthiersforum.com/forum/download/file.php?mode=view&id=57492

Bob

Author:  J De Rocher [ Mon Oct 23, 2017 5:08 pm ]
Post subject:  Re: Soundhole reinforcement

Another approach for binding the sound hole is to treat it as another ring of inlay. I bend a ring and then rout an appropriately sized channel into the top and inlay the ring. The depth of the channel is a few thousandths shy of going through the top. Later, I rout out the sound hole opening inside the binding ring. In the photo below, the innermost ring is cocobolo sound hole binding.

Attachment:
Rosette inlay 3.jpg

Author:  Haans [ Tue Oct 24, 2017 8:20 am ]
Post subject:  Re: Soundhole reinforcement

Yup, that's the way Larson's did it in the '30's...
When I did it, the inside ivoroid ring exposed approx 1/2 the thickness of the top. Some folks need to see that QS grain.
Never cared for the idea of anything sticking above the sound hole (difficult to finish), but was a firm believer in sound hole re-inforcement. I used a spruce doubler that ran full span from X to UTB or on Ladder bracing, UTB to LTB. In addition, I also used the 3 braces around the sound hole, or 2 on ladders.
Someone a long time ago demonstrated to me that lightly braced sound holes distort and can cause dissonance.

Author:  printer2 [ Tue Oct 24, 2017 5:56 pm ]
Post subject:  Re: Soundhole reinforcement

I like the ABS pipe idea. I did add a few more clamps yet but I took a picture during the process of clamping.

Image

Oh wait, this was my doing a dry run.

Author:  kjaffrey [ Tue Oct 24, 2017 6:35 pm ]
Post subject:  Re: Soundhole reinforcement

I really like that idea Jay. It would make the clamping and gluing soooo much,easier to handle and since I leave the tops a little thick when installing the rosette.

Author:  J De Rocher [ Tue Oct 24, 2017 6:56 pm ]
Post subject:  Re: Soundhole reinforcement

I nominate Fred for this month's Award for Creative Excellence in Clamping Accessories! [:Y:]

Author:  printer2 [ Tue Oct 24, 2017 7:16 pm ]
Post subject:  Re: Soundhole reinforcement

J De Rocher wrote:
I nominate Fred for this month's Award for Creative Excellence in Clamping Accessories! [:Y:]


I didn't want any marks on the sides, I already scraped them smooth. I think I will get another lid for the other bout, when actually gluing and clamping the soundhole trim I had the inner tube go around the whole exterior of the guitar. When taking off the clamps no marks. Got to love Mother when necessity calls. Or something like that.

Author:  Ken Franklin [ Wed Oct 25, 2017 12:58 am ]
Post subject:  Re: Soundhole reinforcement

Here is a jig made by Link Van Cleave that makes the binding more uniformly round. I can get it close on the pipe and then heat it up on a hot plate. I like to do a scarf joint at the ends.

Attachment:
IMG_1058.jpg


Attachment:
IMG_1059.jpg

Author:  Ruby50 [ Wed Oct 25, 2017 2:31 pm ]
Post subject:  Re: Soundhole reinforcement

Just did some cuffs on the legs of a dressing table - the legs were 1-3/8" and the cuffs were .075" spruce. I boiled them for 15 minutes and wrapped them around an appropriate sized dowel and let them dry. Worked well with careful stock selection.

https://www.flickr.com/photos/ruby1638/35176717312/in/album-72157680433239633/

I love the idea of the hose clamp around the form. I have glued the soundhole binding into an extra rosette groove before final sanding, and made it almost full depth, glue on one side only. When I sanded the top, the middle plug just fell out. Not my idea.

I also love the interior split pipe clamp - next time.

Ed

Author:  Haans [ Wed Oct 25, 2017 7:41 pm ]
Post subject:  Re: Soundhole reinforcement

Test!

Here's an old 12 string ladder with sound hole doubler...

Image

Looks like I will be able to post photos again...I hope.

Author:  SnowManSnow [ Wed Nov 22, 2017 9:43 am ]
Post subject:  Re: Soundhole reinforcement

I wanted to revisit this.
So, I’m nervous about gluing a “binding strip” to the inside of the hole for some reason... I guess I don’t trust my luthier powers yet... and I’d hate for it to pop off if hit by a pick or something.
What about making what is basically an inner rosette that covered the area where the sound hole will be cut before thicknessing from the back and then cutting the hole from that? Would this leave a weak area?
I guess, if I want this to be part of my arsenal in the future I just need to cut some practice sound holes and do it right until I get it right.
Well, thanks for the conversation. Haha


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Author:  SnowManSnow [ Wed Nov 22, 2017 9:49 am ]
Post subject:  Re: Soundhole reinforcement

J De Rocher wrote:
Another approach for binding the sound hole is to treat it as another ring of inlay. I bend a ring and then rout an appropriately sized channel into the top and inlay the ring. The depth of the channel is a few thousandths shy of going through the top. Later, I rout out the sound hole opening inside the binding ring. In the photo below, the innermost ring is cocobolo sound hole binding.

Attachment:
Rosette inlay 3.jpg

Yup. Like this
Already addressed
Sorry for raising the dead


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Author:  giltzow [ Wed Nov 22, 2017 11:31 am ]
Post subject:  Re: Soundhole reinforcement

Hey SnowManSnow

If I understand your drawing correctly: I do some of my sound holes like that. Not a binding but an inlay. Pics below:

Image

Image

- Mike G

Author:  giltzow [ Wed Nov 22, 2017 11:47 am ]
Post subject:  Re: Soundhole reinforcement

Here's another pic with more detail:

Image

Author:  SnowManSnow [ Wed Nov 22, 2017 12:53 pm ]
Post subject:  Re: Soundhole reinforcement

Yea that’s what the original idea was
It doesn’t seal the end grain but does look nice;)


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Author:  jeffhigh [ Wed Nov 22, 2017 1:43 pm ]
Post subject:  Re: Soundhole reinforcement

Besides appearance, don't forget the structural aspects of soundhole reinforcement and bracing.
Cutting the channel for the rosette leaves the soundboard quite thin in this area, and compressive forces from the string tension have to pass through a fairly narrow strip of soundboard outside the soundhole.
I just had to do some extensive repair on a CSL macafferi big mouth, which had warped like a potato chip both sides of the soundhole. The plastic rosette had popped out of it's groove too
No reinforcement, no bracing, what were they thinking?

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