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Sick Weissenborn
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10137&t=49635		 Page 1 of 1
Author:  jogyth [ Mon Aug 14, 2017 2:51 pm ]
Post subject:  Sick Weissenborn
Hi good folks!

I'm an amateur that just fixes my own and my mates electric guitars - at least to a certain level. But now I've got my self an accoustic project and I don't really know where to start. I'm not expecting you guy's to talk me through it all (alltough you are very welcome if you have the time and patience :-D ) - but I'm hoping to get some pointers on where to start - what to read up on and/or what to look out for...

I've got this cheap ol' Weissenborn. I guess it could not take the heavy gauge strings in combination with the open G tuning... So the bridge has pretty much come off. And it has "dragged" and reshaped parts of the body with it ...

Since I'm kinda broke at the moment, buying a new cheap Weissenborn is not an option. So I figured it would be worth a go spending some time on trying to make it well again. If I fail, it's not the end of the world. If I succeed - I think I'd go ahead and change the nut and the tuning keys too - at some point in time.

I'm thinking that the saddle probably should come off completely and be "cleaned" up. The fixing point too (cleaned up that is). In principle I suppose I can just glue it back on the same spot. But the reshaped body... How do I level it out again? Heat it up somehow an put it upside down on a bench and under some pressure?

I sure hope some of you can give me a nod in the right direction!

Best regards from Norway!
Author:  Freeman [ Mon Aug 14, 2017 9:16 pm ]
Post subject:  Re: Sick Weissenborn
Regluing the bridge is fairly straightforward - remove it completely, sand and scrape every bit of glue off both the bridge and top, reglue it with either an AR type glue or better yet, hot hide if you have it and can work with it. You can use the pins to locate the bridge and deep clamps with some sort of caul inside to keep from crushing braces

Image

The top is far more problematic and I'm not sure how that failed. Have you looked inside at the bracing - has any of that come loose. A Weissie should have a basic X brace with probably a couple of tone bars between the legs of the X and a bridge plate. Here is fairly traditional Weissenborn bracing however there are lots of variations./

Image

anyway, make sure that the top hasn't pulled loose from the brace or that they haven't failed. If so you are going to need to figure out how to glue and clamp them and that is not always easy.

One of the bonuses of this type of guitar is that if you can't fix the bellied top it really doesn't matter - the action will be a little higher but since its strictly a lap slider, so what. You've got a fairly tall saddle - that has certainly applied a stronger lever arm to the top - probably part of the reason the bridge and top are failing.

In the old days Weissenborn's used a piece of fret wire for the saddle so they weren't very high. I use bone like yours and my saddles stick maybe 1/8 inch out of the bridge slot. I also use a bone nut and try to keep the strings an even distance (1/4 - 3/8) off the fretboard

Image

Last comment, I string my guitars with medium gauge strings 0.013 to 0.056 or so. I like a heavier first string, at lease 0.014, some players will go up higher than that. A heavier string keeps you from hitting the side of the neck when you tilt your bar and play stuff on the first string. I tune to either open D or open G, honestly with mediums the tension isn't that high , somewhere around 165 - 170 pounds.

Good luck with your project - Weissies are really fun to play.
Author:  jogyth [ Tue Aug 15, 2017 3:09 am ]
Post subject:  Re: Sick Weissenborn
Koa,

Thanks a billion for your response - with images and everything! And a really beautiful instrument in your examples too.

Looks like you've also pulled a wing nut through the bridge to tighten up while glueing? I'm afraid the word "caul" does not mean much to me - nor my native google translate... I've been contemplating that for a while; how to set a clamp inside the guitar without destroying the braces.

And by AR glue - you mean Aliphatic Resin? Like for instance Titebond original wood glue?

Luckily all my bracings are intact. And my guitar has a basic X brace pretty similar to the one in your picture. The strange thing though is that the body is pulled up below the bridge, but in front of the bridge (north of) the boydy is in it's usual place. That gives me a bump that makes the bridge sit at an angle (guesstimated to almost 30 degrees) - with the highest point at the south end. As you point out - it might not matter at all, but it sure looks strange :-D

Medium strings will certainly be the way to fly this thing in the future. And my plan is to tune this to open D or C. I have a lap steel and a dobro too - so that whay I can play in three different tunings at any time :-). And when my pocket fills up - I'll buy a new (proper) Weissenborn and my life will be complete :-D.

Looking forward to this little project now. It sure would make me feel good to salvage this poor guitar.
Author:  profchris [ Tue Aug 15, 2017 4:04 am ]
Post subject:  Re: Sick Weissenborn
A caul is just a shaped block which you clamp on to. So, for the lower leg of one of your bridge clamps, you need a block which is taller than the brace(s) which the clamp has to reach over. Probably a wood block with some cork on the top would do it (the cork is to avoid the edges of the block crushing the top). Ideally the top of your block would have the same curve on it as the underside of the bridge.
Author:  jogyth [ Tue Aug 15, 2017 4:18 am ]
Post subject:  Re: Sick Weissenborn
Of course! Thanks for the explanation. That cork sure needs to look like a half circle on this guitar... That's going to consume some time to cut to the right angle :-D
Author:  Freeman [ Tue Aug 15, 2017 10:49 am ]
Post subject:  Re: Sick Weissenborn
As Chris said, a caul is something to distribute the pressure of clamping and to keep the jaws of the clamp(s) from denting the wood. I made a special caul out of something called UHMW (its a very dense plastic used in industry) that I use for the inside of bridge repairs. It is angled to fit inside the X against the bridge plate and is taller than the braces. One important thing is that glue will not stick to the plastic - glue will run thru the pin holes so if you want to use wood you should wrap some waxed paper around it. My caul has slotted holes in it because I repairs guitars with different pin spacing - two small bolts thru the holes position the bridge and helps to apply some of the clamping pressure.

Image

There are other types of bridge clamping cauls but this works for me. On the top I have three little blocks of wood, padded with something like cork. The ones on the outside are wedge shaped to fit the wings of the bridge.

And yes, sometimes I spend more time making jigs and hardware and cauls and stuff than actually doing the repair. AR glue is Titebond.

If the top isn't going to come down you might consider sanding the bottom of the bridge slightly to reduce that angle. I don't see any problems but then again, I don't have the guitar in front of me.

ps - I'm going to say it once more - don't just use a block of wood inside the guitar for the caul - glue will run thru the holes and it will become permanent. You will need to drill the holes out and ream them after you are done.
Author:  jogyth [ Wed Aug 16, 2017 7:50 am ]
Post subject:  Re: Sick Weissenborn
Koa,
Thanks for underlining the importance of not using wood-cauls inside the guitar. I can easily see that is a rocky mistake that I could have easily done!! Well - I've ordered my glue and will start cleaning under the bridge (and the bridge itself of course). I also need to find some clamps that might fit - preferably without spending $200 since I'm not really sure I'll ever do this again ....

This little project is going to take me a while. Finding the right tools, preparing cauls, cleaning, testing, rehearsing etc. And I have 2 jobs, 2 kids and a wife for startes (haha). But at least I now know how to proceed - so (again) thanks a million for that you good folks!
Author:  truckjohn [ Thu Aug 17, 2017 9:45 am ]
Post subject:  Re: Sick Weissenborn
It looks to me like they glued a flat bridge onto a curved top. Thats fairly "conventional" - but it also ends up putting some huge stress on the glue joint at the wings of the bridge.

Personally - I like to see the bridge gluing surface contoured to match the top. My opinion is that we are less likely to see bridge failures because the wings started pulling up - which then creates a death spiral.... Less glue surface = more pull per square inch of glue surface left = more localized deflection = more wings pulling up = less square inches of glue area = more deflection....

Unfortunately - this means you need to make up a new bridge to make up the height difference once you hollow out 1/8".... But a bridge blank is still relatively cheap in the grand scheme of things....
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