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I want any joint to be clamped . I would think that something as thin as this and as flexible will still stick but clamping affords a better joint. Without it you will have a thicker glue joint . I would experiment and do 2 tops ,one clamped and one not and see if there is a difference.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I've used it on some finger braces, but I clamp all main bracing.

If you have a gobar deck, I see no reason why not to use it. You can rub the joint a bit then press with the fingers, wait a while, but then do put some gobars just to make sure. Seems like the safest way. That's what I did so far with both fish and HHG.

Yes the fan braces should not be arched, you make them flat no matter how much doming you use.

Hauser did not use a dome, it seems. His tops are mostly flat, with a bulge behind the bridge probably created by forcing the top in the hollow of the bridge, also probably by some fallaway in the side profile? It's pretty obscure how he built, but it was not exactly in the Spanish way.

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Build log

My recollection is that the same GAL article stated that a rubbed bridge adheres much more tightly than clamped. So, it may not be that each method, done properly, is equal. Clamping can pull parts apart, between the clamp points. Just some thoughts, as I have no personal experience with rubbed joints.

There is nothing simpler than a go-bar deck. Using rub joints for braces seems like a false economy to me.

Rubbed joints have been used in woodworking since the inseption. That said it is typical to rub the joint then clamp in place during cure out.

Filippo, just make a lid and support rods for your solera, and use it as a deck. One piece of plywood, and some threaded rod, washers, lock nuts, and wing nuts. I made mine so they would be consistent and could be moved off and on without adjustment, but that's because with my spring loaded go bars, the distance is critical. With a standard go-bar, distance is not critical, as I understand it.

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Waddy

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Since the X brace is radiused at least it is if you use a radiused top and the soundboard starts out flat how would you perform a rub joint for the this brace?...Mike

Rubbed joints with HHG work and they work extremely well. I've done many Back and Front plate joints using that technique as well as heel laminations.
i once tried to glue on a front harmonic bar using a rubbed joint. I abadoned the attempt, sadly for the life of me I simply can't remember why - it was too long ago but it obviously wasn't going as well as I'd hoped. Thinking about it there doesn't seem any logical reason why it shouldn't work so perhaps it's a matter of practice.
Gluing fan braces is a little different, these are usually pressed into the curve of the Solera. With that in mind I suspect that achieving a good rubbed joint fit is much more difficult, your effectively working against what the fan braces want to do - which is to return to their original shape.

If rubbed out in the form it will take the shape. That said I would think that the stress of the top trying to return to its natural state would likely cause joint failure in a smaller radii dome like backs. Personally I would not trust stressed skin rubbed and non-clamped joint because of the top or back trying to straighten back out. Now on a joint where the perpendicular piece is self supporting, well that is a different question all together.

While I’ve used the process of rubbing to join both the tops and backs of violins without clamping I haven’t done so with flexed joints like bracing on guitar tops. I would think any joint that flexes would require some clamping of some kind whether it be a go-bar or your finger. Some pressure would need to be applied until the glue sets.

Here’s a site with some further information on the use of hide glue:

http://www.deller.com/newpage8.htm

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Michael Lloyd

“I was born to ignorance, yes, and lesser poverties ...
I was born to privilege that I did not see ... I didn’t know it, but my way was paved” – John Gorka

I don't know, other than I saw them being used, in an on line slide show, and liked the straightness of it. I'm not a fan of bowed bars, for some reason. Maybe because I can see myself knocking them out of place and seeing them flying all about. Probably not realistic, but I am a Klutz of the first order!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Being a Piano Tech ,I can tell you that most Piano manufacturers have been springing in their ribs/braces for years . ( straight braces forced into a radius against the soundboard ) . Us pianomen are well ahead of the game ! (my attempt at being humorous )

This has the affect of leaving the soundboard in a state of compression rather than expansion ,and much better able to cope with humidity changes and the like.

The only downside is that it is difficult to predict the final radius you're left with ( even with increasing the dome to compensate for any springback ). For piano makers , the repetition of the process enables them to be able to predict fairly closlely what radius they will end up with.

As for rub joining : I always do this ,,,,, and then clamp.

A lot of violin makers and the like merely use a rub join only to
join plates ,then lay them aside to dry ( hide glue will pull these joins together quite tight upon drying off )

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CRAIG LAWRENCE of AUSTRALIA
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I'll just go against the usual council and say I often do it the way Eugene does it. It works just fine. You just have to hold the brace down until the glue gels. I also want to have the top pressed into the solera with a cam clamp or two between the fan braces.

I think in the US or if you were not initially trained to think and build that way it seems risky and scary. I clamp the cross braces, but the fans just paste right on. If i do use clamps on them I only leave the clamp on 15 minutes and move on. I've never had a fan brace pop off.

I don't agree with gluing the bridge on as only a rubbed joint. I do the bridge with a rubbed joint and slip it back a forth until it locks into it's final position, but then I clamp overnight. Or at least for three hours and then don't put string tension on it for 7 or 8 hours.

The rubbed joint on the bridge keeps you from needing index pins or any other lining up system because if you get the technique the bridge ain't going anywhere after you do the rubbed joint. I just calculate where the bridge needs to be for compensation and center and mark the front
corners with blue tape tabs on the top.
Some people think that's not fussy enough or technical enough, but it works and it's direct and fast. Something you might think about regarding Gene Clark is that he's been building classical guitars for a long time, since 1959. He learned a lot of his technique and hand tool making skills from a violin maker, so he clearly conceptualizes guitar construction in an older way. He also talks about building the guitar not from a place of fear, but from a place of direct action. Fear of this or that is not part of his discourse. I think over the years he's tried lots of ways to build and arrived at, for lack of a better less cliche way of saying it, the the Zen less tools approach.

I don't even glue the bridge as a rubbed joint. I glue it without rubbing, finger pressure for approximately 4 minutes, let go and it's done. I've been using that method for some 3 years and I'm still waiting for a failure.

Michael, how liberal are you with the glue when doing the bridge this way? Regular thickness?

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Build log

I size the bridge first, thin glue and let dry. Sand very lightly to cut back on the raised grain. You may want to size again. I stick small, layered masking tape tabs at a few points around the bridge perimeter to help location. Regular glue (NOT thick) on the bridge and simply locate. Some makers will pull off the bridge at this point and add more glue, I guess that really does ensure that enough glue is in the joint. I haven't done that on the last 6 or so bridges.
The one thing you must be careful of is deforming the top with your finger pressure. You may need to position a wooden prop in the Guitar to
avoid that - the prop also has to be the correct size to prevent that distorting the top.

Hi folks,

I'm emerging from the background since this subject is of great interest to me. I also read about Eugene Clark's methods and am planning to incorporate them to the best of my understanding. A couple months ago I send a question to AL asking for some clarification about Mr. Clark's methods and Mr. Mattola kindly passed my inquiry along to Mr. Clark, adding that we may, or may not get a response as Mr. Clark is somewhat reclusive and has neither email or a telephone (I wish he would write a book and pass his knowledge along!)

I'm guessing that one reason that Clark glues his fan braces with a rubbed joint is that he shapes the braces before gluing, making it difficult to clamp. He also mentioned that he uses a clamp to push the soundboard into the solera before gluing a brace on.

Another point that I think is important to Clark's method (because he mentions it frequently) is that he uses no relief (forward tilt) in his necks. So, to proper bridge saddle height is achieved by the dome in the top alone (hence the importance of dishing the solera deeper to allow for springback).

I'm making a new solera with a dish per Clark's dimensions and see how it goes...

Regards to all,

Bart Hovis

If my opinion matters, you need some 3mm, maybe more, of depth for a no-tilt neck. For such a deep solera (and maybe even for a regular depth one) you should ditch the '37 plan and try a later type of Hauser, as they have thinner tops. In any case Hauser did not use a deep Spanish type of doming. He built flat, I have to repeat it. Forcing a near 3mm thick top in a deep solera really risks a lot of springback.

Combining a tilted neck and a deep solera will result in a too low bridge.

To summarize, if you want to stay true to your plan, use a slight tilt (I think 2mm), and very shallow doming. I don't know what is the string height for that plan but the normal height for a classical is from 10 to 12mm at the bridge. You also want the plane of the unfretted fingerboard to touch the bridge at about 3-3.5mm. Some builders might use a sightly higher point. Some use a lower but that must be avoided as you might get that "low bridge with no saddle sticking out" situation.
It might sound a little better but it has two major drawbacks: you will often touch the soundboard with your nails, and in case the neck angles up in time, or want an extra low easy action, you wont have enough saddle left to lower it.

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Build log

Fillipo,

I've two soleras right now and I used to have a third. I no longer have the first one, which I actually made under Eugene's guidance. I have diverged a bit from Gene's basic way of arching, my arching right now is flatter. I have one solera with a larger plantilla and the it has 3/32nds of depth and the other a 1927 Santos pattern which has about an 1/8th of depth.

I think I remember Eugene making his solera at 3/16" deep. That would allow for some spring back. My Santos solera used to be that deep, but I cut it down around the edges to make it shallower. Eugene also shapes the sides and cross section profile of the fan braces by planing and sanding, then he presses them in and cuts the relief on the ends after the glue sets.