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CA for tops and backs....
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10101&t=16542		 Page 1 of 2
Author:  Chris aka Sniggly [ Sun Mar 23, 2008 4:39 pm ]
Post subject:  CA for tops and backs....
Anyone doing this now?....or is everyone using white or yellow? I am about to join and was curious if I could use CA....seems a good match to since you want the glue to be really hard....
Author:  Jim Kirby [ Sun Mar 23, 2008 4:58 pm ]
Post subject:  Re: CA for tops and backs....
CA works well for Rosewoods - its all I use there. I have no experience joining anything but several of the rosewoods, so I can't say for Mahogany, maple, etc.

CA can stain tops badly, so I'm guessing you won't get any positives on that one.

Jim
Author:  Daniel M [ Sun Mar 23, 2008 4:58 pm ]
Post subject:  Re: CA for tops and backs....
I have used (medium thickness) CA for joining backs, but not for softwood tops. CA can stain softwoods. When using CA for bindings & rosettes, it's important to seal the top after routing, to prevent staining.
Author:  Hesh [ Sun Mar 23, 2008 5:54 pm ]
Post subject:  Re: CA for tops and backs....
gaah gaah gaah gaah gaah :D
Author:  DYeager [ Sun Mar 23, 2008 5:57 pm ]
Post subject:  Re: CA for tops and backs....
I use thick or, for preference, IC-GEL, from BSI, to join both spruce and wrc plates for a well-known classical maker. These are for experimental projects, but I follow HIS usual practice, because he insists that there is often sinkage over a titebond line when he french-polishes. I was skeptical at first, for reasons of ultimate strength - earlier work with superglue convinced me that I wasn't going to use it for stressed construction - but this stuff gets a grip! Sounds counterintuitive, using the thick varieties for the kind of perfect joint you'd tend to make when joining a top, but there it is....I joint the parts, spread the glue, clamp, and walk away for a few hours, because I don't accelerate.

Oh, and no staining.

Dan
Author:  DYeager [ Sun Mar 23, 2008 6:00 pm ]
Post subject:  Re: CA for tops and backs....
Hesh, could you give us the technical explanation?

Dan
Author:  Hesh [ Sun Mar 23, 2008 6:15 pm ]
Post subject:  Re: CA for tops and backs....
No-way Dan buddy - I am just not a fan of using CA for structural aspects of guitar building. Although not a technical explanation CA has not been around and in general use for more than 50 years so we have no history of how well the glue joints will hold up over say 100 years.

But to each their own I say. As for me I am a HHG fan for joining plates, gluing braces, bridge plates, bridges and where ever else it makes sense.

Let me add that I too am experienced with CA for non-guitar applications and I am surprised that you would use a gap-filling viscosity for plate joining. I would be concerned that an imperfect joint would bring the glue joint in contact with the finish. For FP and shellac this is probably not an issue but it would not surprise me if solvent based finishes like nitro and CA do not like each other.

Lastly it's a good idea here to be very clear, and you have been Dan so this in not directed at you, but someone will read this, pick up some crap crazy glue from the grocery store check-out line, join a top, get stains, poor results, and then we will see posts here asking for help.....
Author:  DYeager [ Sun Mar 23, 2008 6:35 pm ]
Post subject:  Re: CA for tops and backs....
Darn, I was hoping for a formulaic expression, or at least a philosophical exlanation, of "GAAH".

OK, OK, I certainly do understand GAAH on a gut level, and you did see that I had reservations about CA for ultimate strength, but that was before I tried BSI's gel. As to longevity, well......are we building Ramchargers (perhaps the poor choice) or Ferraris? As Stirling (for the pound sterling) Moss (for the Ministry Of Speed Sports) once said (sort of) "It doesn't matter if the formula car falls apart as it crosses the finish line, as long as it crosses it first."

What?

Dan
Author:  DYeager [ Sun Mar 23, 2008 6:47 pm ]
Post subject:  Re: CA for tops and backs....
Sorry, I got carried away, there.

The viscosity of thick CA seems to be pretty close to titebond, and an accurate joint is an accurate joint, and all I can tell you is that the finished part is every bit as strong as a joint glued with PVA. I realize that you are comparing to HHG, and I admit, freely, that there is no comparison - HHG is the ultimate, but not many of us use it. And I just haven't heard anything about nitro attacking CA, or is it the other way?

Dan
Author:  Hesh [ Sun Mar 23, 2008 7:07 pm ]
Post subject:  Re: CA for tops and backs....
Good argument Dan and sorry for the use of "GAAH" - I am on a gaah kick today...... :D

But I would think that we want our guitars to cross the finish line first now AND in 100 years. That's my primary beef - no history of long term CA use for musical instruments.

I will say that one of the things that I like about CA is that the joint can be super thin if everything fits perfectly. It's also a light weight, in terms of weight, glue when compared to say epoxy.

But try this, do a glue-up of some scrap and make three of them. One with CA, one with Titebond, and one with HHG. And then chisel the pieces apart and chisel the glue off. you will find Titebond and CA to be pretty easy to chisel off but the HHG will be like glass, very hard and tough to chisel off. To me this also probably, although I can't prove it, indicates lower dampening as well or that HHG will transmit vibration better.

You mentioned that you don't use HHG and I would encourage you to try it. HHG use and tap tuning seem to be a couple of the things that we fail miserably on these forums to demystify properly for people and probably scare them needlessly. HHG is such an incredible glue and it cleans up so very well that I will go so far as to say that I think that it is easier to use than Titebond for applications that can be properly clamped in time.

Again - who knows and I am sure you and the builder that you work with have great reasons for using CA.
Author:  Chris aka Sniggly [ Sun Mar 23, 2008 7:35 pm ]
Post subject:  Re: CA for tops and backs....
Got it.......I need to try this HHG thing. I went ahead and put the top together with titebond. If I don't like it I'll buy another one.....(as I skip off into the sunset picking flowers and grinning brightly at anything and everything). bliss
Author:  Erik Hauri [ Sun Mar 23, 2008 8:42 pm ]
Post subject:  Re: CA for tops and backs....
I imagine that CA gel would not wick as easily into softwoods as the thin stuff would.

I think lots of folks use CA to glue their bindings, then shoot nitro over them....no issues that I have heard of.
Author:  Jim Kirby [ Mon Mar 24, 2008 6:26 am ]
Post subject:  Re: CA for tops and backs....
So, Dan proved me wrong off the bad on the top joining issue. I hadn't thought about using thick stuff there.

Hesh, if you have a chance to talk to Jean Larrivee, ask him how many gallons of CA he has gone through. (He said once in an interview that he buys it by the drum). There isn't much in a guitar that he doesn't use it for, although I'm not sure how he joins tops.

At any rate, I've never seen a problem with a Rosewood back joined with CA.
Author:  KenH [ Mon Mar 24, 2008 6:40 am ]
Post subject:  Re: CA for tops and backs....
While CA has a sticking power that is excellent, I have never glued anything with it (structurally) that has held up for long. Seems the stuff has some kind of shelf life and will eventually fail....usually when you least expect it to. I base my opinion on things like plastic, not wood. The only thing I use it for is flooding an abalone rosette and abalone and pearl inlays. Nothing structural.
Author:  Hesh [ Mon Mar 24, 2008 6:53 am ]
Post subject:  Re: CA for tops and backs....
gaah Man you CA users tend to really stick together........ :D

Ken buddy you and me bro!!! [:Y:] :D
Author:  jmanter [ Mon Mar 24, 2008 7:13 am ]
Post subject:  Re: CA for tops and backs....
Hesh wrote:
but it would not surprise me if solvent based finishes like nitro and CA do not like each other.


Hesh, I may be mistaken about this, but I was under the impression that thin CA was the preferred method of repairing chipped nitro finishes (drop filling). If this is true, I don't see the conflict in using the two together.
Author:  Hesh [ Mon Mar 24, 2008 7:42 am ]
Post subject:  Re: CA for tops and backs....
Manter I wish that you guys would use at least your first name in your signature following your posts so that I could address you respectfully by your first name.

I completely agree with you and I stand corrected. Perhaps my aversion to CA use in guitar building for structural components is emotionally based making my position in fact baseless. Probably so.

But.... :D when I am asked what glues to use for guitar building I really do favor HHG, Titebond/LMI White, and recently West Systems epoxy for fret boards. To each their own. gaah :D
Author:  Mark L. [ Mon Mar 24, 2008 9:07 am ]
Post subject:  Re: CA for tops and backs....
5 months, 1687,,, gaah gaah gaah [uncle]
Author:  Jim Kirby [ Mon Mar 24, 2008 9:08 am ]
Post subject:  Re: CA for tops and backs....
Hesh wrote:
gaah Man you CA users tend to really stick together........ :D



Ouch... :lol:

That's what the acetone bottle is for!
Author:  Michael Dale Payne [ Mon Mar 24, 2008 9:28 am ]
Post subject:  Re: CA for tops and backs....
Mike Collins has me really hooked on Fish glue for a lot of things but plate joints is one of the easiest places to use HHG as open time should not be and issue So I do my plate joints with HHG.
Author:  Jim Kirby [ Mon Mar 24, 2008 11:35 am ]
Post subject:  Re: CA for tops and backs....
Mark L. wrote:
5 months, 1687,,, gaah gaah gaah [uncle]


Yes, but he doesn't understand CA ;) ;) :lol: :lol:
Author:  Daniel M [ Mon Mar 24, 2008 11:44 am ]
Post subject:  Re: CA for tops and backs....
Model airplane builders have been using CA for many years. With a fuel mix of alcohol & synthetic oil running all over the structure regularly, extreme loading, (Destructive testing at it's most exciting as the model is violently strained through farm fencing) high vibration etc etc. I have never seen a well fitted CA joint fail. Failures happen next to the joints regularly.
It's true that most models don't last long, so the longevity issues have yet to be settled. But... Many guitar builders are using CA exclusively for joining oily woods & have been doing so for years. I haven't heard any first hand reports of failures, only innuendo & rumour.
Given an excellent initial bond, we have to consider what would, over time, degrade the adhesive. UV has a deleterious affect on most "plastics", but only a fool leaves his guitar in direct sunlight for extended periods of time. Guitars usually live in a pretty protected environment.
I think that most of the negatives we hear about CA are speculative. As with anything "new" you pays your money & you takes your chances. I will continue to use CA (judiciously) & hope for the best. (Subject to change at any time...)
BTW, I did a hurry up repair on a severely cracked Larivee soundboard over 25 years ago. Seven cracks, the shortest of which was four inches long. The instrument is owned by a professional musician & is used daily. The repair STILL isn't pretty, but it looks as good today as it did then. When I get a chance to play that guitar I always poke & prod the repairs & there is no sign of a problem... yet.
I tried a similar repair a few years ago on a cracked Cedar bouzouki top. The pee yellow staining looks awful under finish. It doesn't show looking directly at it, but with a bright light coming in from the side it is horribly obvious.

I have also used CA & fibreglass to repair epoxy / glass engine cowlings on full sized aircraft. These repairs are subjected to some pretty extreme conditions & have hung in there just fine over the years.
Author:  Michael Dale Payne [ Mon Mar 24, 2008 12:43 pm ]
Post subject:  Re: CA for tops and backs....
Being both a guitar builder and a RC Airplane builder for many years I can say I have seen CA hold up for many things quite well. That said and without predigest to any one point of view I can also say CA is a more brittle adhesive. Subject to cold temp shock failure depending on the sub straight it is used on. Also while medium and thick CA are gap filling due to their brittleness not all joints in model aviation are good places for CA. there are times the resilience reflex of softer adhesive like epoxy will prevent damage to surfaces under sudden but short lived stresses like landings. I fly two 80”+ wingspan 15 to 30 lbs planes that I would never consider using CA in areas such as vertical and horizontal stabilizer joints and or main landing gear structures due to its brittleness. I also fly many park flyers that weigh less than 2 lbs and use nothing but CA on.

In lutherie I think the biggest issue is the reparability or clean joint separation or removal issue and the end grain seep issue. I have used CA a lot for binding but am moving away from it in favor of slower set glues. I use CA to pore fill in some situations and pre bending of Ziricaote to avoid with grain splits.

CA is a god send for many tasks. But like any adhesive there are good places to use it and some not so good places to use it. Personally I would not use it for a plate seam joint but that is just my opinion.
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