Traces of glue

[Matt Haugen]

I have been kicking around the idea of trying to attach braces with contact cement and I am wondering if this would be a bad idea. If so, why? My reasoning for this is that I am growing tired of the cleanup and I believe if I tape off an area and apply the contact cement, once the brace and top/back are pressed together there will not be any squeeze out. Thank you_ Matt

[thefishinmusician]

No, that will not work at all

[Ned Knepp]

Personally, I don't think I've ever seen a contact cement joint that was "solid" enough that I would consider this. All of the contact cement that I've seen is more a bond of glue to glue than a bond of wood to wood. I don't think the joint would hold up under stress for very long and I think it would tend to dampen the vibration propagation throughout the instrument. I agree that it's a pain to clean up but I never feel like I have complete glue coverage if I don't have just a bit of squeeze out.

Just my opinion.

Ned

[Ronnie Nichols]

Being a guy who is willing to try different things, I understand your frustration with the glue cleanup process. The contact cement would probably work. I doubt if that glue would know whether it's holding a brace or a piece of veneer together. I don't know how well it would hold up under the stresses of an instrument. One thing that has helped me deal with the cleanup of excess glue is Frank Ford's little trick of using a plastic soda straw to remove most of the sqeeze out. You cut it at an angle and it does a pretty good job of removing the excess. If you apply the masking tape as you stated, this may also help to ease the burden of glue removal. I don't know what type of glue you have been using in the past. I won't try to start an argument about which glue to use. Obviously, if you're using hide glue this would be harder to do. I've buiilt and repaired a lot of instruments with the yellow "Carpenter's" type glue and I've never had a problem with it. I recently built a counter top from curly maple laminated with this type glue. The end cut-offs were laying around and I tried to break them apart. The joints all held and the maple broke somewhere else besides the joint so I'm pretty well convinced that this glue is as strong as the rest of the wood. Frank Ford is a big fan of hide glue and I agree that it is good. Frank has forgotten more about this business than I'll ever know. I just can't justify the extra work required to use it in building. I once repaired an old guitar and reattached all the top and back braces with CA glue. It turned out to be a great sounding guitar. You might try a little experiment with the contact cement on some scrap to see how strong it is before you actually try it on an instrument. I hope your project goes well.
Ronnie Nichols

[C Herb Hickman]

I would agree with your first two replies. The contact cement will remain relatively rubbery and will absorb energy from the soundboard, robbing you of sustain. You might not always want all the sustain you can get, but you want your instrument to be capable of the sustain. So you want a hard glue joint. The yellow carpenter glue or original Titebond will fill that bill. Hide glue or the instrument maker's glue possibly better, the latter being a practical possibility. The hide glue will work well if you're fast enough and the joint easy enough to set and clamp.

[Jim Bancroft]

Contact cement has it's uses, but not for gluing bracing or most anything else on an instrument, except maybe a pickguard.
Maybe I don't understand, are you doing repairs or building an instrument?

Titebond or hot hide glue is the proper glue for bracing, and both cleanup easily with a damp rag or sponge. If you are working through a sound hole, contact cement would be more of a problem than the traditional glues as far as cleanup, then you want to apply tape first, complicating it even more.

If you are gluing bracing with the top or back off, cleanup is simple.
Also if you do get contact cement where you don't want it, it won't cleanup with water.

Jim

[Matt Haugen]

Thank you Jim. (and everyone else). I am rebuilding a parlor guitar. I have always been loyal to hide glue and after all of the helpful information, I will continue to do so. The idea that brought this on was that I have been working on a coffin case and I decided to apply some veneer. I used contact cement for this application and it worked perfectly, so I started thinking about other possible uses. Please don't think that I am lazy, I am fine with the cleanup, I was just thinking of trying something new. Thank you all for the responses.

[Jim Bancroft]

The contact cement is probably OK for the case repair, but not for instrument work. Contact cement is elastic when dried and great for certain applications. With instruments you want a glue that dries hard, basically for good sound transmission, and good wood to wood adhesion.

I have used contact cement in the past for gluing down lifted fabric on vintage instrument cases, but I found that titebond actually works better for that job than contact cement. Hide glue should work great too.

Contact cement for brace repair certainly would be something new, but, to save yourself some grief or the next person that works on that guitar, I wouldn't use it.

Jim