Acoustic Guitar Construction

From Chris Schwartz:

If I could eliminate one myth from the national wood-consciousness, it would be that you shouldn’t wipe off wet glue from a joint and should let it set to a more solid state.

Lots of people – including glue technologists and working craftsmen – have studied the problem. Here are the facts.

Wiping Wet Glue

Wiping wet glue away with a wet cloth will not dilute the glue at the joint, starve it or weaken its bond (unless you use a fire hose).
Wiping wet glue away with a wet cloth will not dilute the glue and cause “glue size” or a clogging of the pores and ruin your finishing efforts (unless you are sloppy about cleaning up the glue or don’t dress your surfaces with a sander or handplane).
Wiping away the wet glue will allow you to see any gaps in your joinery while you can still take things apart and fix them.
Semi-hardened glue can be tricky to remove. Let it get too hard and you can tear away chunks of wood fibers at the joint. Remove it when it’s only skinned and you will just make a second more difficult mess to clean.
Letting the glue harden completely before scraping it off is more work than I like to do. And you can tear out chunks of wood.
To wipe away wet glue, take a clean cloth that is wet but not sopping wet. Clean the glue away from the joint using circular motions, like waxing a car. Don’t be a snowplow. When you start to see glue smears, dunk the rag in water again to get the glue off.
Regular surface prep with sandpaper and/or handplanes will remove any glue-clogged fibers. In making many many panels since 1993, I’ve never once experienced glue size (or a joint failure).
Ignore anyone who tells you different.
Live happily ever after.
Yes, this applies to hide glue, white glue and yellow glue.
No, I don’t know about poly glue or epoxy. Those aren’t typical furniture-making glues.
— Christopher Schwarz

I never wipe glue with a wet rag ---that can make a royal mess and when done on the "A" surfaces the residue soaks in and seals the wood making it a down the road finishing issue.

I use a sharp paint scraper for clean up

http://www.kennethmichaelguitars.com/bi ... raper.html

And this is a great products which deals with any residue issue:

http://www.de-gluegoo.com/

Well, I don't know for sure about the consequenses. But I always clean up squeese-out and leaving a tiny edge of glue on the joint side that sucks in. Never had a brace failure up till now.

My last two guitars were made with hot hide glue, and that cleans up really easy.

But what is the reference here ? Failing braces? Tone? Plate movement?

2 cts
Herman

Just a clean-up article I found on a woodworking - not guitarmaking - site, H.

Many glues, when diluted, seal the surface in a different way than most finish sealers do. Hence, a potential visible difference under finish, as Ken suggests. Depends on how dilute, the type of glue, etc. When I was in construction, trim carpenters would do a water wipe of excess glue and it drove us nuts, trying to get an even finish over the residue. As far as water wipe up weakening the joint, what Dave posted makes sense.

I used titebond on Windsor chairs and got glue all over the seat as I assembled the back and spindles. It did leave a stain if not cleaned up properly. I discovered a FWW article suggesting dilute yellow glue as a sizing to seal the surface before staining on problem woods. So when I had a butternut seat, I cleaned up with water after glue up and then the next day brushed on a glue sizing. I did not need the sizing, so sanded it off; but I was assured of an even coloration when I put my shellac finish on. It was just insurance and not much trouble. Wetting down to raise the grain and dents is a useful step in chairs.

I don't know how much one would want to wipe water on a guitar but you can think about how to apply my experience. My biggest problem with squeeze out is on the sound board bracing and I am not going to put much water there.

I see so much conflicting advice I experiment for myself. I 'm working on build numbers 3-5 now I'm just learning.

Bob Howell wrote:I used titebond on Windsor chairs and got glue all over the seat as I assembled the back and spindles. It did leave a stain if not cleaned up properly. I discovered a FWW article suggesting dilute yellow glue as a sizing to seal the surface before staining on problem woods. So when I had a butternut seat, I cleaned up with water after glue up and then the next day brushed on a glue sizing. I did not need the sizing, so sanded it off; but I was assured of an even coloration when I put my shellac finish on. It was just insurance and not much trouble. Wetting down to raise the grain and dents is a useful step in chairs.

I don't know how much one would want to wipe water on a guitar but you can think about how to apply my experience. My biggest problem with squeeze out is on the sound board bracing and I am not going to put much water there.

I see so much conflicting advice I experiment for myself. I 'm working on build numbers 3-5 now I'm just learning.

Hi Bob, welcome to the forum!

It is the uneven application of glue residue on a surface to be sealed that causes issues. An even treatment of lets say a top with glue as a sizing agent to seal the surface would be OK. A wipe from cleaning up binding glue less so. Wetting the top to raise the grain is a very useful step on a guitar.

Around braces I clean up hide glue with water. With PVA I wait 5-10 minutes and clean up the gelled balls of glue from the squeeze out.