General questions - wood glues

awoodfellow · Post by **awoodfellow** » Sat Aug 20, 2005 3:34 am

Folks,

After reading through some of the posts here, I'm amazed at the level knowledge and years of experience acquired and shared here. Any guitar owner could reap an education thumbing through these posts.

I have a question regarding glues. The black plastic pick guard on my acoustic Guild D25/6 has pull up quite severely. It actually looks as though it has shrunk. It has begun to curl or roll its edges a bit. This D25 has a mahogany top.

I need to glue it back down, however, I want to remove the residual glue from the original application.

Short of using abrasive paper, what could I use to remove the old glue from the mahogany top? And what type of glue should be used to lay it back down?

I thought of the Gorilla glue brand, but then I back pedaled on it.

Thanks!

ambrose

seoigh · Post by **seoigh** » Sat Aug 20, 2005 3:43 am

DO NOT USE GORILLA GLUE!!!!

The secret to guitar glues is that they MUST MUST be unglue-able. What happens when the pickguard wears out? Gorilla Glue it and you'll NEVER get it off. I'd have to think that a heavy disc of Gorilla Glue would probably affect the way the top resonates, too. Ditto for any other permanent glue, e.g. epoxy. Always use things like carpenter's glues, animal hide glues, etc. on guitars. The only exception is when you are repairing broken chunks of wood -- things that should be one piece but aren't anymore, like a cracked off headstock.

Go over to www.stewmac.com and look around. I imagine something there will work just fine, both for a remover and for a glue.

jingle_jangle · Post by **jingle_jangle** » Sat Aug 20, 2005 5:05 am

Ambrose, the problem is not how to glue it down. The problem is how to get it off the guitar and replace it before it causes damage to the guitar.

Brad is right--gorilla glue has no place on a guitar. It's amazingly strong, but besides being irreversible (it's a moisture-activated polyurethane) it requires two open-grained surfaces to work properly. Neither the pickguard nor the sealed guitar top plate fit this bill.

This shrinking/curling is a pretty common thing with older flattop pickguards. You should try to replace the guard earlier rather than wait, as curling guards have been known to split and/or warp the top if left to their own devices.

Heat is the best way to soften the adhesive and it must be applied carefully. you can try a hair dryer for gentler heat. This usually works. Pros will use a heat lamp or gun, but this can cause damage to the instrument in unskilled hands.

You should have a new guard made. Greven Guitars sells many styles and sizes, pre-cut out of a plastic material called "Tor-Tis". They can match yours perfectly. Use a self-adhesive peel-and-stick sheet from Stew Mac to adhere the new pickguard into place. This is StewMac #4597, and only costs a few dollars. Greven's guards run about $25-50, but, hey, it's your baby, right?

Most luthiers get between $150-200 to do the job for you.

jingle_jangle · Post by **jingle_jangle** » Sat Aug 20, 2005 5:09 am

To remove the old glue, once you have the old guard off, mask off the guard area carefully and scrape off the old adhesive with a single-edged razor blade held vertically. This is not for the faint-of-heart, but done carefully it yields good results. The top should be as close to flat and glue-free as you can get it. Try not to scrape through the finish on the top--this can be quite thin on some acoustics.

awoodfellow · Post by **awoodfellow** » Sun Aug 21, 2005 5:03 am

thanks folks,

advice heeded!

'brose

ken_j · Post by **ken_j** » Sun Aug 21, 2005 5:03 pm

My former Guild D40 was finished after the guard was installed. That is why some Guilds had problems with cracked tops. Since the guard was adhered directly to the wood, it did not allow for proper expansion and contraction due to co-efficiency differences. Having it peel and loosen may have been a blessing in disguise. If there is no finish under the pickguard I would consider appling a few thin coats before installing a new one. Guild changed this at some point. I'm not sure when.

awoodfellow · Post by **awoodfellow** » Mon Aug 22, 2005 3:04 am

Ken,

And that is exactly the case with my D25. The guard was applied directly to the wood. Thanks for the tip!

On another note. Guild is now, and has been for a few years, owned by Fender. I went to the Fender site to find some contact info for the Guild division. Basically there is no info at all. I want to find out exactly what was used for the original clear finish on the D25. Seems like Guild has become the red-headed stepchild.

I've had to hand write a letter ( jeez

) and actually put a stamp on an envelope and snail mail my questions. Honestly, I don't know how the Guild people can deal with Fender. Maybe I'm missing something.

The folks from Rickenbacker are quickly becoming by favorite people!

'brose

ken_j · Post by **ken_j** » Mon Aug 22, 2005 8:23 am

"I want to find out exactly what was used for the original clear finish on the D25."

Paul would probably know. I am not sure.

jingle_jangle · Post by **jingle_jangle** » Mon Aug 22, 2005 9:27 am

Ken, thanks for the referral, but I am not too sure about the chemistry of Guild's finishes year-to-year without actually inspecting the guitar.

Ricks, Fenders and Gretsches, no prob.

awoodfellow · Post by **awoodfellow** » Mon Aug 22, 2005 10:40 am

appreciate the help, ken.
thanks paul.

gt76 · Post by **gt76** » Tue Aug 23, 2005 5:06 pm

This thread came just in time. I was just looking to purchase another guitar and noticed a brown glue around the base of the strap pins. The guy that owned it said he uses "gorilla glue" when he installs strap locks and has done this to all his guitars. Is this reason enough to pass on the purchase? I'd never heard of "gorilla glue" until this.

dale_fortune · Post by **dale_fortune** » Tue Aug 23, 2005 6:05 pm

Gorilla Glue is just a brand name for a polyurathane glue that requires a little moisture(water) to set it off. It is actually a great product for the right use. For glueing up something that you don't want to come apart, say a broken peg head or other things similar. A lot of the older guitars had pickguards that were made of acetate. This stuff shrinks over a period of time and causes serious problems to the Spruce tops on acoustic guitars, it takes the grain of the wood with it as it shrinks causing it to seperate. As for the GG glue on strap pins, I wouldn't worry about it as for a buying factor, you can always take them out and fill the holes with a wood dowel then put the strap pins back in.

jingle_jangle · Post by **jingle_jangle** » Tue Aug 23, 2005 6:12 pm

Gorilla glue is something my students buy because they "want the best", not realizing how tenacious this stuff actually is.

I wonder if those strap lock screws will EVER come out without destroying the heads. It will take a vise grip to break them free. I've had GG on metal parts that required a sharp chisel to break it free.

But Dale is correct--in extreme cases the hole can be redrilled slightly larger and dowel-filled.

Speaking of which, GG is excellent for loose chair legs and stringers, and stuff like loose stairway posts.

gt76 · Post by **gt76** » Tue Aug 23, 2005 6:43 pm

Thanks for responding. It appears from what you stated that as long as I don't plan to remove the strap pins, everything should be okay and it should cause no damage to the guitar. Thanks again.

johnhall · Post by **johnhall** » Wed Aug 24, 2005 6:25 am

Gorilla glue works rather nicely to fasten the kerfing in acoustic guitars where the sides join the front and back. As noted above, it's very tenacious and this is one part of a guitar you don't need to come apart. It's also nice in some situations because it foams a bit when applied, reaching into voids that might otherwise be missed during gluing.

I built a railing surrounding my deck out of Honduras mahogany some years ago, using Gorilla glue in some of the joints and the wooden plug bolt covers. This deck gets constant salt water spray on it from the ocean and it's just as solid as the day it was built.

I guess it's just like anything else- you have to know where and when to use the right "tool".