Before gluing braces . . .

What're You Doing?
Bob Gleason
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Re: Before gluing braces . . .

Post by Bob Gleason »

Waterbase glues, like Titebond, do not have gap filling properties. They are not like epoxy or Gorilla Glue. The tighter fitting the joint is, the better waterbase glues work. I think that is, technically speaking, the reason that smooth planed joint surfaces are better than rougher sanded ones. However, that may not matter with a large gluing surface like a brace. It may matter more with much smaller surface joints like top and back center seams. I am not by any means skilled enough to confidentally plane a spruce top to thickness, but making braces and joining tops and backs with a plane is relatively easy and far more satisfying to me than using sanding or power jointers. However, as I said before, modern glues will compensate for limited craftsmanship and the end product will probably be fine whether you plane or sand. Planing is better, but it may not actually matter in the end.-Bob
tippie53
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Location: Hegins, Pa
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Re: Before gluing braces . . .

Post by tippie53 »

when in doubt learn to test your process.
I , like Bob agree the mating surface of the joint is 100% critcal. If you force a joint , it is doomed to fail.

I have tested my joinery techniques and here is what I learned. Toothing doesn't really to that much of anything.
even dust doesn't seem as much to make a joint fail . what I did find is

clamping time and techniques
Torrified wood takes a longer clamp time I do 24 hr min.

How old is the glue and how is it stored
so use fresh glue.

When in doubt test a joint.
tite bond will tell you that you can unclamp in 45 min. I have pulled them apart on purpose to see and was surprised how how well the bond was.

HHG Fish white glues have different clamp times.

No need to over tighted a clamp. But this is one this I did find , glue will act like a lubricant and allow things to move , water based glues need to dry to glue tight , these are hide glue and fish.

White ( elmers ) and yellow ( tite bond and elmers carpenter glue ) are PVA and these all cure. There is a chemical reaction that completes the bonding process.

this all sounds like over thinking but in the end , a good cover of glue , is when you see glue and the wood under the glue. You want to see a little squeeze out not a flood.

when you break the bond you want to see wood fibers come up and stay in the glue joint. That is a successful joint. So learn surface mating and clamping procedures.

Water wipe up doesn't effect the glue. I use a sharp stick to get the worse up. I wait about 5 min to let the glue boogafy and then use a soft tooth brush and brush in the same direction.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
rcnewcomb
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Joined: Wed Jul 29, 2015 9:04 pm
Location: San Jose, CA, USA

Re: Before gluing braces . . .

Post by rcnewcomb »

boogafy
Another vocabulary word!
- Randall Newcomb
10 fingers in, 10 fingers out - another good day in the shop
tippie53
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Location: Hegins, Pa
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Re: Before gluing braces . . .

Post by tippie53 »

yup Definition : when glues sets up much like a good booger
Origin Latin root Boo Scary secondary root iffy not so scary
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
bftobin
Posts: 64
Joined: Sun Aug 24, 2014 12:27 pm

Re: Before gluing braces . . .

Post by bftobin »

A fresh surface always gives the best results when gluing. If the braces have been sitting around for days, I'll give a quick swipe with a scraper. Sometimes I use 1000 grit sandpaper, but a scraper is ideal. Alan Carruth has all the tech data.
Gary Davis
Posts: 10
Joined: Fri Dec 02, 2022 7:06 pm

Re: Before gluing braces . . .

Post by Gary Davis »

^ I'm thinking now I'll have to wait until I get back from vacation for gluing. I'll be scrapping the bottom of the braces then and maybe a bit of the soundboard as well.

Thanks y'all.
Diane Kauffmds
Posts: 3256
Joined: Sun Mar 09, 2014 8:13 pm

Re: Before gluing braces . . .

Post by Diane Kauffmds »

I call it boogering up, but boogafy is better.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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