Hot hideglue or Titebond for crack repair

Hi all,
Whats the best way to glue this crack securely, is hot hide glue better than titebond original, or is it 50/50?
The crack is 3 1/2" or 100mm, is clean and fresh (no dirt or dust) and has seperated from the back brace (the back bracing is still secure to the dentures and is not split or cracked).
As the distance is short and there is the brace that runs across it, would cleats be necessary and if so which is preferable, a small spruce square, or glued fabric, or brown paper glue?
I'm happy to repair it , but don't want to use the wrong method (The finish is french polish which I can sort out after the fix) any input would be great, cheers

impact happened here, on the lower back edge;(

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mark

I'm not an expert on it, but I would think the hide glue would be preferable to the titebond. Acoustics wise, there isn't going to be a lot at play here, but the hide glue would likely minimize the changes in tone and resonance. Just make sure you properly clamp everything. The worst result would be a brace that rattles.

~DB

Without question if it was on my bench it would be HHG all the way. Under no circumstance would I use any type of PVA for a repair like that.

I would do the crack repair first and then assess whether it required any reinforcement. Something that clean without any crushing of fibres can usually get by without patches. I've only used spruce or fabric for patches, and they wouldn't need to be all that big.

I am thinkign about the restoration I want to do on the vintage pineapple Ive got and was looking into hide glue becasue I want to do it right ad have the finish come out nice,, as it has several cracks.

but Ive never used hide glue before and havign to have a boiler and all that is beyond my means

then I saw this stuff, titebond hide glue that doesnt need heating etc

http://lumberjocks.com/reviews/337

has anyone had experience with this?

Im not towarried abotu the the uke it if was realy a good one I wouldnt try to do it myself , but its nice old koa and i want to do try and do the best job I can within my means.

The reviews on Titebond hide glue are not good. I'd avoid it if I were you. A double boiler for HHG need not be expensive. I use this one, less than $12 at Amazon.com.

You can also do one small job at a time and heat up a little in the microwave. Frank Ford describes this on his website. Here is one page where he describes the procedure. There is another where he describes heating the glue up itself to 180F but I can't find it on short notice. Troll through his website. There is a lifetime of learning and info there.

I use a baby-bottle warmer, purchased second-hand because it was old and dirty (you should see it now). Works fine on the hottest setting.

ProfChris said:

I use a baby-bottle warmer, purchased second-hand because it was old and dirty (you should see it now). Works fine on the hottest setting.

Click to expand...

I second the bottle warmer, I got mine on eBay for less than $10 delivered to my door. I use a glass baby food jar inside the bottle warmer, works great. And definitely check out frets.com for tons of info.

kenikas said:

I use a glass baby food jar inside the bottle warmer

Click to expand...

Did the same to start with, but if you let your glue set in the jar then after a while it flakes tiny shards of glass off the inside. A plastic tub, if you can find one, is even better.

The problem in this case is that now the crack is contaminated with the wrong kind of glue. White glue does not stick well to itself, nor does hot hide glue stick well to white glue contaminated wood. If this had been done with HHG in the first place, even if the repair didn't go well, it would be reversable and re-repairable.

This situation is analagous to shutting the barn door after the horses escape.

The most difficult of all repair and restoration work is un-doing inappropriate past work.

I don't mean to be harsh, but what I'm saying here is A) the truth, and B) is common knowledge among repair luthiers. We hate to be handed someone else's mistakes; there's rarely a good or cost-efficient ending to it. On vintage instruments, bad repairs devalue a piece much more than the original damage. This may or may not be a vintage uke, but the approach to a decent repair would be the same in my shop. Hot hide glue.

Is there a tone resonance issue with some glues? or is it more of a problem for repairs. I haven't come across the resonance tone issue in what I have read until now

You'll open up a big can of worms when it comes to discussions about tone from a HHG built instrument compared to one with PVA. Religious type fervour on both sides. I'm on the HHG side for several reasons, but I'm happy to let others build with whatever glue that they choose.

1. It's by far the easiest glue I've used to glue braces and joining plates. Doesn't clog sanding belts.
2. It's invisible under finish. Not so with PVA
3. My instruments sound better when built with HHG over PVA
4. Repairs are simple when you know that HHG was used.

I believe Rick will have more to say about this and his discussions with the people over at Martin.

Allen and I are on the same page here.

PVA glues are like a thin layer of rubber between pieces of wood. Some are harder, like the LMI white glue, some are horrible...Titebond 2 and 3.

HHG molecules shrink as they dry, literally pullling the pieces of wood together. HHG is harder, making for (probably difficult to measure...) possibly better acoustic coupling between pieces of wood. Luthiers who have used both tend to believe that with at least body joints, HHG assembled instruments sound marginally better. But we live in the margins and that's where we have a chance to make a difference.

There is absolutely no doubt that HHG glue lines, properly done, are less visible than with any other kind of glue. The joints tend to be tighter (see first comment), and the glue allows for finish touch up much better than PVA glues. I've done major crack repair with HHG that utterly disappeared under finish touch-up.

HHG allows for bragging rights, and that means higher prices. If you want a custom shop Martin guitar glued completely with HHG, that'll be a $1,500.00 up-charge, folks. Damn right I tell people we use HHG for most body joints on acoustic guitars and ukes. It's worth money.

And using HHG is just NOT that big a deal. Beginners are too easily scared off. Learn to deal with it.

Thanks

I started into wooodworking using PVA, using it mostly out of ignorance. I've been using titebond products for years with pretty good results to show for it. I've built a few dog sleds, which have held up extremely well given the stresses and weathering they contend with, which has led me to a false sense of trust. I've also been using it for cabnetry and furniture building.

I've recently been learning a bit more about glues, and become sold on Hide glue, but haven't yet made the leap, partialy because of expense and because it's a little more technical than just squezing a bottle. Also my shop setup isn't ideal, poor heat, so I do all my gluing in the living room in the middle of the night. But given some of the above links for inexpensive heaters, I'll be putting in an order .

Unfortunatlly, I have allready joined my backs and fronts and inlaid some rosettes with PVA, oh well it's a learning process.

Thanks again

For dog sleds, Titebond 2 is just fine. Epoxy is probably better.

You can use squeeze bottles with HHG...I use 3 oz bottles that I keep in water in the glue pot. You don't want to glue cold surfaces, but a heat gun will help or a closed off cabinet under a workbench with an incandescent bulb to get the space and anything you put in up to around 90 degrees F. Strad did not exactly have central heating in his violin shop...

This PVA you speak of. . .is it perhaps an abbreviation for "polyvinyl acetate"? If so, that's the kind of polymer that bubblegum is made from. No wonder the glue is rubbery.

---

Dan

C'mon, Bolly. . .let's fire up the cuatro!

Yes, it's polyvinyl acetate...and it's similar to the "aliphatic resin" glues...the yellow "carpenter's" glues. One of the issue with these convenient glues is "cold creep"...the tendency of a joint to very slowly move under long term tension or shear. We don't want that in instruments.