peghead crack - do i really need hide glue?

[mark kaye]

i have a friends Gibson ES335 with a peghead crack
i did some reading & hide glue seems to be the recommended solution, but i have no experience with it
i have some very good wood glue from Lee Valley (2002 GF) and was wondering if it would be OK in this situation
this is a fresh break & has never been repaired before

mark

here is a link to the PVA Lee Valley glue
http://www.leevalley.com/wood/page.aspx?c=1&p=45104&cat=1,1...

[Bob Webster]

As usual, Frank says it the best and you can find his thoughts on hide glue at http://www.frets.com/FRETSPages/Luthier/Data/Materials/hideglue.html. One of the most attractive attributes of the stuff, second only to its VERY easy water cleanup, is that it will draw a very well fitting joint together as it drys and shrinks in the joint. That's why it's my favorite glue for purfs and bindings. Might be a bit of a trick to get it into the peghead crack. Just keep thte part to be glued well warmed so that the glue doesn't gel before it gets where it's going. CA is much better at wicking into a joint but the hide glue joint will have much better strength and longevity, I believe.

Best of luck,
Bob

[Russell Vance]

I havn't been able to get a product spec sheet for this glue - however, it sounds like the standard PVA stuff used by furniture makers and therefore is designed to have a little 'give' to allow for gaps and flexing in such things as chairs. This is not what you want. High solids content is for gap filling and compromises the strength of the joint.

We use cross linked PVAs (Titebond II) for all our neck/peghead repairs and highly recommend this particular glue.

Regards, Rusty.

[Arnt Rian]

Hi Russell,
why do you recommend Titebond ll? Most instrument builders I've seen comment about it don't like it much, and claim that it dries less hard than for example Titebond original or LMI's 'instrument maker's glue'.

Here is what Franklin International (manufacturer of Titebond) has to say regarding PVA glues in general,
...Because PVA glues tend to “creep”, or slowly stretch under long-term loads,
they are not recommended for structural applications....

Here's the whole thing (.pdf format)
http://www.titebond.com/download/pdf/ww/GlueGuideTB.pdf

Hide glue is wonderful, but a good alternative in case you need more open time or like the convenience of a glue that is liquid at room temperature is fish glue. It dries equally hard and has other similar properties (shrinks as it dries). It is not quite as easy to clean up, and needs longer clamping and curing time, though.

[Russell Vance]

Yes, thankyou, you are heading in the right direction - having talked to Titebond at length in the past and just recently to update on new stuff, it goes like this:
Titebond Original (Aliphatic) has a harder glue line and is the lowest creep of the Titebond series (original , II,III)
Titebond II is a cross linking PVA and may creep over time under structural load - Titebond III - ditto.

However, we are not building space shuttles here and one should not have a panic attack the moment 'creep' is mentioned - creep only becomes an issue in high load applications - we got by with PVAs for quite the while before the stronger cross linked PVAs and Aliphatics came along - the structural loads we are talking about in well made guitars are minimal - most bridges pop because they have been cooked in the back of the car or poorly made, prepared or assembled in the first place. We also test our glue systems under load and heat just to amuse ourselves - and also meet our QA requirements.

Furthermore, when doing repairs to shattered pegheads and delaminated fingerboards I need a glue that can get through a 22 gauge hypodermic with plenty of working time. In this case there is virually no effective alternative.
But, regardless, - hide glue is fine for what you wish to do and can be enjoyable.
Rusty.

[Mike Kolb]

Yep, I vote for hide glue, all day. Bob's right-on with the "draw-together" aspect. For peghead repairs, I'll make my mix a bit on the thin side and a little hotter than usual (for help in wicking-down deep into the joint), then brace-open the crack as far as it wants to comfortably go, heat the crack area with a hair dryer and work quickly. Don't worry about working clean, as the cleanup is easy after all's said and done. Good luck!

[mark kaye]

OK, the hide glue wins
here are the specs for the hide glue that Lee Valley sells
===
Our granular hide glue is a very strong one (rated 260g± Bloom strength) with a correspondingly short open time; it is good for uncomplicated assemblies where strength is of paramount importance.
===
i will experiment until i become comfortable before tackling the guitar
thanx

mark

should i clamp it tight i.e. try to get the joint seam as minimal as possible, or clamp with moderate pressure & let the glue shrink as it dries & close it?

[Bob Webster]

For the purpose of getting better viscosity, you might want to take a look at the 192g technical gel that LMII sells. It very much the standard for instrument making and will be a bit less viscous than the 260g stuff will be. Also, pursuant to Rusty's input on syringe loading, one trick I've used is to make the glue per usual and then fill a 10ml syringe with it, place the needle on the syringe, stick a piece of cork or whatever on the needle, and stick the whole assembly in the water bath of the glue pot. That keeps it hot and ready to go.

Don't clamp it so crushly tight that you starve the joint but don't count on the drying/shrinking glue to close gaps that could have been closed by moderate clamping pressure.

Cheers,
Bob

[mark kaye]

I have successfully glued the headstock
the seam is quite tight
is there a waiting time for the glue to cure properly before i repair the lacquer finish?

mark

[mark kaye]

i thought i was successful!!
the guitar is back & is opening up on the same crack that i glued
there are stress cracks in the lacquer finish towards the body that i can't explain - see pictures
i thought i had done a great job, i practiced on some dining room chairs with the hide glue & thought i had it under control - i heated the joint with a hair dryer to warm the wood up & used a syringe to inject the glue all the way into the joint - i clamped it for 24 hrs and then worked on the lacquer for a week before restringing
what should i do now??

mark

[Greg Mirken]

That's discouraging, Mark. From your description, you did everything right. What does the inside of the crack look like? Any visible glue?

The lacquer cracks are interesting. They were not there when you had the guitar before, right? You didn't have it in your shop when it opened up again?

[mark kaye]

it's hard tell about the inside of the crack as it only opens a hair-width even with a fair amount of hand pressure on the head stock
i did have glue ooze out when i clamped it - maybe clamped too tight?
there were no stress cracks in the lacquer with the original break or when i gave the guitar back - he has used it a lot in the last month tho

mark

[Mike Kolb]

My own schedule is to let the hide glue cure for 24hrs.... and I have NO basis for choosing that, other than "gut hunch". Whenever I do a hide glue repair, I'll keep the cleanup towels and drippings nearby and let them dry, too, just to keep an eye on how the mix is behaving and drying. When the glue on the cleanup rags is dry and brittle, it seems right that the repair is about the same. Same thing with epoxy repairs....I'll mix in a disposable cup, but keep the remnants handy just to observe what the state of the epoxy is in the repair.

PS: after thinking about it for a minute, if the crack was deep and the glue had to wick-in a considerable distance, then maybe 2 days would be better than one. Again... a gut hunch.