Hide Glue Gram Strength for Neck Set?

[Tyler Bolles]

Hi Luthiers,

In my intro post I put up pics of my afflicted bass. I'm at the point where I'm ready to start sticking things together (gluing in shims then re-fitting the neck), and I'd love if somebody might weigh in on the appropriate gram strength to use for the neck joint.

I saw the old thread on hide glue, but wanted to get specific.

Also, is there a good source aside from Bjorn (who I think has a minimum order of 5#)? I'm finding Milligan and Higgans 192gs, as well as 192 at Luthiers Mercantile, then some places that have a range from 200-350+.

Thank you in advance!

-tyler

[Matthew Tucker]

I reckon high-clarity 192 from tools for working with wood (http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=PROD&Store_Code=toolshop&Product_Code=MS-HIDEGL.XX&Category_Code) is fine (and dandy) for most jobs. The difference will be the joint, not the glue.

(edit: The OTHER reason i like the high clarity glue is that it doesn't appear to go off as fast as less-refined HHG! It tends to gel and dry in the pot rather than go mouldy overnight like other glue batches I have!)

[Tyler Bolles]

Thanks, Matthew. I'm taking my time with the joint, for sure!

[Thomas Erickson]

If the joint is decent (any joint) I wouldn't worry about the glue not being strong enough. I'd rather re-glue a joint any day than see something broken where the joint could have popped.

Which isn't to say I want a bass that comes apart all the time either, but in that scenario I don't think the glue is usually the problem. ;)

[james condino]

aside from Bjorn (who I think has a minimum order of 5#)? I'm finding Milligan and Higgans 192gs, as well as 192 at Luthiers Mercantile...

From my conversations with all of them, Milligan and Higgins supplies both Bjorn and Luthier's Mercantile, as well as many of the other US commercial suppliers, so all of those hide glues are the same. I believe they are the only current domestic manufacturer of hide glue. The main differences in ordering from the various places are the minimum order amount and corresponding pricing.

j.

[Ken Smith]

From my conversations with all of them, Milligan and Higgins supplies both Bjorn and Luthier's Mercantile, as well as many of the other US commercial suppliers, so all of those hide glues are the same. I believe they are the only current domestic manufacturer of hide glue. The main differences in ordering from the various places are the minimum order amount and corresponding pricing.

j.

I don't think he was waiting to get this done. He posted pics of the glued in neck 2 weeks later, about 3 months ago. Maybe your info will help the next guy. Probably..;)

[Robert J Spear]

I'm a little late to the party, but thought I'd toss in my two cents' worth about hide glue. Yes, right now Milligan and Higgins is the only company left in the US that makes hide glue.

The hide glue you use is your preference, but it is important, I think, to remember that even the weakest grade of hide glue makes a joint stronger than the wood itself. High gram-strength glue is a problematic term for me. The test measures how much force it takes in grams to depress a steel rod of a certain diameter to a depth of 4 mm into a glue cookie. The glue cookie is made under certain conditions that I can post here if anyone is interested. The more weight it takes, the more the gram number increases. This is really a test of glue hardness, not necessarily strength. While the contention is that high gram-strength glue is stronger, I have never seen any data that supports this claim.

Working alone as I do, what I value in hide glue is a long open time before tacking. I find that the high gram-strength glues require more dilution with water to keep them consistent, which essentially diminishes their strength, and that the open time gets progressively shorter. This means that the glue gels faster. In the highest strength glues, I have found that when I glue together big pieces, like the boards that make up a top or back, the glue at one end is already drying before I can get coverage at the other end. It will be past the tack point before I can get the pieces in clamps!

I now recommend standard hide glue in the 160 - 200 gram range, if you can find it.

[Arnold Schnitzer]

I totally agree with Robert (by the way, welcome!). I used to use 315 gs hide for gluing up top and back plates, the theory being that the strongest glue should be used on the permanent joints. But it was always a "Chinese Fire Drill" trying to get the glue spread, put the joint together and clamp it up before gelling occurred. For the last several years I have used exclusively the 192gs from Bjorn, and I have never had anything close to a joint failure. The open time is longer, and the clean-up seems easier too. I personally add a little urea to the glue to suppress gelling for a few extra seconds, and of course warm up the pieces before spreading the glue.

[Tyler Bolles]

Thanks to all for the added info!

Arnold, could you be specific about how much urea you add?

And yes, the neck set went fine. I've been playing on the bass for months since, and with a better-fit neck joint, the bass sounds and plays better than it ever did!

[Scott Pope]

This is really a test of glue hardness, not necessarily strength. While the contention is that high gram-strength glue is stronger, I have never seen any data that supports this claim.

...

I now recommend standard hide glue in the 160 - 200 gram range, if you can find it.Indeed. Hardness and shear strength are two completely different attributes. A "high number" on one attribute does not necessarily indicate a "high number" on the other.

[Robert J Spear]

Indeed. Hardness and shear strength are two completely different attributes. A "high number" on one attribute does not necessarily indicate a "high number" on the other.

That has been my experience, and you raise a good point. For a luthier, getting pieces glued together is only half the battle. At some point down the road, the instrument will likely need work and some parts might have to be disassembled. If glue with a super-characteristic in some aspect is used, there could be a nasty surprise. Nothing like trying to bash the top off an expensive instrument at the head block when the glue is not behaving as expected. One of my chief complaints with Chinese instruments is that they often use bone glue in the lower-grade models. Bone glue is classified with the hide glues in terms of strength, but it is a much different beast! Um, animal? Er, creature . . .