Official Luthiers Forum!

This article compares various glues (OBG, HHG, PVA, etc). https://www.finewoodworking.com/2007/07 ... -your-glue

The experiment set up seems reasonable. I leave you to decide that. The surprize result was that OBG was as good as HHG. And PVA was very good.

Holding strength is not the only concern in this business. Repairability is a concern too. But I was impressed OBG rated as well as HHG

Mike

So the Gib**n custom shop is cheating, no surprise there they were caught red handed poaching...

They advertise that they use HHG on the assembly of the Custom shop Lesters. OBG is not HHG nor is it what they used to assemble Les Pauls in the coveted era of 58 - 60. If I were someone who paid $5K and up into the $11K range for a Murphy Labs, Custom Shop Les Paul and found out that they did not use HHG on my top I would be pissed.

There is a long standing expression that many of us in the business use, "good enough for a Gibson." Makes perfect sense now, again.

Also, before I go this application the drop top is pretty uneventful with tons of wood-to-wood gluing surface and no tension or stresses unless Townshend gets ahold of it. Or, in other words not an application that I would expect any glue to fail in.

To be clear my disgust with Gib**n is with management not the products produced in Kalamazoo. I own two Les Pauls, a Firebird, a 76 ES 175, a 2004 335 and a SG with Lollar high-wind imperials so I b*tch a lot about g*bson but I love em too when no one is looking...

Oh and one more comment: As the woodworkers here consider using OBG be aware that no one ever asks a Luthier if you used OBG.... they only seem to look for and ask about HHG.

Tradition in Lutherie is like the force in Star Wars, very, very strong.

I am pretty ignorant here, but I did read other things on this site about OBG and HHG, I think.

Somewhere, there are posts mentioning how to extend open time for HHG by adding chemicals (urea?). But the posts did not claim that this makes the glue no longer HHG.

Also, for OBG I read that once it dries, it is identical to HHG.

So is OBG just a brand name for a particular formulation of extended HHG?

Just asking.

OBG is hide glue mixed with urea (the stuff in pee). Lowers the crystallization temperature. When it dries, it’s still hide glue, but it has urea still in it. (Or salt). It apparently has no impact on strength. But it ain’t the original, so folks will continue to debate. I would LOVE to see a side by side comparison with HHG and OBG for applying bridges. Until I do, it’s HHG or PVA

The addition of urea does weaken the hhg in relation to the amount added.

Even if you never intend to use OBG, the videos on the website have a lot of information. Some on HHG and some on OBG. But, geared to furniture repair and veneer, etc.

I’d be curious to try some of the OBG. If the joint still fails at the wood and not the glue line, would that not make it strong enough by default? I mean, once the glue is stronger than the wood, does more strong count for anything?

Besides strength, we want our glues to have longevity. Does the presence of the urea make the OBG more likely to absorb water from the atmosphere and eventually fail? Any chemists here that can comment? We know HHG will last a couple of millenniums. PVAs have been around for less than a century, but so far, so good. I had a CA joint last for 40 years strong and then fail—it just dropped apart with no strain on it.

So far, I’ve had good luck with the most recent version of the LMI instrument glue (a PVA, I think). It sets a bit faster than Titebond and cures a bit harder. When it gets thick, it’s time to demote it to fixtures and open a new bottle.

Good question about longevity, and interesting about the CA…

I'm pretty sure the addition of urea goes way way back in time.

As for Titebond, it's absolutely perfectly suited for guitar building from beginner to master builder, many of whom still use Titebond, some of whom laugh at all of us who use HHG.

There is plain and simply no right or wrong glue to use and some of the best guitars in the world have been built with HHG or Titebond. I would wager a bet that most of us here use TB, HHG, CA, possibly even epoxy on every build we do.

Using TB and laughing at HHG users is a funny concept, I find HHG is faster and easier for most of the areas where it is commonly used on new builds - bracing, joining plates, etc. For these operations, using TB is doing it the hard way. And you get to charge more using HHG

There are other operations in guitar making or repair where HHG is certainly more work or more fuss. In many cases HHG has advantages which make it worth using anyhow (bridges is a prominent example) but we all have to work in the way we most enjoy or which is most efficient for us.

Since the bottle was being heated in a water filled glue pot it's possible the contents were regular HHG and the bottle was just being used for application. I have bought Titebond by the gallon (it's much cheaper that way) and refilled smaller bottles for ease of application. With HHG I use small two ounce applicator bottles heated in a water filled hot pot. It makes the process more convenient.

I concur... Titebond is a perfectly adequate glue for guitars which will never need repair. For those guitars which will need repair, an adhesive that does not creep both hot and cold and is not a joint contaminant when the time comes to reglue that bridge or top bracing after a heat event (or joints made with thick, creepy glue lines) is preferred. Lots of time to figure out what that glue might be after the first couple of instruments.

Again, adequate is just fine for now, despite lots of glue-related 'whataboutisms' which might be raised. As a bonus, that first guitar will likely become a repair tutorial, so may continue to serve an important roll in the 'you don't know what you don't know until you know it' process of craft education, as well as insight as to the preferences of repair professionals.

_________________
For the times they are a changin'

- Bob Dylan

True. But since other operations were being done with a regular glue pot, and the fact that they happened to have an OBG bottle hanging around makes me doubt that.

Dave