Steaming for hide glue joints

[Paul Burnside]

There was a seminar at the GAL convention at which the presenter showed his technique for gluing tops and backs to sides. He pre-applied hide glue to the kerfing/sides and the top and let it dry. Then he positioned them and his clamps, then used a portable steamer to push steam into the joint to activate the glue while tightening the clamps. Has anyone tried this? If so, do you have any issues with the steam separating the linings from the sides? I'm guessing exposure time is key here - just injecting enough steam but not too much. Thoughts?

[Bob Gramann]

I have used a drop of water followed by a hot iron to reactivate previously applied hide glue to close a joint. Torres used to light some alcohol poured on a top heat the glue joining the top to the sides. I haven't done steam except to release a dovetail joint.

[Markus Schmid]

There was a seminar at the GAL convention at which the presenter showed his technique for gluing tops and backs to sides. He pre-applied hide glue to the kerfing/sides and the top and let it dry. Then he positioned them and his clamps, then used a portable steamer to push steam into the joint to activate the glue while tightening the clamps. Has anyone tried this? If so, do you have any issues with the steam separating the linings from the sides? I'm guessing exposure time is key here - just injecting enough steam but not too much. Thoughts?

About an year ago I used for my first time James Ham's HHG "steamer method" - on a sopranino ukulele build and it worked a treat. No way to de-glue the linings I had glued on (also with HHG) the day before, even applying steam deliberately. The trick seems to be that once the gap is closed it would be really hard to get enough steam into the wood (I mean this literally, as you don't get steam "into the joint", it only gets there through the wood) to weaken the joint enough to separate.

[Paul Burnside]

About an year ago I used for my first time James Ham's HHG "steamer method" - on a sopranino ukulele build and it worked a treat. No way to de-glue the linings I had glued on (also with HHG) the day before, even applying steam deliberately. The trick seems to be that once the gap is closed it would be really hard to get enough steam into the wood (I mean this literally, as you don't get steam "into the joint", it only gets there through the wood) to weaken the joint enough to separate.

Exactly what I wanted to know, thanks so much Markus. My steamer arrived today, but it'll be a few weeks before I'm ready to use it. I'll let you know how it goes.

[Chuck Tweedy]

My concern with this method is that it will completely throw off the "dry wood assembly" that I work to achieve.
I'm not using it for a guitar body.

[Markus Schmid]

@ Paul: glad you found my post useful, thanks for your feedback!

My concern with this method is that it will completely throw off the "dry wood assembly" that I work to achieve.

Then you probably want to stay away from water based glue at all.

On a more serious note: Before I had tried it out I was a bit concerned about this too. But keep in mind two things:

1. as one "humids up" the involved parts by the same amount (whether just using Titebond , HHG alone or you are reactivating HHG) this really seems not to be a point of justified (yet at first sight understandable) concern.
2. apparently the reactivated HHG sets quickly enough to not allow to cause problems where the sides with its lining are "cross grain" regarding the top.

I'm not using it for a guitar body.

Last but not least everybody should accomplish building tasks in a manner he/she feels comfortable with. Sometimes it is worth our time trying out something, especially if someone else has done it before. I dared to use James Ham's steaming method I had first read of in AL#102 (summer 2010) and I don't regret it. Gluing on the back with HHG and steam really works. I'm not saying one could not screw it up, but its harder to screw it up than it is using Titebond or anything else, including HHG without steam - at least for me.

[Jason Rodgers]

I'll say it again... FIIIIISSSSHHHHH GLUUUUUUE!

[John Hamlett]

Here's a story some may find interesting.
I glued two "tone bars" to the underside of a mandolin top, after first chalk fitting them for a near perfect fit on the curved, carved surface. When the HHG dried and I removed the top from the go-bar deck, I found a small gap where one of the bars had tilted a little. I resolved to remove the bar, re-fit and re-glue it. I turned on my espresso maker and started shooting steam at the gap while trying to start a palette knife blade under the bar. I wasn't having much success, so I continued steaming and working with the blade. Still no success, the tone bar was just not coming loose. I gave up, decided to let it dry and carve the tone bar out and fit another. When everything dried out and I inspected the tone bar, the joint was tight and gap free. I pondered the situation and decided to leave it be rather than replace the bar.
So, no, I haven't -deliberately- used steam to activate pre-applied hide glue, but that experience showed me that it certainly works well, and that well made joints are not likely to steam apart in the process.

[Chuck Tweedy]

Then you probably want to stay away from water based glue at all.

Certainly water based glues do swell the wood they are in contact with, and I've witnessed distortions from this (marriage strips come to mind).
But I imagine this is less than bathing the instrument in super-saturated air. I've not tried it or studied the process in any depth so I really can't say.
I do like fish glue though for closing the box - works great for me.

[John Hamlett]

Weigh the wood before the glue joint, weight it immediately after gluing, weight it after it dries completely. If the wood was kept at the same relative humidity the whole time, the difference between the final weight and the weight immediately after gluing is the amount of water introduced. The difference between the first and last weights is the solid portion of the glue.
Moisture content in wood is normally stated as percent by weight, and if we calculate 8% of a guitar (for example, assuming the guitar is all wood and is at 8% moisture content), we can calculate the volume of water in the guitar. If we then look at the volume of glue used, we can see how the moisture introduced compares to the moisture that is already in the wood.
I'm not giving any specific numbers, that's not my point, the point is that these are things we can figure out.

[Chuck Tweedy]

That certainly is a do-able experiment John. Wish I had time.

[Randy Roberts]

Paul,
Correct me if I'm wrong, but I don't recall that he let the HHG dry. I'm remembering he let it gel. Am I having senior moments?

[Chuck Tweedy]

The whole thing is in the latest issue of AL.
I don't know if it is dried or jelled glue. Seems like jelled would make a lot more sense - again I know very little about this process.

[Alan Carruth]

He lets it dry, and does not do anything to smooth up the resulting surface, if my reading is correct. The slight roughness is enough to let in the steam.

Alan Carruth / Luthier

[David King]

Well I for one think that if the steam is hot enough it won't add much moisture to the wood, not enough to worry about for the few seconds of exposure needed re-activate the glue seam. I would love to have a pallet knife that blows steam out through the surfaces or the edges. Think how handy that would be.

[Woodrow Brackett]

It's just not necessary. In a resonably warm shop you've got a good 90 seconds to get a joint closed and clamped. Heat the parts some with a heat gun before applying the glue and you can easily double that time. I used to add a little urea to hide glue for installing tops and backs, but found that isn't necesary either. Mario has an excellent video on youtube closing the box with hot hide glue. He's efficient in the video but isn't rushing like some kind of mad man. (I'll try to find the video and post a link)

I'm an avid hot hide glue user but I believe some different type of glue would be better than letting the glue dry, then steaming to get it closed. (Maybe that's just me) I'm not doubting it works, but it seems like it would be a pain, with potential to causing other problems.

David, I love the idea of a pallet knife than injects steam. That would be great for repairs.

[Mark Swanson]

In one of Dan Erlewine's writings, he shows a piece of tubing flattened out and sanded or ground as thin as can be with the other end clamped into his steam hose. That's not a knife but it can be slid into some awfully thin places to inject steam. I've used this idea and it does work well for certain things.

[Alan Carruth]

Woodrow Brackett wrote:
"It's just not necessary. In a resonably warm shop you've got a good 90 seconds to get a joint closed and clamped. "

I think how 'necessary' it is depends on what you're doing. Jim Ham makes 'cellos and upright basses. It's really important to get the overhang even all the way around. To do that you really have to dry clamp and glue in stages. I can see where steaming the joint, as he does, would be quicker and neater than removing a few clamps, trying to work glue in with a pallet knife, and replacing the clamps, all without getting glue all over the place. With the glue already in place you don't have to worry about it running all over the inside surface of the plate, he doesn't even have to remove the clamps to get the steam in, and the alignment is not going to be disturbed. 'Horses for courses' and the Brits say...

Alan Carruth / Luthier

[Woodrow Brackett]

Good point Alan. My brain, and thinking tend to be one dimensional (or less). Since I mainly build acoustic guitars I assume every conversation is about them. I did make a bridge for a double bass once. If I were to glue the plates to the ribs on one of them it would take a miracle, instead of steam. LOL

[Mario Proulx]

Honestly, using HHG is so easy, all of these hat tricks are completely unnecessary! See the video:

http://youtu.be/y2SuYAYJ5oQ

I'm closing a dreadnought body here, in real time. No problems, and I'm not rushing. use a stopwatch if you wish to see how much open time I allowed, and you'll see it's well under the window, and my shop is rarely warmer than 68 degrees. You simply have to be prepared.