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Thermally modified spruce & hide glue?
http://luthiersforum.com/forum/viewtopic.php?f=10101&t=51659		 Page 1 of 2
Author:  B. Howard [ Wed Feb 27, 2019 2:31 pm ]
Post subject:  Thermally modified spruce & hide glue?
I have a job that specs a torrified Adi top and HHG construction. I have used both, but not together. So I am seeking all sage advice and pearls of wisdom regarding this combination well in advance.

Thank you all in advance.
Author:  meddlingfool [ Wed Feb 27, 2019 2:50 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
In my experience with torrefied tops (20+ guitars) it drinks a lot more water than regular wood and needs to be clamped longer. Whereas with normal wood I'm content to take it out of the deck after 25-30 min, I leave hide glue/torrefied in the deck overnight. I also use more glue than on regular wood.

Torrefied wood is really its own thing. I'm sure you can experiment with the offcuts.

Beyond that, it's proven to be no difficulty.
Author:  meddlingfool [ Wed Feb 27, 2019 2:53 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
Also if you plan to use torrefied bracing, be extra vigilant about runout as the stuff is actually quite brittle. I stopped buying torrefied stock and started selecting and sending in my own stock.
Author:  jfmckenna [ Wed Feb 27, 2019 2:55 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
I'm actually building two right now with both Torrified top and bracing. I have not started yet and was actually considering posting the exact same thread so I will watch with interest.

I did build one guitar with torrified bracing on a standard top going on a few years now with no issues.

But the torrified stuff does feel different doesn't it?
Author:  meddlingfool [ Wed Feb 27, 2019 4:16 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
The torrefied stuff is different feeling for sure, almost like driftwood. That's what I was angling towards in the moon spruce thread, to see if it was noticeably different in any way...
Author:  jfmckenna [ Wed Feb 27, 2019 4:18 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
Driftwood is a great way to describe it.
Author:  bcombs510 [ Wed Feb 27, 2019 4:34 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
Slightly tangential - A little over a year ago I built a tenor uke with torrefied top and bracing. The materials came from SM. I used HHG, including for the bridge, and no issues so far. It's a Uke though, so take it for what it's worth.
Author:  Barry Daniels [ Wed Feb 27, 2019 7:58 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
I haven't use this stuff yet, but if it is extra thirsty, how about adding a bit of extra water to the HHG and making it on the thin side.
Author:  LarryH [ Wed Feb 27, 2019 8:25 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
A note about Hide glue and torrified tops, NOT to be taken as gospel, but in a Video with Dana Bourgeois he said he stopped using Hide and switched to fish glue because of 'issues' with Torrified tops and hide glue...
Author:  B. Howard [ Thu Feb 28, 2019 8:00 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
LarryH wrote:
A note about Hide glue and torrified tops, NOT to be taken as gospel, but in a Video with Dana Bourgeois he said he stopped using Hide and switched to fish glue because of 'issues' with Torrified tops and hide glue...


I attended a presentation he gave and remembered him mentioning that, part of why I posted this. I also remember the entire time he was talking about his wonderful new finish In a mystical form of psuedo-science speak and wrapping an already known and used materiel in a veil of mysticism to make it sound like magic.... so I treat everything else I heard that evening with a fair deal of skepticism....
Author:  LarryH [ Thu Feb 28, 2019 9:26 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
B. Howard wrote:
LarryH wrote:
A note about Hide glue and torrified tops, NOT to be taken as gospel, but in a Video with Dana Bourgeois he said he stopped using Hide and switched to fish glue because of 'issues' with Torrified tops and hide glue...


...a fair deal of skepticism....


Always wise IMO...
Author:  jfmckenna [ Thu Feb 28, 2019 9:27 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
What were the issues that Bourgeois experienced with HHG and torrified wood? Braces popping loose?
Author:  bluescreek [ Thu Feb 28, 2019 9:55 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
disagree about it being thirsty the process changes the cell structure and it won't absorb water like raw wood. You need to just allow 24 hr clamp time for safety . I don't like torrified braces but if you use them also 24 hr clamp time and shape them on the sander as much as you can. This wood is very chippy and doesn't scrape well so don't use a scraper or hand plane. I have been using this for a number of years and made 20 guitars with it. Be sure your blades and bits are very sharp. My glue preference here is fish glue. HHG is ok but be sure you use something to help with open time. A hair dryer or heat lamp.
Don't over clamp .
Author:  B. Howard [ Thu Feb 28, 2019 10:10 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
bluescreek wrote:
disagree about it being thirsty the process changes the cell structure and it won't absorb water like raw wood. You need to just allow 24 hr clamp time for safety . I don't like torrified braces but if you use them also 24 hr clamp time and shape them on the sander as much as you can. This wood is very chippy and doesn't scrape well so don't use a scraper or hand plane. I have been using this for a number of years and made 20 guitars with it. Be sure your blades and bits are very sharp. My glue preference here is fish glue. HHG is ok but be sure you use something to help with open time. A hair dryer or heat lamp.
Don't over clamp .



Yes, My experience with modified wood has been the same, dry and chippy. Very disagreeable to shape with cutters. The process by which they do this is basically the same as used to make charcoal, heat with no O2. Just a lower temp....Thankfully not using modified bracing material, just regular Adi.

Warming parts beforehand definitely. Would you also recommend keeping the joint warm while clamped for a period of time afterwards as well?
Author:  jfmckenna [ Thu Feb 28, 2019 11:37 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
This gets me wondering if good old Titebond might be the best. I'm actually wondering if CA would be the best... I know *gasp.

Interesting discussion here: http://acousticguitarconstructionforum. ... 0&start=10

But as you can imagine the discussion goes back and forth.

Quote:
I got some answers from:

Peter Cefalu, RC Tonewoods and Sons:
"I have heard not to use hide glue, but titebond."

And from:

Larry Anderson, Technical Support, Stewart MacDonald:
"We have been using Fish Glue to join the torrified tops in our kits and it has worked well. Hot hide glue will work well too, but the longer working time with the fish glue is helpful so the glue can be absorbed better by the wood fibers."
Author:  meddlingfool [ Thu Feb 28, 2019 12:38 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
FWIW, I use titebond, clamp overnight, and don't have problems...
Author:  bluescreek [ Sat Mar 02, 2019 2:48 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
NO CA
If you use fish or original tite bond you should do well just allow extra clamp time. 24 hr minimum
Author:  DanSavage [ Mon Mar 04, 2019 5:13 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
B. Howard wrote:
Yes, My experience with modified wood has been the same, dry and chippy. Very disagreeable to shape with cutters. The process by which they do this is basically the same as used to make charcoal, heat with no O2. Just a lower temp....Thankfully not using modified bracing material, just regular Adi.


I use OBG exclusively for the torrefied top/torrefied braces for the guitars I re-top. I leave them clamped for 24 hours.

I'm not sure you're going to get the full benefit of a torrefied top with non-torrefied braces. I've used torrefied braces on all the torrefied tops I've done, so I've become accustomed to the sound they make. I recently played a factory torrefied top guitar of the same brand, but it had non-torrefied braces. It didn't sound as good as the fully torrefied top/braces.
Author:  jfmckenna [ Mon Mar 04, 2019 6:55 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
Why do you clamp for 24 hours? I've been thinking about this lately since this thread got bumped. Is it just a 'just in case' kind of thing? I built a guitar last year with torrified bracing on a standard red spruce top and used Titebond and made no changes. I clamped for 1 hour and moved on. So far so good.

I'm not trying to argue, I'm just curious if there is some good scientific reasons on clamping for so long. And if the answer is, 'shut up and just do it,' that's fine too ;)

I can see where having a go bar deck would be good in this instance. At 24 hours clamping time it would literally take me a week to brace a top.
Author:  meddlingfool [ Mon Mar 04, 2019 8:53 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
I clamp it longer because it makes me feel more comfortable.

Earlier in the thread I called it a 'thirsty' wood, whereas John pointed out that in fact it takes water in more slowly, and he's right imo. So I say thirsty because I am more generous with the glue, but I leave it clamped longer because the glue seems to take longer to dry, at least with water based. Haven't used any non water based glue...
Author:  LarryH [ Tue Mar 05, 2019 10:30 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
jfmckenna wrote:
This gets me wondering if good old Titebond might be the best. I'm actually wondering if CA would be the best... I know *gasp.

Interesting discussion here: http://acousticguitarconstructionforum. ... 0&start=10

But as you can imagine the discussion goes back and forth.

Quote:
I got some answers from:

Peter Cefalu, RC Tonewoods and Sons:
"I have heard not to use hide glue, but titebond."

And from:

Larry Anderson, Technical Support, Stewart MacDonald:
"We have been using Fish Glue to join the torrified tops in our kits and it has worked well. Hot hide glue will work well too, but the longer working time with the fish glue is helpful so the glue can be absorbed better by the wood fibers."


From that same very interesting thread, just read the link...

"FYI, all of my glue failures with torrefied tops came using TB original. I wish I knew why but I don't. Since my last failure I have used fish glue exclusively on torrefied wood (tops and braces) with no further failures."

I've never had TiteBond fail on anything so can't attest from direct experience but I switched to fish glue for most glue operations mainly out of curiosity and have found it to simply be a great glue. Dries hard and will glue almost anything, even glass and steel (according to the label of LMI's fish glue). Did an experiment on an epoxy carbon fiber sandwich and spruce, gluing the glass smooth epoxy to the spruce and the spruce came apart instead of the glue joint. Amazing stuff.
Author:  jfmckenna [ Tue Mar 05, 2019 11:39 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
My only concern with fish glue is moisture. There have been some horror stories about guitars coming apart that were built with fish glue and reside in some humid areas of the world. Of course player care has a lot to do with that but then we luthiers need to deal with error handling as much as possible too. I have used fish glue for gluing bridges on and many other applications and have yet to have a problem but there are many that have. So it concerns me. Of course the bracing is at least inside the box and it's not under as much stress as a bridge.

But it is great stuff for sure. I just used it to glue some plastic cowlings to aluminum cylinders and it's stuck fast. Of course I used fish so that in the future I could take these things apart for repair too ;)
Author:  LarryH [ Tue Mar 05, 2019 11:47 am ]
Post subject:  Re: Thermally modified spruce & hide glue?
Yeah none of it is an easy call and I think there are horror stories about any glue one would choose, including the TiteBond story alluded to above, which I have never heard of TiteBond failing, and searched for OBG and found out it stands for Old Brown Glue and a thread where it is considered not compatible with guitar building as it's too soft? Is that true? No way to say at least from my experience so as usual you pays your money and you takes your chances...
Author:  doncaparker [ Tue Mar 05, 2019 12:15 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
On Old Brown Glue: It is nothing more (or less) than traditional hot hide glue with urea added in to keep it "sort of" liquid at room temperature. A fresh bottle, used pursuant to its instructions (which include heating it up a little), can be used for guitar building without problems. Like any glue, if it is not fresh, or if you don't follow the instructions, problems can arise.

I personally favor making my own hot hide glue and adding however much urea I need to accomplish the goal of the moment. It is all more fresh and reliable that way.
Author:  B. Howard [ Tue Mar 05, 2019 12:23 pm ]
Post subject:  Re: Thermally modified spruce & hide glue?
jfmckenna wrote:
My only concern with fish glue is moisture. There have been some horror stories about guitars coming apart that were built with fish glue and reside in some humid areas of the world.



Have had this experience. Every bridge I used FG on came loose.

I have always had good success with AR glue on thermally modded wood and the stuff we used was cooked harder than tonewoods. I am going to run a few tests with the HHG.
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