Official Luthiers Forum!

I've been thinking about this on and off since I just did a reset and getting close to finishing my own guitar. The dovetail is the one place I would like to use HHG but it requires moisture to release it. It's easy to induce steam into the dovetail but not so much under the fretboard. Heat alone won't do it so I'm considering using Titebond over the top of the guitar where it's very easy for future reset using heat alone. Tell me I'm wrong.

Does anyone else post the same thing in different forums. I kind of think it's a waste of time but maybe not everybody is a member of every guitar building forum so on the outside chance I may be missing out on someone's valuable input, I do it.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

Equilibrium moisture content for the wood we work with, as well as bound moisture in the glue provides enough water to allow heat alone to release fretboard, bridge, etc. If you want to use Titebond on the extension as a fuse for load management (à la Mr. Proulx?), or to encourage some cold creep between top and fretboard to minimize impact of long-term shrinkage of ebony and cross-grain joint geometry, that's fine, but I've not seen any issue getting 192g or 315g HHG to release.

_________________
For the times they are a changin'

- Bob Dylan

you are misinformed you don't need moisture , heat will release glue. Where did you get the information?
I use HHG and tite bond and have reset well over 1000 necks.
We use steam in the joint more for the heat than the moisture. The fretboard is released with pure heat . I use a heat blanket
but have seen heat lamps used for this.
Glue will release at about 145F

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I got it from Frank Ford. He did some tests and found that it won't release with heat alone unless you're practically burning the wood.

http://www.frets.com/FretsPages/Luthier/Data/Materials/GlueTest/gluetest.html

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

[quote="Woodie G"]Equilibrium moisture content for the wood we work with, as well as bound moisture in the glue provides enough water to allow heat alone to release fretboard, bridge, etc. /quote]

I wonder what went wrong in Franks experiment.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

Frank is usually on the money. In my experience, most any glue starts to soften around 180, but a little moisture helps most organic glues release.

_________________
"Act your age, not your shoe size" - Prince

Not to argue with Mr. Ford by proxy, but in my experience, it is quite common to find water around the periphery of the fretboard extension after heating for release, suggesting there is plenty of water available in the timbers I have worked with at Greenridge. Higher gram strengths of glue require higher temperatures/more heat for release, but on the paltry number of neck resets I've done - certainly no more than 70 or so - I've not seen any issues even with the strongest glue we used (315g HHG).

I prefer HHG to Titebond for creep-free hold and easy release...unmolested vintage Martins are always an easier reset or bridge reglue than the later Martins with Titebond or similar goop used to fill up the dovetail socket. No comparison on cleanup...Titebond is miserable stuff, while HHG is a hot water wipe.

_________________
For the times they are a changin'

- Bob Dylan

not to go against what anyone said here, because i dont disagree with it, but as an alternative you could use fish glue. I've released a few fretboard extensions (not thousands) with just heat and it was fine. One thing I have read recently (from the Somogyi book) is that Titebond creates a bond by seeping into the wood thus some destruction of the wood is necessary to clean the joint after removal. HHG creates a much more efficient bond using just the absolute surface of the wood (not penetrating into the cellular structure. With that said, I am unsure where fish glue fits into those categories.

Just some thoughts.

_________________
-Marcus
http://www.bailieguitars.com
Instagram | YouTube

I use a heat lamp for fretboard extensions and bridges. Since I learned to let them finish heating up I have not had any problem getting them to release. I do like to dip my spatula in the HHG water to get the spatula hot and also get it a bit wet. Adds a bit of extra moisture in there and I think it helps.

_________________
Steve Smith
"Music is what feelings sound like"

After reading a little further down the page on Frank's site I found that stress and heat will cause HHG to release, though not as cleanly as Titebond in his test. So that helps to explain why heat and a spatula work. His tests aren't very scientific and he didn't repeat the test as much as I would like but I think he nailed it. I'll stop worrying about this now. Thanks for your input which caused me to do a little further reading. You guy are right and I'm wr.. wro... Oh well, it's not the first time.

_________________
Hutch

Get the heck off the couch and go build a guitar!!!!

Not to pile on, but just to confirm: HHG is a pleasure to work with in terms of just using heat (no water or steam) to loosen it. Yes, the glue is more heat resistant than Titebond, but it has its limits, just like anything. I had to remove a back from a guitar not long ago, and it had been glued on using HHG. Using a heat gun and a frosting spatula, I was done in a few minutes. Easy peasy.

Both fish and HHG have more than enough available moisture to release with heat alone. Rather than work from second or third-hand knowledge, glue up a test article and try it for yourself. Again, timber EMC is unlikely to be lower than 5%, and that does not include the moisture trapped in the glue film. Some words of caution:

- Very slow heating with inefficient methods simply dries out the wood and may make higher strength HHG a bit reluctant to release without very high temps

- Just as in side bending, a quick rise in joint temp that balances temperature at the wood surface (scorching) with turning the joint into a dehydrator (prolonged low heat) is the path to reliable release without wood temps that can open center seam joints or slip the neck block.

_________________
For the times they are a changin'

- Bob Dylan

The way Woodie's advice translates into action in my limited-capacity brain is:

Hurry up and get the parts hot that need to get hot in order to release the glue joint you are targeting. Don't go so far as to scorch the wood, but don't drag it out, or else other joints start to unglue, and you dry the wood out unnecessarily.

I consider it good advice; that's what I do.

agree with Woodie no extra water needed. Been pulling bridges and necks for 22 yrs I admire Frank Ford but in this case I think he may have made an error

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Frank heated up his samples in an oven which would tend to dry out the joint before it reached the release temperature. I think heating a joint by applying a hot iron or heat blanket to the wood has less of a tendency to dry it out.

I remember the tests Frank Ford ran. They are described in the AL Big Red Book #5, I think. He set up some lap joints that were stressed by hanging weights (metal clamps, I think) from the pieces that were only supported by the glue joint. So, if the glue joint were to fail, that piece of wood would fall down. He put them in an oven and cooked them at increasing temps. The hide glue joints tolerated significantly higher temps than Titebond.

I think ovens affect the wood and the joints in a different way from concentrated heat sources. That may account for the discrepancy.

Having said that, I think the tests he ran are great for assessing how a guitar would fare when stuck in the trunk of a car on an extremely hot day. Maybe not so useful for determining how to take a joint apart on purpose.

EDIT--

Posted at the same time as Barry, so a bit repetitive.

It's also possible that Woodie and I, living in the swampland the Mid Atlantic has become deal with an antecedent moisture condition in the glue joint much wetter than Frank Ford, who lives on the edge of the desert.

Convection versus conduction makes a difference. (Don't ask me what that difference is.)

And don't forget radiation! Scores of bad sci-fi movie plots would not work without it! But seriously, we have all three in the shop:

Conduction: Silicone blankets and soldering guns
Convection: Heat guns and water-bath glue pots
Radiation: Heat lamps and the common laser rifle, carbine, and pistol

(Sorry...all the others had some sort of gun in the description, so needs must when OCD kicks in)

_________________
For the times they are a changin'

- Bob Dylan