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[QUOTE=JJ Donohue] But I was actually planning to try the finishing resin as a product for gluing the FB...perhaps with thickening agents added if need be. Folly perhaps... but if existing inventory can be used for multiple purposes, I'm all for it.[/QUOTE]

I wouldn't do that. I tried that once to glue a cocobolo plate together for an electric and ... let's just say it didn't work.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I've been using West System on boats since I was about 11 years old, and love the stuff. Due to the low viscosity, I am an advocate of a 2-step bonding process, with a filler-thickened layer in the middle. It may depend on your clamping pressure, but you certainly can get a starved glue joint with an un-thickened epoxy on a porous wood. In hydroplanes built with 3mm marine ply mahogany over a sitka spruce frame, this isn't a risk you want to take hitting waves at 100mph. It may not be necessary if you're cautious with your clamping pressure, but I still prefer to at least slightly thicken with filler on any porous or soft woods.

As to reversibility, it softens and comes apart nicely with heat.

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Eschew obfuscation, espouse elucidation.

Thanks, Brock. Since I already started some test samples, I'll just let the test go to completion. I'm comparing this to hardware store epoxy.

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JJ
Napa, CA
http://www.DonohueGuitars.com

I can say with certainty that the West Epoxy releases very easily with heat, no moisture needed. I have also always used a thickener on the fretboard to neck joint as David described.

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David White, Toronto

"All my favourite singers can't sing."

[QUOTE=Mattia Valente] John: that's the first time I've ever seen anyone advocating the use of thickener for epoxy in a wood lamination/instrument building setting. Could you elaborate? I'm currently using 30 minute Z-poxy for my fingerboards.

Semi-related note: how do unmixed epoxy components do with exposure to sub-zero temperatures? Left my bottles out by mistake recently, dipped a few degrees below zero, and they seem fine, but I'm wary. If it were titebond, I'd have thrown it out.[/QUOTE]

Mattia-
As I said in my post to Hesh, gluing a FB is a low-stress application compared to a lot of jobs where epoxy is used so you can probably get away without filler/thickener.
You can check out the User Guide at the WEST/Gougeon site for recommendations:
WEST
Additives are recommended for most epoxy uses except for wetting out fiberglass. For good bonding, most surfaces should be wetted with straight epoxy before thickened epoxy is applied.
Overclamping is not recommended.


Freezing will not harm WEST or SystemThree epoxy resin or hardener, and I think the same would be true for ZPoxy. The resin can crystallize if frozen. If the resin crystallizes, heating the resin container in a water bath will liquefy the resin so it can be used again.

Cheers
John

[QUOTE=JJ Donohue]Thanks, Joe...I am in no hurry to glue up the FB and was planning this testing anyway. No special trip necessary. We may have a meeting soon anyway when Hesh and I invite you for Chinese food in Angola in a few weeks...stay tuned! If I need the West then, I'll let you know.[/QUOTE]

Mmmmmm, I'm ready!

Oh, I didnt know you could get that stuff apart with heat, I know west systems to be very tough stuff!

sorry for casting a shadow of doubt, I have much to learn about epoxy.

Matt

This is an interesting read on epoxy and I too have much to learn about the subject.
Sounds like epoxy can be removed with heat but I'm wondering about a couple things. Will the epoxy reset if heated for the purpose of straightening a neck such as one with backbow or a twist.
Also wondering about the mention of this being a "low stress application". Seems like it would become a "high stress application" when the truss rod is tightened as the fretboard would tend to creep along the neck. What are the "cold creep" properties of epoxy?
I hope these are not "dumb" questions.
Thanks
Nelson

[QUOTE=npalen]
What are the "cold creep" properties of epoxy?

[/QUOTE]

Good question Nelson!

I'm interested in this as well since I've had 2 failed epoxy joints using Loctite 30 minute epoxy from the local hardware store...and it was as a result of a truss rod applying force as you suggested.

This stuff generally has very good anti-creep properties and cures glass hard when fresh and mixed properly. In my case, I used old material and it cold creeped...another lesson learned!

The West product that Hesh highlighted seems ideal since it is sold in small quantities. I plan to give it a try.

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JJ
Napa, CA
http://www.DonohueGuitars.com

[QUOTE=Hesh]    Dave buddy the problem, as I see it, with HHG beyond the minuscule open time is that it is a water based glue just like Titebond.   Using a water based glue, and the warping that can result , is why I tried epoxy instead for this application. If I stayed with a water based glue I would use Titebond or fish glue and give my nerves a break over the rush required using HHG.
[/QUOTE]
Thanks Hesh, I was just curious to see if anyone did use hide glue for fretboards.I guess not.I'm not going to try it. I'm going to go ahead and give the West system a try since it IS possible to remove with heat.
Good thread!    

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Anderson Guitars
Clearwater,Fl. 33755

Dave...I used HHG on this joint on my first guitar. Got a severe back bow. Used epoxy since and never looked back. Don't use HHG here!

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JJ
Napa, CA
http://www.DonohueGuitars.com

I would like to give the West packets a try also. What would be the shelf life?
Thanks
Nelson

The nice thing about the packets is that the hardener stays clear. When you buy it in quarts or gallons, the hardener will start to amber once exposed to oxygen. Gougeon Brothers say that this does not effect the curing or strength of the epoxy, but it can lead to an unsightly glue joint when in a visible area.

It's certainly more expensive per ounce to use the single-use packets if you use much of it. If you use it rarely however, it can be cheaper in the end as opposed to discarding a 3/4 full jar of red/amber hardener after a year. I used to keep a couple graduated syringes around and fill them from the single use packs. This way I could still use smaller measured amounts as needed, not having to discard most of a single-use packet after a small job. I use it enough now that I buy it in cans, but I still keep the syringes filled for small jobs.

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Eschew obfuscation, espouse elucidation.

Talking or thinking about "epoxy" as a generic term is like talking or thinking about varnish or spruce as generic terms.   There are literally thousands of formulations for epoxies, and you really can't make any generalizations about them.

Todd has come across some of the ones used in aircraft construction which are post-cured at 250 F.   I've come across ones in my early days working with techs at Ford Aerospace on carbon fiber bas necks that were cured at 350 F., and had working temperatures above 400 F.; these were used in communications satellite construction.

As for the WEST stuff, look at it this way.   It's used in the construction of extreme "maxi" ocean racing sailboats where stresses and punishment far exceeds anything any of our guitars should ever have to go through.   Ditto for temperature extremes.   Many of these yachts are made with a combination of wood and carbon fiber which is interleaved with wood layers in especially high stress areas like where chain plates are attached...these are where standing rigging is anchored to support masts and jib halyards.

While I understand concerns about epoxies...whether joints may be undone, cold creep, etc., if you take the time to study up on what's been done outside of our little guitar making scene you'll be quite reassured that if you choose the right epoxy, hardener, and additives for particular jobs, you'll get great results.

BTW, David Collins' comment re. 3 layers of epoxy may have gone right past a lot of folks.   What he's doing is wetting the two surfaces of a glue joint with straight low viscosity WEST epoxy, and then he's adding a middle layer of thickened epoxy.   You can do this quite easily by mixing up a small batch, brushing a thin layer on both surfaces, then adding in a filler to the remaining batch, mixing it in well, and then brushing that onto one side of the wetted joint.   Then clamp.

I've been using epoxies for fingerboard gluing for about 30 years now.   I tried polyurethane for a while, but got very inconsistent results. The WEST stuff is fantastic, and I'm going to try David's 3 layer system. I like that idea a lot.

As for Mark Blanchard's issues with incompatibility with finishes, I shoot McFadden's rosewood sealer/isolator onto everything. It locks in any oils or other chemicals that may inhibit any kind of finish cure.   Good old shellac would probably work great, too, and there's still no better sealer for under nitro lacquer than shellac.    

[QUOTE=DaveAndy]
...I wonder if anybody actually uses HHG for fingerboards??...[/QUOTE]

I do...it's the only glue I use.

You could squirt some Bloxygen into the opened cans of epoxy to keep oxygen away from the surface.   As the gasses in Bloxygen (argon, nitrogen, and carbon dioxide) are slightly heavier than air, they should stay as a protective blanket for quite a while, and you could always re-top from time to time.

One of the other things I love about West System is how good Gougeon Brothers tech support is. They publish a lot of instructional data and advice, usually available at their retailers or from their web site. They are also very good about responding to personal tech support questions.

They describe as the "two-step bonding process" exactly as Rick described if you go to their web site and click on the "Using West System Epoxy" tab. Wet both surfaces, then thicken remaining epoxy and add as middle layer. It allows good saturation in to the wood with the low viscosity wetting, then ensures a good layer that won't get starved with the thickened part.

There's a whole lot of good info there if you feel like reading for a while.

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Eschew obfuscation, espouse elucidation.

[QUOTE=Rick Turner] You could squirt some Bloxygen into the opened cans of epoxy to keep oxygen away from the surface.[/QUOTE]

Why do I always forget that stuff exists? I should certainly start keeping that around the shop.

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Eschew obfuscation, espouse elucidation.

Great stuff David, John, and Rick.

I have this stuff from my SIII days, would this silica thickener, of course with a respirator on while working with it, be a good choice as a thickener for the middle layer?

Bloxygen is a must if you work with tung oils like Waterlox, too...

a good choice as a thickener for the middle layer?

I think so, it looks similar to the silica I use that I got from Lee Valley.

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David White, Toronto

"All my favourite singers can't sing."

[QUOTE=Hesh] would this silica thickener, of course with a respirator on while working with it, be a good choice as a thickener for the middle layer?[/QUOTE]

Colloidal silica works well as an additive for bonding, but is tough on tools- not really an issue for FB gluing. The other choice recommended by WEST for general bonding/lamination is microfibers- milled cotton fibers.

Hesh- if you pm me your mailing info, I can send you some microfibers in an envelope- something to keep Homeland Security busy in the New Year...

Cheers
John

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Eschew obfuscation, espouse elucidation.

Anyone happen to know whether the West System 101-T will reset after heating? (Back to the neck straightening question above)
Thanks
Nelson

Epoxies do not release with heat and then reset. They are thermosetting resins, not thermoplastic.   Any heat that will soften them to the point of release or movement is likely to destroy the adhesive qualities of the glue line.    If you're trying to heat bend a neck, don't count on slipping the glue joint. At best you'll be able to kind of bend the wood itself.

Google this stuff if you really want the skinny.   Try "termosetting vs. thermoplastic" for instance.