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Is evo stick PVA wood adhesive (general wood glue) ok to use instead of titebond? Is it possible to get the joint apart with heat like other guitar glues?

Edit: Second question. Has anyone tried using cascophen (resourcinol formaldehyde glue) for gluing backs together. It dries extremely hard and brittle, so it should have good acoustic properties (I think ).

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

I looked at the product info for the PVA adhesives on Bostik's site and there is no tech sheet on them so I may be missing the whole story. I've not seen them on the store shelves. Generally, PVA glues are not very popular here except for the LMI glue and it is a hybrid with some magic ingredients. The concern about them is they have potential to "creep" under a load and are also reported to have a muffling effect to the tonal profile vs Titebond original (alphatic resin) glue, LMI, hide and fish glue. If it's all you have I doubt it will make a difference that anyone would be able to hear. The joint between the bridge and top will be the main place where concern about creeping under load is warranted. Just make sure the PVA is fresh (ie: no vinegar smell) and prepare that joint as close to perfect as you can before applying it.

Resourcinol formaldehyde glue sounds dangerous and expensive to me. No experience there.

Mark

Thanks for the info. I think the glue I'm talking about may be an English make so might not be available in the USA. Basically it's just an ordinary PVA. I'll use titebond instead though.

I'm currently studying at a boatbuilding college and building this in my spare time so I have all sorts of strange glues available to me! Cascophen is one of the strongest glues around and you end up with a black glue line, so I thought it would make a nice visual break as I'm not using a back binding strip. I'll try it out and see how it goes.

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Hi Peter, What kind of wood is that on your guitar?

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Pat

Sorry - it's not my guitar. It's just a nice picture of a Traugott guitar. Maybe I'd better change it!

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"I am always doing that which I cannot do, in order that I may learn how to do it."
Pablo Picasso

https://www.facebook.com/FenskeGuitars

Mark, that is news to me, or at least partly. Other than hearing about Elmer white glue being crappy (and I don't think it was in this forum), I don't remember reading anything about other PVA glues in general being of less quality than Titebond original. Also, Titebond has the same flaws any PVA glues has when comparing them to hide glue or fish glue.

But then again, I'm not here that often so maybe I've mist a couple of threads...

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

From Wikipedia: http://en.wikipedia.org/wiki/Wood_glue
Hobbyists commonly use polyvinyl acetate (PVA), also known as "white glue" or "hobby and craft", and aliphatic resin emulsion, commonly referred to as "carpenter's glue" or "Yellow glue", which has similar relative ultimate strength. The two have different grip characteristics before initial set, with PVAs exhibiting more slip during assembly and yellow glue having more initial grip. PVAs are non-toxic and very easy to use, but hard to repair since nothing else sticks well to the hardened glue.[7] PVAs will creep under constant load.

Titebond Original is an alphatic resin emulsion.
Titebond II and LMI are PVAs.

They both create a joint which is stronger than the wood they join so no issues with quality if fresh. Search for Tim McKnight's study of tonal and curing characteristics of different adhesives. The bottom line is he found LMI, hot hide and Titebond original gave the best numbers for tonal performance.

Ho boy, my bad!

I always thought yellow 'carpenter's glue' was PVA.

Thanks for clearing this up Mark!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

It actually is PVA. The wiki article is wrong. Just goes to show you can't believe everything on the Interwebs.

From Franklin: http://www.titebond.com/product.aspx?id=d4d28015-603f-4dfc-a7d9-f684acc71207

Type: Aliphatic resin emulsion Calculated VOC: 10.7 g/L State : Liquid Weight/gallon : 9.2 lbs. Color : Yellow Chalk temperature: * Approximately 50°F. Dried Film: Translucent Flashpoint : > 200°F. Solids : 46% Freeze/thaw stability : Stable Viscosity : 3,200 cps pH : 4.0 Storage life : 24 months in tightly closed containers at 75°F.

If AR glue can become PVA or vice versa please explain.

Regarding the unrepairability of PVA glue: I've never had any trouble getting LMI white glue to stick to old, hardened LMI white glue. The old glue is water soluble. Sand it, wet it until it gets sticky, apply fresh glue, and clamp.

I haven't used Cascophen, but I have used another brand of room-temp cure resorcinol on the back center seam of guitars. It worked great, and allowed the back to be steam bent after gluing.

My understanding is that AR glues are a subset of PVA - polyvinyl acetates with additional resins in emulsion.

I also thought ARs were PVAs slightly modified for longer open time. In that regard it also strikes me that aliphatic resin was the more vague name (with a techy edge) some marketing dpt could find.

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member of the guild of professional dilettantes

Aliphatic resin is a trade term used by Franklin for their formulation of PVA adhesive. It is rather generic and doesn't mean that much, kind of like "liquid glue". It is yellow because they dye it yellow. IMO it is an excellent product, but the 'AR' designation and yellow color were done for marketing purposes.

It's my understanding that all formulations of PVA adhesive vary somewhat, but they are still PVA - not a entirely different thing like say acrylic resin glue. Comparing AR to PVA is like comparing Kleenex to facial tissue.

Win!

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I agree that the terms aliphatic resin and yellow glue are more marketing than anything. Yellow dye was added to differentiate Titebond from the first generation (lousy) white glues that appeared in the 1940s. My own terminology for aliphatic resin has always been "resin modified PVA." They perform better than plain PVA because of the resin based tackifiers added to the formula. With that said, I have personally empirically tested one excellent performing modern white glue: Gorilla wood glue. However, it is a type II and unless you are using RF other products will be far superior.