Official Luthiers Forum!

I'm new to epoxy. I plan on cutting the knot out of this backplate, and joining a piece of the waist scrap to replace it. I was planning on using epoxy as you guys had recommended. What brand or type would you use,(5 min. epoxy?), and do you just clamp it using tape till it sets?

Mark,
Don't use 5 min. epoxy. Use somehting like Smith, System 3 T-88,or West System. Any of of these would work fine.

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Jim Watts
http://jameswattsguitars.com

West System Epoxy IIRC the numbers are 105 for the resin and 205 or 206 (fast slow) for the hardeners. You can probably buy it locally. Check their site. They sell to the boating world.

It is great stuff.

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

Since we are on the epoxy subject, what would you guys think of marine epoxy? it has an open time of one hour...

Thanks Todd, you're right, WEST SYSTEMS is available at Lee Valley, they also have this Cold Cure brand that they say can be used as an adhesive and as a sealer

http://www.leevalley.com/wood/page.aspx?c=1&p=20013&cat=1,11 0,42965&ap=1

Any thoughts about it?

The guy I worked with on my first guitar uses West Systems exclusively (for epoxy needs) and it's great stuff. I bought mine at a place called West Marine.

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Eagles may soar, but weasels don't get sucked into jet engines.

Thanks for your help guys, it is really appreciated!
Mark

[QUOTE=ToddStock] Serge - System III, West, and MAS are all great brands, ...[/QUOTE]


Just to be clear... the stuff we use to fill pores with IS NOT GLUE....

Ask me how I know....   

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

How do you know, Brock?

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Rian Gitar og Mandolin

[QUOTE=Arnt] How do you know, Brock?[/QUOTE]

Arnt the epoxies we use for pore filling are "Finishing Resins" or should be anyway. They are not good at all for strength bonding but are great for pore filling. They were originally designed to be a finish film resin for fiberglass construction. They self level better than adhesive epoxies and most are highly UV resistant They also sand better and don't get as hard as adhesive epoxies.MichaelP38981.4175810185

Hey Michael, thanks for that explanation. I thought that I knew some of that background and I wasn't about to fill with 5 min stuff , but I appreciate that info.

Donovan

[QUOTE=D Stewart] Hey Michael, thanks for that explanation. I thought that I knew some of that background and I wasn't about to fill with 5 min stuff , but I appreciate that info.

Donovan[/QUOTE]

I have know those that have used 5 min adhesive cut with DA but most quick set epoxies get hot so quick that they tend to be brittle and yellow with time

If you don't have the need for large amounts of epoxy glue, I'd suggest the long-cure that Stew-Mac sells. It's a 1-1 mix ratio, and I've had good results with it, though I haven't used it on a guitar yet. As an experiment once, I put a small glob of it on a piece of plastic and let it dry for a couple of days. I couldn't dent it with my thumbnail, and when I tried to bend it, it snapped (with much effort). That's the kind of "glass hard" result that's advantagious for much of lutherie work.

Brock/Michael, are you sure your statements apply to the West System product? I have used it as an adhesive successfully (although not under a lot of load) and just checked their web site which seems to indicated is is designed as an adhesive.

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David White, Toronto

"All my favourite singers can't sing."

[QUOTE=drwhite] Brock/Michael, are you sure your statements apply to the West System product? I have used it as an adhesive successfully (although not under a lot of load) and just checked their web site which seems to indicated is is designed as an adhesive. [/QUOTE]

No, I *** DO USE *** West Systems Epoxy 105 Resin and 205 & 206 hardeners as GLUE.

I do not use zpoxy, system III or other pore fill epoxies as glue. (I was out of glue epoxy once and thought I would 'give it a shot'... and let's just say it didn't work. )

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

I have used Araldite epoxy glue thinned with alchol as a pore filler on several guitars. Other than the tendency to gum up the sand paper it works well, I have not experienced any yellowing or brittleness issues. I wonder if the problems you describe have anything to do with the amount of epoxy that is left under the finish? I sand everything down to bare wood so the filler only remains in the pores. You have to be careful when you get close or you will open new pores of course. I'm not saying this is teh perfect epoxy for the job, but I know it works OK.

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Rian Gitar og Mandolin

It may for other but I don't leave any sunificant amount of epoxy on the wood. In fact I sand to the wood the make a 60%epoxy/40%DA mix which is near water thin and rag on just to maintain wet color.


West system epoxies are a good bit different than the 5 and 20 min hardware store variety epoxies West systems has a couple of different resigns and several different hardeners each resin can use. It is also a marine epoxy and is UV resistant. So though it is a good adhesive epoxy it also has the qualities desired for a pore filler. Like I said It is a bit of a different bird that hardware store adhesive epoxy