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Thank you Alan!

The assumption here being that- at least in this situation- epoxy makes a stronger bond than other glues? Specifically, stronger than the glue being used to assemble the box?
Thanks
pvg

When epoxy is used correctly on end grain, e.g. components are primed prior to assembly, then IMHO that is correct.

Cheers

Kim

Hi Kim - newbie question here - what do you mean by 'primed'? I'm guessing you mean slathering some epoxy on the surfaces to be joined and letting it penetrate a bit before joining, but I wonder if there something more to it I'm not aware of.

I've been out of touch all day, but Kim has the right of it. I feel the epoxy gives a better bond on the variable surface of the "end grain" plywood.
I epoxy the block to the sides as well. My blocks are machine sanded to the arc of the sides at the butt. This leaves a fair amount of plywood adhesive exposed at the joint. Again, I feel it's safer to use epoxy in this situation.
I haven't heard the expression "primed" used in this context before. On Epoxy joints I rub glue into both surfaces before assembly. Is that what you mean, Kim?

Pretty much.

I use Smiths Allwood, (very good product by the way) they suggest it is good practice to accurately measure both parts and stir well for at least 1 min, allow the mix to rest for 10 to 20min, stir again, apply the mix to both surfaces and if there is any exposed end grain, allowing the mix to sit on the wood "for at least half the pot life prior to assembly" I guess this could be considered a 'partial' prime and would be all that is required for guitar end blocks.

A full prime would not be used in guitar construction. It is however recommended for end grain to end grain joints or when bonding very uneven surfaces. It is achieved by applying the rested epoxy to both surfaces, leveling, and then allowing the epoxy to fully cure on each component. A fresh batch of epoxy is then mixed and applied sparingly to the primed surfaces for assembly.

Cheers

Kim