Epoxy grade on joining wings
 

Before I became savvy about epoxy and learned I should use 30 minute epoxy to join wing halves, I put together a WM P-51 wing with Bob Smith 20 minute 'finish cure' epoxy.

Will this slightly lower grade epoxy compromise the strength of my wing joint?

Epoxy grade on joining wings
 

I always thought 30 minute epoxy was recommended so that you had enough time to properly align the wing halves before the glue dried.

I have used 5 min. epoxy on wing halves before without any ill effects. I would not worry about it.

Epoxy grade on joining wings
 

The extra cure time also gives the glue more time to "soak" deeper into the wood before it solidifies. Otherwise, the glue might only bond to the outer layer of wood and simply peel the outer layer off. I'm sure 20 minute epoxy would be fine, but I would NOT use 5min. Some people use only 5 min and have no trouble, but I would rather error on the side of safety and use 30minute (plus, I am slow :) )

Regards,
Philip