Strongest Joint?

What is the strongest joint one can use for wood projects? Project will be under lots of pounds of pressure. Don't want it to beak or bend. Thank you in advance!

mikeasaurus2 months ago

The strongest joints are along grain to grain, and with plenty of surface area. For example, a finger joint.

This is discussed more in the Glue Lesson.

achatman (author)  mikeasaurus2 months ago

Thanks. I should be a little more specific. I'm a newbie woodworking girl building an electric, solid body, lever harp out of 2 inch cherry. About 4' x 3'. Top joints will be withstanding over 900+ pounds of pressure. Top will be horizontal grain and 2 arms will be vertical grain. Can't just run a bead of glue and slap together. Need a strong joint, i.e., biscuit, miter, locking ??? something for extra strength under tension.

Since the top member is supported on both sides you'd be surprised how much glue can hold. I mentioned surface area in my original reply. For your application a multi lap joint (think of a finger joint with long fingers) would work well.

Glue and surface area, combined with the top member supported on both sides, would provide plenty of strength at the joint. There's lots to consider when making an instrument under tension, such as the thickness of the members you are using. You're wise to be asking lots of questions!

Before committing to anything, I suggest performing some samples of the joints I mention and see what works best for you. You can easily mock up a few lap joints and put them under load to see how they perform.

Your project sounds really interesting. Please feel free to ping me again with a message privately and I'd be happy to learn more and help.

achatman (author)  mikeasaurus2 months ago

Love that joint and the advice to make mock ups and test them. I'm finishing up the blueprints now to get best dimensions. Next step is test joints! Thank you very much!!!