Official Luthiers Forum!

Hello. Is the a way to improve a bad back joint?

I would cut it apart and try again... Make sure that it looks good before you glue it.

_________________
Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

You can inlay a back strip into it, about 2/3rds of the backs thickness. then with the joint reinforcement on the inside you'll be good.
Then again Steve's suggestion above is pretty solid

_________________
Jim Watts
http://jameswattsguitars.com

Juan is this for an arch top or conventional acoustic?

I would cut that out and do it again regardless of what it's for, that will show in a big, not good way.

Jointing is an acquired skill of hand plane use and I've found that my own jointing game vastly improved with just a little practice on sacrifice boards. Lots of ways to do it but two things the friend who taught me to joint plates conveyed to me that really helped were, three things actually:

1). Super sharp plane and it's so important that sharpening skills really need to be in place to successfully get great joints.

2). Assuming the proper plane(s) a shift in our weight/pressure from the back of the plane to the front corresponding to where the blade is in the joint. For example if you are nearly through the weight should be on the front of the plane, just starting the cut weight on the back of the plane.

3). Link Van Cleave who taught me and he had his own woodworking TV show on the West Coast and he was also Jim Krenov's apprentice and later Link taught at Jim's school Jim taught me that we can see a bad joint with the naked eye and the idea of candling or holding to a window and such is not necessary if we have decent vision.

What makes this helpful, not having to candle is you can take a swipe and check it out right way so another swipe can come quickly if it loos lousy.

Anyway practice on some scrap the learning curve of the weight shift goes quickly, the sharpening learning curve takes a bit longer but pays off big time in time with everything else.

Hope this help.

Thank you very much for your replies and for your time!

Is an archtop, the external arch is ready and the shape is sawn. I have experience glueing flat top plates, but this 1” joint is a devil!

One other thing that I learned is if your shooting board is not flat, you can swipe the edge all you want and you'll never get a good fit. So, make sure that the shooting board is flat.

_________________
Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Yes, good advice, thank you.

I have sawn and redo the joint.

The archtop construction is a true challenge!

Interesting, Hesh. Just the opposite of what I do.

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com

Front to back weight shift….me too Pat.