Overlap on body wood. How much is enough?

[LowNloud1]

Attempting to make a bass body (first time) from some Sapele that a friend gifted me.

I have cut it into 4 pieces about 10" x 20" x 1" thick. My plan is to butt 2 pieces to form a top and butt the other two together to form the bottom then glue them together.

My question is, how much overlap/offset between the centerline is needed when I glue the top piece to the bottom?

 

[RichterScale]

By top and bottom, do you mean bass and treble sides, or front and back?...

 

[bobdabilder]

You don't need any overlap. We build 2 piece bodies all the time with a single glue joint. You're simply making a top and bottom each out of 2 pieces, right?

 

[RichterScale]

If it's 4 pieces, I cant think of any reason why the center glue lines would need to be offset. Nothing will be any weaker being centered than if it were offset.
Also, it would be very noticeable and not look good if they're not centered.

 

[HaMMerHeD]

Yeah. Not building a brick wall here. No offset needed.

 

[Arie X]

so basically a 4 piece body. no overlap needed unless you want to accent a lap joint for artistic purposes. i recently did this on a Lyre with a 6 piece poplar lamination.

do a trial run of your glue process before your fingers get wet. in reality, i suggest a glue roller for large areas. also, if you aren't aware, glue is really slippery so you will have to figure out how to keep stuff from swimming around while clamping or dead weighting.

 

[Beej]

Attempting to make a bass body (first time) from some Sapele that a friend gifted me.

I have cut it into 4 pieces about 10" x 20" x 1" thick. My plan is to butt 2 pieces to form a top and butt the other two together to form the bottom then glue them together.

My question is, how much overlap/offset between the centerline is needed when I glue the top piece to the bottom?

The gang's got you covered, I just wanted to say welcome and that you have a fantastic hive mind here to help with every single step of the way. Tell us more about your plans, there's nothing better in life than to build basses and talk about it with like-minded people.

 

[LowNloud1]

By top and bottom, do you mean bass and treble sides, or front and back?...

I mean 2 pieces for a top and 2 for a back, to form a body blank.

 

[LowNloud1]

You don't need any overlap. We build 2 piece bodies all the time with a single glue joint. You're simply making a top and bottom each out of 2 pieces, right?

Correct.

 

[LowNloud1]

It would be advantageous to be able to not have to offset the center joint. Not having done this, I appreciate the benefit of everyone's experience.

So, as long as I properly prepare the joints where the edges meet, I can join all the pieces at one time, clamping them properly? (Widths have been smooth planed)

 

[RichterScale]

I might glue the left side top and back and the right side top and back together separately, then joint/plane the mating surfaces and glue the sides together.
Unless you have a special jig to clamp all 4 pieces from all sides at once, it may slip around while the glue is wet and be a real pain to keep in place.

 

[dwizum]

I will second @RichterScale's suggestion. Glue up two sandwiches, each one the full thickness and half the body width, then joint the edges and glue them together as if you were making a typical two piece blank.

 

[lark_z]

I glued up pine strips that had been ripped on a table saw to the desired slab thickness. Just edge to edge gluing in a single layer (as others have indicated). You'll be fine whatever you decide. The serious woodworkers often state that the glue joint is stronger than the wood.

 

[Matt Liebenau]

You can glue everything at once but if you can prep the edges after gluing then, as others have said, it's probably easier to glue each top and back then glue the 2 halves together. Either way you go try your clamping routine dry first and remember the blanks will move around a lot more once there's glue on them.

 

[Arie X]

i would do a sub asm of top and a sub asm of bottom, then a final asm of both. it's a lot of water for the wood to take in doing all of them at once. otoh, you'll need to surface the glue sides of both halves for the final asm.

the thinner top and bottom "plates" are best glued with a jointing fixture.

for the final sandwich, moving blanks isn't that hard to deal with. just fire a few staples into the glue area and cut out the center portion of each leaving 2 small pointy barbs poking out. these will engage the piece to be glued and will prevent slipping. just make sure they are in areas that you won't have cutting tools in later on.