Butt-Joint Glue UpSuggestions

[Steve N]

Thanks


The only issue there is that once I force the skirt board into a curve to fit around the stair case -I think there will be some stress (tension) on the end joint.


I suppose a scarf joint is probably the classic solution – but I think the backer scrap (with perhaps a lap) will be a good way to go for me.

It would sure give you something solid to attach to.

[JGrout]

long scarf joints

[Steve N]

3/8" thick ply of any kind, cutting scarfs would unearth a lot of partial ply, I'm thinking that may not be so stable, especially wrapped on a curve. It wouldn't be my first choice, but I can't see it working in my minds eye. If it actually worked, well there ya go

[JGrout]

Last one I helped with we just butted the wiggle wood together and let the veneers hold it together 

the difference was that we used vacuum bags to veneer using a frame to set the spiral 

I also think you are looking at the scarf differently , I just rip the stock long (as in a couple of feet) then attach with glue)

[Alan S]

3/8" thick ply of any kind, cutting scarfs would unearth a lot of partial ply, I'm thinking that may not be so stable, especially wrapped on a curve.

The link I provided earlier in this thread described scarfing 1/4" ply for bending into a kayak.

[mike4244]

Don, I have used " wiggle board" the stuff that comes from Australia often. You can easily bend a 12" radius let alone a large radius like you need. You do not need anything but a simple butt joint. Are you veneering over the wiggle board?
mike

[Cooler]

I've joined plywood (3/4") by making a large half-lap joint.  Essentially it is more a continuation of the plywood than a real joint.  As I recall I made a 6" lap on both pieces and glued and clamped.  A longer lap will make a stronger joint, at some point it is going to be as strong as the plywood itself.  I have no idea how to calculate the required length.  It probably is going to be seat-of-the-pants engineering.