On Thu, 14 Apr 2005 08:40:56 -0700, a_gunther wrote:

Lloyd Sumpter wrote:
Hi,

I'm building a plywood camper, and need this group's expertise.

I need to butt-join (don't ask me to scarf - I don't have the time
or
the talent!) two pieces of 1/4" Mahogany plywood. My question is: how
easily does the join bend? I need to bend the plywood fairly
aggressively
(can't tell you the exact radius, but it's quite a bit) and if I do
it the
way I want, I will have to bend the joined part.

My join will be a "standard" epoxy butt-join, with epoxy resin and
tape
on both sides of the join.

Any ideas?

Lloyd Sumpter

You won't get a smooth bend if you use glass and epoxy on both sides of
the joint unless you taper the ends of each side of the joint so that
the glass doesn't make the joint thicker than the rest of the panel.
That, however, would be more difficult to do than a scarf joint. One
other method which I have used successfully in areas where the bend is
not extream and strength is not a big issue is the double lap joint.
You need a portable router for this. I use a trim bit with a piece of
spine to even up the laps. It is much faster and easier to do than
either a scarf or dealing with tape and epoxy. If you manage to get
the lap depths and the grain just right, the joint is invisable and it
bends well.


Thanks for the reply!

I used that lap-joint on the floor, when I discovered that 6 1/2ft is 78
inches, NOT 66 inches (DOH!!!). But since the bottom of the floor doesn't
show, I taped one side as well. And of course that part doesn't bend.

I think you have the image sideways, though: the seam is longitudinal.
Think of a jonboat-like structure, where I'd be bending the bottom up to
form a bow, and the seam is lenghwise down the keel.

But you're right - there's not a lot of strengh required here, so I might
just do the lap-joint, and possibly tape one side (to ensure
water-tightness!) How much do you lap (I used an inch on the floor)?

Lloyd