> You said you used 3M bubbles (micro-balloons maybe?)

the container says "3M Bubbles"

for the thickener...
> My CLC instruction manual says to use Silica powder (Cab-o-Sil) in the
> scarf joints.

Mine does as well. Jason from Noah's said this should work fine.

I guess I don't know the difference between your 3M bubbles
> and Cab-o-Sil except I envision the bubbles to be more for filling gaps as
> opposed to connect wood. Hopefully people here can educate me.

Me too, I have no idea.

> The Cab-o-Sil I used in the scarf joints made a very strong joint. In
> fact, I made up a test piece and the wood failed before the joint
> (somewhat similar to yellow wood glue joints).

If the joint was over
> compressed before the epoxy hardened, the joint could have been
> "starved", resulting in a weak joint.

After apllying the epoxy I put down a 1" X 4" peice of pine over the joint and put a five gallon jug of water on that. could that have starved the joint?

Did you allow the epoxy to
> harden a sufficient amount of time prior to flexing the wood? When I did
> my scarf joints, I did them in a 55 - 60 F cellar and I let them sit 48
> hours prior to moving them.

I'm in a basement that is about 70 F. I let the epoxy dry for about 15 hours before taking off the weight. I was told 12 hours to dry. I lifted the wood by the joint to test it and everything seemed fine. Today, about 40 hours after I epoxied, one broke while I was turning it over to sand the other side.

> If the joints are weak, it's best to make them all fail at the wood
> interface and start again.

What's the best way to do this? Just apply pressure until it snaps?

I don't know why you can't remove the epoxy
> from the scarfs (probably with a belt sander - don't forget the dust mask)
> and re-epoxy provided you can remove the weak epoxy and get down to wood
> again. This method will allow you to keep roughly the same boat length.

the break isn't very clean, to clean things up I will have to cut off some wood and rescarf after sanding some.

> Hopefully other people here will contribute as well and give other
> suggestions.

Thanks for the suggestions.