HELP with cracks in BT joint!

[Rocketeer Gator]

I also posted this in my build thread but looking for any help I can get. The BTs are 6" dia. and the max the seam was, due to tubes not being perfectly square, was about a 1/16" on about a third of the seam.

NEED IDEAS!!
In the pic is the seam of the 2 BTs joined with a coupler,I had pressed spot putty/filler into the seam before sanding and painting.When I went to do more finishing work on the BTs I noticed the cracks.I sure don't want this to happen after the finish paint job is done.
Anyone have any idea how to keep this from happening?Would chipping all the filler out and maybe filling with an epoxy/fiber mix keep it from happening?

 

[Marc_G]

Yeah, spot putty isn't elastic enough to handle this kind of application. I think an epoxy/filler solution would do well, as long as it had sufficient elasticity and bonding to the surface of the tubes.

 

[hornet driver]

Yep, spot putty's not gonna cut it ! Epoxy /filler is a good solution---Might want to try FG FILLER--Basically it's resin with chopped glass---very durable---we call it gorilla snot---wally world has it in the automotive area.

 

[Rocketeer Gator]

This is the first time I joined tubes of this size but lesson learned.
Would this stuff I found on amazon do the trick?
If so I'll look for something similar at wally world tomorrow or would epoxy and chopped carbon fiber do the same thing?

 

[hornet driver]

YEP, That's the stuff----warning---do not over do it---tough to sand---H

 

[Rocketeer Gator]

Ok THX much bud!