At 07:30 PM 3/2/2011, Jake de Villiers wrote:
>You forgot to allow for the metal insert on the back side.

No I didn't -- those rivets have backing plates which are much
thicker than the insert and would if anything spread the stress over
a wider area.

>  That, and Acrylite FF is much more brittle than the soft plastic
> the coolant tubes are made of.

I totally agree.  However we're starting from Go Westy's observation
of stress cracking in the plastic tubes, so I think the comparison is
not entirely far-fetched.  I'd have used aged tube material except
that first I haven't any and second the polarizing technique would be
well beyond my resources as I've no way to get thin sections (and
maybe it's not optically active anyway).

As you said, time will tell.  It might be interesting to ask Go Westy
how much time elapsed between their installations and the
observations of cracking.

Cheers,
d