We could not come up with a satisfactrory handy-dandy bead roller when we
installed radiators in our long-eze; we ended up braising a 'bead' onto the
exterior of the tube's surface.  We paid special attention(lots of fine
inspection, filing, and buffing to our satisfaction) to the circuitous
lump(bead).  My partner and I are satisfied that it will suffice as a 'bead',
and that it will retain what ever clamping devices, and hose, that we end up
utilizing.
    Would welding have been OK?  JB Weld?  What are some other bead building
options?  What detriments would each method create?  Is there any possibility
that any of these methods would weaken the 2"  tubes locally, or increase the
liklihood of stress risers, or future stress cracks occuring? What aluminum
tubing should be best?  We did not use a t6, as we were afraid that it would
be too hard, nor did we use a dead soft aluminum tube either; I think we used
6061-t3.

JB Weld would work but you would have to machine a telescopic section
of tubing with the bead that had a bond area of about 1/2 inch long.
It would not weaken the tube but it would increase the diameter
slightly and make it a bit more difficult to slip the rubber hose
over it. Making a fitting that slipped inside of course would
reduce the ID. Aluminum age hardens as I recall. I think T-0 would
be fine as long as there was no mounting stress.

Paul Lamar
 
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