HBrew Vertical Insulator Question
 

I'm planning on building a home brew 40 meter vertical from 6063 drawn
aluminum tubing. My question is what commonly availble pvc tubing, pipe or
conduit will slip over or into the base section of the vertical. The final
tubing sizes will or can be:

O.D/I.D.

1.250/1.134
1.0/.884

Hope someone has tried this as I don't want to order the tubes then find I
need a specially milled base insulator. Doesn't have to be too strong as it
will go into a chimney mount. I think it can be done as one of the Butternut
antennas has it but as a center insulator.

TIA Tony WA6LZH