[TowerTalk] Adding Expanding Foam inside boom

[jimlux]

On 4/26/18 3:34 AM, john at kk9a.com wrote:
> I'm not sure how you would completely fill a 12' piece of tubing with the
> foam and I think it would have the potential to trap water.  I like to
> keep my booms completely open (no end caps).
> 
> John KK9A
> 

the other problem is that the foam may not "cure" properly in a sealed 
(or nearly sealed) container.  The tesla coil community has fooled with 
this to make large toroids by doing stuff like filling a truck tire 
inner tube, or a ring of expandable duct, with the foam, in an attempt 
to "rigidize" it.

I think the take home from all those experiences is that "it depends on 
the brand and type of foam"