RE: Notes-Questions-Article-All

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Been there, done that.  There were two problems.

First, this is a blind process - you can't see inside the toroid to know how
full it is and when to stop adding more.

Second, the nature of the expanding foam that I used (called "Great Stuff,
at Home Depot) is that it continues to expand with great force over a long
period of time.  It will burst the seam where you join the flex duct ends.

Gary Lau
MA, USA

 -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
Sent:	Saturday, September 01, 2001 11:56 PM
To:	tesla-at-pupman-dot-com
Subject:	Re: Notes-Questions-Article-All

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Hollmike-at-aol-dot-com>

anyone ever consider punching a small hole on the inside of their toroid and

injecting that expanding foam insulation into it?  might add some rigidity
to 
the toroid.  Don't know - just came to mind. 
Mike 



>
> >Toroid Design:  Has anyone tried joing the ends of flex duct with a 
> >pressure tight seal.  If it could be done then the flexduct toroid could
be 
> >slightly pressurized.  This would add more rigidity and immunity from
small 
> >bumps.  If a seal is not possible then maybe a balloon or an innertube? 
>
> I tried that once. When the duct has pressure applied to the inside it has
a 
> tendency to twist. Instead of a toroid, I ended up with a figure 8. Ruined
a 
> good piece of 8" duct that way. 
>
> later 
>
> deano 
>
>