Date: Sat, 21 Jul 2012 19:17:54 +0000
From: Manfred Mornhinweg <manfred@ludens.cl>
Subject: Re: [Amps] Silicone hose from Flex Technologies
When you need custom silicone parts, such as tube chimneys, they can
often be made completely from RTV sealant. Just find or make a suitable
form, smear sealant into it, let it set, then remove the form.
I have made many small silicone parts by making forms on a lathe and
filling them with RTV sealant. Polyethylene is a perfect material for
those forms: Inexpensive, easy to work with, and it doesn't adhere to
silicone, so it's easy to remove the cured silicone piece from the form.
For those tube chimneys, you can use any suitably sized tubing or rod as
form, wrapping it in polyethylene film (cheap from the hardware store)
to avoid adhesion. Then you smear RTV sealant over it, using a spatula
to get a roughly even thickness and trying to avoid air bubbles. Don't
worry about the ends, just make your silicone hose long enough. When the
sealant has set, you can trim off the excess length, obtaining a nice
clean finish.
I have never tried these RTV silicone pieces in the microwave oven, but
I have used them in radio equipment without observing any trouble.
Manfred
## You would need one heck of a lot of silicone to make one sheet for a
chimney. Just buy the silicone rubber sheets from mc master carr in the usa.
You roll it into a cylinder.. then use silicone rubber glue to glue the edges.
Silicone rubber glue looks sorta like regular RTV glop.... but is high temp
stuff,
made for gluing silicone rubber sheets. The sheets are reddish colour. They
will
take a huge amount of heat. the sheets are also used in exhaust systems on
trucks etc.
You can also get flexible silicone rubber hose... in large diam too.... used
for front brake cooling
on high performance cars. ( see it up to 3” so far). Alpha uses rolled up
sheets too.
later..... Jim VE7RF
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