X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mtiwmhc12.worldnet.att.net ([204.127.131.116] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2131820 for flyrotary@lancaironline.net; Thu, 21 Jun 2007 12:33:51 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.131.116; envelope-from=keltro@att.net Received: from mwebmail36.att.net ([204.127.135.75]) by worldnet.att.net (mtiwmhc12) with SMTP id <2007062116330911200db0ree>; Thu, 21 Jun 2007 16:33:09 +0000 Received: from [64.250.200.77] by mwebmail36.att.net; Thu, 21 Jun 2007 16:33:08 +0000 From: keltro@att.net (Kelly Troyer) To: "Rotary motors in aircraft" Subject: Re: Proseal was Re: PP construction methods Date: Thu, 21 Jun 2007 16:33:08 +0000 Message-Id: <062120071633.16871.467AA8430005F4CE000041E72160466648019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Mar 24 2007) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_16871_1182443588_0" --NextPart_Webmail_9m3u9jl4l_16871_1182443588_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Marv,Tracy,et al, Any numbers on the degrees of heat that Polysulfide or the newer Polyurethane can handle without degrading?? -- Kelly Troyer "Dyke Delta"_13B ROTARY Engine "RWS"_RD1C/EC2/EM2 "Mistral"_Backplate/Oil Manifold -------------- Original message from marv@lancair.net: -------------- Polysulfide is an old standby in the insulating glass industry for sealing the edges of insulating glass units (think thermopane). It sticks like grim death to most substrates (as long as they're clean and degreased) and it retains a good bit of its flexibility for a very long time. Typical insulated glass units sealed with the stuff would carry a 20 year warranty against seal failure as long as the sealant was properly protected from the elements and especially the sunlight... it degrades rapidly with high exposure to UV. The only thing I know of that's stickier are the more recent polyurethane sealants, but the industrial versions I'm familiar with are not readily available to the general public and are sold only in 50 gal drum quantities accompanied by a 5gal pail of catalyst. Both products can put up with pretty high heat levels, so they are well suited to a wide range of applications. A big difference between the two, although not germaine to this discussion, is that poly sulfide does not provide a moisture vapor barrier, ie, it's permeable to water vapor, whereas polyurethane isn't. "Ed Anderson" wrote: """ That Polysulfide is remarkable stuff. When I started to put together the two parts of an 2 1/4" instrument case, the 3/8" thick flange and the 2.25" tube, I scratched my head over how to join the two. Set screws were simply too labor intensive, crazy glue was too brittle - but, I had some "tank sealer" left over (years on the shelf) which I mixed a small amount together, smeared a thin amount on the inside of the flange and pushed the tube in. Once it set I could not get the tube out of the flange without destroying the aluminum tube. Really sticks and doesn't turn brittle. Ed """ --NextPart_Webmail_9m3u9jl4l_16871_1182443588_0 Content-Type: text/html Content-Transfer-Encoding: 8bit

Marv,Tracy,et al,

Any numbers on the degrees of heat that Polysulfide or the

newer Polyurethane can handle without degrading??

--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold

-------------- Original message from marv@lancair.net: --------------

Polysulfide is an old standby in the insulating glass industry for sealing the edges of insulating glass units (think thermopane). It sticks like grim death to most substrates (as long as they're clean and degreased) and it retains a good bit of its flexibility for a very long time. Typical insulated glass units sealed with the stuff would carry a 20 year warranty against seal failure as long as the sealant was properly protected from the elements and especially the sunlight... it degrades rapidly with high exposure to UV. The only thing I know of that's stickier are the more recent polyurethane sealants, but the industrial versions I'm familiar with are not readily available to the general public and are sold only in 50 gal drum quantities accompanied by a 5gal pail of catalyst. Both products can put up with pretty high heat levels, so they are well suited to a wide range of appl ications. A big difference between the two, although not germaine to this discussion, is that polysulfide does not provide a moisture vapor barrier, ie, it's permeable to water vapor, whereas polyurethane isn't.

<Marv>

"Ed Anderson" <eanderson@carolina.rr.com> wrote:
"""
That Polysulfide is remarkable stuff. When I started to put together the two
parts of an 2 1/4" instrument case, the 3/8" thick flange and the 2.25" tube,
I scratched my head over how to join the two. Set screws were simply too
labor intensive, crazy glue was too brittle - but, I had some "tank sealer"
left over (years on the shelf) which I mixed a small amount together, smeared
a thin amount on the inside of the flange and pushed the tube in.

Once it set I could not get the tube out of the flange without destroying the
aluminum tube. Really sticks and doesn't turn brittle.

Ed
"""
 

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