X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp111.sbc.mail.re2.yahoo.com ([68.142.229.94] verified) by logan.com (CommuniGate Pro SMTP 5.2.1) with SMTP id 2845371 for flyrotary@lancaironline.net; Sat, 12 Apr 2008 22:01:40 -0400 Received: (qmail 42326 invoked from network); 13 Apr 2008 02:01:39 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=OrBtEDrOMc4Pss3F3nXN6+H43TgY5iinw6a2D6c1rgWcUu/HEVvILaIinIXYY9uDrfuTrYl67c6fdnfre5lAe8QjV8YntqtGyvpjWhcG8XapC4873+0QwdN19bgzCvxB8av7+zE3HH1T8jXQsSW8n8XSRKuitFvZANf7vcqVjiQ= ; Received: from unknown (HELO mom) (downing.j@sbcglobal.net@75.41.24.211 with login) by smtp111.sbc.mail.re2.yahoo.com with SMTP; 13 Apr 2008 02:01:39 -0000 X-YMail-OSG: HsgKmnwVM1lgKoXUfcOFV5kjXR82T6RIDJjGKGpsoor6qipWvkjQ8dgmxFMJEqbIjrTco7IjCvHc9hzuWGe._7KY1OXH0alxd4x4ShVMTjy_mI3numg5j7bE133GRnTir2mH2DZ.WiRzBuw- X-Yahoo-Newman-Property: ymail-3 Message-ID: <000c01c89d0b$46778c20$4001a8c0@gateway.2wire.net> From: "John Downing" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: adding a tubing bead Date: Sat, 12 Apr 2008 22:08:32 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01C89CE9.BF0136E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_0009_01C89CE9.BF0136E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, JB Weld would be my choice from experience as a mechanic in the gas = compression industry. That material is awesome. As I recall, Tracy = even used it in the intake runners in the block after removal of the = valves. JohnD ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Saturday, April 12, 2008 10:55 AM Subject: [FlyRotary] Re: adding a tubing bead Subject: [FlyRotary] Re: adding a tubing bead Al, you could do like Tracy did on his original, wrap a string = coated with epoxy around the tube. I hope that idea it still works, as = I did mine that way. JohnD Yes; but what epoxy? Most epoxies lose strength rapidly above about = 150F. What keeps the bead in place at 210F when the pressure is the = highest? You would want to use an epoxy that was good to 300F. Whether it works depends on the connection configuration. Just = consider the x-sectional area of the connection, the expected pressure, = and the constraints counteracting the force. Some connections don't need = a bead at all. A short coupling hose in a straight line where things = are constrained at both ends needs no bead. The pressure forces offset. = A longer hose with a 90 degree bend needs a bead or the pressure will = blow the hose off the connection. Just some rambling thoughts . . =20 Al ------=_NextPart_000_0009_01C89CE9.BF0136E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Al,  JB Weld would be my choice = from=20 experience as a mechanic in the gas compression industry.  That = material is=20 awesome.  As I recall, Tracy even used it in the intake runners in = the=20 block after removal of the valves. JohnD
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Saturday, April 12, 2008 = 10:55=20 AM
Subject: [FlyRotary] Re: adding = a tubing=20 bead

Subject:=20 [FlyRotary] Re: adding a tubing bead

 

Al, you could do like=20 Tracy did on=20 his original, wrap a string coated with epoxy around the tube.  = I hope=20 that idea it still works, as I did mine that way. =20 JohnD

Yes; = but what=20 epoxy?  Most epoxies lose strength rapidly above about = 150F.  What=20 keeps the bead in place at 210F when the pressure is the = highest?  You=20 would want to use an epoxy that was good to 300F.

 

Whether = it works=20 depends on the connection configuration.  Just consider the = x-sectional=20 area of the connection, the expected pressure, and the constraints=20 counteracting the force. Some connections don=92t need a bead at = all.  A=20 short coupling hose in a straight line where things are constrained = at both=20 ends needs no bead. The pressure forces offset. A longer hose with a = 90=20 degree bend needs a bead or the pressure will blow the hose off the=20 connection.

 

Just = some=20 rambling thoughts  . . 

 

Al

 

 

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