X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from imf22aec.mail.bellsouth.net ([205.152.59.70] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1873907 for flyrotary@lancaironline.net; Wed, 28 Feb 2007 10:21:05 -0500 Received-SPF: none receiver=logan.com; client-ip=205.152.59.70; envelope-from=rusty@radrotary.com Received: from ibm67aec.bellsouth.net ([65.6.194.9]) by imf22aec.mail.bellsouth.net with ESMTP id <20070228152000.IBTC10815.imf22aec.mail.bellsouth.net@ibm67aec.bellsouth.net> for ; Wed, 28 Feb 2007 10:20:00 -0500 Received: from rd ([65.6.194.9]) by ibm67aec.bellsouth.net with ESMTP id <20070228151957.ECEG8793.ibm67aec.bellsouth.net@rd> for ; Wed, 28 Feb 2007 10:19:57 -0500 From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: engine mount 4130 vs 304 SS Date: Wed, 28 Feb 2007 09:19:53 -0600 Message-ID: <000201c75b4b$e82e1f00$6e01a8c0@rd> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01C75B19.9D93AF00" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 Importance: Normal Thread-Index: AcdbRlLmiGTstLK2TGe2wQPGxq3UTwAA9r4Q In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0003_01C75B19.9D93AF00 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Something Richard Sohn told me, and I soon after found to be VERY true. The HAZ of stainless weldment will rust almost as easily as mild steel if not properly treated. It must either be buffed to the original shine, passivated/pickled, or painted. Since you won't have access to the inside of the tube, going stainless may not get you much. Hi Ernest, I can't say I've ever heard of, or thought about this problem. I know that the weld will carbonize (I think that's the correct term) if air is allowed to contact the weld before it cools a certain amount, and shielding gas can be used inside the tube. Would this prevent the rusting you're talking about? I actually have two thoughts on the mount. One would be using square tubing, and the other is just using angle. The angle would allow me to weld, bolt, or do both. It also gives a nice flange to bolt to without concern for crushing a tube. You can hang lots of engine stuff off of that flange if needed, so it's pretty convenient as well. Thanks, Rusty ------=_NextPart_000_0003_01C75B19.9D93AF00 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable Message

Something Richard Sohn told me, and I soon after found = to be=20 VERY true. 
The HAZ of stainless weldment will rust almost as = easily as=20 mild steel
if not properly treated.  It must either be buffed to = the=20 original
shine, passivated/pickled, or painted.  Since you won't = have=20 access to
the inside of the tube, going stainless may not get you=20 much.

 
Hi=20 Ernest,
 
I can't = say I've ever=20 heard of, or thought about this problem.  I know that the weld will = carbonize (I think that's the correct term) if air is allowed to contact = the=20 weld before it cools a certain amount, and shielding gas can be used = inside the=20 tube.  Would this prevent the rusting you're talking=20 about?  
 
I actually have two thoughts on = the=20 mount.  One would be using square tubing, and the other is just = using=20 angle.  The angle would allow me to weld, bolt, or do both.  = It also=20 gives a nice flange to bolt to without concern for crushing a tube. You = can hang=20 lots of engine stuff off of that flange if needed, so it's pretty = convenient as=20 well.   
 
Thanks,
Rusty
  



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