X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 28 Sep 2007 08:36:04 -0400 Message-ID: X-Original-Return-Path: Received: from msgmmp-1.gci.net ([209.165.130.11] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2356372 for lml@lancaironline.net; Thu, 27 Sep 2007 21:51:00 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.165.130.11; envelope-from=ogrady@gci.net Received: from [10.0.1.8] ([24.237.13.108]) by msgmmp-1.gci.net (Sun Java System Messaging Server 6.2-3.03 (built Jun 27 2005)) with ESMTPA id <0JP200DXU2FMAW00@msgmmp-1.gci.net> for lml@lancaironline.net; Thu, 27 Sep 2007 17:50:11 -0800 (AKDT) X-Original-Date: Thu, 27 Sep 2007 17:50:03 -0800 From: Thomas O'Grady Subject: Re: [LML] Cracked Engine Mounts In-reply-to: X-Original-To: Lancair Mailing List X-Original-Message-id: MIME-version: 1.0 X-Mailer: Apple Mail (2.752.2) Content-type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Content-transfer-encoding: 7BIT References: I might add, it is a good idea to wait at least 24 hours and preferably 72 hours before pronouncing it free of cracks. Tom O'Grady On Sep 27, 2007, at 10:45 AM, Craig Berland wrote: > > I thought I would pass along a little information about welding > 4000 series steel. I am not sure what material the Lancair engine > mounts are made from but if it is a 4000 series steel then the > material must be preheated before welding and then post heated for > 1/2 hour after welding to prevent cracking. 4340 steel is much > more prone to cracking than 4130 but they both will crack if not > processed correctly. If I was going to repair a cracked engine > mount, I would have it magna-fluxed after weld repair to check for > cracks. Very small cracks may show up, but if they can be removed > with a little de-burr, then the welds are OK. That is, they are > OK, if processed correctly. > Craig Berland