X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 07 Jun 2012 11:48:01 -0400 Message-ID: X-Original-Return-Path: Received: from nm5.bullet.mail.sp2.yahoo.com ([98.139.91.75] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with SMTP id 5584764 for lml@lancaironline.net; Thu, 07 Jun 2012 01:42:31 -0400 Received-SPF: neutral receiver=logan.com; client-ip=98.139.91.75; envelope-from=browncc1@verizon.net Received: from [72.30.22.78] by nm5.bullet.mail.sp2.yahoo.com with NNFMP; 07 Jun 2012 05:41:56 -0000 Received: from [68.142.200.226] by tm12.bullet.mail.sp2.yahoo.com with NNFMP; 07 Jun 2012 05:41:56 -0000 Received: from [66.94.237.123] by t7.bullet.mud.yahoo.com with NNFMP; 07 Jun 2012 05:41:55 -0000 Received: from [127.0.0.1] by omp1028.access.mail.mud.yahoo.com with NNFMP; 07 Jun 2012 05:41:55 -0000 X-Yahoo-Newman-Id: 985075.82122.bm@omp1028.access.mail.mud.yahoo.com Received: (qmail 97995 invoked from network); 7 Jun 2012 05:41:55 -0000 X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: dj8nMMsVM1nA1Iynh0bPrq822v4TUnXU8Yjx8IZxtxDEngs 29NlhsCG0oNpqiy0Yw0Udi4ROx6KWWbfsJFmR.qNw5QClulIgwYOf4dibIvl JIhN16xMY2TrDrs0TzDVbzE2_.zOKRJ8Zm0H4Rw_b5czguT4iQxXDJa7VctJ XkmWN9xr.kIflXmX8z2lhn6z3cPR3A6bsFxfsjBir4HAvXYNK6zITeCFphaC _Mh9s2d2Q8dGmeQWhhxt3B0gunv59piRzfQG8z4ME.LsHZbanswz7wJEayZ_ 2Zk8Lf.._raNYgHYPVrLgndi75edm3GyogyQSadkHZYq9Ms41grnRZyBjWR2 VruZdFy2uVsbcE1wF35Wa3RaogAkBrj85AyBEdxA8hXAMA3C1_Z2Bz0GTC7N TRfauYvcYjS4BQkrc5leuiJBjPWK5n540XZL8kNeyrmLmizd2Pbol6gLJnoY 6QTVdpQ8oIQ-- X-Yahoo-SMTP: F49l9g6swBC0R9n8vJIbm7Tf3P8Xlmia8rHIwTlO__Ml Received: from new-host.home (browncc1@72.64.105.53 with plain) by smtp102.vzn.mail.bf1.yahoo.com with SMTP; 06 Jun 2012 22:41:55 -0700 PDT From: Charles Brown Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-1--36738090 Subject: Re: [LML] Re: Speaking of defrost X-Original-Date: Thu, 7 Jun 2012 00:41:54 -0500 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1084) --Apple-Mail-1--36738090 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 I had a Cessna 172 that got windshield crazing badly -- one spot on the = left, one on the right, just above the defroster vents. The Cte of = plexiglass is large, the Cte of the canopy rim is approximately zero -- = a bad mismatch. I've plumbed my defroster to diffuse the hot air over a = wide area before it hits the canopy, and plan to use it as little as = possible. On Jun 4, 2012, at 9:48 AM, Douglas Brunner wrote: My presumption is that it came from the defrost. When I built my plane, = I put in a duct system beneath the glare shield that directed hot air up = to the canopy. In retrospect, I think I made it too effective. =20 I used to leave the defrost on long after the canopy had cleared. I had = a long trip =93through the soup=94 in Western Maryland, Pennsylvania and = Ohio during which I believe the defrost was on the whole time. = Immediately after that leg the canopy showed some significant = cracking/crazing.=20 =20 Now I switch immediately from defrost to heat (or off) as soon as the = canopy is clear. --Apple-Mail-1--36738090 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 I had a Cessna 172 that got windshield crazing = badly -- one spot on the left, one on the right, just above the = defroster vents. The Cte of plexiglass is large, the Cte of the = canopy rim is approximately zero -- a bad mismatch. I've plumbed = my defroster to diffuse the hot air over a wide area before it hits the = canopy, and plan to use it as little as = possible.

On Jun 4, 2012, at 9:48 AM, = Douglas Brunner wrote:

My presumption is that = it came from the defrost. When I built my plane, I put in a duct = system beneath the glare shield that directed hot air up to the = canopy. In retrospect, I think I made it too effective.<= /div>

I = used to leave the defrost on long after the canopy had cleared. I = had a long trip =93through the soup=94 in Western Maryland, Pennsylvania = and Ohio during which I believe the defrost was on the whole time. = Immediately after that leg the canopy showed some significant = cracking/crazing.

Now I switch immediately from = defrost to heat (or off) as soon as the canopy is = clear.

= --Apple-Mail-1--36738090--