X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: <marv@lancaironline.net> Sender: <marv@lancaironline.net> To: lml@lancaironline.net Date: Mon, 16 Jan 2012 12:34:50 -0500 Message-ID: <redirect-5352296@logan.com> X-Original-Return-Path: <colyncase@earthlink.net> Received: from elasmtp-scoter.atl.sa.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5351969 for lml@lancaironline.net; Mon, 16 Jan 2012 08:44:42 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.67; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=sdu0ZzTsCk8mTEaAO/XaWnVy4c81zyFuVv20A6IdK09bhSiG5osgkrKNzMEEqtgF; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [72.73.82.72] (helo=[192.168.1.24]) by elasmtp-scoter.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from <colyncase@earthlink.net>) id 1Rmmr0-0003Yq-Ok for lml@lancaironline.net; Mon, 16 Jan 2012 08:44:07 -0500 From: Colyn Case <colyncase@earthlink.net> Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-100-521895195 Subject: Re: [LML] Re: Ceramic exhaust coatings - careful y'all X-Original-Date: Mon, 16 Jan 2012 08:44:06 -0500 In-Reply-To: <list-5351076@logan.com> X-Original-To: "Lancair Mailing List" <lml@lancaironline.net> References: <list-5351076@logan.com> X-Original-Message-Id: <DB223E14-844F-48AE-B14D-B59F259A2C0B@earthlink.net> X-Mailer: Apple Mail (2.1084) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da9409891b604f6846616e1bc3fe395af97cc350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 72.73.82.72 --Apple-Mail-100-521895195 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii That data makes it pretty clear. I had a mechanical engineer/metallurgist friend who was a pilot at one = point. His comment on the equipment was "Airplanes barely work. = Helicopters don't work" I think this exhaust situation is an example = of "barely work". Those margins are really thin. So does this also mean that it is better to paint stainless black than = leave it shiny? Colyn On Jan 15, 2012, at 10:39 AM, Frederick Moreno wrote: Insulation wrapped on exhaust pipes and coatings that reduce the surface = thermal emissivity both raise exhaust pipe temperature.=20 =20 So what?=20 =20 At these temperatures, the strength of the 321 stainless steel = generally used in exhaust pipes is dropping like a rock - small = temperature increases result in big strength decreases - and creep = resistance drops even faster. =20 Oxidation is also increasing dramatically with temperature.=20 =20 In short, the exhaust pipes will fail much, much sooner due to cracking = or wall thinning. If you are driving a turbo, you run a double risk = because of the high pressures inside the exhaust pipes upstream of the = turbo that stress tubing walls more and create blow torches when cracks = form.=20 =20 In short, don't do it unless you pledge to inspect the pipes more often, = like every time the cowl is off, and unwrap the pipes for a very careful = inspection at EVERY annual.=20 =20 Data below. Out of curiosity I made an Excel plot, attached. It makes = the point even better than the table below. Creep strength virtually = zero at 800C =3D 1432F =20 Sorry 'bout that. =20 Fred Moreno =20 2. Properties at Elevated Temperatures=20 Short Time Elevated Temperature Tensile Strength Temperature, oC 600 650 700 750 800 850 Tensile Strength, MPa 390 329 280 230 190 140 Creep data=20 Stress to develop a creep rate of 1% in the indicated time at the = indicated temperature. Time Temperature oC 550 600 650 700 800 10 000 h Stress MPa 180 100 70 40 10 100 000 h Stress MPa 120 80 50 25 5 Creep Rupture Stress Time Temperature oC 500 600 650 700 800 1 000 h Stress MPa 270 180 140 70 30 10 000 h Stress MPa 240 130 90 50 10 100 000 h Stress MPa 200 90 50 15 5 =20 =20 Subject: Re: [LML] Re: Ceramic exhaust coatings =20 One other thought, I have heard both sides of this argument before as = well. I also heard it is nearly impossible to weld / repair pipes with = this coating. I found a solution that solved the problem cheaply without = making the pipes more difficult to weld. I wrapped my entire exhaust = system with hot rod exhaust wrap. I bought it at the local auto parts = store in the 1" width. Spruce sells it as well. I tested the stuff with = a torch in the hangar on my hand and was amazed how well it insulates. I = have 2 layers in some very hot places on the pipes. In addition to = reducing the inner cowl temps, It also tames the vibration of the pipes = and reduces noise.=20 Cheap, relatively light and effective... Fwiw. <321 SST strength vs temp.xlsx>-- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html --Apple-Mail-100-521895195 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii <html><head><base href=3D"x-msg://615/"></head><body style=3D"word-wrap: = break-word; -webkit-nbsp-mode: space; -webkit-line-break: = after-white-space; ">That data makes it pretty clear.<div>I had a = mechanical engineer/metallurgist friend who was a pilot at one point. = His comment on the equipment was "Airplanes barely work. = Helicopters don't work" I think this exhaust situation is = an example of "barely work". Those margins are really = thin.</div><div><br></div><div>So does this also mean that it is better = to paint stainless black than leave it = shiny?</div><div><br></div><div>Colyn</div><div><br><div><div>On Jan 15, = 2012, at 10:39 AM, Frederick Moreno wrote:</div><br = class=3D"Apple-interchange-newline"><span class=3D"Apple-style-span" = style=3D"border-collapse: separate; font-family: Arial; font-style: = normal; font-variant: normal; font-weight: normal; letter-spacing: = normal; line-height: normal; orphans: 2; text-indent: 0px; = text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; = -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: = 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: = auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div = background=3D"" scroll=3D"yes" bgcolor=3D"#ffffff" style=3D"margin-top: = 5px; margin-right: 10px; margin-bottom: 0px; margin-left: 10px; = font-family: Arial; font-size: 12pt; "><table id=3D"INCREDIMAINTABLE" = border=3D"0" cellspacing=3D"0" cellpadding=3D"2" = width=3D"100%"><tbody><tr><td id=3D"INCREDITEXTREGION" width=3D"100%" = style=3D"position: relative; direction: ltr; font-size: 12pt; "><div = id=3D"INCREDI_TEXT_AREA" style=3D"padding-left: 2px; = "><div><div>Insulation wrapped on exhaust pipes and coatings = that reduce the surface thermal emissivity both raise exhaust pipe = temperature. </div><div> </div><div>So = what? </div><div> </div><div>At these temperatures, the = strength of the 321 stainless steel generally used in exhaust = pipes is dropping like a rock - small temperature increases result = in big strength decreases - and creep resistance drops even = faster.</div><div> </div><div>Oxidation is also increasing = dramatically with temperature. </div><div> </div><div>In = short, the exhaust pipes will fail much, much sooner due to = cracking or wall thinning. If you are driving a turbo, you run a = double risk because of the high pressures inside the exhaust pipes = upstream of the turbo that stress tubing walls more and create blow = torches when cracks form. </div><div> </div><div>In = short,<span class=3D"Apple-converted-space"> </span><strong><em>don't= do it</em></strong> unless you pledge to inspect the pipes more = often, like every time the cowl is off, and unwrap the = pipes for a very careful inspection at EVERY = annual. </div><div> </div><div>Data below. Out of = curiosity I made an Excel plot, attached. It makes = the point even better than the table below. Creep = strength<span = class=3D"Apple-converted-space"> </span><em><strong>virtually = zero</strong></em><span class=3D"Apple-converted-space"> </span>at = 800C =3D 1432F</div><div><div> </div><div>Sorry 'bout = that.</div><div> </div><div>Fred = Moreno</div></div><div> </div><div><p align=3D"left"><font = size=3D"2"><b><font face=3D"Arial,Helvetica">2. Properties at Elevated = Temperatures</font></b><span = class=3D"Apple-converted-space"> </span><br><font = face=3D"Arial,Helvetica"><b>Short Time Elevated Temperature Tensile = Strength</b></font></font></p><div align=3D"left"><table border=3D"1" = width=3D"100%" cols=3D"7"><tbody><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">Temperature,<span = class=3D"Apple-converted-space"> </span><sup>o</sup>C</font></td><td>= <font size=3D"-1" face=3D"Arial,Helvetica">600</font></td><td><font = size=3D"-1" face=3D"Arial,Helvetica">650</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">700</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">750</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">800</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">850</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">Tensile Strength, MPa</font></td><td><font = size=3D"-1" face=3D"Arial,Helvetica">390</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">329</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">280</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">230</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">190</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">140</font></td></tr></tbody></table></div><p = align=3D"left"><font size=3D"2"><b><font face=3D"Arial,Helvetica">Creep = data</font></b><span = class=3D"Apple-converted-space"> </span><br><font = face=3D"Arial,Helvetica">Stress to develop a creep rate of 1% in the = indicated time at the indicated temperature.</font></font></p><div = align=3D"left"><table border=3D"1" width=3D"100%" = cols=3D"7"><tbody><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">Time</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Temperature<span = class=3D"Apple-converted-space"> </span><sup>o</sup>C</font></td><td>= <font size=3D"-1" face=3D"Arial,Helvetica">550</font></td><td><font = size=3D"-1" face=3D"Arial,Helvetica">600</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">650</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">700</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">800</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">10 000 h</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Stress MPa</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">180</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">100</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">70</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">40</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">10</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">100 000 h</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Stress MPa</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">120</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">80</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">50</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">25</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">5</font></td></tr></tbody></table></div><p = align=3D"left"><font size=3D"2" face=3D"Arial,Helvetica"><b>Creep = Rupture Stress</b></font></p><div align=3D"left"><table border=3D"1" = width=3D"100%" cols=3D"7"><tbody><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">Time</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Temperature<span = class=3D"Apple-converted-space"> </span><sup>o</sup>C</font></td><td>= <font size=3D"-1" face=3D"Arial,Helvetica">500</font></td><td><font = size=3D"-1" face=3D"Arial,Helvetica">600</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">650</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">700</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">800</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">1 000 h</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Stress MPa</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">270</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">180</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">140</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">70</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">30</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">10 000 h</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Stress MPa</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">240</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">130</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">90</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">50</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">10</font></td></tr><tr><td><font size=3D"-1" = face=3D"Arial,Helvetica">100 000 h</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">Stress MPa</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">200</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">90</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">50</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">15</font></td><td><font size=3D"-1" = face=3D"Arial,Helvetica">5</font></td></tr></tbody></table></div></div><di= v> </div><div> </div><div><i><b>Subject:</b></i><span = class=3D"Apple-converted-space"> </span>Re: [LML] Re: Ceramic = exhaust coatings</div></div></div><div><div dir=3D"ltr" = id=3D"IncrediOriginalFontSize" style=3D"font-family: Arial; font-size: = 12pt; "><div> </div><div>One other thought, I have heard both sides = of this argument before as well. I also heard it is nearly impossible to = weld / repair pipes with this coating. I found a solution that solved = the problem cheaply without making the pipes more difficult to weld. I = wrapped my entire exhaust system with hot rod exhaust wrap. I bought it = at the local auto parts store in the 1" width. Spruce sells it as well. = I tested the stuff with a torch in the hangar on my hand and was amazed = how well it insulates. I have 2 layers in some very hot places on the = pipes. In addition to reducing the inner cowl temps, It also tames the = vibration of the pipes and reduces noise. </div><div>Cheap, = relatively light and = effective...</div><div>Fwiw.</div><div><br></div></div></div></td></tr><tr= ><td id=3D"INCREDIFOOTER" width=3D"100%"><table cellspacing=3D"0" = cellpadding=3D"0" width=3D"100%"><tbody><tr><td width=3D"100%"></td><td = id=3D"INCREDISOUND" valign=3D"bottom" = align=3D"middle"></td></tr></tbody></table></td></tr></tbody></table><span= ><321 SST strength vs temp.xlsx></span>--<br>For archives and = unsub<span class=3D"Apple-converted-space"> </span><a = href=3D"http://mail.lancaironline.net:81/lists/lml/List.html">http://mail.= lancaironline.net:81/lists/lml/List.html</a><br></div></span></div><br></d= iv></body></html>= --Apple-Mail-100-521895195--