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. =
&nbsp; His comment on the equipment was "Airplanes barely work. =
&nbsp;Helicopters don't work" &nbsp; I think this exhaust situation is =
an example of "barely work". &nbsp; 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&nbsp;reduce the surface thermal emissivity both raise exhaust pipe =
temperature.&nbsp;</div><div>&nbsp;</div><div>So =
what?&nbsp;</div><div>&nbsp;</div><div>At these temperatures, the =
strength of the&nbsp; 321 stainless steel generally used in&nbsp;exhaust =
pipes&nbsp;is dropping like a rock - small temperature increases result =
in big strength decreases - and creep resistance drops even =
faster.</div><div>&nbsp;</div><div>Oxidation is also increasing =
dramatically with temperature.&nbsp;</div><div>&nbsp;</div><div>In =
short, the&nbsp;exhaust pipes will fail much,&nbsp; much sooner due to =
cracking or wall thinning.&nbsp; 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.&nbsp;</div><div>&nbsp;</div><div>In =
short,<span class=3D"Apple-converted-space">&nbsp;</span><strong><em>don't=
 do it</em></strong>&nbsp;unless you pledge to inspect the pipes more =
often, like every time the cowl is off, and&nbsp;unwrap the =
pipes&nbsp;for a very careful inspection at EVERY =
annual.&nbsp;</div><div>&nbsp;</div><div>Data below.&nbsp; Out of =
curiosity I made an&nbsp;Excel plot, attached.&nbsp; It makes =
the&nbsp;point even better than the&nbsp;table below.&nbsp; &nbsp;Creep =
strength<span =
class=3D"Apple-converted-space">&nbsp;</span><em><strong>virtually =
zero</strong></em><span class=3D"Apple-converted-space">&nbsp;</span>at =
800C =3D 1432F</div><div><div>&nbsp;</div><div>Sorry 'bout =
that.</div><div>&nbsp;</div><div>Fred =
Moreno</div></div><div>&nbsp;</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">&nbsp;</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">&nbsp;</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">&nbsp;</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">&nbsp;</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">&nbsp;</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>&nbsp;</div><div>&nbsp;</div><div><i><b>Subject:</b></i><span =
class=3D"Apple-converted-space">&nbsp;</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>&nbsp;</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.&nbsp;</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=
>&lt;321 SST strength vs temp.xlsx&gt;</span>--<br>For archives and =
unsub<span class=3D"Apple-converted-space">&nbsp;</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--