X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 10 Apr 2009 20:23:04 -0400 Message-ID: X-Original-Return-Path: Received: from nschwmtas02p.mx.bigpond.com ([61.9.189.140] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3576338 for lml@lancaironline.net; Fri, 10 Apr 2009 08:47:41 -0400 Received-SPF: pass receiver=logan.com; client-ip=61.9.189.140; envelope-from=frederickmoreno@bigpond.com Received: from nschwotgx01p.mx.bigpond.com ([58.170.150.244]) by nschwmtas02p.mx.bigpond.com with ESMTP id <20090410124657.KILA20136.nschwmtas02p.mx.bigpond.com@nschwotgx01p.mx.bigpond.com>; Fri, 10 Apr 2009 12:46:57 +0000 Received: from Razzle ([58.170.150.244]) by nschwotgx01p.mx.bigpond.com with ESMTP id <20090410124651.FDYY26071.nschwotgx01p.mx.bigpond.com@Razzle>; Fri, 10 Apr 2009 12:46:51 +0000 From: "Frederick Moreno" X-Original-To: "'Chuck Jensen'" X-Original-Cc: "Lancair Mail" Subject: RE: [LML] Jefco X-Original-Date: Fri, 10 Apr 2009 20:46:48 +0800 X-Original-Message-ID: <8C45DFF1A3FC4FC4A237BB5AFA83540B@Razzle> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_015D_01C9BA1D.7994E9B0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Thread-Index: Acm5xASQ8YWVuGAMTj6H2nTpUExzoQAFdfqQ Importance: Normal X-RPD-ScanID: Class unknown; VirusThreatLevel unknown, RefID str=0001.0A150202.49DF3FC1.002C,ss=1,fgs=0 X-SIH-MSG-ID: qB8yF9f6TFa2kTAvmTy2alorgFm6/gF5uMhSBI0wt0lHEVbGsd/fRMq9cqZB34zi0C46dEOVTyFic63kTY7TuN22K7lWSrLZ5/E2 This is a multi-part message in MIME format. ------=_NextPart_000_015D_01C9BA1D.7994E9B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Crystallizing of the old Shell Epon 862 followed the same pattern. It = would turn milky and a bit slushly if allowed to cool too far for too long. = Put it into a container and heat for a couple of hours (I think 140F was the magic number here as well) and it would come good and tests showed it to = be OK. However, if it crystallized in the Sticky Stuff Dispenser, the = presence of residual crystals in the pump would stimulate low temperature re-crystallization. So you need to heat the whole pump, or clean it thoroughly before returning the reclaimed resin to the pump.=20 =20 Resins are generally very stable and can be reclaimed. =20 Hardener systems are different. Many crystallize due to presence of = water vapour or carbon dioxide, and when they go, they are gone. Into the circular file, order more.=20 =20 Fred Moreno =20 -----Original Message----- From: Chuck Jensen [mailto:cjensen@dts9000.com]=20 Sent: Friday, 10 April 2009 1:01 AM To: lml@lancaironline.net Subject: RE: [LML] Jefco=20 =20 "The jefco resin in the 5 gallon drums if left on a concrete floor or steel floor the resin can pull the cold up into the container and ruin the resin. Make sure the resin is stored properly for long use." =20 Not to put too fine a point on it, but 'cold' does not exist. Cold is simply the absence of heat, so the heat in the Jefco may conduct down to = the cold floor, but such conduction is not a major factor in a media = freezing. The heat radiation and conduction to the surrounding air is a much = bigger loss. Some concrete slabs, in contact with the ground, may actually = stay warmer than the air and, ever so slightly, protect the Jefco from = freezing. =20 Next, it should not be assumed that, because the Jefco got cold and crystallized, that it is ruined. We use polymer by the ton, literally, = and if our polymer freezes and crystallizes, we must rewarm the polymer to = about 140F to dissolve the crystals. Thereafter, the efficacy of the polymer = is fully restored. =20 While this observation is pertinent to an epoxy and styrene system that = we use for a non-aviation purpose, it's important to understand that such experience is fact specific; in this case, product specific. I defer to = the manufacturer of Jefco as to what their recommendation is for their = products. Out of an abundance of caution, they may say not to use it for = structural components, but I doubt there is any problem with non-structural = components. =20 You can confirm the viability of the components if you do a PCP (process control program) bench sample to confirm that the components cure to a = rock hard product when applied to a test strip. Chuck Jensen=20 -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net]On Behalf Of marv@lancair.net Sent: Wednesday, April 08, 2009 8:06 PM To: lml@lancaironline.net Subject: [LML] Jefco=20 Posted for "Justin Hawkins" : All Lancair customers the build shop did a test on the Jefco resin, if it gets close to freezing even for only a matter of minutes the resin can crystallize and its properties ruined. So if that happens clean the pump replace the resin. =20 The jefco resin in the 5 gallon drums if left on a concrete floor or steel floor the resin can pull the cold up into the container and ruin the resin. Make sure the resin is stored properly for long use.=20 =20 =20 =20 Justin Hawkins =20 Lancair Airframe & Technical Support =20 Lancair Int. Inc. =20 250 SE Timber AVE =20 Redmond, OR 97756 =20 justinh@lancair.com =20 =20 541-923-2244 ext 121 =20 =20 =20 -- =20 For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_015D_01C9BA1D.7994E9B0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Crystallizing of the old Shell Epon 862 followed the = same pattern.  It would turn milky and a bit slushly if allowed to cool = too far for too long.  Put it into a container and heat for a couple of = hours (I think 140F was the magic number here as well) and it would come good and = tests showed it to be OK.  However, if it crystallized in the Sticky = Stuff Dispenser, the presence of residual crystals in the pump would stimulate = low temperature re-crystallization.  So you need to heat the whole = pump, or clean it thoroughly before returning the reclaimed resin to the pump. =

 

Resins are generally very stable and can be = reclaimed.

 

Hardener systems are different.  Many = crystallize due to presence of water vapour or carbon dioxide, and when they go, they = are gone.   Into the circular file, order more.

 

Fred Moreno

 

-----Original Message-----
From: Chuck Jensen [mailto:cjensen@dts9000.com]
Sent: Friday, 10 April 2009 1:01 AM
To: = lml@lancaironline.net
Subject: RE: [LML] Jefco =

 

"The jefco resin in = the 5 gallon drums if left on a concrete floor or
 steel floor the resin can pull the cold up into the container and = ruin
 the resin. Make sure the resin is stored properly for long = use."

 

Not to put too fine a point = on it, but 'cold' does not exist.  Cold is simply the absence of heat, so = the heat in the Jefco may conduct down to the cold floor, but such = conduction is not a major factor in a media freezing.  The heat radiation and = conduction to the surrounding air is a much bigger loss.  Some concrete slabs, = in contact with the ground, may actually stay warmer than the air and, ever = so slightly, protect the Jefco from freezing. 

 

Next, it should not be = assumed that, because the Jefco got cold and crystallized, that it is ruined.  We = use polymer by the ton, literally, and if our polymer freezes and = crystallizes, we must rewarm the polymer to about 140F to dissolve the crystals.  Thereafter, the efficacy of the polymer is fully = restored.

 

While this observation is = pertinent to an epoxy and styrene system that we use for a non-aviation purpose, = it's important to understand that such experience is fact specific; in this = case, product specific.  I defer to the manufacturer of Jefco as to what = their recommendation is for their products.  Out of an abundance of caution, they may say not to use it for structural components, but I = doubt there is any problem with non-structural = components.  

 

You can confirm the = viability of the components if you do a PCP (process control program) bench sample to = confirm that the components cure to a rock hard product when applied to a = test strip.


Chuck Jensen

-----Original Message-----
From: Lancair Mailing = List [mailto:lml@lancaironline.net]On = Behalf Of marv@lancair.net
Sent: Wednesday, April 08, 2009 8:06 = PM
To: = lml@lancaironline.net
Subject: [LML] Jefco =

Posted for "Justin Hawkins" <JustinH@lancair.com>:

 All Lancair customers the build shop did a test on the Jefco = resin, if
 it gets close to freezing even for only a matter of minutes the = resin
 can crystallize and its properties ruined. So if that happens = clean the
 pump replace the resin.
 
 The jefco resin in the 5 gallon drums if left on a concrete floor = or
 steel floor the resin can pull the cold up into the container and = ruin
 the resin. Make sure the resin is stored properly for long use. =
 
 
 
 Justin Hawkins
 
 Lancair Airframe & Technical Support
 
 Lancair Int. Inc.
 
 250 SE Timber AVE
 
 Redmond, OR 97756
 
 justinh@lancair.com <mailto:justinh@lancair.com>
 
 541-923-2244 ext 121
 
 
 

--
 
For archives and unsub =
http://mail.lancaironline.net:81/lists/lml/List.html
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