X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 16 Aug 2005 12:57:41 -0400 Message-ID: X-Original-Return-Path: Received: from [137.118.16.124] (HELO relay0.av-mx.com) by logan.com (CommuniGate Pro SMTP 5.0c1) with ESMTP id 670762 for lml@lancaironline.net; Tue, 16 Aug 2005 11:35:22 -0400 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.124; envelope-from=pinetownd@volcano.net X-Virus-Scan-Time: 0 Received: from [137.118.16.62] (HELO mx1.av-mx.com) by relay0.av-mx.com (CommuniGate Pro SMTP 4.2.7) with SMTP id 256001675 for lml@lancaironline.net; Tue, 16 Aug 2005 11:34:34 -0400 Received: (qmail 9677 invoked from network); 16 Aug 2005 15:34:34 -0000 Received: from 65-165-167-203.du.volcano.net (HELO DennisDell) (pinetownd@volcano.net@65.165.167.203) by 0 with SMTP; 16 Aug 2005 15:34:34 -0000 X-CLIENT-IP: 65.165.167.203 X-CLIENT-HOST: 65-165-167-203.du.volcano.net X-Original-Message-ID: <004a01c5a277$ff40ec60$6601a8c0@DennisDell> From: "Dennis Johnson" X-Original-To: Subject: WLS Primer Shelf-Life X-Original-Date: Tue, 16 Aug 2005 08:34:21 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0047_01C5A23D.4CC87EC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0047_01C5A23D.4CC87EC0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable The data sheet that came with my WLS primer says it has a shelf life of = 12 months minimum at 70=B0 F. There is no maximum shelf life published. = If it is like other epoxies, I expect the shelf life is much longer = than 12 months, particularly if it's not exposed to extreme = temperatures. =20 You can always do a test sample. Mix up a small amount and apply it to = a scrap piece of composite that is prepped in your customary way. Give = it a week or so to fully cure and then try scratching and sanding it to = see if it acts the same as it did when fresh. =20 You can also do an adhesion test: cut an "X" on your cured sample, with = each leg of the "X" an inch long. The cuts should cut completely = through the cured primer finish. Cover the "X" with tape that's = aggressively sticky (Scotch tape works). Make sure the tape is stuck = as tight as it will stick and then peel the tape off. None (or very = little) of the primer should lift off with the tape. If it does come = off, it means that either the primer has gone bad or your customary prep = methods need to be improved. I've had a couple of good telephone conversations with WLS' paint = chemist, Victor. He's always called me back and seems to know just = about everything there is to know about aircraft paint. Maybe he was on = vacation when you called; I'd give him another call. =20 Best, Dennis Johnson Legacy #257 (in final WLS primer) ------=_NextPart_000_0047_01C5A23D.4CC87EC0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

The data sheet that came with my WLS primer says it has a shelf = life of 12=20 months minimum at 70=B0 F. There is no maximum shelf life = published. If it is like other epoxies, I expect the shelf life is = much=20 longer than 12 months, particularly if it's not exposed to extreme=20 temperatures.

You can always do a test sample. Mix up a small amount and = apply it=20 to a scrap piece of composite that is prepped in your customary = way. Give=20 it a week or so to fully cure and then try scratching and sanding it to = see if=20 it acts the same as it did when fresh.

You can also do an adhesion test: cut an "X" on your = cured=20 sample, with each leg of the "X" an inch long. The cuts should cut = completely through the cured primer finish. Cover the "X" with = tape=20 that's aggressively sticky (Scotch tape works). Make = sure the=20 tape is stuck as tight as it will stick and then peel the tape = off. None=20 (or very little) of the primer should lift off with the tape. If=20 it does come off, it means that either the primer has gone bad or = your=20 customary prep methods need to be improved.

I've had a couple of good telephone conversations with WLS' paint = chemist,=20 Victor. He's always called me back and seems to know just about = everything=20 there is to know about aircraft paint. Maybe he was on vacation = when you=20 called; I'd give him another call.

Best,

Dennis Johnson

Legacy #257 (in final WLS = primer) =20

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