X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 21 Jul 2014 07:25:46 -0400 Message-ID: X-Original-Return-Path: Received: from omr-m07.mx.aol.com ([64.12.143.81] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6990499 for lml@lancaironline.net; Sun, 20 Jul 2014 20:48:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.143.81; envelope-from=vtailjeff@aol.com Received: from mtaout-mbb02.mx.aol.com (mtaout-mbb02.mx.aol.com [172.26.254.110]) by omr-m07.mx.aol.com (Outbound Mail Relay) with ESMTP id 863607000008E for ; Sun, 20 Jul 2014 20:48:20 -0400 (EDT) Received: from [10.51.40.35] (mobile-166-147-096-146.mycingular.net [166.147.96.146]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mtaout-mbb02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id 7BA73380000A9 for ; Sun, 20 Jul 2014 20:48:19 -0400 (EDT) From: Jeff Edwards Content-Type: multipart/alternative; boundary=Apple-Mail-E7C0D9EA-7E98-43F7-A1C1-34F0686B0176 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) Subject: Re: [LML] Nicopress oval sleeves - copper, tin plated, or zinc plated? X-Original-Message-Id: <5D474868-9AAA-4F7D-B42B-835E0254FA21@aol.com> X-Original-Date: Sun, 20 Jul 2014 19:48:14 -0500 References: In-Reply-To: X-Original-To: Lancair Mailing List X-Mailer: iPad Mail (11D257) x-aol-global-disposition: G x-aol-sid: 3039ac1afe6e53cc635365af X-AOL-IP: 166.147.96.146 --Apple-Mail-E7C0D9EA-7E98-43F7-A1C1-34F0686B0176 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable John, Galvanic corrosion occurs when two dissimilar metals on the anode cathode sc= ale are put together. So yes it is a concern if you have the wrong sleeve. Jeff Sent from my iPad > On Jul 20, 2014, at 7:26 AM, John Cooper wrote: >=20 > Since one of my Nicopress sleeves failed, I've learned more than I want to= know about these things. Nicopress recommends using the 428 series tin-plat= ed sleeves on stainless steel cable, but Lancair sells the 18 series plain c= opper sleeves. Aircraft Spruce doesn't sell the tin-plated sleeves in Americ= a (they do in Europe), but instead they sell the 28 series zinc-plated and t= he 18 series plain copper sleeves. The only company in America that I can fi= nd who sells the Nicopress tin-plated sleeves is VER, and they have a $50 mi= nimum order so I would have to buy 200 sleeves. Grainger sells some off bran= d tin-plated sleeves made in China. Do I really want to use those? I don't t= hink so. The copper alloy is crucial to the longevity of the crimp, I think,= and who knows what I would be getting. McMaster-Carr sells some "TIN-Plated= Copper Oval Compression Sleeve for 3/32" Rope Diameter, 3/8" Sleeve Length"= . No Country of origin listed, but they do say "All sleeves meet MIL-STD 518= 44". Unfortunately, the length before crimping is listed at 3/8" rather than= the 7/16" that MS51844 Rev. E calls for. So I'm flummoxed. >=20 > Does anyone know of a source for the authentic, Mil spec. Nicopress 428-3-= VG tin plated oval crimp sleeves for 3/32" stainless steel cable? >=20 > OTOH, does the plating really matter? Is galvanic corrosion really a conce= rn in the foot-well? I noted that my failed copper crimp sleeve had blue cop= per corrosion all over it. Sure, I used the wrong tool originally, but could= corrosion have been a factor in the failure? Possibly, according to this Ki= tplane article The Big Squeeze. It's a great article from 2013 answers a lot= of my questions, including: >=20 >> Why three types? The idea is to match sleeve and cable finish for the lea= st damaging galvanic potential between components. While any copper sleeve c= hoice will initially withstand the rated load when installed on either galva= nized or stainless cable, corrosion will weaken the mechanical joint given t= ime, the wrong environment, and the wrong combination of materials. The spec= ifications are quite specific. Bare copper or zinc-plated sleeves are used o= n galvanized carbon steel cable. Tin-plated sleeves (or as noted previously,= stainless steel sleeves) are used on stainless cable. There are no exceptio= ns. >=20 > and... >> Zinc-plated sleeves on stainless cable has been an obsolete recommendatio= n for more than 40 years. >=20 --Apple-Mail-E7C0D9EA-7E98-43F7-A1C1-34F0686B0176 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit
John,

Galvanic corrosion occurs when two dissimilar metals on the anode cathode scale are put together. So yes it is a concern if you have the wrong sleeve.

Jeff

Sent from my iPad

On Jul 20, 2014, at 7:26 AM, John Cooper <snopercod@comporium.net> wrote:

Since one of my Nicopress sleeves failed, I've learned more than I want to know about these things. Nicopress recommends using the 428 series tin-plated sleeves on stainless steel cable, but Lancair sells the 18 series plain copper sleeves. Aircraft Spruce doesn't sell the tin-plated sleeves in America (they do in Europe), but instead they sell the 28 series zinc-plated and the 18 series plain copper sleeves. The only company in America that I can find who sells the Nicopress tin-plated sleeves is VER, and they have a $50 minimum order so I would have to buy 200 sleeves. Grainger sells some off brand tin-plated sleeves made in China. Do I really want to use those? I don't think so. The copper alloy is crucial to the longevity of the crimp, I think, and who knows what I would be getting. McMaster-Carr sells some "TIN-Plated Copper Oval Compression Sleeve for 3/32" Rope Diameter, 3/8" Sleeve Length". No Country of origin listed, but they do say "All sleeves meet MIL-STD 51844". Unfortunately, the length before crimping is listed at 3/8" rather than the 7/16" that MS51844 Rev. E calls for. So I'm flummoxed.

Does anyone know of a source for the authentic, Mil spec. Nicopress 428-3-VG tin plated oval crimp sleeves for 3/32" stainless steel cable?

OTOH, does the plating really matter? Is galvanic corrosion really a concern in the foot-well? I noted that my failed copper crimp sleeve had blue copper corrosion all over it. Sure, I used the wrong tool originally, but could corrosion have been a factor in the failure? Possibly, according to this Kitplane article The Big Squeeze. It's a great article from 2013 answers a lot of my questions, including:

Why three types? The idea is to match sleeve and cable finish for the least damaging galvanic potential between components. While any copper sleeve choice will initially withstand the rated load when installed on either galvanized or stainless cable, corrosion will weaken the mechanical joint given time, the wrong environment, and the wrong combination of materials. The specifications are quite specific. Bare copper or zinc-plated sleeves are used on galvanized carbon steel cable. Tin-plated sleeves (or as noted previously, stainless steel sleeves) are used on stainless cable. There are no exceptions.

and...
Zinc-plated sleeves on stainless cable has been an obsolete recommendation for more than 40 years.

--Apple-Mail-E7C0D9EA-7E98-43F7-A1C1-34F0686B0176--