Date: Fri, 27 Jan 2012 21:26:46 -0600
Reply-To: Tom Hargrave <thargrav@HIWAAY.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Hargrave <thargrav@HIWAAY.NET>
Subject: Re: Aluminum to brass thread galling
In-Reply-To: <CAH+nQ0HvsHDLPq1YfMQGOZhxV-GeXJeouPuxhtVTAM+7gVoQbQ@mail.gmail.com>
Content-Type: text/plain; charset="us-ascii"
Loctite is a great product. It provides lubrication during assembly then
sets up hard.
Thanks, Tom Hargrave
www.stir-plate.com
www.towercooler.com
www.kegkits.com
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
John Bange
Sent: Friday, January 27, 2012 8:59 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Aluminum to brass thread galling
Last week I finally finished getting my '90 automatic non-GL work van back
on the road. One of the things I added was a SmallCar transmission cooler.
The kit uses NPT taper threaded to barbed fittings to attach the hoses to
the Mesa-type cooler. Lacking any particular instructions, I opted to use
teflon tape to seal them. The first one threaded in easily. The second one,
not so good. About two turns into it, the torque required to turn it went
WAY up. Attempts to reverse and get it out only jammed it up tighter.
Eventually, a big pipe wrench an d a bench vise separated the two.
Apparently the threading of one or the other was not wholly kosher and the
teflon tape was not very helpful lubricant and the aluminum of the Mesa
cooler meeting the brass from the barbed fitting combined for some pretty
good galling.
My solution was to use copper-based anti-seize compund, and it worked pretty
well. I removed the other fitting and discarded its shredded teflon tape
with copper anti-seize as well. In the end, it worked out just OK. The
ungalled side is sealed just fine, but I suspect there's an out of spec
threading issue on the other and it oozes ATF just enough to make a slight
mess, though not enough to leave so much as a drop on the driveway (an
improvement over the old leaky VW heat exchanger at least).
So now that I've wasted everyone's time and you're all looking at your
watches saying "cool story, bro", I come to my question: What's the best
thread sealant to use in a situation like this? Anyone have a suggestion for
something I might use to seal up the threads on the galled, buggered, leaky
side?
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1382 / Virus Database: 2109/4771 - Release Date: 01/27/12
|