Shows you what whacks the swedes are--as if it really could be determined
what the most benign substance was. When your A arm falls off because
someone used a split lock instead of locktite and proper torque the
equation might shift a bit. Then there's the cadmium on the the lockwasher
poisoning some guy working in a plating plant. No one really knows how to
add up those costs. Is it better to keep your '57 chevy or to buy a new
car with better pollution controls? Big calculation with a lot of
variables, and no one really does them. Full circle to the Hydrogen
powered car.
My big worry about split locks, even good ones, is that to work, one end
has to dig into the flat and one end into the bolt head. Then you keep
torquing which tries to pull the washer apart. If you bring the bolt to
anywhere near it's torque limit the washer gets deformed. the only place
they really seem to make sense is when the part can't handle full torque.
In other words, when you are not using the bolt the way it should be used,
then they work.
-----Original Message-----
From: Michael D. Porter
To: Susan and Jack Brooks
Cc: FOT@autox.team.net
Sent: 2/13/2003 12:31 AM
Subject: Re: Retorquing head gaskets
Susan and Jack Brooks wrote:
>
> FOT,
>
> As with Michael, I found that time alone allowed for additional
torquing with
> composite gaskets. I first discovered this with my Norton motorcycle.
The
> "flame ring" gasket at the bottom of the jugs (cylinders) compressed
overnight.
> If you didn't wait, and installed the head, there was no going back to
retighten
> it. The next day, significant retightening was required. Waiting one
more day
> provided little or no further tightening.
>
> When I installed composite gaskets in my TR3, I retightened the next
day,
> without needing to loosen first. I also retorque hot immediately and
retorque
> cold 500 miles later.
On the still similar subject, Bill Babcock related a funny story about
vibration and an old BSA he had, and it reminded me that up until the
time bus production ceased here, we were still using lockwashers
everywhere. Occasional Loctite use for some specialized fitting, but
still lockwashers.
At one point, we were having a rash of fan adapter failures and I
discovered that the assemblers weren't using Loctite 242 as they had in
the past. Bolts were loosening up (if you think vibration is bad with a
wet-sleeve engine, try a 10 liter 4-cylinder 4-stroke diesel), and I was
absolutely confounded--went down to talk to them, asked why they
weren't. "We're not supposed to--QA told us not to." Called QA, and was
told that we had a memo from Volvo saying that Loctite was not to be
used in any of their plants, since it was a cancer-causing agent.
Huh? So, I pulled up the MSDS from the Loctite web site, and sure
enough, it was listed as carcinogenic. Because of the very old, and
still suspect, study showing that saccharine was carcinogenic in mice
studies, Loctite was carcinogenic--it's about 6% saccharine.... (And,
yes, it occurred to me that it wasn't carcinogenic in application, and I
really don't think it's tasty enough to make a meal of, either.) Later,
in emailing someone from Sweden, I asked about this, and was told that,
in Sweden, there's a law about using the most benign substitute
available. Oh, there's a substitute for Loctite that's not
carcinogenic?, I asked. Yes, said he... lockwashers. <smile>
Cheers.
--
Michael D. Porter
Roswell, NM (yes, _that_ Roswell)
[mailto:mporter@zianet.com]
Don't let people drive you crazy when you know it's within walking
distance.
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