Nolan,
Good points
----------
> From: Nolan Penney <npenney@erols.com>
> To: Glenn Stauffer <stauffer@voicenet.com>
> Cc: mgs@autox.team.net
> Subject: Re: Fuel Tanks
> Date: Wednesday, April 09, 1997 6:18 PM
>
> Couple of comments about your FAQ or whatever from a motorcycle list
about handling rusty
> fuel tanks.
>
> While chemicals such as muric acid or vineger (my favorite) are very good
at disolving rust,
> they cannot handle stuck chunks. The rocks the author eschewed are quite
usefull for
> knocking stuck chunks of things lose so the chemicals can do their work.
A suggestion I saw
> once (and have never used since I learned of it after doing the last
tank) is to use
> aquarium gravel. Small, lots of sharp edges, should scrape things very
well and very
> quickly. Especially compared to the rounded gravel pieces laying in the
driveway.
>
One thing I didn't like about this FAQ (sic) was the suggestion to use
Muriatic acid. This is pretty strong stuff - even the fumes will rust
nearby unprotected metal - had this problem when I was using an open vat of
this acid to de-rust steel parts. I buy phosphoric acid in solution sold
as milkstone remover at the farm supply store. It works very well, and, I
might be wrong, but I've always been told that phosphoric acid leaves a
coating on the metal that helps resist further rusting. One fellow once
suggested (on this list, I believe) that I use phosphoric acid diluted with
water as a panel prep. Wipe the panels with an acid-soaked cloth and then
dry them well with a towel and compressed air. No rinse. It seemed to
work, but I did this where I wasn't spending a big chunk of change on the
top-coat paints.
Fish tank gravel doesn't sound like a bad idea. Most of the gravel at my
disposal is limestone which doesn't like acid, so I've used a handful of
cheap nuts (the metal kind) to break up the large deposits. Though
muriatic acid might take them off without the abrasive action.
> I would also strongly advise against using a tank coating chemical. The
manufacturers, even
> the one who makes the best, Krem, will admit under some pressuring that
it will fail within
> a few years at best. Giving people like me more money as you pay me for
taking out of the
> tank what you just payed me to put in the tank. People really have done
both when I was a
> motorcycle mechanic. A car fuel tank may hold up better with this then a
motorcycle beause
> of the lower vibration and beating a car tank would get. But I still
wouldn't do it for
> love nor money.
>
So why does everyone recommend using the tank coats? I'll try one of my
bike tanks without it and see whether that works.
The Buick club magazine had a write-up on tank restoration. Their
suggestion for car tanks was to cut holes in the top of the tank and use a
combination of acid and grinding wheels to remove all traces of rust. Then
weld metal back in to cover the holes. Not a bad idea for irreplaceable
tanks. I've thought of doing this on a bike tank, even - especially to
gain access for removing dents. Of course, you need to remove all traces
of gas and fumes from the tank before cutting and welding.
Glenn
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