RE: (ET) Pop-rivets, body rot

["Pieter Litchfield" <plitch attglobal net>]

My e15 suffered the same problems, and I used some of the solutions
described below -

Mine had a heavy poly bag surrounding the batteries front and back - it was
a flat sheet that had been folded envelope fashion to make a square box 
(top
open) and had a fiberboard liner in the bottom, 1 drain hole dead center
bottom.  I believe it was original equipment.  Due to a tear or two,
however, the trak got acid "rot" along the back edge of the box and one 
rear
corner.  Since I know a lillte about "farmer welding" I bent, cut and
sectioned in some new sheet metal.  It still looks like a repair after
painting, but has mechanically held up well for 10 years.  All I use for a
liner is a good paint job, and so far there's no problem (I do check it
annually).


-----Original Message-----
From: owner-elec-trak cosmos5 phy tufts edu
[mailto:owner-elec-trak cosmos5 phy tufts edu]On Behalf Of David
Tiefenbrunn
Sent: Monday, April 10, 2000 09:34 PM
To: elec-trak cosmos5 phy tufts edu
Subject: Re: (ET) Pop-rivets, body rot


At 03:37 PM 4/10/00 -0400, Allan wrote:

>The lower part of the battery compartment is rusted right through
   [snip]
>The frame looks fine, but the battery box is in trouble.

>Any advice / comments on how to repair this?

The first thought that comes to mind is to find a small metal fabrication
shop.
Or you could make your own.  I would probably make it from 4 pieces rather
than the original 2,  unless you have a brake that is capable of doing the
job.  I have bent sheet metal using a pair of heavy angle irons or bar
stock with big "c" clamps to hold the sheet where the bend will be.  Then
use a block of 2x4 and a 2 Lb hammer to gradually form the bend.  You need
a vise or something to hold the clamped assembly stationary while
hammering.  I would copy the bends on the original metal,  and where the
back is,  make another 3/4" L.  Then use a flat sheet for the back,  using
screws to hold everything together.

> Also, it looks like the
>box is rusting out from the inside, probably due to battery acid,
>despite the plastic tray.

One of the trak's I have known came with a polyethylene liner in addition
to the tray.  The tray will only help protect the bottom (frame).

>  Any suggestions on how to prevent this
>problem in the first place?

I am considering a few:

Waxoyl the inside of the box.  Waxoyl is an automotive undercoat / rust
preventative coating that does not get hard and crack.  I have had good
luck with it on my cars.  Even on bare metal.

Cheaper and messier would be "painting" the inside with heavy grease.  I
don't really like this one for the fire hazard aspect.  I do have grease on
the battery terminals,  and *no* corrosion there.

Another possibility is to make a liner out of the PVC shower floor liner
that I found at Home Depot.  It is about 1/16" thick,  flexible and tough
enough to survive the batteries banging into it.  The corners would have to
be carefully solvent welded.  Or it might work to wrap it around the
batteries,  letting the plastic tray catch the bottom edge.  Use a generous
overlap,  and be sure the lower edge laps inside the tray.

>I'm considering lining the box on the inside with fiberglass.

Check to be sure that the fibre glass is rated to withstand strong acid,
or it will not help,  and could even make things worse.

When the tractor is being recharged,  keep the covers open to minimize the
concentration of acid mist.  Don't keep using old 1/2 dead batteries that
vent more than new ones.

A set of Hydro caps would be a great solution,  but I fear they are too
tall. :(
They are not cheap,  either.


Dave

Dave  Tief.  N1WWY
Addie Tief.  N1XQP
Tribble,  Noodles,  Cecil,  Bandit,  Scooter and Magic.
Visit our web page at http://pages.cthome.net/dandahp