Fixing rust around battery tray

There was rust around the battery tray of my recently purchased 1988 Carrera coupe. I removed as much as I could get to, including a small hole in the pan just to the left (when facing the front of the car), where the previous owners had deftly caulked and painted. I then treated the rusted areas with rust neutralizer, and put a galvanized plate over the small hole. I have 2 questions:
1. There is undoubtedly more rust under the battery tray, but I cannot get to it. Can I just forget the problem for now, or am I risking having the cancer spread until it affects the structural integrity of some panel?
2. The affected parts (gas tank support with battery tray, and the floor pan just in front of the gas tank support, are relatively inexpensive (a few $100s). But how are they attached to the car? Are they bolted, welded, or bonded in some other way? Is this something an amateur can do? The most compliucated thing I have done on a car is changing a rear spring on a Ford Escort, so I dont want to attempt something like this and make a mess of it.


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John

You should be able to see your battery boxes from inside the fender wells. To properly insure you stop the rust in the boxes you need to get down to bare metal. Once you have done that I would recommend you get the kit from POR-15 (www.por15.com) to make the repairs. As for the front suspension pan. It is held in by spot welds. There is much discussion on the topic of replacment of the suspension pan and tank support. In fact I am almost done with this very project. Go to the archives and do a search under "front suspension pan" to get the info. For what it cost to get someone else to weld the pan I was able to purchase a very nice MIG welder and do it myself.

Kurt V
72 911E

John,

If you treated the area with a generous amount of the type rust neutralizer that leaves a 'conversion coating' of phosphate, then I wouldn't worry about it too much, assuming your electrical system is operating in the normal range of 13.2-14.5 Volts. It probably wouldn't hurt to pour a good bit of primer/sealer in the crevices for future protection.

The only reason there is rust in the area is that the Voltage regulator died in the past, and started cooking the acid out of the battery! I recommend a permanent Voltmeter be installed, such as in a panel mounted in the console, as there really isn't much room for more gauges in the dash. You shouldn't have to wait until you smell Sulphurous fumes to find out the Voltage regulator has failed! High system Voltage is hazardous the lamps in your car, too, especially the quartz-iodide bulbs!

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Warren Hall
1973 911S Targa

Dear John
I had exactly the same problem with my 86 Carrera- seems more common than one might expect!.
Get underneath the car and have a good prod around with a screwdriver!.
If all seems firm then you may be alright with Warrens suggestions with rust converter etc.
If in doubt you may want to get someone to give some quotes as Mine was rotten and I had a large area cut out and replaced.Be sure as the front suspension is v. cose to this area!.
It involved removing Gas tank etc.
total job cost $1056 (26 Hrs labor) including paintwork etc.(N.Y. -Hamptons,Long Island Prices!!!)
I have since replaced alternator, battery Distributer, ignition cables, plugs......
and the list goes on!
but a voltage gauge as warren suggests seems a great idea.
hope this is of some help!

Along these same lines...what does everyone think about the battery pads. I got one for my 88 just for insurance but is it snake oil. If so I guess it won't hurt anything...right?
Buck
88 coupe