Battery tray repair and questions

[amehl]

I started my battery tray repair this weekend. What a mess, but it's not as bad as I have seen.

The funny part is, this car has full service records so I know exactly which Porsche "specialists" are responsible for the work. It is a mess of silicon in there, and they even stuffed some steel wool to give the hole structure. Anyhoo vent over.

My plan is to clean it down to the metal, fiberglass it, and then paint/POR15 it as it seems to be the popular rout on this forum.

My question: Is the drain hole on the fire wall the only drain for the battery box? the outer corner is rusted, so I dont know if there was one there as well. Any suggestion to stop the pooling?

Before I started:


The hole stuffed with steel wool


The outside wall where it meets the firewall, was there a drain here?

[John_AZ]

The hole in the bottom picture is the "official" battery drain-passenger fender side.

With the amount of damage to the top, the fender drain hidden will be worse.

You might want to get a decent battery tray from a wreck or seller and have it welded in.
Then you can repair the damage underneath the tray.

GL
J_AZ

[amehl]

Originally Posted by John_AZ

The hole in the bottom picture is the "official" battery drain-passenger fender side.

With the amount of damage to the top, the fender drain hidden will be worse.

You might want to get a decent battery tray from a wreck or seller and have it welded in.
Then you can repair the damage underneath the tray.

I just don't know how realistic that is. Finding a clean battery tray in the north west is going to be a task, and I don't have the tools to do it myself. Is there a way to inspect the fender side drain without removing the fender and/or dashboard? I will take out the carpet and check out the areal under the tray. This is going to sounds blasphemous, but I am not worried about the aesthetics of this repair. I just need to to get it so no more rust will develop, and the area is clean and sealed. Living here is is impossible to avoid the rain.

[amehl]

Question about the lower, fender-side drain. Where does it drain to? does anyone have a diagram?

[mikepellegrini]

Best of my recollection, it dumps in at the top of the wheel well. I believe if you take off the fender liner you may be able to see it.

That's weird: I just looked and my 83 NA doesn't have a drain at the rear, but my 86 Turbo does. Perhaps the 83's was covered over at some point; I don't remember doing that.

Like John said, the absolute correct way to make a repair is to find a good tray and weld it in; or maybe have something fabricated.

But I've repaired several battery trays with fiberglass and it's seemed to work ok for me. Here's one:



That's my son's finger poking out from inside the car.

I got as much rust as I could off, then sprayed a lot of rust reformer - like POR15 - it stops rust and converts it into a paintable compound. Then I used fiberglass to re-do the bottom, and to make it water tight.

This particular job (my son's 84 NA), the holes ended up being a lot larger than in the first picture (we're talking fist-sized) , so I put a piece of sheet metal down before I started the fiberglass. A couple layers of cloth and lots and lots of resin. Then I painted it black.



The repairs seem to be holding up well. I haven't had any leaks yet.

[amehl]

That is super helpful. Thanks. I am likely going this rout too.

So no one has a diagram of the drain? I just want to see where it drains to, and how it gets into the passenger side.

[Bukowski]

Wondering if a rubber mat would be useful to cushion the metal from direct contact of the battery case - if that leads to the problems with this area - not the mats with chemicals to neutralize acid.

[amehl]

Thats a common addition to the repair from what ive seen. I plan on doing something. At least putting down thick rubberized tape or something.

[kdjones2000]

The only drain on my '87 924S is that one in the front, draining to the firewall.

My '88 late model has the side drain, which seems to work much better. I think it is an early vs. late model year thing.

[amehl]

Originally Posted by kdjones2000

The only drain on my '87 924S is that one in the front, draining to the firewall.

My '88 late model has the side drain, which seems to work much better. I think it is an early vs. late model year thing.

I dont suppose you could take a few pics?

[FLYGEEZER]

Clean it good and get a can of "flexseal" as seen on TV. That sheet really works good and it's fast & easy.

[amehl]

Ok this is what I'm talking about. I want to know where this drain goes, maybe i can partially rebuild what is gone.



does it just train into the fender?

[amehl]

Update:

Went the common rout: Sand, strip, POR15, fiberglass

It isnt pretty but its water tight!





Thanks for the tips!

[mikepellegrini]

Looks great. Congrats!

[curtisr]

The hole(s) in my battery box were beyond big and the source of what seemed like an eternally wet carpet.

After a bit of over-engineering: new metal, rubberized roof-repair tape and a layer of rocker panel coating over it all I was ready to laugh at the rain! But then I realized that the battery was now standing too high...@#$%! Anyways, I redid it and all was well. I did, however, have to drill a new exit for the water and fabricate a waste pipe (?) for it and a hold-down strap as well.

All you plumbers should recognize the source of my strap.

[amehl]

Originally Posted by mikepellegrini

Looks great. Congrats!

I respectfully disagree!

But Like I said. No water is EVER touching the tray again.

[mikepellegrini]

Function triumphs over form.