Mello

Today I took out my battery to address the issue of a leak in the passenger footwell. Actually water hits the carpet in two spots. Anyway, I took out the battery. The battery is a 3 year old die-hard, and looks fine. Under the battery tray was a battery mat. Under the mat was a sheet of clear plastic, a little thicker than a garbage bag. Under that is a mess!

At the back edge of the tray is a hole a little smaller than a dime, unsucessfully sealed by the PO with silicone sealant. When I look in it, I can see the passenger floor mat.

At the front edge the tray is a long crack, about 5 inches long. The crack is bad enough where I can make it worse by pushing with one finger. If I shine a flashlight into it, I can see the light when I stick my head in the footwell.

Luckily, my computer hasnt been affected yet. The rear hole drips onto the carpet, I guess the front crack drips behind the computer if anything. Also, my The middle of the tray looks fine. At least the drain was clear, so too much water doesnt build up in the battery tray.

Now how do I fix this? I've read in the archives that you can't really weld in that area. Is fiberglass sturdy enough? Any recommended people for this job in the nyc/LI area? Thanks in advance! P.S. I'll post a picture when I get batteries for my camera.

J Berk

If you search, I believe you'll find a few people who've repaired this area with resin and mat-fiberglass....strip down to bare metal and proceed.

500

Clark's Garage also has a write up.

sayporsha

I repaired mine with sheetmetal patches stuck on with urethane windshield adhesive, coated with autobody seam sealer, then painted to match. Of couse, I cleaned the **** out of it before laying it all down. I also swore to never put another lead acid battery in there again - went with the Optima red-top.

Mello

Sayporsha, how bad were the holes/cracks in your tray?

sayporsha

Mine was about as bad as you describe yours, although I didn't have a hole at the rear yet. I attached a picture of the "before". You really have to clean your tray all up to see the extent of the damage.

You have to fabricate the front patch so it angles against the firewall & wheel well to help support the weight of the battery & prevent flexing of the tray. If you can rivet or screw it to the firewall it will be stronger. I imagine the other hole you have is on one of those stamped risers at the back of the tray. If it's not too bad, you can cut sheet metal patches to cap off each of the risers. You need to do all of them to make them all the same height.

After cleaning everything I used Permatex rust converter to stop the rust. Then I primed everything before putting it together. I used urethane windshield adhesive to apply the patch because it sticks well, seals everything and remains flexible. I used autobody seam sealer to finish sealing it and give it a factory look. I primed it again, then painted to match.

I lined the bottom of the tray with a 3/16" sheet of ABS plastic to protect it and evenly distribute the weight of the Optima battery. I didn't take pictures of the process, but I'll post some "after" pics - hopefully you can tell what I did.

Mello

Yea, my crack goes along the front edge too. And yea, the hole is on one of those raised things on the back. Just like yours.

sayporsha

The repair:

Mello

Thanks alot for those pics! Very helpful. One more question. Can you tell me about the type/thickness of sheetmetal you used, and where you got it? Mike

mrwolfe

Mello-

Man am I going to save you a metric a$$-ton of work and money on this one... All you need is the super starter sample kit of POR15 and the Powermesh Reinforcing Fabric from por15.com (~$15 and ~$7). Your baby will only be off the road no more than a weekend.

The Problem:
I too had the dreaded battery compartment rust/holes/leaks/etc. To the point that even the slightest rain / car wash created a small lake in the rear passenger floorboard. I spent months trying to track this puppy down: Climbing under the car to spray water in all the joints (small seam separations found), pulling the interior to check the sunroof drains, etc. Finally three weeks ago, I removed the battery… What a mess!!!

The Solution:
Based on the recommendation I found from a few other members on Rennlist, I decided to give Por15 a try. I used my dremel to clean-up and cut out the rusted holes as much as possible; pulled out the PO's botched patch job attempts (he was not even close to fixing the problem); wire brushed off all the surface rust will a high speed drill; and then taped off the entire battery compartment side-walls with painters tape. I cut a few small patches of the powerMesh fabric and did a dry fit (there were several holes in the corner that I needed to work up on to the side-walls); prepared the surface as per the instructions and materials supplied in the kit; applied a preliminary cover coat of Por15; set the powerMesh into the desired places; coated them religiously and then waited a day for everything to dry (I stored the remaining Por15 it in the fridge to prevent it from setting – I put a layer of wrap between the can and lid). The next day I repeated the whole process.

I started on Friday evening and by Sunday afternoon (4 hours of labor time invested total) I was pouring 2 gallon pitchers of water into the battery compartment. The passenger firewall was bone dry and every drop of water was exiting via the drain hole as intended. In the near future, I plan on coating the battery compartment with that rubberized bed-liner paint used in trucks (although I do not really think it is necessary). The battery compartment is completely rock solid.

A couple of recommendations... Read and then re-read the por15 and powerMesh directions. Make sure you have everything laid out as needed before you start (sounds obvious I know, but once you start you do not want to stop). And most importantly, be sure to use the supplied rubber gloves and mask off EVERYTHING you do not want to get Por15 on. This stuff is like mustard. And no matter how careful you are once it is on, it is on for life.

Best of luck

MrWolfe

Mello

I'm definitely going to look into that one too. Thank you MrWolfe!

sayporsha

I used 16 gauge galvanized sheet steel. I got a small sheet of it from Home Depot. It's much cheaper from a steel supply place, though.

BTW, this car is now totaled so I decided to pry the patch off to see how well it stuck. It was very difficult to remove, and it COMPLETELY took the primer off the treated rust. That said, if I had to do it over I would skip priming the treated rust and apply the adhesive/patch/sealer directly to the treated rust, then primer & paint to match. The treatment converts rust to a paintable primer - apparently one that sticks better than a sprayed on one.

ibkevin

The hole in mine is so bad I had to install dipsticks in the DME and KLR

Yep, this has BoneheadPO written all over it. To top it off, the battery had an 1/8" hole drilled in the top so decent cornering sloshed acid into the tray

Thanks MrWolf, this will go on my winter list.

Mello

Did your car still run with the computer looking like that? I hope mine doesnt look like that. Maybe I'll do a combination of the two methods mentioned above.

ibkevin

Believe it or not, yep. Judging by the amount of deposits on the boards they got wet frequently. It's a good thing Porsche put drain(?) holes in the corners of the covers.