Rust near battery - how bad is this?

[Thrasher]

While working on my charging system, I took out my battery for testing and got a good look at the corrosion in my trunk near the battery. Here are a few pix:







It's probably due to gassing/acid from battery because my car is rust-free otherwise.

It doesn't appear to be structural, but the metal is flaking apart in layers and is crumbly. But, it has not eaten completely thru.

Would a good coating of POR-15 be sufficient to prevent it from worsening? It's not pretty, but is concealed and if not a structural issue, I can live with it.

[Thrasher]

PS: that white powder you see is not cocaine I'm smuggling, but baking soda I spread after tilting the battery to remove it, spilling a few drops of acid.

[Fl Ted]

What does the metal under the battery look like ?

[pwd72s]

Another reason for installing a totally sealed battery...I'd suggest removing all the rust flakes you can, then try to neutralize any remaining acid before using the Por 15...

[Thrasher]

Everywhere else looks fine, has grey/tan rubberized coating intact.

The rust is from an old incident/battery. It was like that when I bought the car over a year ago.

Mine doesn't leak unless I'm tilting it to remove, but I'd likely replace it with a sealed unit.

Anyone know of a local source or dependable alternative for POR-15? I want to take care of this before Monday and a ground shipment from Pelican in CA to MO would take over a week.

[Glasgow 911SC]

I'll bet this isn't from battery acid. The bumber shock supports on a bracket on the outside of that skin. Its a great place for dirt and moisture to sit & rot the metal away.

Here's a pic borrowed from this thread.



I'll bet the corrosion looks worse from the other side indicating thats where it started from.

[Rot 911]

Originally posted by Thrasher
Anyone know of a local source or dependable alternative for POR-15? I want to take care of this before Monday and a ground shipment from Pelican in CA to MO would take over a week.

Craig you can probably justify a trip to my house now. I've got the alternator sitting on the work bench and I have 4-5 unopened 1/2 pint cans of POR-15 sitting on the shelf. Black and Silver.

[Thrasher]

Glasgow 911SC :
oh great, now I've got a sick feeling in my stomach. It really looks to me like the same pattern/placement, especially looking at those grommets and where the wires come thru the panel.

I suppose the only way to see the inside is to remove the front left fender? How hard is that to remove?

Kurt, I'm considering the trip up there now, but if it's coming from the outside-in, I don't think painting it on the inside is going to do much to address the problem long-term.

[Rot 911]

Craig I would almost bet money that the rust is from battery acid just from the position and the way it looks. The picture from Glasgow is from a '76 911 that has lived its life in Denmark and has seen 3 decades of salt.

[Thrasher]

I hope you're right, but it sure looks like the positioning is the same. Plus, my 84 is definitely galvanized, so any spread would be slower than a non-galvanized older car.

I'd like to do the POR-15 now from the inside and plan on pulling the fender over the winter to see if there's cancer in there.

Could you possibly ship the POR-15? The only way I'd be able to swing the drive to JC tomorrow would be to leave at about 5:30 AM in my slow jeep and do a fast pickup and turnaround.

It'd get here the same time as the alternator and I could at least get the old one out and do the paint prep in the trunk.

Thanks

Craig

[Rot 911]

Originally posted by Thrasher
Could you possibly ship the POR-15?Craig

Done

[Thrasher]

Noah and Kurt - Thanks.

My bill is getting larger from Kurt's Used Parts, Inc. :-)

I just was in there two weeks ago (had the front valence off the car ) and didn't see anything suspicious, but could really only see the bottom of the bumper shock, etc.

I'll consult Bentley tonight and search the archives, but any tips on removing that huge washer bottle?

[Glasgow 911SC]

What is the other (non-battery) side like? Give it a shove with a screwdriver incase paint is holding it together.

[Thrasher]

Unfortunately, Glasgow 911SC was correct. I got in there and poked around with a screwdriver on Saturday. Here are the results:







This is the pile of gravel/sand material that ended up in my battery box. There was a bit more that came out the back side. The cup is a 32 oz size. It was about 1/2 full before I dumped it. Probably weighed 2-3 lbs and was more like a cement/aggregate mix in there before I dug it all out.



Here are a couple of views thru my foglight opening of what is going on in there.



The good news is that the passenger side is solid. I haven't gotten in behind the oil cooler and horns to see if the junk is in there, but I'll have to do that soon.

The bad news for the rest of you is that this is a direct result of a bad design, meaning there are probably thousands of cases like this waiting to happen.

It seems that my damage is pretty localized and non-structural. Just really some sheetmetal that keeps water out of the trunk and shouldn't be a big repair unless there's more damage than I can locate at this time. It'll be a good Wintertime project.

[Ron.G]

I just went through this same thing on my 80. I bought a section of a front tub and cut out the bumper shock support on the tub to install on my car.

If you have rust there you might also have rust under the windshield washer hose. It goes from the bottle to the fill in the gas flap. The problem is that it is clamped to the shock tower area in the fender well and traps crap between the hose and body.

I had to cut this area out also.

[Thrasher]

I guess I'll find out when I open it up this winter.

[Gunter]

The left fender has the water canister blocking any access to the area.
For any SC, or Carrera, I recommend either removing the canister for a thorough clean-up or getting in there with a high pressure hose.
You need to reach the area above the lamp buckets on both fenders.
Of course, in this case, some metal body work is needed. (Or POR-15)
It's disappointing.

[Thrasher]

Given the extent of this corrosion, I don't think I'll be fully satisfied now unless I actually pull the left fender and remove the damage I find in there.

From what I'm seeing/feeling (I can get my hand in there pretty easily), the damage is (hopefully) limited to that sheet metal getting eaten thru.

My short-term solution will be POR-15 thru the hole and whatever I can reach by removing the wheel and windshield washer reservoir and coming in from the outside.

I suppose I should also block the hole itself to prevent any water from entering the trunk, should I get caught in some rain. I normally only drive the car when no rain is in the forecast, though.

I'm also going to give the suspicious areas that Glasgow911SC mentions in the linked thread. I bought my car a little over a year ago and had actually just recently gone over the wheel wells and pulled out similar amounts of debris, but I attributed that to my PO's tendency to leave the roadway after cocktails.

[Ron.G]

If you want, I can post some pictures of what needs to be done. Might be help full anyway.

[Thrasher]

Yes, please do.