Rust in trunk, what do I do, what do I do?

dbfarr

Member
Sep 17, 2005
191
0
17
Boise ID
The deck lid seal seems to have failed me. I'll order one this weekend. Still, I pulled up the floor covering and found this:

right.webp


left.webp


Then i looked up and saw this:

decklid.webp


And a little closer:

decklidclose.webp


decklidclose2.webp


So I am thinking about doing this:

imageAFV.webp


I am not sure whether por 15 or eastwood rust converter is the way to go. I would like to know exactly how to strip the paint off this bugger. Peel away right, where do I get it, what type?

Looks like I'll have to pull the gas tank and treat it separately, I worry about it getting stuck to he car with Por 15!

The real problem is the deck lid. How do I get the frame off of it in order to treat the rust underneath? What do I attach it back on with?

Any suggestions or best plan of attack would be appreciated... Thanks.
 

Attachments

  • right.webp
    right.webp
    58.7 KB · Views: 989
  • left.webp
    left.webp
    54.9 KB · Views: 376
  • decklid.webp
    decklid.webp
    11.4 KB · Views: 327
  • decklidclose.webp
    decklidclose.webp
    20.2 KB · Views: 238
  • decklidclose2.webp
    decklidclose2.webp
    10.2 KB · Views: 243
  • imageAFV.webp
    imageAFV.webp
    54.8 KB · Views: 956
Welding a Gas Tank

I wouldn't be too anxious to weld a gas tank. The gas fumes get into the metal & even when empty & dry may still blow up. You are better off replacing it. If you insist on welding it like I did once, my father (a professional welder) had me fill the tank with water & keep the garden hose running into it while he was welding. But I still think it's a risk not worth taking. There are too many nice cruise nights still to come to take a chance on missing them.
 
You could have the deck lid chemically dipped to remove the rust inside. There are different opinions both pro and con about chemical dipping though. If you don't dip it though I would get all of the rust out that you can and then pour some POR 15 or some other rust stabilizer in it and move it around to get it in the outside edges where the two panels mate.
 
i wouldn't even go through the trouble of dipping or welding or any of that stuff....

just buy a new tank and bolt it down and POR15 over it all and be done with it....its probably cheaper that way anyways.
 
The tank isn't neccesarily bad. No holes, etc. Eventually, I imagine I'll put a 69 tank in for the extra capacity. However, this needs to be a relatively inexpensive project, I have other pressing needs. Right now, replacing the tank is not in the budget. I am just going to have to do the grunt work and pull the tank.

The tank does not need and will not get, any welding. I was more concerned about the por 15 permanently fixing the tank to the frame, since the site mentions that por 15 will permenantly fix the lid to the can if any is spilled on the lip. Furthermore, I am worried about rust on the mounting surface for the tank.

Any word on how to strip the paint and foam stuff? I've heard peel away, but I am not sure where to get it.
 
The mounting flange that the tank sits on is typically rusted. I'd recommend removing the tank, which just involves removing some screws and detaching the rubber fill hose and disconnecting the fuel-level-sender wires. Then take an electric drill with a wire-brush wheel on it and clean off as much rust from the trunk area as you can. Then sand it lightly to feather-edge the places you sanded off the paint, and treat the bare metal with a rust-converter like oxy-solv or metal-ready to get rid of any remaining rust. Clean with lacquer-thinner before painting. Either replace the tank or clean it up using the same technique and paint it. I like the Eastwood tank-tone paint for painting the tank. It adds a rust-resistant zinc coating that looks nice (IMHO). Put some 3M strip caulk on the flange before you re-install the tank. As far as the best rust-treatment paint, I've used POR-15 with good success but it is a bit tricker to work with than the Eastwood rust encapsulator. Mustangs Monthly did a comparison test between the two a few years ago and the Eastwood product held up better in rust prevention tests in a salt-spray environment. The problems with POR-15 are mostly that it is messy and nearly impossible to remove from your skin, it is harder to get a topcoat of paint to stick to it, and it can have adhesion problems if you don't get the surface prepped properly. I haven't used the Eastwood rust encapsulator but my understanding is that it doesn't have these problems, though prep is always critical on any paint job. Just follow the manufacturers instructions exactly.
 
darkhorse70 said:
The mounting flange that the tank sits on is typically rusted. I'd recommend removing the tank, which just involves removing some screws and detaching the rubber fill hose and disconnecting the fuel-level-sender wires. Then take an electric drill with a wire-brush wheel on it and clean off as much rust from the trunk area as you can. Then sand it lightly to feather-edge the places you sanded off the paint, and treat the bare metal with a rust-converter like oxy-solv or metal-ready to get rid of any remaining rust. Clean with lacquer-thinner before painting. Either replace the tank or clean it up using the same technique and paint it. I like the Eastwood tank-tone paint for painting the tank. It adds a rust-resistant zinc coating that looks nice (IMHO). Put some 3M strip caulk on the flange before you re-install the tank. As far as the best rust-treatment paint, I've used POR-15 with good success but it is a bit tricker to work with than the Eastwood rust encapsulator. Mustangs Monthly did a comparison test between the two a few years ago and the Eastwood product held up better in rust prevention tests in a salt-spray environment. The problems with POR-15 are mostly that it is messy and nearly impossible to remove from your skin, it is harder to get a topcoat of paint to stick to it, and it can have adhesion problems if you don't get the surface prepped properly. I haven't used the Eastwood rust encapsulator but my understanding is that it doesn't have these problems, though prep is always critical on any paint job. Just follow the manufacturers instructions exactly.


Excellent, I was leaning towards the Eastwood product as I am a beginner in any sort of body work (not to mention a novice mechanically-- It took me a year to get my Randall rack right).

Waht about the existing paint and the sealant around the wheel wells. How should I deal with preping the existing paint? How should I deal with the wheel well sealant?

Finally, any other suggestions on how to deal with the rust inside the deck lid?
 
dbfarr said:
...The tank does not need and will not get, any welding. I was more concerned about the por 15 permanently fixing the tank to the frame, since the site mentions that por 15 will permenantly fix the lid to the can if any is spilled on the lip. Furthermore, I am worried about rust on the mounting surface for the tank.

Any word on how to strip the paint and foam stuff? I've heard peel away, but I am not sure where to get it.
That's my 73 trunk you referenced above. I'm not sure what you mean by "foam stuff". Is there a foam gasket between the tank and the trunk? If that's the case an adhesive remover like "3M General Purpose Adhesive Cleaner #08984" does a great job.

Peelaway 7 does a great job of removing rubberized undercoating. I wouldn't recommend it for anything else. I used it on my trunk as an experiment to remove a lot of spray on adhesive put on by the previous owner. Somewhat affective, but I wouldn't do it again. For general paint removal get a bunch of different size and shape wire wheels and go to town.

Por15 isn't rocket science. Just read and follow the instructions. How effective it is, is directly related to how many coats you apply. The real issue is that everything must be bone dry before applying it. If you use their topcoat, there are no adhesion issues. Regarless of who's product you use, you should be preping the metal with hydrochloric acid (metal ready), (thus wearing industrial strength gloves).

I've been toying with using Por15's "fuel tank repair kit" for areas like the inside of the trunk lid. Though I haven't done any experiments or research yet.
 
Dollars to donuts thats too much rust in the trunkfloors to POR15 over. The good trunkfloor in my car looked like that and I can drive a screwdriver thru enough places with ease that it's getting replaced.

Another thing I noticed is if the trunkfloors look like that, the ends of the rear framerails are likely to be toast, I know this was the case in both of my cars and a lot of the ones I looked at.

I'd trash the tank. Too much risk to do anything else. That piece of cardboard scares me, was somebody trying to patch it with that?
EDIT: I also wonder how much rust hides under the tank lips?
 
I think I'd address the source of the leak first and part of it may be the trunk seal but more likely it'll be the window gasket. You might be able to squeeze more butyl sealant stuff between the gasket and glass but its best to r & r the window and change out the gasket and use LOTS of butyl sealant stuff.
 
The cardboard is more like a piece of mdf glued to the tank, I'll take a closer look at it. I don't think its a tank repair, too porous. The PO wasn't real bright, but he wasn't that stupid. Then again, I dont' think I'll just pry it off without some idea of why it's there. Anybody seen something like this before?

I'll take a look at the window seal, but the water only shows up directly beneath the trunk lid. The rear of the trunk area is always dry. Then again, I could be wrong. The new lid seal has been ordered ...

This is the only place I have found any rust on the car, I'll have to poke around with a screwdriver to see how far it has gone. Seems pretty solid so far. Unfortunately, if it is bad, I'll have to just treat it for now, panel replacement is just not in the budget right now, -- period.

But I am possibly in denial, ... I'll need to remove the tank to have a clearer idea.

Maybe i'll have to budget in a tank for this project. A 69 tank w/ 20 gallon capacity sure would be nice ... but then. I'll need a new sending unit, filler neck, fab up spacers to level out the trunk for the taller tank, and etc. etc.

Every time I start a project, it mushrooms -- damn. Just like the timing chain that turned into a new balancer, cover, pump, hardware, one piece oil pan seal, arp oil pump shaft, inner tie rod end, alignment, and of course, engine paint, etc.

Last thing, keep in mind, these pictures were taken just after a fat rainstorm. The trunk is dry now, it doesn't look as bad.

Would photos of any other angle or part of the car give anyone a clearer idea of what I am up against?
 
Platonic Solid said:
That's my 73 trunk you referenced above. I'm not sure what you mean by "foam stuff". Is there a foam gasket between the tank and the trunk? If that's the case an adhesive remover like "3M General Purpose Adhesive Cleaner #08984" does a great job.

I owe you a credit, I apologize. Your post is, after all, the reason I decided to check on this.

http://forums.stangnet.com/showthread.php?t=364913

And your site:

http://www.svend.net/mustang/73mach/73trunk.html

By the way, really nice work . I looked at your pics and was inspired, I hope I can get a finished product similar to yours.

As far as the foam stuff, Its the sealer between the frame rails and the wheel well. I looked at it today and was able to pull a piece off with my finger nails. So a paint scraper will easily do the trick.

danny clemens said:
If you don't dip it though I would get all of the rust out that you can and then pour some POR 15 or some other rust stabilizer in it and move it around to get it in the outside edges where the two panels mate.

Platonic Solid said:
I've been toying with using Por15's "fuel tank repair kit" for areas like the inside of the trunk lid. Though I haven't done any experiments or research yet.

This is interesting, I'll have to look into that. Something with the right viscosity would be ideal -- thin enough to roll around and thick enough to cover. Maybe I'll give POR 15 and Eastwood a call and ask...
 
dbfarr said:
I'll take a look at the window seal, but the water only shows up directly beneath the trunk lid. The rear of the trunk area is always dry. Then again, I could be wrong. The new lid seal has been ordered ...

Don't rule out the window gasket yet. Water could run along the metal between the window and trunk and then drop down. If I were you , I'd get inside the trunk with a flashlight and have someone water down the rear window. But the trunk gasket is a good start.
 
dbfarr said:
I owe you a credit, I apologize. Your post is, after all, the reason I decided to check on this.

http://forums.stangnet.com/showthread.php?t=364913

...

AHHHHHHHHHHH :eek: , it's the thread that wouldn't die!!!! (Referring to its original resurrection by my cars previous owner.)

Seriously though - No apology or credit necessary. Everyone sharing their individual experiences is what makes forums work. :SNSign:

Thanks for the compliments.
Svend