Rust repairs on seat pans

[FiatBen]

Was pulling the seats to pull the carpet, which led to pulling the matting, which in turn now has a floor pan repair project on the '79 Automatic's list, and found this:



This is the driver's seat. The passenger seat is still solid. My first inclination was to hit it with a wire wheel and paint, but when I moved it today LOTS of rust fell out between the metal and the foam. So.........

BTW, someone once told me long ago and I've long since forgotten, but what is the purpose of that strap across the bottom?

[SoFlaFiat]

Ben, that's the AntiBottomOut strap, keeps your ass from going through the rusty seat pan!

[FiatBen]

My intention is to make this very detailed to help those who have not gone done this path before. For those of you with experience, I welcome your comments, suggestions, corrections, hints, tips and warnings.

When I removed the seats, this is what got my attention. I knew the seat bottom pans are prone to rust and I’ve seen much worse.


This is what really got my attention:


In order to effect repairs, the first step is to disassemble the seat and separate the rusty metal frame from everything else.
Remove the 4 Phillips head bolts from the two sliding seat rails (one at each end). Each bolt should have a star washer, which will get lost if you aren’t watching for it:


Then separate the seat back from the seat bottom. There are three 13mm bolts, one on the inboard side and two on the outboard (door) side. The 2nd one outboard required a wrench as a socket would not fit down over it. I also removed the spring and bagged/tagged it so as to not lose it.




There are always new problems that pop up when doing something like this. The plastic cover does not fit tight. The seat back lever is bent and its plastic end is long gone.

With this the seat back seperates from the seat bottom, making things much easier. (Here’s hoping it goes back together as easily.)

[FiatBen]

Next, we have to remove the seat cushion. This is attached to the metal bottom by folding over the edging of the upholstery which has a plastic stiffener in it. Starting at one back corner, I worked my way around. You can lay the seat bottom upside down and kneel on it to compress the foam and make this much easier.





It is similar at the very back, just a wider stiffener. It has to come loose as well.


And now I’m glad I started this because, as usual, the visible rust was only an indication of the amount of true damage.


And here is the cushion loosened from the frame:



Almost to the point of being ready to grind away the rust.

[FiatBen]

At first I thought that the PO had possibly glued the foam to the metal when they recovered the seats. BTW, these seats were recovered with a vendor’s kit. (No way original 35 year old seats look that good!) As it turned out, the problem was that rust has stuck the foam to the frame.


And, as you can see, the surface rust inside the pan was rampant!


And now we have the seat bottom pan, ready to derust, seal and refinish. Let the fun begin!

If you don’t have one of these, go get it. This is a standard angle grinder. I pick these up on sale at Harbor Freight for $15 (before using the 20% coupon). I keep a spare in a box at that price. That way when I burn one up, I chunk it, open a box, mount a blade and am back in business. I bought a wire wheel kit for it at HF as well. It was $9.99 ($8 after my coupon) and includes two braided wire wheels and two cup wheels as well as a steel wire brush and two adapters to fit the wheels to other grinders. So for less than $25 you have a rust removing demon. Thanks to suggestions here I discovered the twisted wire wheels. Man, you have to be careful because this sucker will flat take stuff off (including skin if it ever gets ahold of you.)


I haven’t tried it on the floor pans yet. Almost scared to because it will definitely reveal any weak spots in the metal.
Haven’t really finished the pan yet but obviously this tool is going to clean most of it VERY quickly.



Compare this to the “before” shot above.


Well, this is a good start, huh?

[FiatBen]

Ben, that's the AntiBottomOut strap, keeps your ass from going through the rusty seat pan!

I'm guessing it is an attempt at solving the problem by removing so much metal from the bottom pan. All my older cars have solid pans (well, except some have rusted away enough to look like this one!)

[SoFlaFiat]

Nice work Ben!
Braver than I!!
I chucked my rusty pans!

[4uall]

I have book marked this thread. You do great work I finished my off with some POR15 made them bullet proof

[fredguaz]

Nice work!
I will be visiting this soon.
Did you do anything with the upper and lower seat wire springs beneath the foam? Mine are rusty but not completely and thought about rust electrolysis treatment. I was able to save an old rusty motorcycle seat pan using this method.

I have not seen it mentioned on this forum so for those unaware:

Basically get a big plastic trash bucket. Connect pos of battery charger to piece of rebar on side of bucket. Neg to piece. (Don't let them touch). Fill with water. Some put salt or baking soda in water. Turn on charger. Rust will convert to a paintable substrate. Works well on badly rusted metal where mechanical removal will destroy part.
Here's a good link:
http://antique-engines.com/electrol.asp

[FiatBen]

Yeah, have heard of electrolysis. If the pan was so far gone I was worried about losing metal, I think I'd go out to the barn and find a better set to rework.
If I was going to treat things like springs, I'd probably soak them in Evapo-Rust. That stuff really works. As it is, if there are any springs in the seat bottom, I don't see them, and I'm not inclined to take the seat back apart. Anyone got pics of the insides of the seats?
The springs in the back seat are fine, no real rust problems there, but I might hit them with rust converter just to make sure.

[FiatBen]

Not all parts can be accessed with a grinder mounted wire wheel:


I went over the pan, hitting any areas that showed rust or paint bubbles. My goal was not to get to bare metal, or I would have used a chemical stripper. My goal is to stop future rust and hope I never experience using the AntiBottom Out safety strap! Thanks SoFlaFiat for that image!





Next, wipe it down with mineral spirits, MEK, or similar solvent cleaner. Then hit it with two coats of rust converter spray, prime and paint, reassemble.

[FiatBen]

Well, as long as I’m here, I might as well take a look at the back tilting mechanism. Maybe I can figure out how to secure the plastic cover and deal with the back release handle, which has not only lost its plastic cap but looks bent to me.
Removing the cover – one Phillips head screw and gentle prying:


Underneath it are the two 13mm bolts that hold the seat tilt mechanism in place:


The backside of the tilt mechanism:


And I think this is how the cover stays firmly in place, but it doesn’t all seem to fit together. Looks to me like the plastic pin should drop into the hole with the retain and its spring clip holding the pin in place. Anyone know more about this?

[MrJD]

Suck it up and buy a good angle grinder. I did the same thing (cheap ones) years ago, then I bought a really nice DeWalt and its 10x the tool, and has lasted ever since while working 100% perfect. The tool quality will blow your mind.

With a good welder and a dewalt angle grinder, you can rebuild a fiat spider, lol.

[4uall]

here you go http://www.fiatspider.com/f08/viewtopic.php?f=9&t=7538

[RRoller123]

The back release handle is supposed to have that little bend at the end, the black plastic semi-sphere fits onto it. So that's one less thing to worry about!