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Discussion Starter #1
I thought I was ready to start painting this weekend, until I looked closer at my floor pans. The area under the raised pedestal that the seats attach to has rust. From the previous posts I gather that many choose to cut the pedestal from the floorpans and preserve the area, then re-attach the pedestal.

Question:

I am not a structural engineer, but it seems to me that a circle shaped cut can be made on the top of the pedestal big enough to get a hand and tools in the closed space to do preservation, and still maintain structural integrity. Has anyone done this before?
 

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A seam correctly welded will have twice the rigitity strength than a non-welded area of comparison. That is why (in theory) once you weld on one side, it requires twice the amount of heat to weld the opposite side.
 

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If your plan is to cut it up and leave a hole in it in order to "preserve" the car better...I'd suggest saving yourself the trouble and not cutting it up to begin with...but that's just me.

I'm trying to picture the area you're talking about. Is your car a convertible by any chance? I can't tell what type of '66 you have from your profile. Also are you talking about a little surface rust, or are chunks of your floor pan coming out of the access holes for your seat screws?

Just curious.

Phil
 
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In reply to hoosierbuddy, I have a 66 Coupe, Vinyl top. The area that I am talking about is a raised area under each of the two front seats, spot welded to the floorpans. I wished I could send you a picture - sorry. However, it has 4 holes to accomodate the bolts from the seats, and you attach the nuts from under the car. There are access holes sealed by rubber grommets for this purpose. The only access to the space between the floor pan and the top of the platform that the seat attaches to is the access holes under the car and the 4 holes that the seat bolts go to. Get the picture? Anyhow it is hard to see in the void, even with an inspection mirror. But I was able to pull out some small rust flakes. I think though, that most of the rust is surface type. I still think that I can cut about a 10" dia hole in the platform (pedestal?), without compromising the stuctural integrity. The area where the bolts attach has ridges stamped on either side of the holes, for structrual strength. Hope this clears it up.

So back to the question, do you think I can cut the 10" holes? Or just forget about the rust? /forums/images/icons/smile.gif
 

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Hi,What you're talking about are the seat flatforms. The best thing to do, of course, is take them up. Any decent welder can do this pretty quickly, I would think. The next best thing is spray the inside liberally with something like POR 15. Haven't used this but I think you need to treat the surface first, which will be pretty hard even with a larger access hole cut into the pans. The third option, if you comfortable the platforms are still in decent shape, is to temporarily seal the platform holes on the top, get underneath and liberally spray in something like Rust Check, then put the bottom plugs in and let sit for awhile. When you put the seats back in and the bottom rubber plugs in (I'd use new ones)that should prevent any more moisture from gettin in. Mark
 
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Taking the seat risers (platforms) out is not to bad a job, time consuming, but not to bad. If you'll take a wire brush on an angle grinder, and go all the way around the flange, you'll see all of the spot welds. If you'll use one of the spot weld cutters, or I used a Titanium drill bit, it goes fairly quickly. I agree with the other post, if you'r only looking at surface rust, I'd use one of the liquid rust stoppers, I prefer Ospho (available at Ace Hardware) and a brush of some sort, and work it from all of the access holes. If your worried about not getting it all, your probably going to work harder at cutting and welding a hole back in, than just taking it out to begin with.
 

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If you don't want to remove the seat risers, then do Jaeger83's 3rd suggestion. Get a bottle of rust convertor and spray a bunch of it in from underneath. I found a rust convertor at the local hardware store that isn't much thicker than water. You could put a pint or so in an agricultural sprayer and stick it through the access holes and hose it down.

Cutting a 10" hole to eliminate the potential of future rust damage is not a good idea. Even if rust never sleeps, it would take it YEARS to do as much damage to your car as cutting a 10" hole in it would.

The reason I asked if it was a convertible, is because this area on a convertible is actually 3 layers rather than 2...because you have a bracing pan under the floor pan to beef up an obvious weak area in the unibody. This is a weak point on all mustangs because the frame rails end fore and aft of here and the floorpan/seat riser area is what gives you what little structural rigidity a modified falcon unibody has (which ain't a lot).

If you absolutely feel driven to cut large holes in yours, I would suggest you AT LEAST get some 20 gauge sheet metal and weld covers over the area when your done.

IMHO you would me MUCH better off doing nothing at all that you would be hacking this up.

Phil
 
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Okay, uncle! I won't cut a 10 inch hole. Thanks alot for all the opinions and help. I think I will go the rust converter option. By the way SWMBO agrees with you guys! (I hate when that happens!) /forums/images/icons/smile.gif Really though, thanks for the input from all of you guys. I guess I was disappointed that my weekend paint project would be delayed, and I was looking for a quick fix to keep on schedule.

Dave
 

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Easiest way to take care of your concerns is to buy a spot weld cutter and an electric drill and cut the spot welds out.....

then with a flat chizel tap a hammer in between the floor pan and seat mount risers....remove them and bead blast the floor pans....
epoxy primer them.....as well as the under side of seat risers....then POR-15 them (just don't por15 the small areas where the welds are to take place...

Then reweld the seat risers back on.....sand smooth and re epoxy primer and por-15 the area around and on the prepped welded surface for a good seal. Tis won't affect structural strength, alignment and such.....just make sure the car is level and don't move it around till it is done.
 
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