I searched the board and I couldent find any specific information about fixing rusted pinch welds. The one on the passengers side looks pretty salvagable but the one under the drivers door is half gone from rust and the rest of it looks pretty compromised. I was thinking about cutting out the pinch weld all together and welding in some 1/8in mild steel flat stock or small square tubing.

Has anyone done this or have any advice

Thanks

 

i wouldn't weld a plate over it all, if anything you can cut out the seam and weld it where all the joints meet and then weld a plate over that. if you remove the seam then the sandwich will be free to move around so you must keep them all formed together.

 

This is what I'm dealing with. I circled the area that I am planning to cut out and the area that the arrow is pointing to I believe is the bottom of the structural hoop that is usually under the rear seats or storage bins



Thanks in advance for any help

 

yeesh!

i would find a restoration shop nearby and see what suggestions they can offer, the rust has gone too far inboard to focus on the seams any longer.

 

SO what should I do.. I really dont care about having a pinch weld. I just want to stop the rust and get structural ridgidity as high as possible for the least amount of money.



I am thinking about cutting out both pinch welds all together and replacing them square tubing, and then running some small square tubing from the frame rails to the square tubing in an x pattern and spot welding it to the floor pan in a few areas. Tying the floor the rockers and the frame rails together... big job I know... but I think it would be a hell of a lot easier than doing any sort of cage...

What I really need to think about is how much money do I want to spend on this car... is it worth putting money into because the shell looks really nice it just hs some rust issues under the car.





It would cost me quite a bit to get another rolling shell with paint in this condition.
So I am wondering if I should fix this car or scrap it before I spend any more money and get a fresh shell to work with

 

i aggree with the restoration shop......that looks pretty deep and they might know a trick or something to help with that

 

that is going to require cutting out sections and welding in new material, grinding and repainting. like i said i would find a auto resto shop in your area so he can point you to which areas will need what work. pics are only pics, what you need is an eye on it to seehow deep the rust goes and how far in.

 

sell the car,like you said it looks great.

then buy another with less rust.

 

I payed 1500 for it. Its got some mods already. RB sway bars, KYB agx stuts RB springs, a 10 gal fuel cell, a griffin radiator, . I dont know what the rims are but they are around 16-17lbs each, its got some no name tires up front but nitto 555r drag radials out back.

In parts alone I should be able to make some money back but I need most of those parts to complete the project I want to do.. All I really need is a cheap rust free shell that looks pretty.

 

I have a friend that has a completely gutted S5 gxl he would sell for damn cheap

 

If you're trying not to waste money, you might want to just buy another rx-7 that is a clean shell but all stock, a good runner... then swap your desirables over to the clean shell, putting the stock stuff into the rusted shell. At least in the end in this approach you wind up with the car you want and another car you can sell to recoup some money.

It really depends on how much time and space you have available man.

 

I would agree with these guys man, I remember seeing you make a thread on this beauty (at the time) on torquecentral. but I would cut your losses but a good roller and swap all the parts over. Or just strip the car down to the frame and have some restoration work done, when the rust is like that I would think it would be best to either sell it without all the nice parts for the same price or fix it properly.

 

Man i would tackweld something pretty strong in there to hold it in place, then i would manucfacture a new peice and weld it in there, just get some mild steel maybe .100 looks like a pretty easy repair. Make sure you cut out all the rust and deoxidine and prime it before you weld it togetheror the rust is just going to come back. Wouldnt scrap it if you had the skills to fix it, you will appreciate the car more when your done

 

If you really like the paint on the car you can take all the body parts off this car , fenders , rear quarter panels, front and rear bumpers, hood, doors etc off it and put it all on the next car.

Im not sure if youd be able to get every part off this car though that youd need to have the same exact body/paint, but at least youd get most of all the good stuff.

 

I agree with what he said, but you need to make sure its all fixed 100% the right way so it will last.

 

i had the same prob on mine ( well about 100 times worse )

all i did was cut it out and welded a plate over both sides

it still passed the MOT in the UK

not sure if this helps or not to be honest

 

I am planning on getting a welder for christmas this year and I'm planning on a bunch of projects but one of them is cleaning up the car. Initial goal is to try and make the chassis rust free.. if I cant do that I'll replace it. I really wouldent care about it but at this point if I want to continue to race I need a roll bar and I'm not gonna invest in a roll bar in a rusty chassis. I just dont think it makes sense

 

If that is the worst rust you have, I don't see a problem with repairing it. Just remember that the rust is usually a fair amount farther out than what you see. Also, there is a reason for the pinch welds other than ease of assembling the car. They add structural strength. Don't listen to guys who are not bodymen/restoration experts. Properly repaired you should have no strength issues. If you are going to install a rollbar or cage make sure your mounting points are plated in more than one plane. This will make it much stonger and less likely to punch through. By the way, I have more than 30 years experience doing restorations and building race cars. Good luck.

 

The only problem with repairing that is it is multiple layers, and inside the sill. If you have some experience with sheet metal, you can cut out the effected area and then rebuild it one panel at a time, starting from the inside out. This is a considerable amount of work and not a first welding project.

What would be easier would be to find that body section from a wrecked vehicle. You can even order most of it at Mazda (chassis parts catalog is in the FAQ). You will still have to deal with multiple layers so a considerable amount of cutting and patching will be required.

If you just want to stop the rust, you need to make sure to grind it down to one layer. Then use something like POR-15 to prevent further rust.

 

Yeah I plan to keep grinding till I see fresh metal and see how much I've cut away and then make a decision at that point. I know I could find a clean bare shell for short money if its really terrible. I the rocker is rusted but it looks a lot more straight forward to fix.. the floor looks a little more complicated mainly because I cant see how its put together from the outside. Most old cars have floorboards that end at the rockers, this has a section about 3" across between the actual inner rocker where the floor boards end(in the car) and where the pinch weld is. Thats the part that looks rotted the worst.

 

Repairing rust that goes through many panels is fun...

You have to take it all part part by part, and then build it back up part by part...

Rusty...


Remove all the rust layer by layer...


Then weld the new metal back in piece by piece...

 

Obviously that repair involved many more parts... but you get the idea...

 

-----CounterAct ---- Corrosion Protection look this up this works 100%

 

Nope, it doesn't.

This is the same type of device that CounterAct sells:
http://www.ftc.gov/opa/1996/07/rust3.shtm
http://www.ftc.gov/os/1996/11/d9274.do.htm

 

no, I said CounterAct.not the same type of device that CounterAct sells.