arkady151

iTrader: (15)

I have an 88 triple-black vert which I purchased about a month or so ago. The plan is ofcourse to do a TII swap. The car originally had 330,000 miles on it , stock engine at that. The interior is in great shape and everything electronic works fine. It seemed to have some rust around the fenders but that didnt worry me that much until I went to pull the ecu and found this...



The original plan was to coat the underside of the car with herculiner to prevent any rusting but after I found that I decided to pull the interior too and do the inside just like I saw in Trav's thread https://www.rx7club.com/2nd-generation-specific-1986-1992-17/91-vert-painting-progress-crystal-white-lots-pictures-427958/ . Well I wasnt that lucky after the whole interior was pulled not only was my whole ******* dash held on by like 4 screws but I had even worse rust to worry about....

To the right of the drivers seat



Behind the drivers seat




Along the drivers door side, probably the worst part since it goes to the floor and also through the side and under it



Same rust spot , view from under the car



My plan is to cut out the bad portions and weld in new ones for the stuff thats through the floor. Question 1 , What should be the thickness of the metal , which I will be weldding? .I want to treat the surface rust with muriatic acid as recommend by a few members on here. I know I have to make sure I rinse , rinse and rinse again and use plenty of protection when working with it but my second question is should I mix the acid with water to dilute(sp?) it a bit or use it in its full concentrated capacity?.

As you can see I removed all the rubber that was covering the underside, mainly because I wanted to be sure I got all the rust and I wanted to herculiner it anyway. So I've been going at with a wire brush bit in a drill thus the polished look of the panels. My next step would be to primer the body with Eastwoods Rust Encapsulator http://www.eastwood.com/shopping/pro...e=PRODUCT&RS=1 and use their Chassis Black which comes with the kit to paint the suspension peices.

So far does this sound good , I havent purchased the Eastwood kit yet so is there anything better that I should use?

Last question is about the body plugs as shown here...


Metal body plug glued to chassis with some compound


Rubber plug , just plugged into the body


What are they for? I personally dont see a purpose in them so what would stop me from welding those areas shut? If I should keep them what glue or sealant should I use to glue the metal ones back in? Where can I buy new rubber body plugs? Does the dealership still sell them? Can I buy them somewhere else and not get bend over?

A big thanks to anyone who answers these for me.

Aaron Cake

iTrader: (1)

That doesn't look too bad. Some wire brush work will expose any real problems. Expect a few pinholes, but those can be sealed with the appropriate coating (ie. POR-15).

Common areas for rust to form since water pools behind the seat. Does the top leak?

That's bad. It's a complicated area to repair since the sill, floor, pinch weld and door jam all connect. The view from the underside makes it look like the inner part of the sill is OK, which makes things easier.

Is this your first rust repair? If so, practice on a FLAT area that won't be seen. Areas like the floor or storage bins. You're going to want to use a 0.023 wire, with the wire speed turned up and the voltage/current turned down. If using flux core, you're stuck with 0.030" as the smallest. It's more frustrating, but will get the job done. Either way, make a patch that fits PERFECTLY to lesson the chance of burning through. It's easiest to cut the rust hole into some kind of normal shape (square, rectangle) and make a panel to match. Put a tack weld in every few inches, then fill in between them. Grind flat, reweld, then grind again. Don't grind into the good metal since you don't want to make it any thinner. Weld through primers are great for this since welds and new metal will aggressivly rust in a short time unless protected.

Use something slightly thicker then the replacement. I generally use 2MM thick for these kinds of repairs.

No idea. I don't use muriatric acid for this. I use a product from RestoMotive (the company that makes POR-15) called "Metal Ready". It's basically phosphoric acid with a zinc ion, used full strength. Has the same effect as muriatic acid.

The acid just stops rust, it will not prevent it. To prevent it, you need to deny the metal any moisture. A coating like POR-15 is what you need (I'm big on POR-15, can you tell? ).

I'm partial to POR-15. It's very expensive, a pain to work with and make a huge mess. But it just plain works.

Good info here: https://www.rx7club.com/forum/showthread.php?t=468413

Many of the rubber plugs are in place so that the car can be rust proofed via oil spray. The ones that just go through the floor don't seem to serve any purpose, so I don't see any major harm in welding them up.

If you just want to glue them back shut, then any auto parts store should have seam sealer which you can use. They will also sell replacement rubber plugs.