I've been looking for an fb for 3 weeks now. and every singe lcar has had some degree of "storage bing rust"-- that is, rust on the inside of the wheelwells.

while the outsides of most of thes cars are perfectly fine, the inside of the wheelwels invariably have patches of severe rust on them. the smallest patch i've seen was about 6 inches by3 inches.

just severe is this sort of thing? is the wheelwell repairable? like i said, the rest of cars are usually fine...

Ive done some searches on this, and I found a lot of doom and gloom, as well as one picture of a car that had a brand new wheelwell welded in. is this a lot more horribly involved than it sounds?

 

Anything can be fixed ...


its just a case of is it worth it

I paid £50 to have both rear arches repaired during an £800 revamp of the bodywork on my car

but that was the only rust in the entire car so it was worth doing it, but if the rest of the car is rusty I wouldn't bother

 

I wouldn't worry excessively, as long as it isn't too severe... in my experience, even *mint* looking RX-7's usually have this problem to some small degree.

In other words, if the rest of the car is nice and what you're looking for, I wouldn't pass it up just because of a little bin rust. That said, you can always point it out and use it as a bargaining aid.

 

You'll have to judge whether or no the rust has become structural. It's an easy fix - the area is out of sight, so you can just grind the rust away (and weld a patch over if the hole is large).

 

Assuming the rest of the car is in good shape then I wouldn't worry too much about it, unless the wheel well crumbles when you touch it (like my parts car), as long as its solid, and seems to be mainly surface rust then go for it. all of my Fb's have it, I hope to address it soon, but I'm not too concerned with it.

 

https://www.rx7club.com/forum/showth...t&pagenumber=2

Look on page 2 for wacky rotary's link. that's when you have tooo much rust.

My car did have a consiterable amount, but nothing like that. I just ground it out with a wire brush bit, and patched it with fiber glass. I probably should of neutralized it first, but i didnt think to do that at the time. So, yeah like everyone said. It is fixable.


edited for spelling

 

Thats my plan.

 

Any rust can be combated with stuff called Por-15. go to www.por-15.com

 

does it fill the big holes too!

 

They do also have it as a putty like jb weld. Given enough I am sure you could fill some big holes

 

Does anyone know the cause of the infamous bin rust? My 84 and my folks 85 are otherwise in mint condition (alright, my paint is pretty faded) but they both have a little bit of rust in the bins. It must penetrate from the outside through a seam or something because with both examples I have it starts about halfway up the seam under the bin. If it were moisture inside I would think the rust would have started at the bottom of the seam, not the middle.

Using this logic (flawed as it may be) just grinding out the rust and/or patching with replacement metal and/or using POR-15 isn't going to stop anything. POR-15 only works if oxygen is completely sealed out and the other two do nothing but give mother nature fresh metal to oxidize. If what I suspect is happening (moisture coming from outside the wheelwell) then it needs to be addressed from the outside as well.

Is there a thread somewhere that addresses this? I've searched in the past, but the term 'bin rust' has been typed about a million times. If someone could shed some light on this I'd greatly appretiate it as this is something I intend to put a stop to this spring. Thanks.

 

I think its caused by capillary action

The reinforcing plate is spot welded to the exterior of the panel and because there is a small gap between the two sheets of metal the water is drawn in between the two and hey presto RUST

 

The water gets in through a couple of small holes in the wheel well. They're higher up near the shock mount. Mazda must have used the holes for some manufacturing procedure. Look at the wheel well from the outside and you should be able to find the holes. The problem is there are actually two layers of sheet metal here. An inner that you can see when you remove the storage bin, and an outer which is exposed to the wheel well. The water comes in through the holes that are suprisingly poorly sealed and sits between the two sheet metal layers. If you see rust when you remove the bin, it's already rusted through this inner layer of sheet metal. Just sprayin rust-x or whatever on the rust that you see isn't really protecting anything.

 

Thanks for the input, guys. So if I MIG up the holes and remove the rust from the bin area I should be okay?

The 84 has rust that is about 1"x4" and the 85 has a little less, say .75"x3". There is no rust on the rest of the cars and my father was heartbroken when I showed him where they were rusting. Pretty unfortunate that Mazda missed this one detail.

I want to fix this once, so I'm just looking for the correct way to do it.

 

Since there are two layers of metal in the wheel well and the rust starte from between them, you'd need to remove the inner layer to get at all of the rust. If you remove the storage bin and see rust, it's already rusted through the inner layer.

 

Anyone selling wheel wells?

 

hmmmmmmmm I wonder how big the market is for pattern repair panels for FB rear arches and reinforcing plates

 

It sounds like you've got at least ten customers on this board alone.

 

Need em for an 85... The brackets are supposedly 20mm lower to make it less tail happy.

 

For a reasonable price, I'd buy two sets.

If I removed the inner panel, addressed the rust, and then welded it back on would this fix the problem? I see what you're saying about the two layers and the rust starting from within; I'm just wondering if it's possible to seperate the two and then remate them.

If this is covered in another thread I apologize - I just haven't found it yet in my searching.

 

Alright, I've searched some more and I think I've found the info I need. It sounds to me like the only way to fix it for good is to remove the inner sheet metal, address any rust, and then reattach.

It also seems to me that even though a car may appear to have zero rust in the bins, it could very well have a good start between the two sheets of metal and it just hasn't reared it's ugly head, yet. I would think that every fb has rust there to some degree. I mean, if it's entering through four holes in the fenderwell, then any car that's been driven in the rain or been through a car wash has the potential for rust there.

I'll be cutting, grinding, and welding before long...

 

Rust fixed

 

Probably more, just about everyone would want a set if they were reasonably priced. I'd be interested thats for sure.

 

For some reason I can't see the picture.

 

Sorry you'll have to right click and cut and paste to get it to work didn't realise but I think the other forum the pics are on restrict external links