Good post!
This is our number one enemy in our cars. Fixing this part should be
stored in the FAQ.

The more detailed the better!


Thanx!

 

well - I guess I'll start posting my progess here too..

I've made new ULSP's - exactly duplicated the stock one, right down to the lip.
I'm not quite sure how I'm going to attach them to the upper link mounting "box" - but I'll figure that out.

I've built a plate for the back wall/floor area too on each side - today I worked on new inner fenderwells. nobody sells them! I'm making them out of an old steel desk - pretty thick steel but it will be strong!

it is a HUGE pain in the *** to make that curve by hand... about 8 hours of work today went into the passanger side one - I think maybe I'll build a jig so I can build these and resell them -there has to be a market! I suppose I could have made it out of two pieces but I think that one is better!

now I just have to weld it to the car - and then that corner is done!

POR 15's secret is in the primer - and it is no secret - it's just phosphoric acid..

phosphoric acid kicks the **** out of rust!

POR-15 is good stuff though, wish it was avaliable here locally as I'd be using it - I'm just going to paint everything, weld it all together, and then paint it again!
there is no rust left in the car - I've cut it all out (aside from some surface crap, I groudn it down and phosphoric acid'd it.

 

Here are the pics from the other side.

 

I need to take some pictures of mine, but all of my rust & rot is localized to the center of that panel, no where near the floorboards.

I'm addressing mine next year with a mini-tub

Whats the deal with every one of these cars rusting there? Is moisture/humidity trapped in that little 'compartment'?

 

The deal is -my guess - is that that ULSP spot welds are not adequately protected from moisture which gets to this area, and rustola, the rust begins.
Puting it another way, my guess is - after the plate is spot welded on, the painting process is inadequate to cover the weld areas. So perhaps sealing that plate to the body would prevent this.

 

bump back from the dead!
this lies ahead of me... and I'm sure of many others

 

bumping this again for anyone else that is dealing with this. I bought my son an 85 that is beautiful inside and out and totally mechanically sound. I didn't see this when I bought it and now we're doing it... Luckily I have a friend that is good at welding and he's helping when he's not working.

 

"The deal is -my guess - is that that ULSP spot welds are not adequately protected from moisture which gets to this area, and rustola, the rust begins.
Puting it another way, my guess is - after the plate is spot welded on, the painting process is inadequate to cover the weld areas. So perhaps sealing that plate to the body would prevent this."

What the deal is that mazda had to put the extra metal plate with the d hole in it to pass the crash tests. Mazda didn't seal behind the plate, and left a 1/4 inch hole for water to do its worst. I cut out the rusted metal on my wheel wells and bolted 1/8 steel to cover the hole. That area isn't load bearing , so as long as it is protected for water, salt, and humidity, it should be ok.

 

Australian cars rarely if ever rust in this spot. Nowhere in Australia are roads salted, but plenty of places are by the sea and rust does attack other areas of the car, the number 1 spot being the rear beaver panel/rear hatch drain hole sill, followed by sunroof, doors and A pillars. BUT for whatever reason, the rear wheel arches are nothing like this.

A friend of mine and I were discussing this and thought one factor might be the rear seat setup we have. US cars have the metal framework for the rear bin setup attached to that point. Our cars are 2+2 and don't have any metalwork connecting to that area.