So as some of you noticed I am in process of removing the old four mounts. As I got them most of the way off I am seeing our little friends It doesn't look like it is really rusty but it has thined out the metal a bit. What is the best way to take care of this? This is an autocross car and sees a bit of twist of the suspension.

Thanks

Sorry about the poor quality pics. I just ran out and snapped them quickly.

if it were me, and it will be soon, I would treat the metal for rust, weld a plate over the area and run you a brace over to the suspension pivot. IMHO

Do you have a chassis stiffening kit installed on the other side of the rail?

That is really all I am thinking of doing but I would like to hear from other guys what they have done. I know there will be some bracing done here as well. We have some very talented guys on here and I am sure there is some good learning to come from this

No... I can if I want as I do have one laying around.

That's what mine looked like. I think the metal was still plenty thick and I just cleaned it up and primed it. Looks a little pitted, but i think it will carry the load fine. Then again, I don't plan on trying to twist the dickens out of it, like do will.

Here's a pic:

Click to view attachment

That looks much like what I am planning.

Damn makes me wish I didn't have a four so I could do that, also makes me wonder whats under my mounts???


The only true way to get rid of rust like that is with one of those little sandblaster things LINK. A total bitch but worth it I think. I went through 500 pounds in my trunk and hellhole though maybe I'm just a masochist

slap some jb weld on there good as new

Just patch it up and take the opportunity to add some triangulation to your suspension console ...
Andy

You know you are always welcome to come over and drink my beer any time.... oh, and if you want to do any work feel free

and if beer isn't good enough I have a full bar...

and I have a hot wife...

I have seen your work and am very impressed.

As soon as my car has paint on it I'll be right over haha

Is tomorrow soon enough?

Wow Paul... I know if I need your help you'll be here quickly

Jon,

I had similar rust issues when I removed my 4 cyl mount on that side. Mine was a bit worse. I think yours is probably still pretty solid. If i was you I would...

1. Media blast it. Especially to remove any rust from the pitted areas that will be hard to get out via grinding or wire wheel.

2. Treat it with Ospho and POR-15

3. Reskin the outside with new metal. I replicated the divit on the bottom right via some extra work on my new skin.

You can see some photos of mine here...

http://motorsport.zyyz.com/project_914_03_02.htm

Thanks Richard. I think what you did will be a little overkill for the section on my car as the rust appears to be localized in the upper area of where the mount was. I am going to clean it, kill the rust, and weld a new nice piece of metal with a brace to the suspension. Almost exactly what the yellow car above has.

If I was closer you'd be right.

Since you're gonna be under there, stinger in hand......DWD alert!

The factory welding on the underside of the suspension console cries out for help.
Seal welding the pointy end of the pinch seam around the ear, then foreward to the firewall & aft to the trans mount will help prevent the cracking on the ear and at the arch over the axle. Smooth out the welding when your done. Piece of cake.
I got away with no cracks and with no other structual fixes for 6-7 years of hard AXing with this done.

BTW, don't get near that rust with Por-15......Rust Mort or Ospho with a coat or 2 of etching primer will see you thru ....till next time.

Any pics of what you're talking about JP? Thanks for the advice. I know better with POR. I used zero rust on the interior and it was amazing.

Not any real good pics, but.......a few accidental views.....enuff to give you the general idea.

If you have room I would do the brace straight forward to the firewall area as that would give more support and wrap a piece around the ear to fasten it to.

You want to measure carefully before doing that. You don't want to find out you can't get your engine back in the car afterwards.

Hey Jon...here is what I did and I believe its where JP is talking about? Sorry for the poor pics but I have misplaced the ones while in progress.....

Click to view attachment
Click to view attachment

Why would that be a problem?

Thanks Josh, I can understand that now. I can see on my car where that would help.

I think those brace mods will toss you outta of GTU class, suspension mods are limited to machining not welding in braces...you can weld up the ear like JP says..

Not in GTU anymore. I'm in MU now. I get to race against Greg Fordahl and a bunch of other ITS 944s

A lot of folks are down on Por-15, but if used correctly and as directed, I think it works great. I think a lot of people make the mistake of not treating the rust before applying it. Por-15 is not a rust converter, it's a sealer/primer. The product the company makes for rust converting is MetalReady which is a converter/metal etching solution.

Just my $.02, now back to the original thread already in progress.

I will have to disagree. The PO did my car properly and there were areas under the POR that still had rust when I redid the floor. Also, the guy that was helping me with my interior showed me a ton of pictures of cars that people used POR on and they were all done correctly by a top notch shop. He showed me a few different products and why he only uses Zero Rust.

When you use the metal ready it turns the rust black. Who's to know if it turns the rust black all the way down to good steel. The best way will always be to remove all the rust and use a good epoxy primer to seal it, nothing seals better than epoxy primer over good clean steel. I have used lots of por 15 but it is mainly to seal the rust and maybe it will keep it from starting up again. My biggest concern is getting other paints and undercoat to stay on top of it. It is a very hard slick finish. if you try to sand it or scuff it and go through what good is the sealer part of the application. On non sanding epoxy primer you can just shoot the type of top coat over the primer and it sticks great and won't ever lift. I haven't had that result every time with por15. I do know acids won't touch por15 and it is really tough stuff if you apply it perfectly.

I usually use por15 on stuff that isn't cosmetically perfect but that I want a tough surface on. It will turn some ugly colors out in the sun so it will need to be top coated if exposed to sunlight. Restomotive sells a tiecoat primer that works good over por15 but that is another paint you will need in the budget. It is a baby blue colored primer.

I had similar rust under my 4 cyl mount but I had a hole underneath> I ended up putting another small patch to cover the little 'kidney bowl' too.
I cut out all the rust as there is the inner heavy-gauge ribbed piece below. Then welded a new skin over the top.

This is the hole I found but the metal underneath was sound. Excuse the welding I was working with my new Miller and was still experimenting with settings -it all ground back flush

I agree. I think people expect it to work magic. I think a common problem is lack of cleaning of oil, etc. The other is that they treat metal that is rusted through and they coat just one surface, so it rusts from the inside out. I have no doubt that "professionals" can screw it up as well.

I also am a big fan of media blasting vs. rust conversion only for two reasons. (1), why convert rust to something else (and probably not get it all) when you can remove it. (2), it creates a "surface profile" that gives whatever you choose (POR or something else) something to adhere to properly.

Also, I think the something like Ospho works much better after a very light media blasting. Try this yourself if you have some Ospho or Metal Ready. Take some new sheet metal. Cut it into three sections. Clean all three (remove oil, etc.). Leave one as is, clean one with a flapper disk on a grinder or use a knotted wire wheel on it, lightly media blast the last one. Then spray all three with Ospho/Metal Ready. You will see that the first two don’t get etched much at all. In fact I think the second one that was sanded, ends up with a polished surface that doesn’t get etched much at all. The last one is etched much more than the other two. Which one do you think will work best with a sealer/primer like POR or some other product?

My 2 cents as well. Sorry for the hijack.

I think that is a good point. I think that is why an epoxy primer is the right thing for 99% of the car. But POR 15 is good if you need to get at areas you can’t spray into. Two examples of this. First is if you are working on an area that you will be covering up (such as multiple layers of metal). I would use POR 15 or a good weldable primer or maybe both in that situation. An example of this for me is my replacement passenger suspension console. I used POR15 on the majority of the interior prior to welding it to the car as well as weldable primer on the areas that would be welded. This was on brand new un-rusted metal. I guess if you want to get out your spray gun and set it up for something that small, then use the epoxy primer, but I think that POR 15 beats it due to convenience in that situation. The second is to use POR 15 to flow via capillary action into seams. That an area that you can’t reach with a spray on primer or with seam sealer.

Crap, I hate replying to my own posts.

I re-read my posts above, and I am not knocking Zero Rust. I think lack of proper prep work or using it on parts that are overly rusted to begin with will cause both POR 15 and Zero Rust to fail.