After the lust and finding some RUST

[tmason]

I fired her you today,[all 6 cylinder] than drove her around,70 Degrees,dry roads and air, my dog on my lap.I think he knows he riding in a classic too!.I know this sounds alittle corny but after waiting all these years to own a e9, and finding a forum like this, no matter what the condition your car is in,it can be just pure happiness to drive one of these cars around. I also know that all of us wished we had that rust free classic but very few of us do. And aftering seeing some of photo's of the projects that this group is doing it really doesn't matter, they are cars are all hand made -- just some have more hand hours than others! Thanks Tim. PS When putting her away for the winter the clock never needs to fall back [imagine that].
http://s557.photobucket.com/albums/ss12/nosamt/74CSA/

 

[MichaelP]

Re: Question on fixing ORC Rust

Do you use some chemical to neutalize the rust before welding in patches?

It may not be that simple. Or maybe it will. :wink:

Since the rockers are the primary horizontal structure that keeps the car from folding in half, there are 3 components to the rocker. The ones with the big holes in your photos are just bodywork. Beneath that are two steel beams that get welded together. See this diagram (parts labeled 7, 8 + 9). The sheet metal sill you removed is number 10 in this diagram.

The question is, what is the rust damage to the two primary structural beams, the outermost of which you can see through the fist-sized hole? You'll have to enlarge the holes to do any patching, so some exploratory surface surgery may be in order. Given the extent of the rust damage to the rocker cover, it may be more expeditious to just remove the whole thing and weld in new parts.

You might check with your favorite parts dealer to be sure you can get new "coverings," as they are listed in the diagram. They're not listed with a price, but not itemized as NLA either, which often means there's a waiting list. If there is a wait (often years) you might resort to sheet metal patching or finding a talented metal beater with an english wheel to make you some new rocker covers.

 

[tmason]

Thanks for the info.Looking inside the holes the frame that you are showing me in the diagram seems to have surface rust but I will cut a larger hole and take some more photos.The car will never be driven in wet whether so I hoping I can just keep it from further decomposing.I've seen a chemical that is applied to rusted metal that keeps from rusting,have you seen this product? Thanks Tim

 

[MichaelP]

I've seen a chemical that is applied to rusted metal that keeps from rusting,have you seen this product?

Several products include phosphoric acid as an ingredient to turn surface rust to a primer ready surface. Phosphoric acid causes iron oxide to chemically convert to iron phosphate and stops the oxide from continuing to eat away at the steel. I've used a product called Ospho with some success, but it only works on the surface. If your rocker beams are rotted to iron oxide below the surface, the phosphoric acid is useless. You need to sand/grind down the rusty object until you're convinced that you are looking at solid steel before applying.

Edit: Don't forget that if rust has eaten away at the sheetmetal of the structural rocker, it doesn't have as much material doing what it's supposed to do, and you may end up with a flexible chassis as compared to new. It will just have to be a judgment call as you sand/grind.

 

[tmason]

Question on fixing ORC Rust

I have finished making my replacement sheet metal patch's for all holes under the ORC and one passenger floor board hole[not pictured] and because this car never see rain again I was just going to have these welded up without treating the inside the rocker? Thanks for any advise.Tim

 

[pamp]

Rust never sleeps

Good thread,
I found new rust on my '74 Right rear floor. Yes , I kneeled, and punched through. Rot's o'shit. Advise ?

 

[tmason]

I just got all showered too! But I had to go check[ and OK]. I just had the seats out for leather reconditioning and floors look clean on the inside.I do have a couple in the holes in drain under spare tire that needs spot welding.But would you spray something inside holes before welding up? Thanks

 

[tmason]

Ok,this is what I was thinking.I have 18 cans of what ever color left over from what ever project that needed Rust-oleum,Sons Cub scouts,wife's Xmas,High School Art Project [33 yrs old of coarse] and yard tools.So I spray everything I have, do you think it will catch fire when welding?

 

[dp]

If you have decided your rockers have enough structural integrity to either "be safe" or to "live with"

1) Rinse the cavity out with "MetalReady" (a Por15 product which converts iron oxide to a phosphated zinc) Be sure to have a catch basin under the weep holes/rockers to catch all of the MetalReady, as it can be saved and re-used.

2) Next rinse with de-ionized water (catch that junk as above and discard at your local recycling station)

3) Next rig a high-flow hair blow-dryer (1500-1800 watts should do it)
so that it blows in there to thoroughly dry it all out, give it a few hours.

3a) If you are putting patches in, you may chose to do this now, but you will need access holes (small) to reach into the cavity for the following steps. These holes can be cut in an obscure location and after you are done plugged with a genuine BMW Gmbh plug!

4) Get a source for the yellow zinc phosphate paint, and paint the entire inner cavity with the stuff. If you are insecure, give it a couple of coats after letting the first tack up for a few hours. You will need a wand-type sprayer to reach in there. Be sure to have ventilation better than you ever thought you would need ... this stuff is nasty to inhale. Good idea to use a full-face chemical respirator to be on the safest side.

5) You may find the wand helpful in application of the MetalReady, also when you go to rinse with the DI water.

6) Do NOT be tempted to use the blow dryer after applying the zinc phosphate paint the yellow zinc phosphate paint. You just have to be patient when awaiting setup and drying. Ideally you resume work when you can no longer detect fumes (remember its nasty, so give it some real time)

7) In case you are wondering why you can only use the yellow zinc phosphate paint, its the only stuff that works. It will complement the MetalReady by penetrating any voids that might have been missed, you REALLY want to get all the iron oxide (rust) converted to inert and the yellow stuff does that. Don't be tempted to skip the MetalReady rinse/prep though, nothing quite like bubbles appearing under your shiny paint 2-3 years after you finished the job.

Hope this helps

 

[pamp]

I feel the pain and after I thought I had all (rockers, etc) Tar and undercoat hideith sin Rats again

 

[tmason]

Thanks dp for this info.I want to fix this correctly for my kids so when I'm gone they can have a classic for their kids or at least thats plan.
Thanks Again, Tim

 

[tmason]

I pulled up both sides of back seat carpeting to get a better look at the rust around the removable plugs.I do have some pin holes to weld up.I need the replacement plugs and do you install the same tar backed form or do you just leave it alone and cover it up? Thanks Tim