Hi all,

I'm working on my floor pans... I have them wire brushed down to bare metal. They are in overall decent shape though there is some rust around the perimeter where they meet the longitudinals. These corners seem innaccesable to all but a small wire brush (toothbrush size). Question is:

1. Should I apply POR 15 Surface Prep, then POR 15 to get in cracks, then Seam Sealer, then maybe another coat of POR 15 over Seam Sealer?

2. Or, should i just do Seam Sealer first over bare metal, partial rust areas around the perimeter? Then follow with POR 15?

Second question... the smaller 'cross tunnel'.. the one where the front seat adjustment bracket mounts, is in poor shape. Rust inside it looks bad... some of the lower edges are gone but it's still largely inaccesable to any tools or painting. I think my options are:

A. Drill some holes in top, blow it out, and spray as much paint in there as I can and call it a day.

B. Cut it out and weld in replacement. But is this part even available? And still how do you paint the bare metal inside after you've welded a new piece in?

Any advice would be appreciated.

Just my .02 but I would not use POR 15. It's really thick and will crack over time (shrinkage and body flex (hopefully you don't have too much of that )) Once it cracks it works just like the old factory tar and traps water. I really like Zero Rust, it's not available at too many places but the local paint shop near me uses it when they do dock restoration at the harbor here, they paint all the metal brackets that are submerged under salt water with it, it holds up for over a year under salt water before they notice any deterioration. I've been using it for 5 years and haven't seen any of the parts I've used it on start to corrode.

For the tight areas you can't get your wire wheel into, heat works wonders- blow torch and then use a small wire brush to wipe away the melted paint etc. Use some sort of rust inhibitor, then paint with zero rust (or POR 15), then use seam sealer, no need to paint anything other than the body color paint over the seam sealer.

As for your cross bar, I believe that they are still available, if not someone can probably cut one out of a donor car for you. You can always use welding primer on the new one before you weld it in place, then just try and get paint sprayed in after it's welded. I'd be careful about trying to get tons of paint in there, seems thick paint will crack and cause problems again. Just stop getting the inside of the car wet

Dan

Yeah I know about zero rust, some parts I used it on do have corrosion... looking more for information on the spray in wax rust preventers made for inner body work.

Where are the tunnel crossmember's still available? Any links?

Restoration Design makes new cross members.. look for #20 on this page.

http://www.restoration-design.com/Merchant...ory_Code=914#17

I wouldnt mind knowing what I could spray down in the tunnel too. I dont have any holes there and I'd like to keep it that way.

I just used this stuff in my tunnel. Don't know how long it will last. The reveiws seem to be good but only time will tell.

http://www.eastwood.com/internal-frame-coa...ray-nozzle.html

Thanks guys

I'm afraid it does not work as advertised ...


Clean off the surface rust and treat the metal with MetalReady or something similar. Spray with a good primer and paint.

If the metal is weak, has holes or is rotten, cut it out and weld in replacement panels. You can use weld-through primer on those areas to give you some protection of the new metal.

I asked a noted porsche restoration guy about using POR 15...he basically ignored my question (which told me something) and told me to use either Benjamin moore iron clad or rustoleum damp proof primer...Neither will you find at home depot etc...But fastenall or BM store which may need to be ordered.

Personally I did ironclad, factory tar pads and then body color ...Specialist said do not use tar but I wanted sound proof. Figured with new seals the idea is to keep water out !

On cross member ...Auto Atlanta does carry that part as reproduction....

Good luck

I have had good luck with Por15, but I think it's all in the prep work. I did the inside of my floor pans with the stuff aftter removing all of thre rust and treating with metal ready, and it looks just like it did when I did the work about 6 years ago.

What about using LPS-3 , a spray rust inhibitor/preservative . better than WD-40 .

I've had good luck reaching hard corners with a Dremel tool with a flexible shaft. Pick your own bit.

My post from '05

What we do in my restoration shop is clean, treat/arrest the corrosion, repair any corrosion that involves very heavy pitting or perforation, treat with phosphoric acid wash, rinse, dry, and paint. We use a undercoating kit that can be purchased at JC Whitney, Eastwood, and other auto supply houses. We treat the entire car, that is all the dead air spaces, boxed support members, etc.

First remove the control cables, and shift mechanism, as well as the pedal cluster, and most of the interior. Mask off the wiring harness with plastic and masking tape. Clean out the tunnel with compressed air and a shop vac. Manually scrape whatever you can reach with wire brushes, stainless toothbrushes, etc. Next you need very hot water and cheap automatic dishwashing detergent (like cascade). You don't want to get this on finished surfaces, as the trisoduim phosphate can dull painted surfaces. Mix up hot water with the detergent, and spray in into the tunnel. With the undercoating kit you get spray wands and different nozzles to blast in the corners, etc. Again, use the shop vac to remove the water. Next rinse with clean warm water, and clean this up. Blow dry with compressed air and the undercoating wands and nozzles. Check out the cleaning job with a light and a inspection mirror, make sure everything is nice and clean. Let it dry for a few days. At this point a little flash rust isn't going to hurt anything. Now it gets more fun! You can use Ospho, Oxysolve, any corrosion treatment with phosphoric acid that leaves a phosphate coating. You mix up the acid as directed, and after you've donned your safety goggles, respirator, and rubber gloves, you spray the area with the acid mixture. Most of them require liberal dousing, and you want to keep it wet for several minutes, longer if you've got more serious corrosion. Next you rinse the acid off with water, and clean it up. Blow it dry. Let it sit for a few days. Last you can use the same undercoating kit to blast your favorite corrosion paint over the treated areas.

This is alot of work, and makes a big mess, but it's the best thing you can do to mitigate corrosion. It's also a good thing to do if you've welded on structural supports like the GT stiffening kit, Mayeur kit, etc. If you don't treat the backside of a panel that you've welded, it will rust.

A thread: http://www.914world.com/bbs2/index.php?sho...=87664&st=0

Update: in many places you can't get cheap automatic diswashing powder with TSP anymore, so a product like "Marine Clean" may be an option. There are some paint supply stores that do sell TSP.

So, what did you decide on?

I have always had good results with using epoxy primer over bare, clean, treated metal. Then the seam sealer then more epoxy primer. In cavities I would use a cavity coating over the epoxy primer. I have bought some of the eastwoods internal frame coating but the results are yet to be seen. Rustoleum is good industrial paint but not nice car paint in my opinion. But, it may work great in a cavity and is a lot cheaper than epoxy primer. It has fishoil in it for weatherproofing. It may not hold up to top coats other than a cheap enamel though. I use lots of it on deer hunting stuff like feeders and such and lawn furniture. Also in my opinion anytime you heat metal to where it changes color you burn it some and it seems to rust quicker.

Perry, you saved me alot of typing. Your proceedure is similar to what I like to do. no single-step process is going to get it done right. one proceedure or product will not cover all conditions or locations.
POR 15 is no good on cleaned metal, it WILL peel. wire wheeled and cleaned metal MUST be etched.
home depot, lowes, Maynards have TSP and Ospho or jasco
sherwin williams, Frazee house paint stores have Ospho, jasco, metal prep (phosphoric acid based)
body shop store, TCP global.com, tri city paint has POR 15 brand metal ready, SEM rust mort, PPG dx 530. I like SEM Rust Mort and Metal Redy because they have a zinc component. SEM is agressive stuff.
ready the instructions carefuly. SEM Rust mort is awesome and powerfull but if layed on thick and left to dry it will be gummy mess.

my advice to anyone trying these proceedures recommended by the pros is try the chemicals on test pieces of metal. there are alot of subtlties in teh timing and technique that we forget to mention or just take for granted because we do it often.

the key is allowing the chemical reaction to happen. the deeper teh rust, the longer you want it to stay wet with the acid. go slow. the little splashes will not feel good on exposed skin of finished surfaces

I do basically the same as Perry. Get ti to bare metal ( done ) next step is either coat it with OSPHO which is more readily available to the average consumer. Or give it a coat of etch primer then a coat of selaer. That is my normal routine. After that I use a spray undercoating form a gun, but a good quality spray can will get you good results. I am finishing up a complete floor install tody and had planned on posting some pics for you all of the normal pitfalls you run into. MY bnigets advise to all is to completely remove the under coating, and most importantly the tar boards inside. you never know what is really there until that crap is gone. For cavities, I have a spray wand I got from Strap On that allows me to shoot Ospho into the longs, I let it sit overnight, run water through to clean and neutralize any remnants, let that dry and then coat over it with Eastwoods rust encapsuletor.A teaser pic

I picked up a gallon of phosphoric acid which seems to be the base of all of these rust stopper products.
It is just the acid used to clean floors and such at HD in the cleaning isle.

I sprayed it on a section that was covered in surface rust (underside of a roof on another car) and it did what I expected...it turned all the rust to dark black.

It may be a good thing to use inside the tunnel...at least as one of the first steps to stop any further rust from spreading.

My philisophy is simple, if its rusted, cut it out and replace it.
In the case of the tunnel, that has a few more challenges, but I have removed the floor underneath the tunnel and cleaned that way with some success.



Rich

What is the necessity of washing and rinsing the phosphoric acid treatment from the treated surface? In the case of inside the longs or tunnel, generally your not painting them so as long as it *converts* the affected area is there a detrimental result that your trying to avoid? just seam weeping?

I used all three steps of the POR15

and I think it worked out great.

(see my blog for pics)

It is my understanding that Acid needs to be neutralized at some point or it continues to do its thing.
Not sure if that is a bad thing or a good thing.
I would wash it out once it hit a stage I like.

rich

The water stops the acid. If you are going over it with another coating, you want to stop the acid, maaan.

rust thread bump...

...and zinc rich weld thru primer on panels that overlap that get welded together

this thread should be flagged as teh rust treatment classic thread

Great info in this thread. I am staring to close up my longs, firewall bulkhead and some other cavities, so was reviewing all this info.

The rinse-with-water-and-let-dry part of the process scares me. I wouldn't have considered it, except that at least three guys in this thread with 100x more experience than me are doing it. Running a water hose through my longs . Guess I'll be doing that as well.

For Scotty B., I thought I read that in your opinion rust encapsulators (not converters) are snakeoil, don't bother, but here you say that's how you finish off the process. Is that true just for cavities, where other options are limited? Or maybe what you are saying is that they are okay if you get rid off all the rust first, just don't use them to actually encapsulate rust?

I like to use a MAPP torch to carefully heat all the nooks, crannies, and especially seams after applying paint prep, metal ready, and water to dry these areas out. Leaving water sitting in your seams for a few days will ensure they will rust.

John

YUP
I have used a paint stripping heat gun to dry out the acid rinse water, to soften and remove the tar on the floorboards, and to help remove gunk and seam sealer from all nooks and crannies. Focused heat is your friend when drying out the prep liquids!

I have been doing the interior rustoration piece-meal, but this Sunday I am planning a full-on attack with Wurth Metal Ready. It was not cheap, but has both the acid and zinc in it. Then, Wurth self-etch primer, then paint (then seam sealer?).

A little flash oxidation will help some of the coatings adhere. I use the wands to blow the cavities dry with compressed air.