Rust! Anybody do DIY undercoating?

[ma4t]

Any tips besides moving to a state that doesn't use salt during long winters?

Here's the deal. I live in Michigan and we have long winters. They use a LOT of salt on the roads. My 2004 Mazda has some small patches of rust that I noticed when I was trying to take off my hitch. It's right there on the frame. I should have taken pictures. In fact, I'll probably take pictures of the other places once I get the stupid hitch off.

I got a grinder attachment for my drill and worked it off, then sprayed it with primer. That's the only thing I had.

Does anybody have any experience with undercoating?

m

[VetteOwner]

undercoatign may or may not work. it will block water from touching the metal but in turn will keep water behind it if it does get back there somehow.

they have undercoating in a can. just follow its direactions and might be fine.

[McPatrick]

I think if there is already rust on the frame, after trying to get most of it of with that grinder attachment, I'd first try and stabalize whatever rust may be left with some of that industrial paint you can use over rust, before putting the underbody coating from the can on it. That way you will not close up a space with still some small pecks of rust underneath taht might still try and spread out again.

[MnFocus]

Way back when I helped a friend "restore" a couple Chevelle's and Camaro's -we used a product called POR-15 on the frames/underbodies . Seemed to hold up to Minnesota salt pretty well . Still available I believe ( ? Eastwood ? seems to ring a bell )

[basjoos]

Its good stuff and I have used it on the rusty spots on my Civic. Their website is www.por15.com.

[Spule 4]

Rust proofing seals the car, no good.

Gotta keep the rust out. Oily metal cannot rust. Fill door bottoms, rockers, frames, etc and spray underneath with a mix of chain bar oil and motor oil, or even use grease in some cases.

A friend has done this for years with Peugeot 504s in North Ohio/Cleveland, and they never rust!

[Ryland]

I've talked to people who sware by linseed oil sprayed to the bottem of new-ish cars, as it stays soft and flexable, I've used an undercoating that only skims over, insted of hardening right away, the idea being that it is self repairing if it gets scrached, but most of the problems I've seen with undercoatings comes when they age, and harden.
I have some rust of my civic that I first sprayed with rust reformer, that stuff that turns rust black, the clame being that it is then paintable, the problem is however that it is water saluable, so you need a solid paint over it, the stuff I have over rust is then covered with clear boat building epoxy, and is visable, it has not yet started to rust again, so it seems to have worked stoped the rust.
so to repair rust my opinion is that a rust nutralizer, or reformer, fallowed by a paint, or if it needs to be filled, an epoxy filler, then paint, and a solid quality clear coat, and if it's in a fender or underbody area a solid rubber spray on undercoating.

[lca13]

Come on, let's go all the way.... cosmoline!

Also, I found that moving my cars from MN to CA did wonders for my rust problems :-)

[jwxr7]

Its good stuff and I have used it on the rusty spots on my Civic. Their website is www.por15.com.
It seems like I'm always fighting a losing battle with rust too:mad: . Even my 2000 gmc is getting rusty rocker panels :( . Does it work well on it's own or did you use the marine-clean and metal-ready along with it?

[Raccoonjoe]

I was looking at something similar to the POR-15, but being a broke-*** college student, settled for something like this:
http://autozone.com/selectedZip,46806/initialAction,accessoryProductDetail/initialR,NONAPP10952/shopping/selectZip.htm
I know folks who have used it....they told me that you just wire-brush off the big flakes of rust, then paint this stuff on. Use 2-3 coats, then use real paint over the top. I've seen the cars that it's been done to.....One is a beauty of a Fiat, and the frame/body that was painted with this has held up very well to several Indiana/Michigan winters.

Personally, I'm going to use this on the bottom of the doors/rockers/quarter panels on Julie, then paint over it with Herculiner. (spray/roll on bed liner) That stuff works like a charm......


On the other hand, I've got an uncle who swears by the used motor oil routine. I've done it, it works. Just drill a small hole in the inside of your door/quarter/whatever, and using a old-school oil can, fill that door panel up until the oil starts to run out the bottom seal. Then run up and down a dusty gravel road a few times, to cover all the oil with dust. This worked well on his 84 Bronco....When he sold it 5 years ago, it was still in showroom condition, after surviving 250K+ miles and 15 years worth of Northern OH winters

[jwxr7]

http://autozone.com/selectedZip,4680.../selectZip.htm

Yeah, that's what I ended up getting too since I'm so cheap :o . It seemed to work on my 87 rx-7 years ago. Only problem I noticed was you really have to keep it dry for the 24hrs before topcoating. Dew formed on my metro overnight after rust treating some areas on the hatch, and it started to flash rust at the edges :mad: . I'll have to redo it soon.

[88HF]

I had some rust in the back of my 89 civic hatch (couldn't find the leak) so I popped a hole in the spare wheel area and used "the must for rust" and put bedliner over it. Worked great. My sister ran with the idea on mine/her/ then my 88 integra and she used the spray cans which suck, and it wasn't textured, and it cracked and peeled. Use the roll on texture roller works best.

[Red]

I do the motor oil/grease method. Makes life a little easier when washing crud off the frame rails

[hypermile]

Try using magnesium strips, the magnesium acts as a sacrificial anode (http://en.wikipedia.org/wiki/Sacrificial_anode). Simply put, the magnesium will rust instead of your car.

[Bill in Houston]

Does anyone screw galvanized bolts/washers into holes in the body work for use as anodes?

[Raccoonjoe]

Those last two suggestions are very interesting. I seem to remember someone trying to sell that as a undercoating solution a number of years ago, but can't seem to find what I'm looking for on El' Google. Don't recall that it went over too well.....

[white90crxhf]

i used RUST BULLET on part of my car, it's been on a year now and no rust has come back, though the finish doesnt look too great since i used the brush they provided. I didnt repaint it either, it looks like galvanized metal in color.

[Spule 4]

Come on, let's go all the way.... cosmoline!

Also, I found that moving my cars from MN to CA did wonders for my rust problems :-)


A friend bought a Panhard PL17 Cabriolet that was covered with that stuff, a monster to remove, but it did preserve the car while in storage for over 20 years!

[ffvben]

3m makes a good can undercoating. the weight of your car can go up if you over use it, this is why new cars only have it sprayed on certain spots like welds or seams to save weight for Fe. if you spray it on the frame be careful when jacking/ putting it up on the lift, even though its dry the weight of the car on the jack might make it slip right off the frame( it turns into mush when putting pressure on the undercoating). its not like a truck bed liner where moisture can get behind and cause rust, it seals water/air from the area and is thick so no stones can chip it easily. but I do like the idea of just using oil, I've seen a few cars with the oil everywhere with the dirt coating but dust/dirt can trap moisture too. what a mess to work on . I've also used the 3m to seal my chimney on the roof of the house ;)

[ffvben]

Those last two suggestions are very interesting. I seem to remember someone trying to sell that as a undercoating solution a number of years ago, but can't seem to find what I'm looking for on El' Google. Don't recall that it went over too well.....

Rusty Jones rust protection?? where they drill small holes in your doors, spray undercoating inside then a few years after they rust like crazy at the small holes they drilled through.

[n0rt0npr0]

I'm glad there isn't any place of business in Michigan that drills holes in cars for rustproofing purposes anymore! I was told that there is a law against doing that here now. I couldn't find that law, but I did find a law that says they cannot use the old chemicals anymore. So sometime in the last 7 years, the places that do chemical rustproofing had to move on and start using a totally new product. The old one was just really really smelly, and would burn the eyes quickly.

They went to a wax-like chemical now, similar to waxoyl.

And if anyone wants a really easy rust stabilizer, try Permatex 81849 Rust Treatment. Three coats within 6 six minutes and let dry for 24hrs. Then paint with any non-water based paint that will stick to it. Works like a charm. I have spots that I did 3 years ago that are still perfect.

Linseed oil is great if you arn't going to keep your car washed in the winter...but if you do, it's gone by the end of February. And theres still 1.5 months of salt/snow left. :(

[ZugyNA]

* oil in door/hatch bottoms and inside frames

* a good rustproofing paint on the outside of frames etc..clean up all rust first though...even the pits

* rustproofing paint...then fabric/thick roof cement OR alum/plastic/rubber-tar adhesived repair tape with roof cement over it inside wheel wells

[Danronian]

On my current vx it had the drill holes and then rust proofing in the panels, and every panel on the car just about had some rust repair, so it really really doesn't work.

To stop corrosion in my wheelwells I always first clean off the rust, apply a sealing paint, then use roofing tar and or rubberized undercoating to cover the entire wheel well. I've never had a problem with rust coming back after this.

[Raccoonjoe]

Does anyone screw galvanized bolts/washers into holes in the body work for use as anodes?

Well, couldn't find the link to the folks actually selling this stuff...but try this....http://www.counteractrust.com/counteract.htm.

Also, saw this forum about the ol' Ford Maverick, where the members were having this exact same conversation: http://mmb.maverick.to/showthread.php?t=4398