More Rust Issues

[MK1_Oz]

At the start of my project in January this year I had the shell sand blasted and etch primed. Since then it has been out of the rain (other than getting slightly damp on its way to have the cage installed ) and kept in my garage.

Since mounting it on the spit I have been able to have a good look underneath and have noticed the attached rust (quite a number of areas like this ). It seems like where ever I have welded this rust is forming.

Question: is this related to the welding? Is this a sign that maybe I need to strip alot of the car? Is this a normal thing to happen - have others experienced this?

I asked a similar question a few weeks ago when the primer got wet going to the chassis guy but it was concluded that a rub over with a scotch pad would be sufficient. The rust below however is a totally different kettle of fish.

Would love to get it dipped and e-coated but dont think they do that is SA plus too expensive.

[ozstang65]

Looks more to be coming from the rail than the welds, ever put anything caustic in there?. Hit it with a wire brush and rust converter then give it some more etch. I ususally keep a small gun with etch in it all the time, just hit any bare metal that you want to protect with it, it can always be washed off later if need be.

[MK1_Oz]

never put anything in the rails although I was considering flushing out with Kurust to kill the nasties. Would be messy so prob wont end up doing.

THat longer section of rust matches up with a section of passenger floor that I replaced. The weld for that is pretty much behind that sill lip.

I hate rust....worries me that I will paint the beast then have rust bleed through the paint

[ozstang65]

No, that's not rust....THIS is rust...





Wire brush/acid it, then etch it and you can leave it for a while (weeks??) and move on to fix some more panels. If the repair rusts before you are ready to put a final finish on it then clean it up and hit it with some rust converter and some more etch. Your finish coat soon therafter will provide you with a final seal. Like others have said, etch is not a final coat, but it is better than leaving bare metal open to the elements.

Etch will wipe off with thinnners (at least Wattyl Super Etch will) so I'm not afraid to use it at any time in the repair process as it can either be removed or redone when you're ready to finish an area. Bare metal anywhere will rust almost instantly and definitely within hours, etch will stop this happening.

I use Super-Etch every repair that I work on. It can be welded through and it will protect any worked on areas until I can work on them again. I keep a small old gun with etch in it at all times when I'm doing body work. I give it a stir every time I need to use it and keep a pice of tape over the breather hole to stop it drying out. It's not a final finish gun by any means but it keeps etch on hand to seal any bare metal at any time that's needed.

[Jason B]

Red oxide paint also works well on rusted area's like welds.

[MK1_Oz]

Sounds like more stripping and etching. Might make sense to leave it and do it closer to the painting process (several months away yet).

Thanks guys

[gen mk 1rs2000]

RUST NEVER SLEEPS

[MK1_Oz]

I need to do some more research on rust. If you chemically treat the top layer of a patch of rust, do the lower layers continue to eat away the steel? Will a tiny amount of rust propergate into a larger patch even if there is paint over the top to keep the air and moisture out? ie will rust create more rust?

[ozstang65]

What sort of environment are you doing the repairs in? Anywhere with persistent moisture/humidity will assist the rust no end.

[ozstang65]

Keep the moisture/air out/away from the surface and rust will stop. Now I think of it, check out Por15.

[ulsterman]

Do some research on POR 15

[MK1_Oz]

I use KURUST in huge quantities which I believe is equal to POR15. Whenever I do a repair I cover everything with KURUST after then etch. It is interesting though, the rust in the pictures above are on the outside of the car whereas the repairs (still rust free) are on the inside.

Car is in the garage in Adelaide so only exposed to normal humidity. I am careful to not even drop sweat on the car!

[gen mk 1rs2000]

[Danny M]

This is why you go out of your way to use the best etch you can and why I used PPG 2pk etch as yes it was edging it's way towards a grand for the material but it never did any of that and once it was welded it sat un coated for a while without issue until touched up and primed and painted. But no I didn't get it wet and no it doesn't wipe off with thinners as you have to get a grinder to shift it!

[jpayne]

Very normal for a weld to rust like that.
wire brush it after it cools then apply quality etch to both sides all around and pray!
perhaps a touch up blast with sand before final paint preparation phase to be sureish

JP

[Momus]

Perfectly satisfactory temporary etch primer is found cheap and conveniently in spray cans at hardware shops and auto paint stores.

[MK1_Oz]

This is what I am facing. I am now very disheartened with the project.

I am finding it so hard to get mechanical tools into these area. I have just about sandpapered my fingertips raw.

[ozstang65]

Sandblaster or Paint Stripper?? Looks like a jack let go at some point in time too....

[MK1_Oz]

Yeah I am not sure how I will remove that rather large dent!!!!!!

I have a SuperCrapAuto DIY sandblaster that isnt too bad. Only prob is the car cannot really be taken out of the shed and the sand goes EVERYWHERE!!!!!! Prob the best option.

Cheers

[Roger Miller]

Show car ??

or

Race car ?