[Benz]

okay so i live right on the coast and do a bit of beach driving.

this is all fun and games until you look at my chassis... (none at all in the body yet) surface rust has started to appear! and if i don't do anything about it its going to eat my car!

now the plan is to go over the whole underside of the car with the usual rust preventing black stuff. (have found allot of sites saying electronic rust prevention devices don't work unless the whole car is submersed in sea water or buried in dirt) but how do i treat the existing surface rust and stop it from surfacing its ugly car eating face again!

(have done a bit of panel work on old cars before and where ever rust has been has started to rust again with-in a year of re-painting)

[coilyzook]

CLR you can get it from most superarkets in the cleaning isle, its with domestos

[Benz]

yeah okay. but how will painting after go?

[coilyzook]

hmm dunno
maybe do clr then sugar soap to make sure the paint sticks properly

[SuperRoo]

I dont have any rust problems but I was looking at hitting my chassis main rails and diffs with a rotary/orbital type sander some time this summer when I have a couple of days off (probably over xmas) then using a Killrust type mat finish paint to cover.

I think a paint with a high zinc content will do the trick. I used this sort of paint on my front bumper and roll bar and they have both held up fine in the two years since I did them.

[lump_a_charcoal]

Spray it up with cold gal, then black over it.

[zookster666]

There is a staun product called salt assault it's meant for the staun massojet they are easy to use and pretty cheap u could use this then paint it then use it after every beach run should help preserve it

[SuziBlu]

Go to a marine store, get some Marine Clean, it contains about 27% Phosphoric acid, the same as in CLR but much stronger.

Give the surface rust a wash, rinse with running water, and then use any one of a number of paints for rust prevention.

Zinc Chromate is about the best metal primer there is.

Give it 3 or 4 coats so that you have no pinprick holes that will allow oxidization to start.

[Benz]

okay great. so the Phosphoric acid will eat the rust. is anything left behind to stop the paint from sticking????

[zukenutter]

I use a a rust deactivator before painting. There are plenty around they actually turn the oxide black and can then be painted straight over the top. I also use this when I strip body panels to bare metal. A quick hit before priming just to make sure it won't rust underneath 12 months later. I painted my Camper trailer frame with Cold Gal and then Kill Rust over the top.

[Benz]

okay.... now i need to work out a time when i can have the jimny off the road for a wile wile i do the whole job properly!

[303zuke]

SuziBlu wrote:

Go to a marine store, get some Marine Clean, it contains about 27% Phosphoric acid, the same as in CLR but much stronger.

Give the surface rust a wash, rinse with running water, and then use any one of a number of paints for rust prevention.

Zinc Chromate is about the best metal primer there is.

Give it 3 or 4 coats so that you have no pinprick holes that will allow oxidization to start.

Yeah, agree on the Marine Clean, but don't stop there.

POR 15 is the best way to stop the rust, but POR paint is hard to topcoat with a matching colour of your car. You might have to be happy with one of the POR colours for your chassis (Black, Grey or Silver).

[something_else]

phosphoric acid is the trick. i just buy it straight and mix it 50/50 with water to thin it out. spray it on in a weed killer bottle, scrub all the loose rust off with a wire brush. and get it in everywhere, youll see that the rust turns darker that means its neutralized. do this 2 or even 4 times to be on the safe side. then you can start to prep it for paint. it wont rust again after that =D

[SuziBlu]

Phosphoric acid is only ever about 27% unless you are commercial and can get it higher. 40%

Use straight.

It does need to be coated after, as it will form a resistant coating, but not impenetrable.

I also use a chemical, that for all means is a paint.

Chemsearch Chelade

Its a polymetric rust converter, meaning, it has a chemical reaction with rust, not good on bright surfaces.

You paint it on lightly rusted surfaces, just so long as its not flake its perfect.

When you paint it on, it goes a sort of green colour, and quite quickly, minutes, turns black.

This is now a very hard non oxidised surface.

Coat after with any rust paint such as Wattles Killrust Red Oxide, and then a further top coat.

If you can get phosphoric acid, excellent, give it a really good clean, and then use quality rust prevention paints, if you cant get the acid, use chemsearch.


The trick for true rust prevention is lots of paint, even a minute pin prick will allow oxygen to come in contact with metal and start oxidation, rust.

[Benz]

black if fine =]

yeah i know.... when i painted my rims i didn't paint them thick enough....
need to do it nice and thick =]