what paint

[racingrepairs]

I want to treat the rusty sub frame and chassis of my car. What type if paint should I use to prevent further corrosion and eliminate the current rust?

[Tekkigizmo]

First remove all loose rust then paint on kurust from halfords it turns the rust into ferric tannate, a bluish black solid surface that can be sanded, overpainted etc, prime the surface with etch primer and allow to dry as it only works once it is dry. Some etch primers are available with zinc in them however if it does not, prime the surface with zinc primer then overcoat with stonechip, waxoil. Stonechip for exposed areas and waxoil for more protected areas. Stonechip can be overpainted with the colour of your choice waxoil cannot. Zinc is used on large ships as a sacrificial metal in a cathode/anode arrangement to reduce the corrosion of the steel/iron

[racingrepairs]

Wow, thank you

[RST]

Have a look at frost automotive on the internet. They do the POR15 system which having used them on previous cars -I haven't seen anything so good since. It was a mk1 MR2 guy originally put me on to them.

When I treated the suspension on my Aristo I didn't realise I had a split glove and I ended up with a black hand for well over a month afterwards. The POR15 chassis paints seem so much more hard wearing and they seem to "thicken up" as they cure. Bit more expensive but you pays what you gets I guess.

PS. I've used the above method as well, you can also use "galvfroid" or words to that effect / weld through zinc primer -can get it from most local industrial counters and that's what lots of classic car guys use. Just be careful if you're spraying acid etch / galv spray unless painting it on -you need a decent half face respirator, it's nasty stuff.

Hope that helps,

Rich

[al/c]

por15 and if you are painting and not powder coating use a 2k system. ps i hate powdercoating

[RST]

PS LoL if I could do it I'd blast and powdercoat parts all day!!!!!!!!! Thats the best way to do it.

[racingrepairs]

First remove all loose rust then paint on kurust from halfords it turns the rust into ferric tannate, a bluish black solid surface that can be sanded, overpainted etc, prime the surface with etch primer and allow to dry as it only works once it is dry. Some etch primers are available with zinc in them however if it does not, prime the surface with zinc primer then overcoat with stonechip, waxoil. Stonechip for exposed areas and waxoil for more protected areas. Stonechip can be overpainted with the colour of your choice waxoil cannot. Zinc is used on large ships as a sacrificial metal in a cathode/anode arrangement to reduce the corrosion of the steel/iron

So I need these layers:
1 kurust
2 etch primer
3 zink primer
4 stone chip
5 hammerite paint

Seems a lot of paint?

[AManInDandism]

I opted for Dinitrol Converust, which seems similar to Eastwood rust converter. I went with POR15 for the top coat. I don't think you need etch primer and the like when using said product, but I could be wrong.

[Tekkigizmo]

Most if not all rust converters contain tannic acid or phosphoric acid or a combination of the two, tannic acid converts iron oxide (rust) into ferric tannate and phosphoric acid converts iron oxide into ferric phosphate. Both are less reactive than iron oxide, other ingredients include a wetting agent and primer.

Etch primer although not essential does have its advantages, while it drys and cures it embeds/etches itself into the metal by a few microns making a stronger bond between metal and paint this makes it less likely to flake off.

Zinc primer again not essential creates a protective layer to slow down corrosion.

Stonechip is a thick rubberised paint available in black and white (I'm not sure about other colours) that stays flexible when dry and as the name suggests it protects against impact damage from stones etc, it is also waterproof if not punctured. If it is punctured remove the coatings from the surrounding area until clean and rust free and recoat. Stonechip can be overpainted but does not need to be, normally on the underside of a car it is left as the final coat but on the sills is overpainted with the car colour.

Hammerite can be used but is not needed and is unlikely to add any more protection but it can be used instead of stonechip on mechanical components like roll bars, wishbones etc. Also powder coating is an option on these parts.

POR15 seems to be quite expensive and preparation is extremely important if you want it to stay put.

Powder coating again preparation is very important and it is then baked on, will the electronics and plastics in a car take the temperature or is it going to be a complete strip down? also powder coating is very hard but can chip and would need to be repaired quickly if corrosion were not to spread.

Zinc plating is not a good idea because it is likely to distort the chassis/body. And also may temper the metal making it brittle.

Zinc spraying is another option but the car would need to be completely stripped/dipped and then sprayed with molten zinc not something you could do at home.

I know it seems like a lot of paint but each has a specific job to do.

[Gullzter]

Good thread.. I have quite a rusty subframe/components, so am i correct in saying i can use this method on wishbones/movable components etc?

[Tekkigizmo]

Powder coat, hammerite but not stonechip not on movable components.