under car coatings

[gavcarter]

any one ever used this stuff? http://m.ebay.co.uk/itm/Chassis-pai...%3A56214ed315c0aa18f857efb6fffd9f12%7Ciid%3A2


no idea why that link is so long....

it for underside of a van, I have wire wheeled and wire brushed all the loose rust off, its had one coat of corroless rust primer, and will be due a second one when a bit more welding has been done.

apparently its good for 5-7 years with just the primer, 10-15 with two coats of there special topcoat. I think a good solid underseal / stone chip type paint will do the job, and probably be cheaper

any recommendations or advice? Don't really have 5 years too see if the corroless works or not lol, it definitely bites into the rust, its hard as rock, even a pain to grind back for welding, seems to be well stuck in there lol

 

[optima21]

Ive decided that on my cars I'm just using jotun 87 epoxy primer

http://www.baysidemarine.co.uk/jotun-jotamastic-87-epoxy-primer-47-litres-2241-p.asp

and am using wintergrade as it uses a 1:4 ratio, so you can mix with standard mixing cups. I painted 2 coats by bush under half of my car 3 years ago and there are only a couple of rust streaks and thats because of bits Ive missed as I've brushed it on, and Ive painted it grey so I can see if its rusting easier than if using plack paint.

Ive finding that its looking better are 3 years on its own that my other car painted with zinc rich primer followed by gravitex stonechip (after 3 years). neither car gets driven much (less than 2000 miles a year), but they are both parked outside all year round so are open to the elements.

you might be brave to follow this route though as most people will recommend upol gravitex or upol raptor

 

[Burdekin]

Rustbuster epoxy is Jotun repackaged. 121 is Jotun smartpack. Save yourself some dosh: https://www.smlmarinepaints.co.uk/primers/jotamastic-range/jotamastic-smartpack

As it's for the underside just go for Jotamastic 87 or 90https://www.smlmarinepaints.co.uk/primers/jotamastic-range/jotamastic-87
https://www.smlmarinepaints.co.uk/primers/jotamastic-range/jotamastic_90

The standard 87 or 90 will bond better than the aluminium grade 87 or 90 so fo under a car the standard grade 87 or 90 is what you want. The 90 can be applied thinner which is the only real difference between the two so as 87 is cheaper I'd just go for 87.

 

[gavcarter]

thanks for the replies, looks like jotun it is, what's the best way to apply? Brush or spray? Can I run it through a cheap shultz gun or will it want to be sprayed properly?
I've never used it before so imagine it would be quite thick....

 

[steveo3002]

shutz gun is too heavy , you would want a spray gun with a big set up like 2.5 mm or brush it on

 

[Swift&Bold]

The 1-2-1 or Jotun Smartpack goes on thicker so is ideal for suspension components or anything in the airstream that will take a direct impact, 87 & 90 is ideal for the floor pan.
Both can be rolled, brushed or sprayed on.

 

[optima21]

I got one of these spray guns a couple of weeks ago for spraying it on. it works fine from a 3hp compressor

http://www.ebay.co.uk/itm/131944206470

although I do apply it by brush under the car

 

[rcx132]

I've sprayed the Rustbusters stuff and Jotun 87 and also brushed them on. I used a 1.8mm LVLP gun and 10% thinner and it went on nicely. Rust busters also recommend the 1.8mm LVLP gun but again at inflated price. It's just a Fast Mover Tools gun, you can get it on ebay for much cheaper.

 

[rcx132]

I got one of these spray guns a couple of weeks ago for spraying it on. it works fine from a 3hp compressor

http://www.ebay.co.uk/itm/131944206470

although I do apply it by brush under the car

Lovely that's got a 2.5mm tip, I thought my 1.8mm was the biggest. For £19 I might try it as I've got a lot of Jotun spraying to do.

Someone on here said they go entire body shells in Jotun 87. I thought I would do the same and then put the 2K body paint on top. Rustbusters say that regular primer is porous and can cause problems when used i a DIY garage, and they advise using epoxy primer instead.