Treating underside + tackling rust

[Iain]

What's the best method of treating the underside of the car after all the original underseal has been removed?

I'm in the middle of stripping most, if not all, of the original underseal off the underside/arches and treating various areas to some rust stopper and fixing any bad rust. I'm currently spraying the bare metal with etch primer, is this right or should I be using red oxide primer?

Would like to paint the underside and arches white so any underseal/body protector that comes in white would be a bonus to save using Hammerite after?!

[ben doodar]

i would use the rust treater stuff youve mentioned than paint on some red oxide, followed by white stonechip and then paint over that, thats how im going to do mine.
benn off here said he had used some good 3m stuff which was like the original elasticated stuff. certainly worth asking him what it was mate.

[Benn]

Tbh if your gonna do it do it right.

3M do a rubberize sealent. Its a 2pac sealer that you'll need a compressure to spray, but will need the gun end.(2pac aas in it comes in a bag thats in bits bits, you kinda open the inner bits of the bag and let it mix) Isnt that cheap tho but worth paying for) Beileve Keith robinison used it on his after i said too.)

But its the best on the market. As as said it drys to a rubbery finish which is paintable and will rezist chipping and so on.

Allso the car needs to be bone dry, and i really mean bone dry. Like ya nans bifta in the middle of the desert.

[ben doodar]

think i might have to try some of that benn. do you have a link to anywhere online that do it? where did you get yours from? did you also say you had a part number for it?

[Benn]

Prob is you need the gun to spray it, and i dont think that will be cheap.
I used iut when working at the bodyshop, and its being used on mne.

I can get the part number yes.

Not seen it for sale, but havent really looked.

[Iain]

red oxide, followed by white stonechip and then paint over that

Benn reckons underbody sealer is better than stonechip as it's stronger. That 3M stuff sounds good but not if I need to buy £s worth of special equipment, brush on or aerosol can me thinks!

Thanks for the replies so far chaps. Still not 100% sure what I'll be using tho!

[ben doodar]

is underbody sealer not just going to be underseal that sticky tar like sh!t tho? cant imagine being able to paint over that?
i have a decent compressor benn so do i need a specialist gun for the 3m stuff or would a normal schultz gun be allright?

[MK999]

I'll be up against the same issues soon, I was just going to hammerite it after some kind of primer... have used waxoyl on it already over the original stonechip stuff and it's worn off pretty quickly on the chassis rails from using axle stands where it doesn't ever really dry. Not sure if hammerite would stand up to it any better though

[Edd]

I'v used two coats of U-pol acid 8 etch primer on the whole of the underside, which will be painted over with two coats of Hammerite. On the splash guards on rear inner arches iv got some U-pol Gravigaurd which comes in a can. If i had a compressor and space i'd go with Benn's idea tho tbh.

[Benn]

That is the only prob, you need a gun attchment to be able to paint most of the good stuff.

Stone chip is ok, but it chips easily and isnt that water proof.
And when you paint hammer right over the top it can become soft again and start to peel off.

If you are wanting to paint over it with hammeright you dont want a sealer that says wet/sticky/ tar like. As it can be a utter cont to paint over.

One of the biggest probs you will get is the factory seam sealer holds and hides alot of water, with means it hides rust and holes.
From what looks like soild metal can be come holed very quickly.

You want a sealer that drys but stays soft, which you can then paint over.
This will take stone chips and being jacked up on and axel stands and such.

Which i'm still looking for for home base rebuilds.