Best under-car paint and underseal?

[jaistanley]

Hi guys,

I'm about to fix a load of rot under my daily shitter and have my project (minty) S50 car in pieces and wondered whats the best underseal and paint to use?

On the running gear I fitted to the iS I painted it all in 2 pack brake caliper paint (after re-furbing my M3 calipers and having loads left) but noticed that that just flaked off over time. On my iS (daily) I want to cover the repairs I make but more importantly for the project car I want to clean/blast/strip anything uner the skin and that I bolt on (think running gear, subframes and under-bodywork) so that it's all minty McMint.

What would be the best prep and paint for durability? I actually think Hammerite is very good as it remains flexible. I've tried that stonechip paint in the past and dont think it lasts long enough. As for under-seal, whats the best to use?

Many thanks..

Jai

[Loony]

When i did the i.s i took all the wheels off and arch liners etc.Then gave it a good jet wash and scrub and left it to dry for a day.Then i used some normal waxoil underseal and just covered the underneath in that.I can not remember the name of it but it comes in a black tin(i think halfords sell it).

[Brianmoooore]

E30 underseal is polyurethane stuff. Avoid using bitumen based stuff, as it eventually hardens and lifts.

[whipsey]

E30 underseal is polyurethane stuff. Avoid using bitumen based stuff, as it eventually hardens and lifts.

where can you get this from brian?

[old_skool]

Professional stuff like Brian is talking about can be got from Brown Brothers or any large car paint factor. I use the 3M brush on seam sealer. It's awesome stuff and smells delightful. When I had a bare shell redone, they used a product they call 'boil in the bag' it is a polyurethane compound which is heated and then blasted on with a gun.

As Brian says, bitumen stuff is to be avoided so stay away from Halfords.

[whipsey]

Professional stuff like Brian is talking about can be got from Brown Brothers or any large car paint factor. I use the 3M brush on seam sealer. It's awesome stuff and smells delightful. When I had a bare shell redone, they used a product they call 'boil in the bag' it is a polyurethane compound which is heated and then blasted on with a gun.

As Brian says, bitumen stuff is to be avoided so stay away from Halfords.

so you used seam sealer to do the whole car are there any benefits to this and what sort of cost am i lookng at and quantites?

[alan325i]

the stuff they use is called Shultz this is sprayed on, costs about £6 a bottle and will need 2 or 3 bottles........oh and a compressor and underbody spray gun (£12 from machinemart)

[whipsey]

the stuff they use is called Shultz this is sprayed on, costs about £6 a bottle and will need 2 or 3 bottles........oh and a compressor and underbody spray gun (£12 from machinemart)

so whats the recomended brand i want something that is going to last

[old_skool]

Shultz is black sticky nasty stuff used by many a MOT bodger! It is bitumen based and makes a right old mess if not careful. The hours I have wasted scraping it away from rusty old MG's. Pacerpete buys this by the van full

Seam sealer is used for creating that factory looking brushed effect seam. I use it round repairs because it works so well AND is the closest I have seen to the BMW product when set. If I had to do a large area then I would use a spray on polyurethane underseal. Ring someone like Oxford Paints (google them) and ask for their technical guy. He will overwhelm you with products.

[whipsey]

OXFORD PAINTS LIMITED
742A Barking Road
LONDON
E13 9PJ


these guys

[Gwynleym10]

http://www.consumablesexpress.co.uk/aca ... alers.html

2nd one down?

~any good for offroad trucks?

[agreen]

can you remove all the underseal and replace with something like hammerite ?

[old_skool]

can you remove all the underseal and replace with something like hammerite ?

Hammerite is for your garden gate.

[fuzzy]

can you remove all the underseal and replace with something like hammerite ?

Hammerite is for your garden gate.

and diff casings.....and brake calipers etc.

[old_skool]

The third one down in that link is the stuff! I had this before and it is the mutts. Very very tough finish but maintains impacts resistance and elasticity.

The brush on super seam sealer is the stuff I use too.

[agreen]

Its just something i am doing to the track car emoving all the old underseal (tedious job ) and was wondering what to replce it with .Thats all

[old_skool]

Its just something i am doing to the track car emoving all the old underseal (tedious job ) and was wondering what to replce it with .Thats all

I really wouldn't use hammerite on any car in any location. I think it's awful stuff but that is my opinion. If you want a cheap and cheerful underseal that'll tidy things up and provide at least a smattering of proper protection then go for schultz, as mentioned above.

Personally I would use a spray on product, then body colour paint followed by a waxoyl style product, thiswas recommended by Ian Haynes as superior to traditional waxoyl. Bilt-Hamber also do chemical rust treatments and removers that look very good.

After all that scrubbing and rubbing down I can't understand why people scrimp on protecting vulnerable metal

[jaistanley]

When I mentioned hammerite in the original post, i meant for painting things like control arms, subframes etc in the hammerite gloss paint. Any reccomendations for this? (short of getting it all powder coated!)

Thanks for the input on underseals though.. All duly noted!

[old_skool]

Jai, just use regular etch primer and black satin aerosol for that kind of stuff. Hammerite on cars is just plain wrong.

[oylegate]

I would definately agree with alan and old_skool. Schutz is the way to go. I use 3M Black Body Schutz with the spray gun. Handy tip, for small areas you can brush it on and leave it for five minutes then go back and dapple it a little with the brush tip and it will give a near factory sprayed on look.

[suzie650]

Schultz is what you say in germany when you have stomach gasses coming back up in a pub (and you're a tad rough)
The 3M product is called Schutz (protection in german)
(Sorry, just had to...)

Working in a bodyshop at times, they will never use seam sealer to do the underside of a car. Schutz seems to be looked at as the best underseal, and I am yet to see it dry off. (It's rubberised... is this what you call bitumen based?) Cheaper alternatives certainly do, though.
They'll use seam sealer around... seams and new welds... like between the front and side panels of a VW T2 after putting a new front panel in...

Hammerite makes every job you might have to do later on a *** in the ***. Definitely not an automotive product!

[old_skool]

Thank you Seb. That was very informative.