underbody prep and paint

bazz55 · Post by **bazz55** » Thu Jun 16, 2005 7:47 pm

hi there i am looking at stripping the under side of my 911 as at present the old underseal has dried out and become flakey... basically i intend to strip the whole underside and under the arches and re-apply... but WHAT do i re-apply... what products would any of you recommend??? What was originally used and can you still get it?? where from??

many thanks bazz

Derek · Post by **Derek** » Fri Jun 17, 2005 8:52 am

Barry

Wurth SKS was the factory applied stuff, needs a special wurth applicator gun. Can I borrow it when You are finished

.

If you wanted I will split the cost of the gun with you.

davidppp · Post by **davidppp** » Fri Jun 17, 2005 9:24 am

Stripping this is very beneficial IMHO.

The old stuff actually hold the water..

Then I have discovered the finest rust stopper on bare, wirebrushed and phosphated metal to be Unidox Zinc-rich primer..a marine product.

I hate underseal, so will make no comment..wax on original body colour would be my choice..

Kind regards
David

Nick Moss · Post by **Nick Moss** » Fri Jun 17, 2005 6:07 pm

I use Upol Gravirex Stonechip. The finish can be varied by changing the air pressure used. You need a special gun, I use a 3M "Ajustable Stonechip" gun

bazz55 · Post by **bazz55** » Fri Jun 17, 2005 10:12 pm

hi fellas thanks very much for the advice!!

Derek do you mean a body schutz gun? i will give you the gun when i have finished as long as i can borrow your engine

David is the product you are talking about available?? and where from?? thanks

Again Nick where is the best place to source the underseal you talk about 3m site??

many thanks fellas a good guide in the right direction

Graham · Post by **Graham** » Sat Jun 18, 2005 12:55 pm

I use Wurths SKS black which is water based and overpaintable,it gives a fantastic finish too.
Its the best I have used having tried Bodyline,UPOL,Wurth Stonechip etc.

Underseals are horrible and always stay tackey,where as stonechips harden/go rubbery when they dry.
We also use Wurth spray sealer on the main joints too which gives a nice finish too.

Barry · Post by **Barry** » Sat Jun 18, 2005 12:58 pm

I've not heard of that, Graham, does it take long to go off compared to a solvent based stone chip?

davidppp · Post by **davidppp** » Sat Jun 18, 2005 3:45 pm

Hello again all.

This is the place I get it from..

I have a tin spare if you get stuck..

http://www.withamoil.co.uk/metalprimer.html

Its called Unidox 90% zinc...very very thick and dries very fast indeed..high build massive lumps develop unless you brush it out very hard and fast..

But two thinnish coats or one thick one followed by a glossy finish is the best rust stopper Ive used..unless you can get really good blasted surfaces when an epoxy product may be better..

Kind regards
David

Graham · Post by **Graham** » Sun Jun 19, 2005 6:27 pm

Barry wrote:I've not heard of that, Graham, does it take long to go off compared to a solvent based stone chip?

No not really,you can force dry it if needed,but I apply and the next day its dry I dont think there is a timescale for overpaining it.If I remember I will look up the spec tomorrow for you,its pretty pricey though,like most Wurth products!

Barry · Post by **Barry** » Sun Jun 19, 2005 11:00 pm

Yes I used to have a Wurth account when I owned a restoration business, the rep was a bit good: I'm still working my way through some of the stuff, so he did well given I closed the account about ten years ago

.

Excellent quality products though, well worth the extra expense.

Dyno Soar · Post by **Dyno Soar** » Tue Jun 21, 2005 10:38 am

Whats the best way to clean the underside of the off in the first place chaps?

Please someone come up with a better alternative then a wire brush and a rotary drill.. I have done that before on my beetle arches and it was a horrible messy job. I hated it.

Bob_Salmon · Post by **Bob_Salmon** » Tue Jun 21, 2005 11:35 am

Dyno Soar wrote:Whats the best way to clean the underside of the off in the first place chaps?

Please someone come up with a better alternative then a wire brush and a rotary drill.. I have done that before on my beetle arches and it was a horrible messy job. I hated it.

Just done mine using commercial paint stripper then wire brush on a big grinder. Hard work and it is still a horrible, messy job!

Bob

Dyno Soar · Post by **Dyno Soar** » Tue Jun 21, 2005 12:28 pm

Man I just don't fancy getting underneath the damn car with a grinder and wire brush thingy.

Yuck..

Perhaps a bead blasters would be a better option.

tanick · Post by **tanick** » Tue Jun 21, 2005 12:35 pm

There was a post on here a while back about somewhere that does a complete strip and re-seal for a couple of hundred quid.

Now I like doing things myself, but there are some jobs that I'll happily pay for and stripping underseal is one of them. I spent most of Sunday morning trying to get waxoyl off my spring plates so that I could paint them (Nitromors works a treat but takes several applications and then I de-greased them just to make sure)

I can't find the post but if you look you might get lucky.

Lightweight_911 · Post by **Lightweight_911** » Tue Jun 21, 2005 1:23 pm

Hot air gun & scraper followed by rotary wire brush & finally 'scotchbrite' pads & thinners...