Underside paint...what to use?

Post by **youngun** » Thu Feb 26, 2009 6:21 pm

Dare I say it.........Ive finished the main chassis welding!!!! Pics to follow.
Im just about finished zinc priming the underside, im then going to red oxide over that as I have a tin knocking about. But what to use after that? Do I just use a big tin of Hammerite black? Or go for special chassis black. Bearing In mind I will be waxoyling over the top.
I figured to just use a few coats of black Hammerite? Any protection on there will be better than what was originally on there surely?.......and that zinc rich primer really does stop the rust.
Opinions?

YG

Post by **Dean** » Thu Feb 26, 2009 6:39 pm

I'll be us POR rust paint, it's suppose to completely lock out the water. I used hammerite 22 years ago on my dry stored moggy chassis. After cleaning it off this year I'm sure it was slightly porous as some areas of the chassis has deteriorated slightly. POR is dearer than hammerite though and I'm sure some people won't like that neither.

The work you have put in already might be alright using hammerite, as long as you re-coat it every couple of years.

By the way, well done... I enjoy looking at the pictures now and again, gives me inspiration..!

Post by **bmcecosse** » Thu Feb 26, 2009 6:41 pm

Not sure of the beneficial effects of red oxide (= RUST) paint! the little tins of 'Garden gate paint' sold in Poundshops are excellent - thick black paint which clings like $%£! to a blanket. Brushes out well too, and dries smooth and shiny - you wouldn't need many. There are also some 'Rustoleum' paints about - which are also supposed to be v good. No doubt someone will say 'POR 15' - which is uberexpensive and greatly over-hyped in my view ! Hammerite is strange stuff - also v expensive and needs special thinners.

Post by **mick64** » Thu Feb 26, 2009 6:55 pm

I would stay away from red oxide as well ,Por-15 sticks to rust and makes a chemical bond if you paint it over paint is will be useless...

I would paint it with ordinary metal/rust paint at b and q...A lot of people use underseal but it is a bugger to get off and repaint....

My old man said old engine oil is the best stuff...

Thu Feb 26, 2009 7:48 pm

i heard that old engine oil is good as well provided you regularly spray it on.

I have also heard that hamerite drys hard and brittle so if it hit by a stone it tends to crack, any water that gets in behind the crack will then be held against the metal.

Post by **aupickup** » Thu Feb 26, 2009 7:58 pm

oil is not very good, as it does come off with the water splashing on the underside if raining

my car was originally ziebarted from new, and the underside is like new, and that was 40 years ago
the only areas that needed any work was the drivers front under cill

Thu Feb 26, 2009 8:43 pm

oil is not very good, as it does come off with the water splashing on the underside if raining

you take your car out in the rain

Post by **youngun** » Thu Feb 26, 2009 10:37 pm

Ive been looking online at frosts, who stock POR-15 chassis black and frosts do their own. Probably just as good!
So I rekkon Ill just slap some of that on.

Nothing wrong with red oxide, used it many a time on all sorts......never let me down.

YG

Post by **DAVIDMCCULLOUGH** » Thu Feb 26, 2009 11:04 pm

I use ACE rust stop, its an American paint thats supposed to be used on oil wells, it dries quite slowly though but once dry its very tough. Whats even better were I buy it has 50% off!!

Post by **bmcecosse** » Thu Feb 26, 2009 11:47 pm

Should have said - before the zinc priming - you should have painted it all with rust killer (usually phosphoric acid) - kills any rust in seams etc, and acts as excellent etch primer for the next coat.

Post by **kennatt** » Fri Feb 27, 2009 8:18 am

my splitty which iv'e had for twenty years,was owned by a guy who used to take it to my friends garage every november and spray the underside with old engine oil,when I aquired it,I spent weeks scraping off all the old gunge underneath, guess what,could still see the original brown paint underneath. To date the only welding has been to the outer sills and an area above the heatshield where the oil had been burnt off,the wheel arches, rest of the floor and chassis and boot floor are original.So not bad for a 1955 and good recomendation for old oil,Its done with three coats of black waxoil at the moment,but wished I'd left the old gunge on,just needed to see underneath it at the time,and it was a bit messey to work on.

Post by **youngun** » Fri Feb 27, 2009 5:12 pm

bmcecosse wrote:Should have said - before the zinc priming - you should have painted it all with rust killer (usually phosphoric acid) - kills any rust in seams etc, and acts as excellent etch primer for the next coat.

I painted rust prone areas with Hammerite Kurust or whatever they call it. Better than nothing. To be honest If the rust took 50 years to get to the level it was at when I bought the car, then Im not worried about major rust for at least 30 years or more considering it will have 3 times the amount of rust protection it had when new! By which time I will have bought a new project and sold this one on.......

YG

Post by **bmcecosse** » Fri Feb 27, 2009 8:27 pm

Kurust = phosphoric acid . Well done - it should be fine.

Post by **youngun** » Fri Feb 27, 2009 10:10 pm

bmcecosse wrote:Kurust = phosphoric acid . Well done - it should be fine.

I had a look on the label earlier just to make sure.....panic over!!

cheers,
YG

Post by **mckenzie** » Sat Feb 28, 2009 7:36 pm

what about stone chip is that any good for the chassis also read some where about painting underside same colour as body then clear wax oil

Tony

Post by **youngun** » Sun Mar 01, 2009 7:28 pm

No point painting it body colour when you dont see any of it?!! Im not doing a concourse resto 'ere!.
Ive just bought 2 litres of POR-15 chassis black, managed to get it cheap as my father is restoring an old Mill wheel at the moment and he needed a shed load for that!
Waxoyl over the top of that obviously!

YG