Painting the underside and inner arches.

[gaf2]

Hi guys, getting near the point in my project where i will be painting the underside. I have wired wheeled it back to pretty much all bare metal, any rust has been cut out and replaced. Looks like this.

https://scontent.fman1-1.fna.fbcdn.net/hphotos-xap1/v/t1.0-9/12065761_958120757580021_6808963115148471913_n.jpg ?oh=42d49c1b76a6d5e2b96720411a63b4ce&oe=56B59F6D

Now i have been reading various threads on here and other sites, am after some clarification. Should i firstly spray with rust converter (I use Vactan), then etch primer followed by upol Gravitex. Do i then need to paint over the Gravitex with high build primer or a top coat?? Or what have you boys done in the past?

Cheers for any input.
Grant

[Southie]

Nick J could be someone worth pm'ing as he's pretty knowledgeable regarding spraying, also Benn is worth a try as well as he's also done plenty of titaviting.

[paul james]

The more layers the better in my opinion. On mine I gave another blast with wire wheel/polycarbide disc then panel wipe just before any painting. I used a bit of rust converter in places, but mostly applied several coats of acid etch/zinc primer. Covered that in a rubbery paint on stuff I can't remember the name of now, then a whole load of brushed on hammerite paint on top, which I can easily just fix with a few brush strokes if it ever gets chipped.

[Iain]

Sounds good, I think Gravitex is a sealed coat in itself but I covered my stonechip with a very light dusting of primer and 2k mixed up without thinners and brushed on. Has stood up to the test of time very well.

[gaf2]

Cheers for the info boys, i think am gonna go with: vactan, etch, gravitex with 5% thinners see how that goes then possibly 2k on top as iain has done.

[Iain]

I painted my whole chassis in por15 before the gravitex too :)

[ledpen]

Degrease and apply a coat of etch primer, if you wish you can apply a coat of high build or ordinary primer as a sealing type coat, then apply gravitex, if using white gravitex you can add a cup full of colour paint the same paint code as your body and mix it up an apply, this way you won't need to over paint anymore and it can be just left, however I sprayed black gravitex then a thinned down coat of high build( as it's hard to get the correct shading if spraying over black), then I sprayed base coat and 2k clear coat, came out well
http://images.tapatalk-cdn.com/15/10/29/40f78de25519057876dc8f338fa54e57.jpg

Black gravitex

http://images.tapatalk-cdn.com/15/10/29/f35fc1053895bae92f98fd235d6c1617.jpg

Thin high build coat

http://images.tapatalk-cdn.com/15/10/29/d7c5524eba266968f9e4d03474410306.jpg

Finished result

[Benn]

I'll be honest and say i don't think Gravtex is that good. Used it for covering welding at the bodyshop. Never found it lasts long.

As Ledpen said, get it in a coat of etch primer.Are you re sealing the seams? (i would to cover the welding marks) If so do that next.
Then for me you want a good under body sealant. 3M make fantastic sealants, as do the people that make the por15 stuff.

If you do use Gravtex stuff, do a full thickish coat, leave it to fully dry for a few days/week then do anything coat.
Then etch it and paint it.
2K paint works well. 4 coats of lacquer is enough. As if you use to much it can weaning the clear when dry.

When its all dry. Give it a good wax and you'll be smiling.

[Edd]

Don't use Gravitex it's utter crap

Mine is all flaking off, probably need to scrape it all off soon

Use a rubberised overpaintable product, 3M for example

[Iain]

I used 3m paintable stonechip and its been great for years.

[Benn]

3M make the best stuff. Simple as that.

If you can afford it use the rubberized stuff i use. Its amazing.

[ledpen]

To be honest mate everyone is going to have a different opinion and think that what they done is the best way which is fair enough, just take all the advice on board and make your own decisions and be happy with it you kow the basic sequence of treating the arches tc it's just up to you on what products you pick within your budget etc

[gaf2]

ok cheers boys. Will ditch the gravitex and go with 3M rubber stuff.

[lee coley]

Once the metal is clean and rust free apply epoxy primer its 100% better than etch primer and is also water/moisture proof.once dry you can apply any filler,primer,paint,sealer etc without further prep. Usually has a 7day window.

Etch primer/wash primer is porous, epoxy isn't.

[slimtater]

Bringing this back up for discussion!

I have had my Sport shell soda blasted and its in epoxy primer whilst it gets lots of panel and repair work done. Its in a garage which has a heater and dehumidifier but I wanted to avoid etch just in case.

I am starting to think about the underside and I was going to go:

http://www.rust.co.uk/epoxy-mastic-rust-proofing-paint/c28117/

then

http://www.u-pol.co.uk/product-cat/250/raptor.htm (the tintable version so Polar White)

then something like this or waxoyl

http://www.rust.co.uk/mil-spec-transparent-complete-rust-proofing-kit-b/p487956

I have heard very good reports about the Raptor but would prefer to use something like the 121 first.

Any views?

[Benn]

I've heard of raptor, but not seen it used. Heard it's good tho.
Waxoyl even the "clear" stuff is still quiet yellow, so will make the white look off colour.

Look at the Bilet Hammer stuff. Same kinda wax like sealant, but is totally clear.

[slimtater]

I've heard of raptor, but not seen it used. Heard it's good tho.
Waxoyl even the "clear" stuff is still quiet yellow, so will make the white look off colour.

Look at the Bilet Hammer stuff. Same kinda wax like sealant, but is totally clear.

Cheers Benn - will have a look. :thumb: