Painting on OE type stone chip

[BHadley]

Hi,

Just bought and refurbed a facelift front valance.
It's ready for priming and stone chip , using the 3m stuff with a shutz gun to re create the OE look .
The valance inside had minimal surface rust to the inner corners so I rubbed off most and rust killed it ( hammerite Krust) then left in zinc primer.

Please Can I have some advise If I paint it like this;

1 coat of Etch primer
Then 1 coat of zinc primer
A coating inside and out of the 3m stone chip. ( this one )

http://www.3mdirect.co.uk/coatings-2/08 ... tle-1.html

No rubbing down of stone guard

Then 2 coats of white primer

Followed by colour coat of base and two coats of laquer

I'm only asking coz the valance that was on car was rotten and I'm trying to avoid a repeat. My bodyshop knowledge is fading after 15 years of not doing it! Lol

Thanks in advance.....

[Kos]

Id use one or the other at the primers stage

[BHadley]

Ok, thanks for reply.

Thinking etch primer then and no zinc primer as the stone chip will soak up most of the road abuse to avoid rusting of metal underneath.

Did read that etch primer is better for adhesion...

Is that the case from anyone's experience ?

[maggspower]

Zinc primer should only be used on bare metal IMO. It's direct contact with steel goes much further than just a coating to keep the water out.

Look up "sacrificial anode"

Zinc primers have a weak bond strength though, best is zinc, epoxy, then the covering of your choice.

This is just my opinion, and not how it would be done in a body shop.

Check out rust.co.uk their products are very very good.

[BHadley]

Thanks, its not so much what a bodyshop would do just what can I do to stop rust at home.

my pattern front wing I painted 2 years ago is showing rust blisters.
I was going to flat back zinc prime and then regular primer and paint etc.

Should I bare metal that to avoid the rust appearing then zinc priming then?

[e30Passion]

Planning on a future bottom underside rebuild with new 3M stone guard as well. Would involve complete strip down and powdercoated rearaxel, sandblasted plated brackets, all new bolts, etc.

Some thinking and a lot of web searching for the best result & rust protection and the conclusion was that everybody does it their own way!

My way.. so far, any suggetions welkom
1. As much back to bare metal as possible.
- Remove/repair rust, sand up roughly, properly clean & degrease before step 2.

2. Zinc prime all bare metal. 2 Coats in total with some drying time in between.
- Sand up with scoth sandpad when completely dry/hardened, properly clean & degrease before step 3.

3. 2 Pack epoxyprimer for the entire underside. 2 Nice coats in total with some drying time in between.
- Sand up with scoth sandpad when completely dry/hardened, properly clean & degrease before step 4.

4. 3M stone guard the entire underside & wheelarches with special attension to edges. Let it dry & harden completely. No sanding afterwards.

5. 2 Pack colour of choice over all stoneguard Let it dry & harden completely. No sanding afterwards.
- I think i'm going beig/grey-ish for the underside and mat satin black inside wheelarches.

6. Lastly 2 good layers of transparant tectyl on the entire bottom underside, wheelarches, inside fenders/valance, brakelines, brackets, nuts & bolts etc. followed by drowning every cavity in & on the entire car with waxoil.. twice!

For the inside of a valance or fender i would ignore step 4 as there's no need for that. Would not skip the rest though. Same for the fueltank or can that be powdercoated after a good inside wash?

I hope this will prevent rust for atleast another 20 years and if it doesn't i don't know what will!

For comparison.. here's a brandnew 323i with 247km on the clock like it just left the factory http://www.ruylclassics.nl/bmw16_eng.htm

You can see how BMW mist a few important spots. No wax in the cavity's, no 2 pack after zinc/e coat and no 2 pack top coat under a good layer transparent or whatever colour tectyl/wax! Just some bare stoneguard with bodycolour overspray after e coat dipping and during or before seamsealing.


And some yellow stuff where it doesn't really matter to much IMO. They say it's from factory and if it is then they didn't do a bad job but not good enough apparently as they started to rot after 10 odd years. This one looks good though

[BHadley]

Cool, the entire underside sounds very involved!

Over the weekend I primer sprayed the front valance panel with zinc spot primed on bare metal only, painted the whole front face in etch primer. Same with the rear corners too.

Should be using the 3m stuff tommorow front and back but not the strip under the head lights.

Then white primer red base and laquer.

Hopefully no runs or sags as I can't really wet flat them out as it will damage the stone guard.

[salam0506]

Hi Guys,

Great thread as I am looking to start the underside of my 4 door 318 and had a few questions for anyone who might be able to answer. I see you guys all going for the 3m stuff but it seems a tad expensive for the whole underside if its going to be about 5-6 cans? Plus on top of that the zinc and epoxy. Does anyone know where I can get these for a good price?
I got a compressor from my cousin with a spray attachment for the stone chip screw on cans, does the zinc and epoxy come in those type of cans as well?

Also mentioned about new bolts and fixings to get everything rust free - is there a package of correct bolts and fitting or just find as needed?

[salam0506]

http://www.ebay.co.uk/itm/4-x1ltr-Mipa- ... 19f4d007ff

Was thinking something like this might suffice (its a bit more within my budget). I appreciate it won't be as good as the 3m but will it work the same? Also what is the difference between schultz and some of the other stuff out there?

[e30Passion]

I really wouldn't be bothered with painting the stone guard except to finish it off with a good layer of 2 pack colour of choice to make it look nice! Putting zinc & epoxy ON TOP OFF stone quard has no use what so ever as you'll be protecting the stone quard and not the metal underneath. So zinc on BARE metal & 2 pack epoxy on top of that but BEFORE stone guard!

Zinc is available in aerosal spraycan. So are 2 packs these days but you can also use the spraygun with compression. Whatever you prefer.

No package for nuts & bolts. You'll need to gather the partnumbers on a list and order at dealers.

[BHadley]

Shultz is not paintable

Stone guard is

Unless stated by whoever makes it .

[salam0506]

Thanks for the reply e30passion - Sorry I was not completely clear about what I meant. I was trying to say that the price of the stone guard will be on top of the zinc and epoxy. So I was trying to find out somewhere cheap to get each and the quantity required. I have not used zinc or 2 pack epoxy before.

would something like this be ok?

http://www.ebay.co.uk/itm/2x-ZINC-GALVA ... 4ab66348dc

and for the epoxy:
http://www.ebay.co.uk/itm/2-PACK-EPOXY- ... 2a372ca5ce

Would I need to brush that on?

[e30Passion]

No i think it's a spray-on primer. So after mixing the components you put it in the cup of the spraygun. The zinc aerosol would be fine i think! Maybe 4 cans or so depending on how much factory underseal has been removed exposing bare metal.

This stuff i have used before. 2 Pack paints in aerosol form. A bit more expensive though but handy if you don't have compression and a spraygun at your disposal Used it on my engineblock and compartment. Good stuff i have to say. Could not scratch it off with the fingernale once hardened.


Shake well for 5 days. Press the button and shake well for again.


Also, when removing the factory underseal i think i'm going to try underseal remover i've seen people use. Some sort of chemical that helps remove underseal a lot easier as it is a horrible enough job.

New undersealing is not that expensive i presume but just a lot of work involved. Rebuilding everything that attaches to the underside is i think because a lot of new parts are required.

[salam0506]

Thank you for the explanation. I am looking forward to getting started on the underseal but yes I imagine you are right about the work and effort involved. Does anyone have a diagram of all the parts on the underside that are to come off and what parts can be replaced for new at a reasonable price?

[BHadley]

The links in the tech section for bmw fans are like a part index and show diagrams in sections as in brakes and then shows all brake parts on the car. It's worth a look .

It's under a sticky when you go in the technical help section

[JimM3]

Just stripped the whole floor back to metal on my M3. It is a very big job. I found various wire attachments for grinder/drill best along with heatgun and scrapers for the tricky bits.

I painted a rust killer/converter around all seals, painted floor with 2 pack zinc rich epoxy primer, sealed all seals with tiger seal, added another coat of primer then used 3m 08800 underseal then 2 coats of topcoat. I cannot recommend the 3m underseal enough. It comes in foil packs and works out expensive but it looks exactly like OEM stuff and is very hard wearing by the looks of it. You need the special gun from 3m to spray the bags but well worth it. After all, you will not want to be doing this job again once you have done it!

Jim.

[e30Passion]

Indeed the 3M stuff is highly recommended by everyone so best to save some cash and get the proper stuff.

You have any pics or thread off the work in progress Jim?

Thank you for the explanation. I am looking forward to getting started on the underseal but yes I imagine you are right about the work and effort involved. Does anyone have a diagram of all the parts on the underside that are to come off and what parts can be replaced for new at a reasonable price?

No problem mate I suppose many parts don't have to be renewed/replaced like swaybar/exhaust brackets etc.. as you can have them goldplated or sandblasted and painted if not to rotten. Other stuff like trailingarms, axle/diff carrier, brake disc splash guards, sway bars, fueltank etc.. can be powdercoated or refurbed whatever way preferred.

Stuff i would replace for new OEM brands:
Nuts & bolts - BMW dealer
Chassis nuts - BMW
Brake lines & clips/caliper kit - BMW
Fuel lines & clips - BMW
Steel brake lines - Ebay
Droplinks from Lemforder - Ebay
Bushes suspension, diff, gearbox etc. from Lemforder - Ebay
Wheel bearings from SKF - Ebay
Brakepads/parts from Ate, Jurid or Textar - Ebay
Whatever more needs to be replaced.
Etc. etc... hard to think of more stuff actually You'll get pretty far with that alone.

Or ring your local motorfactors for a good price as Ebay is not allways cheaper then dealer

You have to make a list yourself using the partcatalog like realoem.com with your chassisnumber.

And remember.. having the proper tools they say.. is everything!

[JimM3]

Not bothered starting a thread. Didn't think it was that interesting...

Stripped to bare metal
[URL=http://s940.photobucket.com/user/jimmy0 ... 1.jpg.html][/URL]

Primed up


Under sealed


Painted



Like I said, it's a hell of a lot of work and horrible when you're lay on your back but it's worth it. The only problem is when you start re-assembly anything old looking looks awful so you end up spending a fortune on all the little bits and pieces.

Jim.

[BHadley]

Wow top work!
I'm leaving my floor underneath alone as I struggle for time as it is!

Family stuff has to come first then the joys of work eat up most of the rest of my time....

[JimM3]

This is the underseal. Allow 20 bags for the whole underside. A bag does not go far at all.



Jim.

[e30Passion]

Not bothered starting a thread. Didn't think it was that interesting...

Shame mate cause it bloody is
Fantastic work there Jim. Just absolutely stunning! You got that completely spotless. Never seen anybody getting the underseal off that clean. It will be my reference when ettempting, probably also laying on the floor

Thanks for the advise!

[JimM3]

Thanks for comments. These wire brushes are ideal for hard to reach areas. Got through about 10 sets.

[e30Passion]

10 Sets Bloody hell. Got my work cut out then! Thanks again