I'm starting to think about bodywork for my 200B, rust is starting to come out in it and the bumpers are rusty and bent.
I don't want to have chrome bumpers really, I want to do them 2 pak gloss black with the rubber bumper holes welded up and so on.
But firstly, how do I remove the chrome from the bumpers?
They're rusty underneath but the chrome is still quite solid on top.
Any ideas that don't involve much expense?

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If you're close to a chrome plater. Take it to them and ask them to "Plate off" the chrome. This is what they need to do before re finishing it anyway. Shouldn't be too much if they're willing to do it for you. But hazardous chemicals they use. Nitric acid i think?

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Ongoing Project: 1972 Datsun 510 S13 SR20Det. http://ozdat.com/forum/viewtopic.php?f=33&t=17898
New Daily: D22 Navara (The new workhorse)
Retired 12/2016: MY98 Subaru Impreza RX
Previous Car: Restored Green 1972 Datsun 510, Hot L18

Yeah I heard it's not cheap, i think because of the chemicals and disposal and stuff.
I was thinking of something a bit more....crude haha.
Wire brush or somesuch.
My bumpers both require straightening, some welding up and stuff anyways so a bit of spray putty over the top of them afterwards will probably be in order before painting anyways.

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Then i'd just sand blast it with 36 grit Garnet or the coarsest grit i could get. Even glass beads? There will probably be a copper layer underneath the nickel also, which would probably come of quite easily after blasting. Sand blasting your bumpers wouldn't cost too much. Other than that. Wire brush on the grinder if you want to spend hours at it. And wear a long sleeve shirt or suffer metal in your arms...

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Ongoing Project: 1972 Datsun 510 S13 SR20Det. http://ozdat.com/forum/viewtopic.php?f=33&t=17898
New Daily: D22 Navara (The new workhorse)
Retired 12/2016: MY98 Subaru Impreza RX
Previous Car: Restored Green 1972 Datsun 510, Hot L18

I'll see what i can do about sandblasting, I don't think my dad has access to a big one anymore (just a little perspex box one), but I'll see what I can get done .

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I've come into contact with a few sets of 1600 bumpers that have just had the chrome rubbed back with wet n dry, then painted over.

As long as the chrome is good and the paint can stick properly, I wouldn't go to the effort of removing the chrome.

Hrmm, so maybe rub them back (getting all the rust off the undersides for sure, then etch prime them and then paint as normal?

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2nd to just giving them a good sanding with a coarse grit followed by a medium grit. Than etch primed, followed by your spray putty and colour.

If the chromes solid and not flaking, it will be as solid as bringing it back to bare metal.

yep agreed, if the chromes flaking though like it sounds like it could be in parts i would lightly grind back them parts then hit em with the sandpaper & then etch prime spray putty etc

I painted the front bar of my B120 some years ago.
From memory I sanded it with #80 paper and after cleaning and metal prepping it to condition the surface, sprayed it with rattle can etch primer.
I did the backside as well because we all know they look daggy in there.
Then some sandable Primer Surfacer.
Followed that with 3 or 4 coats of Gloss Black enamel and it came up sweet.
The key is to prep. the bumper or whatever properly and then you can re-finish it just like any other panel.
Flaking chrome needs to be scraped back to a solid surface and any rust has to be buffed up to remove the worst, then treated with Metal Prep.
You need to pay particular attention to the seams and joins, if any, to make sure there is no corrosion hidden in there.
Body Filler, if used, will probably only bond successfully to any bare metal.
However you could use Automotive Seam Sealer to fill any seams or joins to smooth out the appearance.
Use the Seam Sealer AFTER you have coated the item in Etch Primer to avoid rust appearing later on. Not a real good pic. but here you go.

No corrosion showing and the paint is still tough and nice and glossy

Dent knocking and welding of bumpers in my experience is a pain.
The metal is under so much stress from the pressing at manufacturing that I found the bar would crack when the weld cooled.
Brazing can be used to fill some dents but distortion is a possibility.
Some bars of simpler construction, i.e. a simple pressed "U" shape would be easier to work on since they are relatively stress free.

Anyhoo, what have you got to lose?
Have a go cause it is a LOT cheaper than chroming

P.S. I wouldn't recommend Powder coating or 2Pak paint.
Being a bumper, it needs to flex and the above two products may not handle that too well.
Just my opinion

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Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

I thought 2 pak was quite flexable? I could always add an agent to make it more flexable, did that years ago on a Escort RS2000 I used to own because the whole nose of the car is urethane and quite flexable.
Thanks for the tips .
What is Metal Prep, is that the actual name of a product?

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Metal Prep. is essentially a concentrate of Phosphoric Acid.
You dilute it in water and scrub the metal with a 3m scourer soaked in it.
It conditions the metal, de-greases the surface and converts any remaining rust to inert Iron Phosphate.
It shouldn't be used as a big time rust converter, there are other products more suitable for that.
It is only meant to treat any rust hiding in cracks or pinholes prior to applying a Primer.
You should be able to pick some up at any Crash Repair Supplier, or if you are rich, Autobarn etc.
Don't frigate to wear some rubbery gloves though

If you can add an elasticizer to the 2Pak, why not

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Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

Cool, well that sounds like what I'm going to have a go at then!
Black bumpers .
Beige and black is my colour scheme for the 200B, beige gets all the girls right .

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Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

Thanks mate it turns out i've got diluted phosphoric acid at home already, handy .

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