Painting Chrome

Ok paint people...how do I properly prepare chrome bumpers to paint them? I've been told it's possible so I need some help. Same with the chrome plastic grill. Thanks!

im guess sand it with a fine sand paper then wet sand it

I hit it with 60 grit first. Come back with 400 grit to smooth it all out.

Use a self etching primer and your ready for paint. The better you sand, the better the job. Take your time with the sanding..do it right.

I would assume do all sanding by hand (i.e. no belt sanders lol?)

Just did my wheels and all I did was use a heavy wire wheel on an angle grider, then hit them with some O'riellys self etching primer (1can) and wheel black paint (1can) they turned out Nice!
http://i888.photobucket.com/albums/ac85/1800joedaddy/100_1864_00.jpg

I would assume do all sanding by hand (i.e. no belt sanders lol?)

U can use a sander, just don't dig into any one spot.

the main thing u need to do is make a place for the paint to stick to. thats why u sand it to form little groves but if u go with to low of a grit u will see it threw your paint. i wouldnt go lower then 220

220 isnt gonna get you anywhere , because chrome is hardened and i mean its hard ..... 220 will only get you fine scratches in the chrome. Use 80 grit with a DA .... trust me after you make a few passes you will realise you cant hurt the chrome. Then after you scuff , get some self etching primer .... then your ready for color ..... paint like normal

ok sounds good. now what is DA?

D.A. stands for Dual Action.
The disc rotates and oscillates at the same time to prevent creating sanding patterns in the material that you are sanding.
If the primer you use has some filling capabilities then you don't have to worry anyway.
Don't use a belt sander. They are way too aggressive for something like this. They are made to remove a lot of material quickly.

:whs:
a d.a will really aid the process as long as you have a well enough idea of what your doing, i would start with 36 grit, then 80, prime it. sand it with 180, prime again, 220 then paint.

for the chrome grille, its plastic, do it by hand. skip the 36 grit, start with 80 and do the same thing.

hope that helps!

Just have them sand blasted. Blast them good, epoxy primer or some type of etch primer, coat or two of primer surfacer then paint. After you spend the money in sand papers and time DA'ing the crap out of them, it will be much cheaper and you will never have a problem.

if i did it again i would have sand blasted mine. my body shop did a rough sand, medium, light, then adhesion promoter (i think it was some kind of epoxy, then primer, then paint etc... they have held up really well, but road salt left some nick's in the bumper after about 300 miles of driving in the snow. i had it retouched and its good as new, but if you live in harsh winter area's, blast it and be done.

is there a certain type of primer i should use?

PPG makes a good epoxie primer called DPLF. Use that after you blast them you'll never have an adhesion problem. Most 2k primer will work though. Just make sure you can use it on bare metal without having to etch them.

why dont you get them powdercoated. holds up soooo much better than paint.

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why dont you get them powdercoated. holds up soooo much better than paint.

Can they color match factory paint with powdercoat?

Can they color match factory paint with powdercoat?

No.

Chrome plating is only around .0001" thick....you'll be hitting the Nickel underneath it in no time. I would'nt go hog wild on the sanding, just enough to "rough" the surface. Remember to wash with hot water and soap to remove any organic contaminates. Let it dry off good before you paint. Its important to remove organic and residual contaminates for proper adhesion. If you don't have good adhesion, the paint won't last long at all. Hope this helps.

Chrome plating is only around .0001" thick....you'll be hitting the Nickel underneath it in no time. I would'nt go hog wild on the sanding, just enough to "rough" the surface. Remember to wash with hot water and soap to remove any organic contaminates. Let it dry off good before you paint. Its important to remove organic and residual contaminates for proper adhesion. If you don't have good adhesion, the paint won't last long at all. Hope this helps.

Correction: ".0000015 of an inch"

Chrome plating is only around .0001" thick....you'll be hitting the Nickel underneath it in no time. I would'nt go hog wild on the sanding, just enough to "rough" the surface. Remember to wash with hot water and soap to remove any organic contaminates. Let it dry off good before you paint. Its important to remove organic and residual contaminates for proper adhesion. If you don't have good adhesion, the paint won't last long at all. Hope this helps.

Good luck with this. Chrome is hard. Very hard. To get the surface you need to hold a finish, it's going to take a chit ton of sanding. Just ruffing it up will not last. I can not tell you how many bumpers come my way that the owners though just a D/A sander and some 80grit would do it. I've even heard the " I used the good paint promoter too" line. You need to blast them to get the surface prepped right. Do it right the first time and be done.

Are you talking about going to bare metal?

Bumpers are plated with 2 layers of Nickel...then a ultra thin layer of chrome, or 1 layer of copper, 2 layers of Nickel then the chrome. Its only in the chrome tank for 10-20 seconds. I've managed a plating shop for 7 years, this is how it's done. No offense to anyone.

I'm not saying you don't know chrome. I'm say after 23 years in the refinish biz I've seen what it takes to get it to last. It doesn't have to be any more than a lite blast. You can do it with a sander. He'll you can do them by hand but, it wll take more time and $$$ then just having them blasted. Chrome just needs more than a ruff up and if it's not got enough to get the paint to bite, it will peal. Sence your in the chrome biz. What prep does it take to rechrome a part??

House of Kolors makes an adhesion promoter almost specifically for this. And one of the Muscle Car on spike TV did a show about how to do it. Go to spike's website and you should be able to find it.

This episode, you might be able to find it online.

MuscleCar - Episodes | PowerBlock TV (http://www.powerblocktv.com/site3/index.php/musclecar-episodes?ep_num=MC2009-19&ep_sea=0902)

Number 19 on the page. Amazon.com: MuscleCar: Season 2009, Episode 1 : Video On Demand

I'm not saying you don't know chrome. I'm say after 23 years in the refinish biz I've seen what it takes to get it to last. It doesn't have to be any more than a lite blast. You can do it with a sander. He'll you can do them by hand but, it wll take more time and $$$ then just having them blasted. Chrome just needs more than a ruff up and if it's not got enough to get the paint to bite, it will peal. Sence your in the chrome biz. What prep does it take to rechrome a part??

I understand what your saying and I agree. The prep does have to be done correctly or the paint doesn't last. (bubbles, pits, peeling)

To re-chrome a part in a plating shop.

1. Chrome is removed using a caustic bath, with Direct current applied. The part being the anode. (doesn't take long)

2. The part is then submerged in a hot bath with chemistry that is designed to dissolve the Nickel without attacking the steel. (takes a long time)

There is a trick you can use if you do not remove all the nickel down to bare metal. Sulfuric Acid diluted to 1% will remove smut and oxides and re activate it for plating or paint. Just gotta get it rinsed off and dryed quickly for paint before oxides form again.

3. Once all the Nickel has been removed, the part is ready for sanding or re-polish. If there's copper underneath the nickel, we use Hydrochloric Acid to remove the copper. After the part is re-polished, it's ready to be re-plated.

So why can you not just plate over it?

So why can you not just plate over it?

It's just not chemically structured to do so. If it was attempted, the resulting finished would not be accepted by anyone. (electrical burns, milky deposits, rainbow colors).

Keep in mind Decorative chrome plating is measured in millionths of an inch. Its the nickel that is thick,(.0005 mil)(1/2 thousandths)

You can chemically remove the chrome and re-plate the chrome on top of the nickel(rework only, not something off the street). You just can't put chrome on top of chrome.