Chrome removal

[Toolmaker Tim]

What is the best way to prep the chrome on the fenders and pipes for painting. The chrome on the mufflers is pretty good, but the headers not so much. I don't want to paint the fenders and pipes and have it peal off.

[Crazy Damian]

no need to remove chrome

You don't have to remove the chrome you just have to rough it up enough for the paint to stick.

If you have rust and pitting, I would recommend to start with a good wire brush on a drill or a bench grinder, then after you have done that, check for pitting that might need filled, then sand the whole thing with 600-1200 grit sandpaper make sure not to leave any shiny spots.
use a good etching primer and then paint it.
Personally I have painted quite a few chromed parts over the years and I started using a product made by Bulldog called Adhesion Promoter, I highly recommend it.


Damian

[jamak]

Chrome removal

Damian is on the right track. If the chrome isn't pitted, just use a palm sander with 100 grit sandpaper to rough up the surface and get the shiny stuff gone. You don't have to get thru to bare metal; just make the surface dull. Then go to a 600 grit wet/dry paper,(by hand, or with a flexible sanding block), and get it smooth-and use it wet. Wipe the surface dry, and use some lacquer thinner to leave the surface clean & ready to prime.A coat of primer will tell you if you have it prepped it right. I've always used Rustoleum products with good results for priming and paint.
If the exhaust is pitted, a wire wheel on a drill/bench grinder will get off the heaviest crap, then back to the palm sander with 80 grit-or heavier, depending on the depth of the rust. Then thru the rest of the smoothing process to primer. As the man said; preparation is all. Any pits or rough surfaces will show up when you paint. Pitting will cause the paint to peal, anything else will just make the final finish look crappy. If the pitting on the exhaust is too deep, you may be wasting your time. If you have to grind/sand too deep, the metal could become too thin to be serviceable. Just remember, you have to prep ALL the surfaces; in the crevices of the stamped lines on the fenders, even under the edges. Any chrome left unscuffed will cause the paint to lift. Two coats of primer, with a wet sand using super fine paper,(800-1200),in between, and 2-3 coats of paint will get you what you want. Go easy on the 1st coat of both, and let it dry well before the next coat. I always test the spray density on a test surface.
Of course, you can save yourself the heavy work by sandblasting before you get into the finer prep. But make sure you get all the grit/dust off before you proceed. Compressed air is best for this, but it can be done with soap & water and due diligence. The better you prep, the better the final finish. Good luck.

[TADracer]

The easier way is..

Go to Harbor Freight (or similar store) and buy a small, cheap hand-held sandblasting gun. Use 80 or 100 grit Aluminum Oxide medium and give a sweep blast to all the surfaces. The media is important and Aluminum Oxide is small jaged particles that will open the grain of the chrome. Do not use sand or shells as the medium. The surfaces will come out with a very even and smooth matte finish. Clean with Acetone (or other recommended solvent), prime and paint.

[Toolmaker Tim]

Sandblasting

I can use the shop sandblaster with no problem, I just didn't know if it would rough the surface up too much. With 80 grit aluminium oxide and 150psi it should do the job. Do I use self etching primer on the header pipes? I realise it ends up under the final coat of high temperature paint, but won't the heat make it peal starting the whole breakdown process?

[Crazy Damian]

my 2 cents worth

Painting the headers, and this is just my personal opinion becaue I have never believed headers had to look absolutley perfect, I have always just used a good quality Hi-Temp paint after removing all the rust, I wouldn't use any primer or fillers on the headers because I am pretty sure it would just come off, plus I have always painted the headers black, so you never see little imperfections in them, wire wheel the headers and paint them would be my advice.
If they gotta look perfect, time to pony up some cash for some new ceramic coated or chromed ones.

Damian

[crazy steve]

Painting chrome is always a bit of a crapshoot, depending on what shape the plating is in and how you do your prep work. Ideally, it should be chemically stripped but that costs almost as much as having it replated. If you have any plating that is peeling, a full strip is about the only sure method of preventing more (taking your paint with it).

Sandblasting can be iffy... Chrome is a very brittle metal and using a 'hard' blast media like sand, aluminum oxide, or glass beads can 'shatter' the plating, loosening it from the metal under it; if you have any peeling, blasting will usually make it worse. 80 grit media is pretty coarse, 120 would be better. Keep the nozzle away from the work piece (particularly if you have high air pressure), you're just trying the 'frost' the surface. If you have rust pitting though, blasting is about the only method that will get all of it off.

Wire wheels are the 'poor man's' sandblaster. If you have peeling, sometimes it's the best choice. Avoid this on sheetmetal though; this can generate considerable heat and cause warping. Make sure you wear plenty of protection too... those wires will stick into things (including you) all too easily... DAMHIKIJK

Sanding can work. Use a medium-grit paper (and change it often as the hard chrome will dull it quickly), a 220 or 320 is best using a palm-held jitterbug sander. Don't go finer, you won't leave enough 'tooth' for the paint to grip and your topcoat will chip easily.

You also might think about these: http://keenabrasives.com/Surface%20C...20Type%20R.htm I've been using these for prepping my aluminum for polishing, but they also work very well on harder surfaces (these will clean brake rotors great!). Because they only 'do' the surface, you don't have to worry so much about changing the contours of the work piece. I'd try 'maroon' discs, the blue or gray would be too fine. They won't get all the rust out of deep pits though, you'll still need to blast those.

[WSL91]

Painting chrome is always a bit of a crapshoot, depending on what shape the plating is in and how you do your prep work. Ideally, it should be chemically stripped but that costs almost as much as having it replated. If you have any plating that is peeling, a full strip is about the only sure method of preventing more (taking your paint with it).

Sandblasting can be iffy... Chrome is a very brittle metal and using a 'hard' blast media like sand, aluminum oxide, or glass beads can 'shatter' the plating, loosening it from the metal under it; if you have any peeling, blasting will usually make it worse. 80 grit media is pretty coarse, 120 would be better. Keep the nozzle away from the work piece (particularly if you have high air pressure), you're just trying the 'frost' the surface. If you have rust pitting though, blasting is about the only method that will get all of it off.

Wire wheels are the 'poor man's' sandblaster. If you have peeling, sometimes it's the best choice. Avoid this on sheetmetal though; this can generate considerable heat and cause warping. Make sure you wear plenty of protection too... those wires will stick into things (including you) all too easily... DAMHIKIJK

Sanding can work. Use a medium-grit paper (and change it often as the hard chrome will dull it quickly), a 220 or 320 is best using a palm-held jitterbug sander. Don't go finer, you won't leave enough 'tooth' for the paint to grip and your topcoat will chip easily.

You also might think about these: http://keenabrasives.com/Surface%20C...20Type%20R.htm I've been using these for prepping my aluminum for polishing, but they also work very well on harder surfaces (these will clean brake rotors great!). Because they only 'do' the surface, you don't have to worry so much about changing the contours of the work piece. I'd try 'maroon' discs, the blue or gray would be too fine. They won't get all the rust out of deep pits though, you'll still need to blast those.

I just discovered those not long ago at a Regional Hardware chain Menards. They were half the cost or more of 3m and work awesome. I used them to help cleanup the swing arm and center stand. My guess is that you can get them at Harbor Freight as well as most of the import stuff comes from 1 place with lots of different labels and is everywhere. Even the Craftsman compressor I recently bought was identical to 1 at Harbor Freight, same valve etc etc.

[crazy steve]

I've been extremely happy with the discs; they can be a huge timesaver...

I buy mine from Keen as I haven't found them cheaper (for the quality) anywhere else. I use the 2" size and locally they want $1.50 and up for them! You have to buy a whole box from Keen, but you'll find plenty of uses for them and wonder how you got along without them...

[Rasputin]

I have found that when removing chrome I have had the best luck using 220 grit aluminum oxide in a sandblaster. The chrome looks like a small comet lighting up, when you are actually removing it. Under pressure that grit looks like a comet tail when there is chrome present. Once the chrome is gone it looks that same as regular blasting and is ready for paint using the 220 grit. My MNS is proof of that.
This also works on the MNS black chrome parts. Apparently the aluminum oxide, pressure, and chrome, cause this reaction which is pretty cool to see.
I have done it to dozens of parts and the paint will stay forever.

[Toolmaker Tim]

Options

Sounds like I have a couple options to choose from. I might just try Rasputins because I like doing things like that! A comet in a snadblaster would be neat!

[James England]

Concentrated acid will remove the chrome, right through to the nickel underneath. I accidentally spilled some onto the chromed exhaust trims on my Honda GL1000 and it took the chrome off. It was 13% hydrochloric acid.