I'd get a stiff wire brush and start by getting rid of all peeling and chipped paint. Then get a can of zip-strip or other paint remover and get the rest of it off. If you have super decorative radiators, you'll need some picks to get the paint out of the patterns. Once clean, paint. Spray painting will probably be easiest and you can get a variety of colors. Tape newspapers up for 4-5ft around the radiator - the spray can travel far and wide.

If you want to remove the radiators....when the weather's a bit milder, you can take them to an auto body shop and have them sandblaster. Then you repaint.

However, I wouldn't recommend moving them as the old plumbing parts might be firmly in place. Scraping and paint removal would be the approach I'd take.

thanks very much Kec01 for the information. it is very helpful
bob

You can also use a chipping hammer.

Works well, but it sends paint chips everywhere and you have to be careful that you don't "texture" the cast iron. I've stripped several radiators largely using a chipping hammer. Takes awhile, but it works.

I thank you both for the advice. But, honestly, I was looking for an easier way. This radiator is in the bathroomm, where it is not very easy to get at it, it has a lot of twists and turns on it, making it hard to scrape. Well, I guess i was looking for a miracle.
bob

Silly man, you should know by now that you don't get miracles when it comes to old homes, you only get headaches...

Your only other option might be to have it surface blasted, but that is going to be messy as all get out.

Sand blasting still remains the best method for stripping cast iron radiators.

You have to remove the radiator, so plan on doing the job during the summer.

if it's not just chipping where it gets the most wear, it likely has layers of incompatible finishes on it -depending what it's been painted 'with' over the years (latex, lead-bearing paint, metal enamels) paint chips flying could be a bad thing.

I'm just guessing, but there are paint strippers that you cover with a cloth, and they can pull generations of paint off things...good ventilation's critical (you hear a lot of us hinting this is going to be a warm weather project no matter what, yes?) but you'd be able to get the cloth into places you'd have trouble getting a wire brush into.

I used something called SoyGel to strip layers of paint off my cast iron bathtub. It works pretty well if you leave it on for a couple of hours and then scrape off and wash with soapy water. It's not supposed to be as toxic or dangerous as other strippers (I sure hope it isn't). I love it--it's the best stripper I've found. I don't know if it would be easy getting stuff out of nooks and crannies no matter what method you use, but scraping and using a wire brush would probably do it with the Soygel. It's better than getting paint dust everywhere--you never know if there's lead or not. You can leave the stripper on overnight, covered with plastic so it won't dry out. I order it directly from the manufacturer, Franmar in Illinois.

You can go to an auto parts store and ask for air craft stripper. This is very strong but does a good job. Just make sure you have plenty of ventilation when you use it. Or if you're energetic, disconnect the radiator, drain the water out and take it to a media blasting service (sandblasting) only they use glass bead or steel grit. It would then look like new when painted.

I used the wire brush method, and only took of the loose and chipping parts. I would think at some point either someone painted your rad with a flat paint, which actually absorbs moisture, hence the chipping, or... as mentioned, incompatible finishes.

I bought a large wire brush, used that for the majority, and then a small wire brush (for paint stripping- a wee bit bigger than a toothbrush) and was able to get in some of those nooks and crannies.

I used a black hi heat spray paint, and the black really brought out all the ornate detail. Remember if you do repaint, not to use a metallic - as I understand it, it can seriously cut down on the heat output.

I have had good luck using a power washer to get my radiators cleaned up. On the highest level the water blasts the paint away. You do have to disconnect and bring it outside in the summer but its cheap and relatively fast.

I was in a house yesterday with large old radiators painted silver. There might not have been enough aluminum in the paint to make much of a difference but the more aluminum in it, the less the surface of the radiator can radiate infrared energy to objects in the room. Otherwise, infrared radiation is unaffected by paint color.

Many old radiators were painted with lead based paint (the silver ones comes to mind) and radiators will get hotter if painted with metal or metal fleck paints. This is not a good thing since the temperature is rising because the surface is reflecting heat back into the radiator instead of sending it to the coldest surface beyond.

Sand blasting is best. Oil based primer and paint in any non-metallic color.

Here is a link that might be useful: Cast iron radiators

Alkyd paint actually improves the efficiency of cast iron radiators.

Paint has a higher emissivity than bare iron.

OP is from '08.

Anyway, I would suggest purchasing a radiator cover.

Be very careful with using paint strippers. Those cast iron radiators are individual sections all held together by through bolts and there is a gasket between the sections. Some paint strippers will not only remove the paint, they will also disolve the gaskets.

Well, it depends on the final finish level you are comfortable with. Radiators by their nature collect all manner of dust and dirt. We just accept this and clean them once in awhile. They look (and are) utilitarian. In this case you can buy a wire brush attachment for a drill and take off all of the loose paint. Wipe down with paint thinner or other solvent, and use a can or two of spray paint.

If you run a really clean household, then yeah, you'll have to remove them and have them sandblasted and then powder coated. The powder coating will produce a finish that will be beautiful, long lasting, and much easier to keep looking clean-as-new. The spray can method will dull quickly over time.

Generally,what does it cost to have them blasted?

When we did our raditors 5-6 years ago, a local stripping company charged $20 per section to blast and repaint. Call around your area to find a company that does this. If they're not familiar with it, keep calling till you find someone who is.

Don't work on an old radiator that is under pressure; it doesn't take much to cause the connection to break. In fact it's best to drain the system.

Lead paint would not reduce the infra red radiation from the surface of the radiator but paint with a very high aluminum content might.

Here in Connecticut there's a company that will pick them up, sandblast them and powder coat them. I had the ones in my kitchen done and they are BEAUTIFUL!