Refinishing cast iron radiators.

oldbobcat

I recently acquired several beautiful steam cast iron radiators I would like to repurpose. I found a place that will sandblast them at a reasonable cost. My concern is the inside has rust and debris I don't think will be good for a hot water system.
Is there a way to clean the inside or are my concerns invalid. Tx.

Paul48

Do you know the difference between "steam only" and combination "steam/ hot water" radiators?

oldbobcat

Don't know the difference but I have converter several with TRV valves and they work like a charm. The ones that I'm talking about are built exactly like the ones I already converted.

oldbobcat

My radiators have four openings two on top and two on bottom.
Water can flow across top and bottom and up and down what more would I need?

Paul48

https://s.yimg.com/fz/api/res/1.2/2zuRhNMTw_Zc2vUtfC2Y1g--/YXBwaWQ9c3JjaGRkO2g9NzAwO3E9OTU7dz00MDA-/http://upload.wikimedia.org/wikipedia/commons/f/f1/2006_400x700_one_pipe_steam_radiator.jpg
STEAM ONLY

https://s.yimg.com/fz/api/res/1.2/_TrvhEnGDQIBEg9iguorIQ--/YXBwaWQ9c3JjaGRkO2g9MjM5O3E9OTU7dz0zMDA-/http://kromers.com/wp-content/uploads/Stock-Steam-Radiator-e1364064865138-300x239.jpg

STEAM/ HOT WATER
Notice the connection, or lack there of at the top of the radiator.

Paul48

Sorry..had 2 pictures but it keeps saying they were the same and only posted 1. The one posted is steam only, no connection at the top.

Paul48

I'd flush them out, and pressure test them before I had them refinished.

Paul48

I see...It only posted one actual picture, but the links to the 2 work.

sonofaplumber

I put a wye strainer on the return of each of mine. Pretty cheap and good safety measure. I figure if she stops heating I'll know its plugged!

Also connect a big hp shop vac to a lower port and get some debris out that way. Final step would be to flush by leaving return disconnected during installation and collect with a bucket, or at the purge tee, OR outside with a garden hose. You should leak test anyways especially with old steam rads.

P.S. before sending to sand blaster get some test plugs and wind them in, don't need to trust someone else with that step because they probably won't do it! Would suck to have more sand than you started with in there.

Good luck! This place has made me a full CI rad believer.

oldbobcat

Thanks for the info, the WYE strainer is a perfect application for my old radiators. I was a little reluctant to use these old rads but now am confident the will not contaminate my system.