My late grandfather's garage has what appears to be homemade galvenized steel pipe radiators that run all throughout. As you can imagine after the at least 32 years theyve been installed, they started rusting through and leaking. I'd like to just repair them for the time being, until I can save enough to replace them all with something a little more updated; However, I'm not sure how to go about that.

This is the second time one has leaked. The previous one happened while I was out of state working and I had a plumber cap it and all was well until this year (I'm quite the procrastinator) I was going to braze the small cracks/holes but I got thinking maybe there is an easier way to patch the problem so I can get the heat on before freezing becomes the reason for multiple cracks and leaks.

I thought of going steel to cpvc but I'm not sure I can even do that. Any ideas or just braze the holes? Or do t even do that? The system is drained currently. Thanks