? Is there a way to store a radiator so it wont scale and block ?

I just flush them out good, then hang them from a nail, either on the wall or from a rafter in the garage. Oh! I do tape-over the hose fittings though. Keeps pests from calling it home.

Clean it well, I would shoot a little heavy weight oil in it to prevent corrosion - if it has plastic endcaps I may not - but I have an aftermarket all-copper radiator. Don't use WD-40 as it can actually promote rust. And yes, seal your endcaps.

I was told you need to keep them filled !

i first get mine checked out [free] and small patches if needed and hang them up

At work we just drain them and hang them up. Have had some in storage for over 6 years with no problems that way.