Cast iron Sash window weights

[appletree]

Has anybody found sash window weight a useful source of  Cast Iron? Or are they too varied with hard spots to be usable?

I have just been given a dozen

Phil

[Mike E.]

They make great weights for bottom fishing off shore, Seriously, they seem to drop to the bottom faster and I would be reeling up fish while others on the boat were still peeling out line, less tangles for me as well.

[Pete.]

I brought four home from work, two smaller and two larger. There wan't a whole lot of difference between the sizes I think the larger ones were maybe 30% bigger but the two small ones were unmachinable and the two larger machined quite nicely. I've made quite a few bits and bobs from them.

Bottom line - it's a lottery. Depends on how quickly they were chilled I guess.

[kayzed1]

I do not have a lot of experience in these things, but i do have some that came from a Very old house. One or two that are 4 feet long most round but again three or four that are square. All machine very well and not come across any hard spots ...YET!
Lyn. 

[awemawson]

You can always soften them again, heat to white hot and cool slowly.

Here's a large square one glowing nicely in my 100 kw induction furnace when I had it set up back in  2007

(just had to manually ramp down the power setting so it cooled slowly rather like you would with a pottery kiln to avoid cracking, which was easy as it's a  big knob on the control panel!)

[appletree]

Thanks for the replies, looks like they are worth having, I guess pre cut lengths could be put on the coal fire in the lounge to soften. Don’t know what it is love must have come in with the coal.
Don’t know what might happen to the carbon content?

Phil

[Ray]

I have three about 18 inches long that I turned round.  Two looked good.  The other one has some holes and pits.  I have made model piston rings from one of the good ones and they worked well.  Some will be good and some will be bad.

[vtsteam]

White heat? Uhhhh, nope, that's re-melting it. CI melts at 2200F.
For most gray irons, a ferritizing annealing temperature between 700 and 760°C (1300 and 1400°F) is recommended. If you're going by color that's dark red (see below).

You also don't have to keep it in a ramped powered furnace for cool down. just bury the piece in a bucket of wood ashes to cool slowly. In fact you can also do the heating to annealing temps in a wood fire in the brightly glowing embers with a little draft.

Color             Temperature [°C]     Temperature [°F]
                          From      To         From      To
Black red             426     593         799     1100
Very dark red      594     704        1100    1299
Dark red             705      814        1300     1497
Cherry red          815      870        1498    1598
Light cherry red  871      981         1599    1798
Orange               982     1092        1799    1998
Yellow                1093    1258        1999    2296
Yellow white      1259    1314         2297    2397
White                1315+                   2397+

[krv3000]

 just a tip with the weights leve them  out to go rusty then machine them up in to bar stock then cote them in oil I have made lots of things out of the ones I have

[NormanV]

I once bought a couple of flat irons in order to use the cast iron. They turned out to be a dissapointmant, not only were they chilled and had the handles cast into them, they also had a number of voids in the castings. I'll not bother again.