Modifying sash weights

[Roger H]

Hi all.

After some advice re sash weights. I am fitting some dg sash windows. The sashes need x2 15lb weights per sash. The cast iron weights I have are rather long and I do not think will allow the window to fully open. Is it sensible to try and increase the weight of the weights by reducing length of the cast iron weights and increasing their weight?

If so, how best to do this? Wrapping in lead flashing and getting someone to weld a seam? I can’t think I can dip them in lead (like a candle) very readily given constraints of kitchen apparatus…

Thoughts appreciated.

 

[CliffordPope]

Make a mould to the dimensions you want for the calculated weight and cast your own lead weights.

 

[Roger H]

Might be easiest. Will have to wait 'til the Mrs is out for a while...

 

[CliffordPope]

Might be easiest. Will have to wait 'til the Mrs is out for a while...

My brother and I famously did that once when young. We melted lead in a tin on the cooker and poured it into the frog in a housebrick. Unfortunateky the brick was damp, and the result was an explosion that splattered molten lead over the kitchen curtains. We were lucky to escape uninjured.

When I cast lead as yacht ballast I was careful to dry the mould properly in the oven first

 

[88v8]

Had the same problem:. DG windows wide but short. And hardwood to boot.
I cast my own lead weights in a wooden mould. It smoked rather.
They were 2" square.
One end of the mould was moveable, I calculated the length to produce the desired weight.
I cast in the fixings for attaching sash chain. Where the fixing went through the mould I sealed with plasticine.
I made sixteen weights in all.
Heated lead scrap in an old pressure cooker base on the stove. Bit at a time. Skim off the cullet periodically so the surface is bright and clean.
Worst part was carrying it outside to pour. Heaviest was 16lb, which needs about 20lb of lead as much adheres to the pan. It sloshes in slow motion. Molten metal, the whole thing so hot it almost burns through a pair of gloves plus an oven glove.
And the fumes no doubt less than healthy.
But 36 years later here I am.
Still mad.

The weights are not the combined weight of the sash - for the upper sash the total weight must be a pound over, for the bottom sash it must be a pound under. Otherwise the sashes will tend to creep instead of staying shut.

Ivor

 

[Roger H]

Thanks for advice, especially Ivor's. New weights aren't that expensive per lb but the carriage is a bit steep.

 

[MatthewC]

The weights are not the combined weight of the sash - for the upper sash the total weight must be a pound over, for the bottom sash it must be a pound under. Otherwise the sashes will tend to creep instead of staying shut.

That's good advice - I just wish I had realised that before doing some windows earlier this year! I put one back with all the differing weights in the same position because I assumed that they had known what they were doing - then they both hung a bit short so I had to dismantle and swap the weights around, just because I didn't believe my own logic.

 

[88v8]

One can buy makeweights for the final tweak.

And this fairly critical adjustment is of course why glass used to be sold by weight.

Ivor

 

[a twig]

Was tidying my garden today and found a selection of cast iron sash weights - if they are any good to you you can have them for postage costs. Variety of weights, shapes and sizes, 8 in total I think

 

[Roger H]

Was tidying my garden today and found a selection of cast iron sash weights

Thanks for kind offer - I've got a good source of weights though, and I think the issue is that the old ones are in fairly standard round sections, and by the time you get up to 15lb they are too long to make my short heavy sashes work. I'm getting a fabricator to weld me some eyes onto 45mm square steel sections, so that should do the trick.
Thanks for all thoughts above though.

 

[88v8]

Be sure they will go through the pockets.
1¾" should be OK, I would think.

Ivor

 

[JanJonWestWales]

Make a mould to the dimensions you want for the calculated weight and cast your own lead weights.

just be really careful...hot lead and any amount of water are a very bad combination !!

 

[MattJ]

I weighed the new sash and the old weights, used some old roofing lead to make up two lead rolls of same diameter as the sash weights, temporarily duct-taped them on to test the balance and then when I was happy, epoxy resined the rolls onto the old weights.

My roofing lead was a rectangular sheet, so I weighed that and calculated mass per cm2 so I could gauge the size of the rolls more accurately.

 

[Roger H]

Thanks for all advice. In the end I needed square weights to give sufficient mass while minimising length. I had a fabricator knock them up for a £1 a 1LB and weld an eyelet on them. They worked a dream.