Learning how to stain glass involves lots of lovely mess – Cementing Your Panel.
You can’t learn how to stain glass and stay clean – it’s a rule! The cementing stage is particularly messy, but it’s worth it as it makes your stained glass panels both weatherproof and strong. The idea is that once you’ve finished the stained glass solder stage, you push the leaded light cement under the stained glass lead came, close the flanges down and then clean it up. If you’ve done any glass etching, abrading or sandblasting, it’s best to protect these pieces from the oily mess by putting sticky-backed plastic over them before you start this process.
How to Stain Glass - What you need: all-purpose putty, white spirit and black powder paint OR a pot of ready-made leaded light cement, 30cm sq piece of toughened glass or a tile for mixing on, mixing knife, All Nova Tool, latex gloves, scrubbing brush or toothbrush, whiting (chalk powder), polishing brush, dustpan and brush, newspaper, dust mask.
You can wear latex gloves through out the cementing stage, but unusually in the process of learning how to stain glass, this isn’t actually potentially harmful – it’s just messy. A dust mask is recommended for the cleaning up stage.
How to Stain Glass - Step one: Mixing the cement.
It’s a lot cheaper to make your own, but if you don’t have the ingredients, you can buy a pot of ready made leaded light cement at any stained glass suppliers. To mix your own, get some household putty and knead it until it has no lumps and is malleable. Put it on your mixing glass/tile and mix in some white spirit with the mixing knife, until it’s fairly runny. My students are always surprised how runny it has to be, but you don’t want it too stiff otherwise it’s difficult to push it under the flanges of the lead successfully. When it’s mixed together, add a spoonful of black powder paint to colour the putty black.
How to Stain Glass - Step two: Cementing your panel.
Place your panel on some newspaper. There are different implements for pushing the putty under the flanges – some prefer a scrubbing brush, some a toothbrush, and some prefer using their thumb. When I use brushes, I can’t tell so easily whether I’ve put enough cement in, so I generally prefer my thumb. But if I had a set of church stained glass windows to cement, I think I’d settle for a brush! Work the cement in across the leads – don’t brush up and down the length of the lead, as this removes the putty you’re trying to put in. If you have sufficient time, it’s best to do both sides at once, but you can do one side at a time as long as you clean it thoroughly before stopping.
Step three: Pushing down the flanges.
Next you need to trap the cement under the lead. To do this, use the flat end of the All Nova Tool at an appropriate angle to gently push down each side of the lead onto the glass. You can break your glass at this point, so don’t push too hard. Don’t worry too much if you’re using 5mm lead – there’s not enough width of flange to push down.
Step four: Cleaning up.
Scrape the bulk of the cement off the glass with the All Nova Tool – this can be reused if sealed tightly in your putty pot. Sprinkle with whiting and rub over the whole panel so the chalk dust absorbs the linseed oil. Trace round each glass shape with the ‘beak’ of the All Nova Tool before brushing vigorously with the polishing brush. Again, brush across, not along the length of the leads. You must get all the putty off the lead, otherwise it hardens and is difficult to remove. I sometimes use a toothbrush to do this. Repeat this on both sides. Some of the putty will squeeze through, but don’t worry as you are yet to do the final clean.
Step five: Drying the cement.
It’s important when learning how to stain glass to be patient – not easy I know! But once you’ve cleaned all the leads and glass with the whiting, you need to leave the stained glass panel for at least three days, so that the cement can dry and harden. Then you’re ready for your final clean and polish.
Everything Stained Glass Home Page
