Reinforcments

by Matt
(Melbourne)

Hi Sue,

I'm doing large panels aprrox 1 metre by 600mm (approx 3ft x 2ft). I was taught to use vertical or horizontal reinforce lead straight through the panel, which in turn I learned from other people that I have created hinges, weak lines were the panel will tend to bow on.

I see a lot of this type of reinforcement from established craftsmen so it gets confusing, would appreciate your thought on that one...

Another question, I've also learned the method of using restrip through out sections of the panel as you displayed in an example for another person..would this be suitable for the larger type panels I mention? and is the restrip your using copper foil strip? That's all they have at my local supplier?

And finally are you against using cement putty..

Thanks so much for your time..

Matt

Answer
Hi Matt,

Hinge Joints
Yes, you have hinge joints. That panel would have been much stronger without those vertical lines going through it. We have made many windows that large, and larger, using copper re-strip for reinforcement and one or more horizontal re-bars across the back at installation. The rebars must attach into the window frame in order to give the panel the support it needs.

Any straight vertical or horizontal line the goes from one edge of the panel to the other is considered a hinge joint and should be avoided if at all possible. Even if you use reinforced lead, the window can still fold at those joints. There are ways to get around it by weaving the lead lines, but the technique is too involved (and needs pictures) to include here. It will be included in my eBook, "How To Reinforce a Stained Glass Panel", that will be coming out late summer (USA summer!).

Copper Restrip
When you use copper restrip, it must go from one edge of the window to the opposite edge. It is pliable enough to be able to bend it around curves and corners in order to keep it going in one continuous piece.

We always try to put it in a horizontal direction, but it can go vertically as well. Matter of fact, you can run it in both directions on larger panels. Where one piece crosses over another, cut one of them and make sure the ends touch the piece going in the other direction. That way they will join together when soldered. In most designs, it will be impossible to run restrip absolutely straight up and down or across. It will wander along, perhaps diagonally at points, but still stay in one piece from one edge to the other.

Putty
As for putty...NO I do not approve of cement putty! Putty should not contain cement or plaster of paris. Plaster absorbs moisture (moisture is the number 1 killer of building materials). Cement is so strong it attaches itself to the glass making restoration very hard. Putty only needs to be made with boiled and raw linseed oil and whiting. You can add a powdered black coloring to make the putty black. You can see my Putty Recipe here.

The purpose of the putty is to add strength and to waterproof windows. This type of putty will firm up, be slow to dry, cushion the glass while holding it firmly, last for years, be somewhat flexible and yet at the same time allows for repairs without having to do more damage to the window in taking it apart for the repair.