When building leaded glass panels to be placed in existing wooden frames, you need to make sure the panel is as square as the opening in the frame. The first requirement is to make sure your cartoon is squared, or has right angles at each corner.
I use a “roofing iron” as it is called in the UK. It is a steel tool about 600mm on one side and 400mm on the other. Its original use was to work out the pitch of roofs and check the same pitch was maintained all along the building. The first important thing – now that all roof trusses seem to be prefabricated – is that they still are in production. The second thing is that they all have a fixed right angle.
Using this roofing iron will ensure your corners on the cartoon are right angles. This helps in the drawing of the cartoon as you only need set the iron on the base line and draw the verticals without having to measure the width higher up the cartoon. Of course you should check that the width is still correct at the top, just in case there has been a slip.
Then you have to stick to the cartoon.
When you are setting the battens to ensure the sides are held where you want them while you continue with the leading, the roofing iron again will ensure that you have placed the battens at right angles. You choose which line is to be your base, and nail or screw it into place. Ensure it is exactly parallel to your cut line and then align one side of the iron against it. Place the other batten snugly along the length of the other leg of the iron and you know you have a right angle.
When you are completed leading, but before soldering you can check on the accuracy of the angles by using the roofing iron again at each corner to check on the “squareness” of the whole panel. If the panel is out of square, you can tap on the battens not yet nailed/screwed in place to ease it all back into “square”
No roofing iron?
ReplyDeleteYou could measure diagonally inside your battens to ensure square as well. By measuring diagonally I mean measure from the lower left hand corner to the upper right hand corner to get one measurement. Then measure from the lower right to the upper left for the second (hopefully) matching measurement. If the measurements match up the layout is square.
Place your four battens in on the cartoon, secure the lower horizontal batten in place. Place the two sides in place on top of your cartoon lines. Place the top batten in place. Before securing the three loose battens measure the two diagonals inside corner to inside corner, exactly. (Imagine measuring an "X") If the measurements are exactly the same the battens are square. In the event they are not move them as needed to match the measurements to each other. Once you have the measurements telling you the layout is square secure one of the vertical battens. Now again measure the diagonals before you secure the remaining battens; if all is square secure the last vertical batten. Measure again once you have placed the topmost horizontal batten and if the layout is square; measurements are the same' then secure the last piece. Measure a last and final time with a critical eye to accuracy to ensure square has been maintained.
Always measure using the inside corners. It goes without saying you do need to use straight battens to begin with. Lay the batten on edge on any good flat even surface and the edge should meet the surface end to end without light showing between the (table or bench) surface and the edge of the batten. Take care to cut the ends of the battens square as well. Starting out square early will payoff in hours of saved frustration later on.
Thanks for the directions. I have used this method and it's very accurate. Although, when making a transom for an old house,I almost made the mistake of assuming that the window opening itself was square. I'm glad I checked, because that old house had settled and the transom was way off.
ReplyDeleteGlass of Many Colours,
ReplyDeleteYes, of course you can measure diagonals instead of using a roofing iron to determine right angles. I was attempting to give a quick and easy method. As mentioned in http://glasstips.blogspot.com/2009/06/measuring-rectangular-opening.html
and in
http://glasstips.blogspot.com/2009/05/window-measurements.html
the diagonal method is essential to get the cartoon to match the opening. The use of templates is also a very good practice when making something for older buildings, although not all modern ones have right angles for their window openings. There is a six part series on taking templates for openings here:
http://glasstips.blogspot.com/2009/07/templates-of-openings-6.html
I should add that this tip is about ensuring you get right angles on your cartoon. If you are making a cartoon for an existing window opening you need to make the cartoon conform to the peculiarities of the opening. If you place your battens around the cartoon at the appropriate distance from the cut line, you will have a panel that will fit the opening.
ReplyDelete