Saturday, June 8, 2013

Double-hung, Double-Paned Windows From Scratch - Part 2

As promised, here is the second part of my step-by-step process for building windows from scratch.

If you followed along with the first part (if you missed it, click here), you should now have a pair of window sashes built, ready to have glass installed.  For my construction, I'm going to use real glass.  You could choose to use a different material, some sort of clear plastic or cellophane film, or possibly something else entirely.

The glass that I'm using comes from Sierra Scale Models - seven bucks for 55 pieces of glass, hardly expensive.  Depending on the scale that you're modeling in, you could also use microscope slide covers - they're also real glass, but twice as thick as the Sierra glass.

Cutting this glass can be a bit tricky, and you will waste a few pieces before you master the technique.  The first, and probably most important tip for cutting glass is to work on a hard, perfectly flat, perfectly smooth surface - I work on a 12-inch square marble tile.  The second tip is to secure the glass in such a way that it won't move during cutting, won't scratch, and can easily be unsecured without damage.  I use blue painter's tape for this - turn one piece upside down (i.e. sticky side up), fastened to the work surface with two more pieces of blue tape.  Place the glass sheet on the exposed sticky side of the first piece of tape - this will hold it in place while you're cutting it.

Using one of your window sashes as a guide, place a straightedge (preferably something metal) across the glass and tape it down.

Using a scribing tool (also available from Sierra), make several light passes along the straightedge to score the glass - seven or eight passes should be enough.

Repeat the process for the other dimension of the window sash (width and height).

Carefully slide a razor blade under the scored section of the glass, and using it as a lever, gently lift the scored glass away from the tape.  As I've expertly demonstrated here, if you're too aggressive with this step, or just aren't paying attention, you can easily break the glass.  Store those broken pieces away somewhere safe, and you can reuse them later as trackside debris or litter.

Now it's time to glue the glass onto our window sashes.  It's vital that when you're applying the glue that you don't get sloppy.  Don't use too much glue, don't get glue in the wrong places, don't get glue all over the glass.  Precision is the key.  I've found a glue that works really well for this - a jeweler's glue that I bought from Micro-Mark.  The tube has a syringe-type applicator, allowing for very precise glue placement and flow control.

Place a tiny drop of glue in each corner of the window sash.

Now for the next tricky part - picking up the cut piece of glass, without breaking it, and placing it onto the window sash without smearing the glue.  You can use tweezers for this, but if you do, I recommend wrapping some tape around them to help provide some cushion to protect the glass.  An even better option is to use this nifty suction-cup gizmo.  Micro-Mark sells one, but I found mine on eBay for just a couple of dollars.

Gently place the glass onto the window sash, carefully as to avoid making a mess with the glue.

Repeat for the other window sash, and then take a break.  Let the glue dry for a few hours, preferably overnight.  Tomorrow, in the third and final installment, I'll show you how to put the window sashes into a frame, and ultimately into the wall of your structure.