Posted: 24th, April 2009
(Editor’s note: Click on any of the images to see larger versions for more detail)
In this segment we’re going to focus on the design and construction of a window frame (the casing) with two inner window sashes that swing open on pins. I’m not a professional builder so I apologize if I’m using the wrong terminology for the various parts of the windows–I did a quick Google search so I could have some semblance of consistency. ;-}~
When I started thinking about how I wanted the windows in the structure to look and to operate, the overall design was pretty simple: The outer frame, or casing, would consist of four pieces of Basswood (chosen for its sturdier composition than Balsa wood), and two solid blocks of balsa wood that would be pinned into the casing so they could swivel open and closed.
Once again, I used the same Reaper mini from the previous articles as my standard for measuring how high and wide the sashes and window casing should be. You can see the final results of the measurements in the picture up and to the right. Note that during the actual build process you’ll need to shave off some of inner and outermost sections of the window sashes in order for them to open and close smoothly, otherwise they’ll fit too snugly together which may cause damage to the frames.
For the outer support frame or, window casing, I cut my Basswood to the necessary measurements and then super glued the pieces together. Once the glue was dry, I used my push hammer and drove in eight miniature nails (3/8″ long) as pictured to the left. You need a steady hand and a firm grip to do this, otherwise you’ll wind up driving the nails through the inside (or outside) of the casing and ruining the overall structural integrity of the frame (by splitting the wood). The other thing you need to be careful of is not to push too hard or you wind up breaking the frame apart at the glued seams or worse–splintering or splitting the wood.
For the inner sashes, I used 1/4″ thick Balsa wood and cut two rectangles that would serve to hold the “glazing” that would be added later. In the picture to the right, you can see how the sash took shape from a solid block (on the right), to a window frame (on the left with the marks for cutting), and then a cut sash sitting (unpinned) inside of the window casing (at top).
The thing to watch out for during this process is how much pressure you apply and where you apply it when “carving” or cutting out the aperture for the glazing. I used a regular Xacto blade to cut into the Balsa–with the grain. It’s easy to cut the wood with the grain. Cutting against the grain meant putting a little more pressure on the piece with the non-cutting hand so the wood wouldn’t slip. I split the first two pieces along the grain. That’s when I switched to using an Xacto saw blade (see Part 2 for reference and a picture).
You don’t want to pin the sashes into the casing at this point. There is still a lot of fiddly work (“Fiddly” is a technical term. Use sparingly.) to do before they get pinned into place. As I mentioned previously, you’ll want to sand down the outermost edges of the window sashes so they play nicely together (open and close smoothly) once they are pinned into place. You can see from this closeup how rough the edges of the Balsa can be. A bit of sanding with fine grit sandpaper or a small, fine file will do the trick–plus it will make the surface nicer for staining or painting. You’ll want to sand off enough around the edges to leave roughly a 1/32″ gap between the sash and the casing. This will be important later for the windows to be able to swivel open and closed once they’re pinned into place. (Editor’s note–an interesting observation I made after viewing these pictures: using my macro lens caused some of the closeup shots of the window casing to look “bowed.” The actual piece was perfectly square as I trued up the outer frame with angles and clamps to make sure the piece was square.)
Next we measure the inner dimensions of the window sash so we can cut out our “glazing” that will be pressed into the sash. Don’t be surprised if despite careful measuring and careful cutting your dimensions are a bit wonky, they’re almost inevitably bound to be off by a millimeter or two as a result of cutting by hand. The most important thing to take note of in this step is to make sure you jot down those measurements! (you’ll see why this is important in just a little bit).
For the glazing (glass that will occupy the sash) I used a yellow tinted acrylic that I purchased from one of my FLGSs (Favorite Local Game Stores) called The Last Square. They do mail order so if you can’t find this kind of material at your local gaming or hobby store, they can probably ship it to you. It comes as an 8″ x 10″ sheet and runs about $2.39 per sheet (prices vary depending on the thickness of the acrylic I learned!). I chose to go with the yellow tinted acrylic instead of clear in an attempt to achieve a backlit-by-fire effect. My inspiration was the logo I designed and had my best friend James Blach create for me for another one of my web sites, Safe Haven Games. The sheets come in clear, yellow, orange, red, and a smoky gray as well. If memory serves me well, you can also get a mirrored acrylic (great for modern buildings!).
You’ll want to cut the acrylic as close to the inner dimensions of each window sash as possible so you can “friction fit” the glaze into the sash without having to glue it in place. Super glue will eat this stuff up (dissolve it or severely disfigure it) and PVA (white glue/Elmer’s glue) will leave semi-opaque gobs on the edges.
If you’re working with two sashes at a time as I was when these photos were taken, you’ll want to take care to remember which piece of glazing goes with which sash–and which way it fits into position, hence my comment above about jotting down those measurements.
At this point in the construction process, you’re pretty close to being finished with the build. Before you cut and set the grilles (“Muntin bars”) you’ll want to paint all of the pieces. Make sure you remove the glazing before painting the pieces! You don’t want to wind up with brown slop on your windows. You can always dab some very heavily diluted black ink in the corners of the windows later for a “dirty/smoke saturated” effect. For the window casing, sashes and grilles I used the same combination of GW’s Graveyard Dirt as a basecoat and a wash of GW’s Brown Ink over top of the base coat once it had dried thoroughly. I highly recommend letting the basecoat dry before you apply the ink wash. Balsa wood and Bassword are very absorbent and you’ll wind up making a very muddy looking mess if you apply the ink too soon.
To break up the glazing and make it look like individual window panes, grab those interior sash measurements again and cut out some thin (1/8″ or slightly wider) strips of Balsa or Basswood. Friction fit them into the window by sliding them in at an angle and then pushing the top or bottom with the flat of a file to nudge them into place. You want to make sure they fit snugly before we take them back out and paint them. This can be a frustrating process–I snapped at least a half-dozen pieces in the process of trying to get a nice, straight grille from top to bottom.
Another thing to take note of on this step is that you want to make sure you seal the grille pieces with a good coat of paint before you apply the stain (as described above). Because these pieces are so thin, they will tend to warp if they get too saturated with the ink wash. I’d recommend placing something fairly heavy on top of them and allowing them to dry after the ink wash. Don’t worry about the ink rubbing off–put a steel washer or something of the sort on top to keep the wood straight until dry. Once they’re dry, friction fit them into place. If you have a piece or two that is just short of being stuck in place by friction, a little dab of super glue will do the trick–but be careful to not get glue on the acrylic (using a pair of needle-nosed pliers to insert these pieces helps if you’re using glue. Just don’t press too hard with the pliers or SNAP! You’ll cut right through the wood and it’s back to square one.).
Now that we have everything assembled and painted, it’s time to fit the sashes back into the window casing and check for any swelling that may have occurred as a result of painting and ink washing. You may notice a slightly more snug fit when you put the sashes back into the frames. That’s OK. A little bit of sanding will take care of that. Don’t worry too much about sanding off the paint job you just did–Balsa soaks up paint and ink like a sponge.
Once you’re satisfied with the fit of the sashes in the window casing, you’re ready to “pin” them in place. This requires a little knowledge of how hinged and/or pivoting objects work, a really steady hand, a couple of measurements, an accurate sense of placement, and an offering to the gawds of miniature construction.
You really, really want to get this step right, otherwise all of that work will just go to crap. If you followed the sanding instructions above carefully, you’ll have taken off enough bulk around the outside of the sashes for them to “float” when placed inside of the window casing. Make sure you leave a bit of a gap (roughly 1/32″) between the left and right sides of the casing and the left side of the left sash, and the right side of the right sash when marking where you will drive in your miniature nail (3/8″) to pin the sashes in place.
Using your push hammer, set your nail where it will drive through the top of the window casing and down into the left side of the left sash (while holding the sash firmly in place in the frame with your other hand). Turn over the casing and set the bottom nail the same way. The result should be a window sash that can be opened and closed relatively freely. Careful not to push the window open or closed from the center of the window! You’ll wind up pushing the glazing and grilles out (and possibly breaking the thin, delicate strips serving as window grilles).
Repeat the pinning process for the right sash, test out both windows for clearance, and you’re done! You may need to sand a bit more where the two windows meet when closed. Again, there will most likely be enough paint and ink wash soaked into the Balsa that it won’t look funny after a bit of sanding.
That concludes this segment of our project. Next time we’ll look at mounting the door and window casings into the facade of our building. We’ll also talk about assembly considerations and a very important lesson I learned as a result of being a bit over zealous about building out the front, lower wall of the structure. ;-}~
Until next time…