Monday, July 27, 2009

Making Windows… Part 1

As I indicated in some previous posts, I’m making some wooden storm windows (and eventually some double-hung sashes) to replace those in our house that are either too far gone or missing.

Here’s a list of the tools I’m using:  a table saw, a router mounted in a router table, a mortiser (similar to a drill press), a tenon-jig (for the table saw), and some specialized router bits for making windows.

My table saw is a pretty cheap model from Ryobi, which came with a removable miter attachment with a non-standard t-groove.  The tenon-jig that I purchased requires a 3/4” t-groove, so I had to make my own table saw attachment to take the place of the original one.  More on that in a later post.

Here are some pictures of my router table, with one of the special router bits installed for making the windows:


The bit as installed makes the ogee shape on the inside face of the window and the square groove on the other side for installing the glass (referred to as the ‘sticking cut’).  You can reassemble the bit for making what is called the ‘coping cut’ which is the inverse of sticking cut for where the rails (top and bottom of the frame) of the window meet the stiles (left and right sides of the frame), or you can buy an extra bit that will do the same job so you don’t have to repeatedly take apart and reassemble the bit.

Here are some pictures of a simple test frame I made out of some scrap spruce 2x4s:


For a simple frame that doesn’t need to stand the test of time (like a picture frame, or small mirror, or something similar), this sort of construction would be sufficient, but the only thing holding it together would be the glue where the pieces fit together.  This would not be strong enough for a full-sized window that has to withstand both the challenges of weather, temperature differential (inside of house vs. outside), and being continually opened and closed.

For a strong window that can deal with all of these conditions, you need a mortise and tenon joint (or something similar).  There are other joinery methods that use dowels, biscuits, etc…, but one of the strongest joints is the traditional mortise and tenon.  Those terms sound fancy, but they just refer to the hole (mortise) and the thing that goes in the hole (the tenon).  There’s a really good reference on this type of joint here.

Here are some pictures of part of a test frame I built using a mortise and tenon:

IMG_1369IMG_1373IMG_1374There are several methods for making the tenon, including using hand-saws, a jig for a table-saw, or using router bits.  I opted for a jig to assist with making the ‘shoulder-cuts’.  Then you use the table saw without the jig to remove the rest of the material.  I’m going to do a more detailed post on making tenons later on.

For making the mortises, you can use hand tools (a special chisel called a mortising chisel), or you can use a plunge router, or a dedicated mortising machine.  The plunge router (or drill if you’re careful) don’t give you a nice square holes, so if you go with that option, you have to square the mortise, or round the tenon.  A dedicated mortiser gives you the nice square holes and is the ideal option if you’re making a lot of mortises (which I’ll be doing).

Here’s some pictures of the mortiser:

IMG_1354 A close-up of the bit:

IMG_1355 The bit is actually two pieces, a hollow square chisel, and a drill bit that removes the material inside the chisel:

IMG_1356IMG_1357 The bits come in standard sizes.  The mortiser I bought came with 1/4”, 3/8” and 1/2”.  I’m using 1/4” mortises for our storm windows.

Now that I’ve reviewed the tools involved, I’ll lead you through my first real attempt at making a small storm window that is 22 1/2” (height) by 21 1/4” width.  It is a single-lite storm, so I don’t have to worry about muntins (I’ll do a post on those when I get further into making my windows).

I’m going to make this storm out of a spruce 2”x8” purchased from the local big box that I had lying around from another project.  Normally, you would purchase good quality wood from a proper mill.  My 2”x8” has some knots which you really want to avoid and it’s not the best quality wood.  A lot of wood windows are made of spruce, pine, or cedar.  Spruce and pine are fine for painted windows.  You can also use Mahogany or other finer wood species if you are staining the windows instead of painting.

Here is my 2x8, cut into 2 25” pieces:

IMG_1353 I used my table saw to rip the raw lumber into 2” wide pieces, trying to avoid the knots in the wood wherever possible.  This gave me 4  2” x 1 1/2” pieces 25” long.  My storm windows have to be 1 1/4” thick however.  My interior windows are 1 3/4” thick, but the storms are a little thinner.  So, I had to rip 1/4” off of each piece.  This requires you to remove the guard on the table saw, which I hate doing, but I used protection for my eyes, stood to the side of the blade rather than right in front of it, and used push sticks to keep my fingers well away from the blade.

Here are the final pieces waiting to be cut to length:

IMG_1375 To give your wood the nice clean, straight, square edges it should have, you would ideally use a jointer/planer.  I don’t have one and have opted not to purchase one at this point.  For this window I am using a cheap ripping saw blade, but I have purchased a better quality finishing saw blade that should reduce the appearance of saw blade marks.  I may make a home-made jointer jig for my table saw as well depending on the results I get from the new blade when I get around to installing it.

Sizing the pieces for your frame is pretty simple.  The stiles (left and right of your frame) are the full height of the window (they will have the mortises).  So, they will be cut to 22 1/2” – 1/8” (you have to leave some room in the frame so the storm isn’t too tight), so 22 3/8”.  The rails are the width of the window (21 1/4” – 1/8”, same reason as above), minus the width of the stiles (2” x 2), plus the length of the tenons (2” x 2, since I am doing through tenons, meaning they pass all the way through the stiles), plus a 1/2” for the coping cut (where the cope and stick routed edges overlap).  So, the rails will be 21 5/8” in length.

I’ll end this post here.  My next post will show how to make the tenons on the rails, and I’ll follow that with the mortises, routing the cope and stick cuts, and then moving on to dry-fit, gluing, and eventually painting and glazing.


  1. Wow. Maybe I will consider making my own storm windows. It could be done.

  2. I like reading your woodworking blog come and check mine out also.....@

  3. Thanks for this info; extremely valuable! I was amazed at how little info there is on making windows out in the WWW. Mortise and tenon def. are classic. I was considering using the Kreg system to assemble mine!

    Thanks again for taking the time to post this info!

  4. Darren,

    There's an interesting article over at the Canadian Woodworking forums discussing various types of joints including dowels, biscuits, M&T, pocket holes systems like the Kreg, etc... For certain applications, including window frames, M&T joints (with a peg through both members ideally) came out on top. I would think twice about using pocket hole joinery with screws for a window; the exposure to weather, varying humidity and other environmental conditions could have a detrimental effect on screwed joints.

  5. This blog was very useful for me.This is very easy way to make new windows. Thanks for this post.


  6. All windows wood in a house can be very relaxing. This is a very good way to make it by your own.

  7. I made a complete set of windows for part of my home. Classic casements with modern seals and vintage style locks and stays. Casements with round tops on either end and 6 casements with fixed lihgts above on the side