Replies

1. 
   makita | Aug 03, 2003 11:04pm | #1

     Pat,

     The day in, day out pros at breaktime could probably help you more but I do a little of this and can give you some hints. First, mark your reveals [1/4,1/8 etc.] at the corners and the middle of the run on your window surrounds or door frames. next, cut your side casings for windows or head casing for doors. start out a little long and sneak up on your finish cut, trying it against your reveal marks until it is right on. next, relieve the back of each miter slightly with a sharp utility knife or a block plane or both. now tack the casing  to the frame in two places but no closer to the miter than 8" or so. next, measure long point to long point, or floor for doors, again sneaking up on the final cut. If the miters are tight, tack as on the first pieces; if not,try relieving the backs of these miters also.  If your cuts open at the toe or the heel, try shifting them slightly one way or the other off of the the reveal marks. A variation in reveal will will not be nearly as noticeable as open miter cuts. when the miters look good, finish nailing the casings to the frame and if the casings are sturdy enough to allow it, cross nail the long points of the miters. Before nailing the casings to the wall material, check to see if the outer edges are touching the wall all the way around. if not, shim them ,at places that you intend to nail, so that they don't  move when you press on them. If they move, the miters will likely open up when you nail the casings to the wall. Any slight gaps behind the casing can be filled with a FINE bead of painter's caulk. Not all these steps will be necessary every time, but, in various combinations, they should cure most problems. good luck,

        Chris
2. 
   mike4244 | Aug 04, 2003 12:01am | #2

   First, make sure your dealing with 90 degree corners. Older construction the openings may not be square anymore. Measure the width of the trim, lest say it's 2 1/4" wide. Decide how much reveal you want ( usually 3/16").Measure opening ( 36" for example). Add 2x reveal= 3/8"  + 2xtrim width 4 1/2" + opening 36".

   Overall this measures 40 7/8", this is length of miter LONG point to LONG point then cut. Mark reveal at head and side jambs. Nail head first. Cut left and right miters, stand upside down with long point of miter on floor or sill. Mark top of head trim on each leg and cut. Check for fit, then glue miter and nail with 18 gauge nails on finished jamb, use 4d nails if hand nailing. If trim does not lay flush at miter then slide a putty knife or thin shim behind miter. If you have head room nail down from head into side jamb.Most of the time the trim is not perfectly straight, nail only near the top , come back after glue sets up and work the trim to the jamb for reveal. One hour is usually enough time with yellow glue. You can use molding glue which is tackier, but I found it still takes the same amount of time to dry as regular yellow glue. While waiting for glue to set up you can cut the next opening. I usually use a 15 ga nailer when nailing into studs, or 8d finish if hand nailing. If trim is prefinished I use a 18 ga brad nailer that shoots up to 2" nails, even in the studs.

   Mike      

3. 
   robkelly1 | Aug 04, 2003 04:47am | #3

   What Chris and Mike said about covers it. The only addition I have is on how to handle a frame that isn't perfectly square (e.g., about 95% of them).  First, cut one piece of the correct length with the ends mitered at 45* and nail it on. Then cut the next piece about 2" too long, again mitered at 45* both ends. Fit the corners together so the miters have NO gap at all, and see if the reveal is parallel to the trim. If not, adjust the CMS 1/2* the correct direction and see if it fits. Keep adjusting till the fit and reveal is perfect, mark and cut the other end at 45* at the correct length, and nail it. Then proceed around the frame till done. Once I have the angle correct on the last cut, I cut it about 1/16" too long and trim off a 32nd at a time on the CMS. If you run the end of the wood against the teeth of a stopped blade, hold it in place, raise the blade, start the saw and bring it down slowly, natural run-out of the blade (on my 12" DeWalt) shaves off about 1/32".  The above is for windows.

   For doors, I do the sides 1st at 45* and nail in place. I then use a piece of 12" scrap to get the correct miter/reveal combination on each end of the top piece, cut it long, and creep up on it.

1. 
   mike4244 | Aug 04, 2003 08:20pm | #6

   Rob, try this method for out of square openings. Buy an angle divider, about $10.00, the one I have I got at woodworkers warehouse many years ago. Place angle divider into inside opening and tighten knurl. DO NOT use vernier on tool to determine angle, instead place tool against fence and set saw to this angle. I set the swing arm to the edge of the insert not the blade or the kerfed part of the insert.This gives you the correct angle without test pieces. I also use it for outside angles, but must use a bevel square first to get the angle. The accuracy of the vernier is off on my divider about a half a degree, hence I only use it against the fence of the saw, never read the vernier itself.I used to divide the angle with a compass and set a bevel square to this angle before coming across this simple tool.

   Mike

4. 
   Manchild | Aug 04, 2003 05:42am | #4

   I learned at breaktime how to get the compound miters you need to get tight fits.

   Let's say the drywall is a 1/16" proud of the jam at a corner. Make a stack of shims of varying thicknesses that you can slide along the jam or drywall in order to gauge the difference. Then take that gauge over to the chopsaw. Set your saw to 45 deg. or whatever the corner needs first by trial and error making the piece shorter every time. Once you get that done, then in this case you put the 1/16" shim in the back corner that will be resting on the 1/16" proud drywall. This will give the piece a twist that is putting it in the position that it will have to be in on the wall. The same goes for when the jam is proud. The other stuff mentioned is great advice, but this trick eluded me till some one told me over at breaktime.

5. 
   TomT226 | Aug 04, 2003 02:25pm | #5

   Ditto on what everybody else has posted. Everybody does it differently. On doors, I do the side casings first, and then fit the head, and trim back the miters. If the casing is to be painted, put a little calk on the face of the miter of the side casings first before you nail it in. The calk will stay flexible and not show any minor openings.

   Make a reveal block. Take a nece square piece of hardwood about 3" square, and cut a 3/16" relief in two perpendicular sides about 3/8" deep. To set the reveal, put the block against the side of the jam, put your pencil against it, and run your reveal line along both sides and the top. Makes it easy to line up the casing.

6. 
   Napie | Aug 04, 2003 11:35pm | #7

   If the trim profile is large enough I pre-cut them all, biscuit joint the miter, clamp with spring miter clamps, (the ponted wire ones).  Then nail the whole unit in one shot.  There is enough flex to allow the side casings to move where you need them.