I was wondering if anyone had suggestions on how to glue up mitre joints with a nice tight joint? I am using 5/4 stock. The mitre cuts are a true 45 degree and I have tried biscuits with pin tack and clamping with bessy frame straps. Any help would be appreciated.
From contributor T:
Not sure what the bessey is, but I've glued up some pretty good mitres with a cheap Pony strap clamp and the metal corners it comes with. The finish carpenters seem to favor those wire clips that pinch thins together - for casing and such.
Fine tune the alignment of the two, and grab a roll of regular masking tape. Apply 1.5" or so of tape to one side of the joint running parallel to its length. Rub it down good with a finger. Now reel out some more of that same strip of tape around the corner on tear it off. Stretch it (this is key, stretch it) and stick it down and rub it with your finger.
Do this across the width of the molding and be sure to reverse the starting point of the tape clamps every other strip. If it is a small to medium joint, the tape will be enough. On large joints, I use cauls and any type of clamp I have that will work. Even when I am using clamps, I rub the joints to get a vacuum seal.
You asked how to get a tight joint, and the key for me is to cut it accurately first, then hold the pieces together after applying glue and rub the joint back and forth until it starts to get hard to move (vacuum). I rarely use nails, usually just on in the field stuff like crown molding.
Comment from contributor A:
When gluing up any miter joint, I recommend first spreading a thin layer of glue on each miter and letting it dry. This is done because when you glue up a miter joint, the glue will go into the pores of the wood, making the bond weaker (wood is porous), as opposed to first putting the layer of glue down to make the glue and wood bond much better. Depending on the size and type of the project, you won't need to use nails.
1. Get a roll of filament reinforced packaging tape.
2. Miter the corners accurately, leaving about a 1/64" flat area at the tips.
3. Lay the pieces down on a flat table outside up with the flats abutting, and strap them in this position using pieces of tape about 10" long running perpendicular to the joint.
4. Turn the pieces over and put a fairly thin line of glue in the bottom of the v groove formed by the two pieces.
5. Fold the pieces to form the right angle between the pieces.
6. Strap in this position using more tape. If you had the right amount of glue in the groove, the folding operation will spread it evenly in the joint. To get a tight joint, accurate miters are essential. You may need to adjust your saw.