Gluing Sash Joints
Notes On Gluing Sash Joints
Glued sash are assembled the same as pinned sash, except that the following advice should be adhered to.
We recommend Titebond (R) Type-II water-resistant aliphatic-resin wood glue (or similar) for gluing sash.
The glue, sash, and assembly room should be above 55 degrees f., and preferably above 65 deg.
Three bar clamps are required, one for each rail, as you have to work fast once the glue is applied and until the joints are closed. It is highly recommended that you find a helper.
Be sure to chamfer the tenon ends (as outlined previously) when gluing sash joints. The square ends of the tenon tend to push the glue out of the joint.
Wrap the glue blocks with visqueen to prevent the blocks from adhering to the sash. See picture.
It is recommended to have two people working when gluing sash. One spreads glue in the mortises and on the area on the inside edge of the stiles above the top mortise and below the bottom mortise with a small stick such as a popsicle stick, while the other spreads glue on the tenons and coped ends of the rails.
The glue should be spread thinly but evenly on all mating surfaces. Assemble the sash immeadiately, before the glue begins to dry. Two sash assemblers are much more efficient than one! Elapsed time between beginning glue spreading and beginning sash assembly should be no more than about three minutes. Total clamping time should be about 3 to 4 minutes. Glue open time is shorter than closed time, so get the joints started together as quickly as possible
When joints are fully closed, clean off excessive glue from joints with an old toothbrush and a can of warm water. Wipe the joints dry with a paper towel. Especially make sure that the excess glue is removed from the sash sticking, as it nearly impossible to clean the corners of the sticking once the glue has set.
Make sure the sash are square when gluing, as the joints will not move after the glue has set.
Leave the clamps on for at least 2 hours until the glue obtains initial set. If you can't wait 2 hours, pin the joints as outlined previously before removing clamps.
Click on images below to view at larger size.
Clamp Blocks Covered with Plastic Sheet to Prevent Blocks from Adhering to Sash