Narrow picture frame...how to assemble?

[Handplanesandmore]

No professional picture framers would rely on glue alone for mitered frames. Although a recent video about miters may suggest glue is strong enough, don't put all your money there. For one thing, the test in the video didn't take into account wood movement over time nor did it take account of various kinds of force.

Sizing does help, but it doesn't offer the kind of structural strength a fastener does. Glue alone is fine in ideal situations. I prefer to prepare for the worst......eg the frame or a mitered box is dropped by accident.

If your frame is a big one or important, don't be lazy. Just reinforce the joints and sleep well.

Simon

[Cooler]

We used to corner nail these in our frame shop, but then we got an underpinner. You are not going to invest in an underpinned and the corner nailing only allowed us to unclamp the corners so that the glue could set.  The glue should be enough. Make sure that the joint is not glue-starved and wipe off any squeeze-out with a piece of damp paper towel and then wipe dry.

Are you hanging it vertically or horizontally?  If you are hanging vertically, then just add the dust cover to the back (craft paper).  I always used adhesive transfer tape from a dispenser, but it is available in rolls for hand application.  After applying the craft paper, trim to about 1/8" from the outer edges.  To do this, fold the paper over the edge of the frame for a reference line, and use a straight edge and a utility knife with a fresh blade. 

After you apply the dust cover, lightly mist the back with water and wipe gently with a paper towel.  As it dries it will draw the paper taught. 

If you are hanging it horizontally and have a small profile molding, the risk is that the molding will bow.  In that case, I would use a piece of mat board in place of the dust cover.  It will add enough structure to prevent the bowing.

If you are hanging vertically, then just the kraft paper.  It also gives a finished appearance to the job.