How To Join Picture Frame Corners

How To Join Picture Frame Corners

It is very common to see a “frame center” store today.  They’ve been around for a few decades, offering framing services for paintings, posters, and almost anything else that can be framed and suitable for hanging on your living room wall. 

Many also offer “do-it-yourself” framing classes on the weekends too.  You choose the wood, and the framing center provides the tools necessary to assemble your frame.  Backboards are provided, and even glass to cover the piece being framed is offered.

For the hobbyist woodworker, though, a home shop is likely to have all of the tools and equipment necessary to build a decent frame.  These would include a miter saw, clamps, wood glue, a power drill, and at least a hammer, if not a brad gun. 

There are more tools, though, too, for the more serious framer, and they’re not expensive. Let’s take a deeper look at building a picture frame and the tools that will help you make those perfect corners.

Which Joint Is Most Commonly Used On The Corners of Picture Frames?

That’s easy – – miter joints.

Miter Joint

It’s the most commonly used joint in the framing business by far.  The end of each piece is cut at a 45-degree angle (2 pieces, each 45 degrees, and we know that 45 + 45 = 90) and joined together.  Since 90 degrees is a square angle, we know that each joint in a frame will be square, and 90 times 4 is 360, making the frame itself square.

This is an easy joint to cut.  Most home woodworking enthusiasts will have a miter saw in their workshop, whether it is the old-style manual unit with a backsaw (a hand saw with a stiff brace on the edge opposite the cutting edge to provide control of the blade and more precise cuts), or a compound miter saw. 

45 Degree Cut

Each saw is able to be set at whatever angle is needed for a cut, and in the case of picture framing, we know that angle to be 45 degrees.  A fine woodworking blade is necessary to make a truly clean cut no matter what wood has been chosen for the project.

How Do I Make Good Picture Frame Joints? – Joining Mitered Corners

When it comes to making the mitered joint, though, there are several options for the actual joining. None of them are particularly difficult, although some are easier than others, and some do require special tools.

Biscuits

An oval-shaped piece of beech or particle wood.  A slot is cut in each piece of wood (frame rail) using a biscuit jointer; the biscuit is covered with glue (or glue is put into each slot) and inserted into each slot connecting the two pieces of wood.

When the glue has had ample time to dry, the joint is secure.  If the frame is large and the rails have the available space, a brad or two (small nails) can also add extra strength to the joint.

Splines

A rectangular piece of wood that fits in grooves of each frame rail.  They, too, provide additional surface for gluing, just as biscuits do.  More work is involved with splines to join mitered corners, and the splines will be visible on the outside of the frame corner.  However, they are a viable option for creating a strong corner of your picture frame.

They help reinforce and align the edges.  Softwoods are not a good choice for splines; use a more dense wood like walnut or hard maple.

Pocket Screws

Pocket Hole Jig

Recessed holes are drilled in one frame rail using a special drill guide, and pocket screws (they fit in the recessed hole “pocket”) are used to join the two frame rails.  They require a little extra thought and planning, but they provide an extremely strong joint, making them a good choice for larger frames.

V-Nails

Commonly used in framing, including picture, window, and door frames.  They are like staples in a sense, actually v-shaped, spanning the seam and embedding in each end of the two frame rails being joined. 

V-nailers are used to deliver v-nails.  The business end of the v-nailer has a v-shaped “frame” with a 90-degree angle; the two frame rails are joined in that “frame” while the v-nailer embeds the v-nail across the seam and into each piece of wood.  For small frames, this is overkill, but it is an effective way to create solid joints for larger frames.

No matter which joining method you choose to connect and fasten the frame nails all around, glue is also a good choice.  Give it enough time to dry fully, and be sure to wipe off excess glue with a damp cloth before it dries.

How Do You Clamp a Picture Frame Corner? 

This, too, is easy. 

Picture Frame Clamp

A 90-degree corner clamp will do the job for most any frames you are building in your home woodworking shop.  They are available in local hardware stores, large DIY stores, and online retail websites.  They are not expensive and come in various sizes to match your project needs.

They will provide a 90-degree angle with adjustable clamps for each piece of frame rail to be joined.  The rails will be held in place while you join them, exposing the corner for whichever means of joinery you have chosen.

For larger frame projects where a V-nailer is going to be used, the business end of the nailer will already have a 90-degree “v” that will align and hold two frame rails in place for the v-nail to be embedded.

A miter saw, a biscuit jointer, a 90-degree corner clamp, some wood glue, four biscuits, maybe some brads for smaller frames, and you have all you need to create a frame for your painting, or your kids’ school photographs, or whatever else needs framing.

Miter Saw

For larger projects, perhaps a pocket screw joinery or splines will be needed; and for even larger framing projects, a v-nailer and v-nails.

The basics are still the same, though:  a true and clean 45-degree cut, wood glue, and a joinery plan.  Before you know it, you’re hanging that frame on your wall after a job well done.