The joining system used to assemble these particular frames is called the Hoffmann Dovetail System. This joining system uses special shaped keys, made with ribbed, sloped sides, to connect the mouldings by creating a tight and perfectly aligned joint. The keys come in a bow tie shape and are available in different lengths and colours depending on the frame they are being used for.
This system is ideal for assembling very large picture frames; especially ones that are narrow and/or tall like shadow boxes, canvas floater frames, or extra large stretcher bar frames for artist canvases. It is ideal because it creates a stronger structure for these frames as well as it is safer if being transported as these keys are easy to assemble at home!
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Mouldings |
Keys |
Tools |
![](../img/dovetail_bars.jpg) |
![](../img/dovetail_keys.jpg) |
![](../img/tools_dovetail.jpg) |
You should have 4 or more separate frame pieces - a singular piece is otherwise known as a moulding. The Hoffman Routing machine creates a unique cut or keyway into the edge of the chosen moulding material. This key way will allow you to join two frame mouldings together by inserting a key into this cut out area. Dovetail Keyways (slots) are routed in all mitered ends. |
The joining system we use for these frames are called Hoffman Dovetail Keys. These keys are inserted to join the frame mouldings together, creating a tight and perfectly aligned joint. The Keys are a bow tie shape and they come in different sizes depending on the frame, please note we will send you the correct key for your frame.
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To assemble your frame you will need your keys, hammer and we always recommend good quality wood glue. We may include screws and four flat corner braces for your frame if the frame is particularly large and requires additional support, for which you will also need a screwdriver. |
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Step 1 |
Step 2 |
Step 3 |
![](../img/moulding_dovetail.jpg) |
![](../img/dovetail_joining.jpg) |
![](../img/dovetail_key_join.jpg) |
Grab your first molding and make sure the hollow end of the dovetail key is pointing up towards the sky. Repeat this with a second piece. |
Bring the two mouldings together and line up the adjoining faces, so you get a bow tie shaped hole pointing towards you. This should form a perfect 90 degree angle to form the first corner of your picture frame.
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Whilst keeping the mouldings pressed together, grab your wood glue and add a little bit of glue to the inside of the bowtie shaped keyway. Then press your first key into the keyway, which will then hold the frame together. |
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Step 4 |
Step 5 |
Step 6 |
![](../img/dovetail_two_keys.jpg) |
![](../img/dovetail_key_hammer.jpg) |
![](../img/dovetail_keys_joined.jpg) |
Once you have applied the wood glue, press the second key into the remaining keyway. |
Whilst holding the frame, grab your hammer and begin to tap down on the keys one by one.
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The keys will slot perfectly into the keyway and bind the corner of your frame together, creating a tight seal that should look like this. |
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Step 7 |
Step 8 / Optional |
Step 9 / Optional |
![](../img/joined_frame_dovetail.jpg) |
![Strap Clamps / Band Clamps](../images/belt_clamp.png) |
![](../img/dovetail_screws.jpg) |
Repeat steps 2- 6 for the remaining sides of the frame, attaching the remaining pieces of moulding one at a time. This will leave you with a finished picture frame! |
Strap Clamps / Band Clamps For large frame sizes you may use a Strap Clamp to secure the frame parts in place and enabling even and uniform pressure on all sides when bonding. This will also minimizes the gaps on frame corners. Amazon Band Clamps |
If your frame came with corner braces and screws please grab these for the next step. You should have 4 braces and 16 screws.
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Step 10 |
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![](../img/dovetail_corner_braces.jpg) |
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If you choose to add corner braces after the glue is dried, place the corner brace flat over the top of the corner, this should fit best in between the two keys. With a screwdriver, screw in the frame onto the corner of the moulding. |
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