Frame design for 6'x10' 100-pound mirror? How to mount it to the wall, etc..

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Forum topic by danielhoer posted 03-25-2017 09:55 PM 2306 views 0 times favorited 7 replies Add to Favorites Watch
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38 posts in 633 days

03-25-2017 09:55 PM

Topic tags/keywords: question

Hello! I recently bought a monster mirror that is 6’ x 10’ and weighs at LEAST 100 pounds. I need to design a wooden frame for this thing and also make the frame structurally solid enough that the mirror can be mounted to my wall. My wife is counting on me to show her my woodworking skills justify my future investments into a workshop so a LOT is at stake here!

I don’t want to make this post too long but here are some thoughts I’ve had:

IF I had a table saw, my first thought would be to take some 2×4s, rip off the rounded edges, and then cut a dado/grove to fit the thickness of the mirror and slot the mirror into the dado, but I do not have a tablesaw.

Ideally for aesthetics, mitered edges would be a nice way to go, but I heard that this is structurally quite a weak joint, which makes me think if I did do miters, I would need to add splines to each corner, but again, I don’t have a tablesaw and if I did have one, the only method I’ve seen involves building a V-shaped ‘box’ jig thing which straddles the fence, and then your glued-up mitered corner sits at the bottom of the “V” and you slide it over the blade to cut the slot for the spline (not sure how I would do that with a 10’ board sticking up in the air, though).

A less sophisticated way would be to mount a 2×2 strip horizontally to the wall, let the mirror rest on that strip and then just add more 2×2s on all sides (I could use pocket holes to screw the strips together)...

I have a sliding miter saw, a japanese hand saw, pocket hole jig, hand drill, etc. I could possibly borrow an old router from my dad and buy a router bit that could cut a dado, but I’ve never used a router and wouldn’t I have to build a router table first?

I think I’m going to stop rambling off my ideas and open it up for suggestions. THANK you in advance for any good ideas :)

7 replies so far

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38 posts in 633 days

#1 posted 03-25-2017 09:56 PM

Six feet tall, ten feet long.. it’s about 1/4” thick

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7739 posts in 2129 days

#2 posted 03-25-2017 10:19 PM

Providing you’ll never want to move it, they make a special mastic (glue) that will attack pretty much any mirror to a wall. I once had to break apart a 4’ X 6’ mirror to remove it from a bathroom wall.

I’d attach the mirror to the wall and then make a nice decorative frame around it.

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1366 posts in 1042 days

#3 posted 03-26-2017 01:55 AM


I would avoid construction grade lumber. It typically harbors too much moisture. It may look straight when you get the lumber home, but in a few short weeks, it could start to twist, cup or bow.

Given the lack of tools, building a pair of frames that are glued one to the other may be a good option. It would start with S4S kiln dried hardwood that is ¾” thick. Getting S4S hardwood that is longer than 8’ may be difficult and require a trip to a hardwood lumber dealer. The outer frame lumber, which is the frame that is seen when looking into the mirror, would be wider than the inner frame lumber. The outer frame center opening for the mirror should be ½” smaller than the mirror itself. The corners of the outer frame would be mitered.

The lumber for the inner frame, which is eventually glued to the face of the outer frame, is at least 1” narrower than the width of the outer frame lumber. For example, if the outer frame rails and stiles are 2-1/2” wide, the lumber for the inner frame would be 1-1/2”. The inner frame would feature butt joints and sized to the outside dimensions of the outer frame. The butt jointed inner frame would overlay the outer frame’s mitred joints and add strength to the mitre joints.

Once the inner and outer frame pieces are cut, the inner frame can be glued to the outer frame to form flush outside edges that will become 1-1/2” thick. Glue alone would hold the inner frame and outer frame together if you have enough clamps. If not, or for some added strength, the inner frame could be screwed from the back with countersunk 1-1/4” long bugle head screws to the outer frame. Some edge sanding would flush up the joint between the inner and outer frame. This would then create a rabbet against which the mirror would rest. The rabbet should be 1” wide. The mirror would rest on ¼” of the rabbet leaving ¾” of the rabbet to receive screws to hold the backer in place (per side). A couple of pieces of ½” thick plywood could then be screwed from the back into the outer frame. A few spacers may be required in the rabbet to keep the mirror centered. But leaving at least 1/16” – 1/8” for contraction of the frame could keep the mirror from breaking.

I would probably use pan head screws whose heads are painted to closely match the finish to secure the frame to the wall. The screws would be driven through the frame and drywall into wall studs. I would prefer at least 1” of the screw penetrate into the wall framing.

Hopefully this sketch clarifies this idea…

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38 posts in 633 days

#4 posted 03-26-2017 05:39 AM

Wow thank you so much for such an awesome answer. I like the glue idea as well but I might have to move or take it down at some point so I like the idea of a mountable frame. Thanks for taking the time to diagram that all out for me.. if I could give your answer 5 stars I would !

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421 posts in 2538 days

#5 posted 03-26-2017 10:17 AM

mounts – flush mount heavy duty used em for years

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Craftsman on the lake

2804 posts in 3560 days

#6 posted 03-26-2017 11:58 AM

pretty much what jbrow said. I’ve mounted one of these. Plywood screwed to the wall in several places then make a frame that rabbets over the plywood and covers the frame edge. I didn’t make the inner frame to hold the mirror up. Instead I mounted a small strip of wood on the plywood with several screws that made a lip under the frame and it took the weight. After mounting the frame over the whole thing I put screws around on the outside edge into the plywood edge.

-- The smell of wood, coffee in the cup, the wife let's me do my thing, the lake is peaceful.

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38 posts in 633 days

#7 posted 04-07-2017 08:19 PM

Hi! The mirror is sitting in my house waiting for a frame.. I actually just had an idea – what about using OSB and gluing the mirror directly onto the OSB.. then making a tiny inner frame and covering it with an outer frame.. is there any risk that the wood (OSB) would wrap and break the mirror if the mirror is permanently glued to it??

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