The Framers Forum

Evening framers,

I'm working on a large mirror project for a wall in my home.

I've measured up and the total size will need to be around 1.2 x 1.6m, so for the sake of argument let's assume this is the glass size.

I would appreciate advice on framing a 3mm piece of silvered glass of this size, I'm thinking at least stacked v-nails, a decent profile moulding (currently looking at LJ 727246000), but any other critical considerations?

In terms of backing, I've read about the use of grey-board, is this to reduce weight to more commonly used mdf?

For hanging I am thinking two decent sizes screws/wall plugs (it is a connecting solid wall to next door) and straight onto sawtooth hangers or 3-4 hole heavy duty d-ring hangers

Thanks in advance,
David

That's quite a big mirror size for only 3mm mirror glass. There tends to be a size for each thickness of mirror glass, where it becomes necessary to increase the thickness of the mirror glass, so as to have enough rigidity to prevent to glass for distorting the image and I think that 3mm glass is probably a bit too thin for that sort of size. I make a few mirrors for my shop, every now and then and my default mirror glass thinkness is normally 4mm think.

Lion's keyhole hangers are really good for mirrors and are rated up to 15kg. The brass bezel screws into the wall and the flat plate on the back of the frame hooks onto this.

https://www.lionpic.co.uk/content/produ ... oimage.jpg

Hi David
I make plenty of mirrors this size and over

we have one at home in a very heavy decorated frame which is hung using strap hangers from Frank Scraggs in Birmingham which can hold up to 80kilos
not sure if that's per fixing or per pair but a call to them would answer that

alternatively we also use the sub frame method and then a matching bracket on the wall
try Centrado , I think they have a picture description in their catalogue

I use 3mm for this size and 3mm MDF as a backing also and add felt tape in the rebate
this gives a nice finish to the edge of the glass when viewed from the front - also available from Scraggs

all this though will need a very secure wall fixing
hope this helps
Tim

I use Volara foam rebate tape to cushion the glass in the front. I would whizz a black marker pen around the front of the rebate first, to prevent any reflections of rebate through glass.
Strap hangers would be my first thought or of course you could use Mirror plates! I have occasionally used mirror plates top and bottom rather than sides. I am not a physicist, so am not sure that even makes a difference??

Google "French Cleats".

I've done a few big mirrors (and pictures) using this method and it's easier than trying to use strap hangers IMHO.

One advantage is that you can level the wall bar perfectly. Rather than cut a 45º bevel on the two bars, I keep them
straight and use a couple of mirror plates as retainers. The whole weight of the frame is spread along the wall bar and
you can put in as many wall screws (I like the hammer-in type) as you deem appropriate.

*A mirror will sit exactly perpendicular to the wall if you use a couple of small blocks the same thickness as the cleat bar at the bottom.

I see 2 mechanical problems that need to be addressed.

First, a wood backing (luan plywood or MDF) will strengthen the entire frame if it is screwed to the frame moulding by this forming a secondary framework of support.

Second, the best way to secure the framed mirror is to place the hardware in the wall through the wall studs and secondarily into wall anchors if the wall is covered with drywall or it is a monolithic wall (block or concrete). The larger the screw in the wall the better (M5 or larger). Quality screws are also essential.

Thanks all for your advice

@prospero, do you have any specific recommendations on which french cleats? I've seen the below from Lion though not clear what the weight rating is. Also what do you mean when you refer to cutting a bevel? Looks to me like no cutting should be involved.

https://www.lionpic.co.uk/p/33157/Z-Bar ... 0mm-1-pair

Before you could buy French cleats from some suppliers, it was very normal that individual framers would make these they selves and I can't ever recall anyone seaking information about how to make them. Choosing the necessary dimensions was largely a mater of what made practical sence. Thie pieces of wood needed to be large enough to takethe size of the screws with creating points of significant weakness in the wood when drilling the holes for the screws and other considerations followed in much to same way.

There are not really any hard and fast rules how to do this. I don't expect that every framer makes french cleats to be exactly the same as every other framer. Please don't think that the is some sort of exact specification that we each need to know, it's just not like that. I mostly chop up what ever is on hand on the table saw to dimensions which seem generally reasonable. Trust your instincts. I think that's more, or less what most of us are doing. It's not rocket science, just a little bit of carpentry.

In general both halves of a french are little different to an appropriate length of wooden battern, with a bevel cut on one edge. The angle of the bevel is not super important. I generally go for 30 degrees from the normal 90 edge already present on the edge of the battern. As I said I usually chop up whatever is on hand. I usually various pieces of pine bettern from my local hardware shop, or even odd scraps left over from making something else.

I hope that this helps.

My method for cleats:

If the frame is wide, say 3" or over, I fix a piece of PSE pine maybe 3" wide along the top rail with screws.
The bigger the frame the more screws. I take the cleat over the corner and screw into the side rails which
beefs up the top corner joints tad.
Then, I take a matching piece of PSE and drill as many holes as appropriate in to take the wall fixings.
On solid brisk walls it's easy. I use hammer fixings. Offer the cleat to the wall (having done careful calculations)
and drill though the middle hole into the wall. Wack in the first wall screw, but not to firmly. Get you spirit level
out and level it. Then drill the rest of the holes and wack in the rest of the fittings. Make two little 'catchers' from
mirror plates (or whatever) and screw the to the wall cleat with the one-hole end pointing up and overlapping.
This saves having to use complimentary bevelled pieces, but you can do it if you want to be a purist.
A couple of little blocks at the bottom of the frame will ensure the frame hangs parallel to the wall.
Then just lift the frame on and it should lock into place - as long as you seat it right. Bending the catchers outward
slightly makes this easier.

This makes a really strong and reliable hanging and not fiddling about trying to level it. As long as you get the cleat
running parallel to the frame.

There are complications..... Where the backboard is flush with the frame there is no little 'gap' for the catchers
to fit into. You would have to recess them, but it's not rocket science. Canvases that protrude are a problem, but
in cases like this the cleats can run down the side rails - end grain to end grain. A bit of fettling with spacers might be
necessary to ensure the canvas is clear of the wall.

*That probably sounds like a load of gobbledygook, but I'll provide illustrations if called upon.