Framing a mirror - need t strengthen the bottom of the frame

[SvenSvenson]

Hi all,

I'm about to frame an old mirror (24" square and about 3/4" thick). It's very heavy (in my limited experience) and I'm wondering if the bottom mitred joins of the frame will be strong enough to take it's weight? I think it should be as it'll be glued as well as v-nailed (the frame I want to is is 2-3" wide) and I recall someone stating that the glue is always stronger than the frame, so if anything goes it'll be the frame itself, but I was just wondering if I should put a place or bracket of some sort across the joins?

Thanks,

Steve

[martyn05]

If you are worried then put a couple of brackets on it.

[Spit]

I'd put L-brackets on all four corners. If you only do the bottom corners, it could still break off at the top ones.

[prospero]

I get though a lot of L brackets. If you place them face down (countersunk side) on a piece of scrap wood and give them a knock with a ball headed hammer just on the corner, it will add a bit of bias that will pull the face of the moulding together when you screw thwm down.

[framemaker]

Always better to add some brackets if your worried about the weight. What are you going to use for hanging fittings?

Lion do some 'L plate' brackets, or your local hardware shop may do them. On large or heavy frames I often use 6 mm MDF, cut into triangles and then glued, countersunk and screwed in 4 places over corners.

[scgfull]

In addition to the corner bracing, I use wire to hang heavy items that is attached using 4 points: 2 at the sides as normal then 2 fitted to the bottom rail a few inches in from each side side. I then wire from one bottom point to the same side one, across the back of the picture to the other side and then attach at the remaining bottom fixing.

In this way the bottom rail is taking most of the weight.

Steve

[SvenSvenson]

Thanks for all the tips - picked up some 'L' brackets today. I'll try to slightly bend each bracket, so that when screwed in they pull the mitre together, I'll also try the hanging technique via the bottom frame. For hanging, I've got what my shop calls 'strap hangers', which take 3 screws each.

It's not massively heavy (as I said, 2 foot square and about 3/4 inch thick), but it is fairly substantial.

Steve

[Nigel Nobody]

L brackets are OK for some mouldings, but with others, if they don't conform to the exact shape of the back of the moulding joint, they will break the glue joint and weaken the corner. I prefer to use quarter inch plywood and glue it to the back of each corner to avoid that risk.