GLazing for a large (ish) frame...

[lawrieh]

I have been asked to frame a picture that is 130cm x 100cm which would be the largest frame I have done to date. I have been using 2mm float glass up until now on frames up to 90cmx70cm in size.

Does this larger size mean I should switch to 3mm or thicker glass or possibly to a "plastic" glazing material?

If the switch to "plastic" is needed where do I start?

Styrene Acrylic (cast or extruded?) (2mm or 3mm?)

Also does anyone have any guidelines mouldings, ie minimum width in order to provide sufficient structural integrity? do you ever put a brace between the 2 longest edges to keep the sides from bowing or will backing tape be sufficient?

Thanks

Lawrie

[prospero]

At that size I would be happy to use 2mm glass. As long as it's in a sturdy enough frame and the wall hangings are up to the job. 3mm is arguably stronger, but in real life anything that would break 2mm would break 3mm. And then you have 50% more weight of deadly shards.

If safety is an issue, then go for acrylic. But you would need 3mm or thicker. So weight saving would be minimal. There are other problems with acrylic. Cost for one. And also scratching.

If you have to put braces on the frame to stop it bowing I would say that you need a bigger moulding.

[lawrieh]

Thanks Prospero

2mm would be best for me and customer

The frame is for a modern elegant photo so it should be fairly indiscreet. Should the moulding be structurally resistant to flex in all dimensions or is a particular dimension more important than others? e.g bowing away from side of glass, torsional/twisting, bending along the same plane as the glass? any recommendations for rough size of moulding?

I have been using double D rings for each side of frames up until now with 5/8" screws, if this is borderline are there any other options other than something like a D ring with 3 screw holes ?

[IFGL]

Strap hangers, for me it would have to be a 70 mm + wide frame with a 30 mm + depth in a decent wood if I was going to use 2 mm glass, which I regularly do in pictures of that size.

[prospero]

It's not so much the width/depth of the moulding. It's more the area of the cross section. The bigger it is, the more glue area. But when you get to glazed frames of this size it's sometimes better to take the frame out of the equation altogether and use a sub-frame. This type of construction makes for great strength and stability.


http://theframersforum.com/viewtopic.ph ... ilit=jobby


Makes hanging easier. At this size it's wise to abandon all thoughts of rings and wires.