Frames Bowing

[Jonny2morsos]

Did a couple of frames for a customer about 6 weeks back and he returned with them today because thay had bowed!

Job was as follows 20" X 30" photo montage from Snapfish on glossy paper. Dry mounted and framed without a mount using 3mm econospace to distance from glass. Back held in with bendy tabs as I had to keep checking for dust due to working on the inside of the frame after glass cleaning to insert the econospace. The frame was sealed at the back with gummed paper tape and d rings and a cord to hang with.

The frames have been hung in a modern cavity insulated house and not close to a radiator. When laid on a bench the centre of the long side on one frame had a gap under of about 10mm and the other of about 5mm!

The one with the greater deviation I laid face down and ran a knife blade around the tape in the gap between the moulding and back board. It immediately went virtually flat.

Any ideas anyone?

The customer is especially concerned about glass breakage as he has three children in the house and is wondering about a deeper frame but would this cure the problem (whatever it is).

Moulding is Arqadia 446 400 000. Could the moulding be at fault - not fully seasoned?

Any help would be appreciated.

[pramsay13]

It's quite a small moulding for a picture that size, although it sounds like the moulding isn't to blame if it straightens out when you release the tape.
Sounds like the tape is pulling the moulding out of shape although there shouldn't be too many temperature variations in that kind of house.
A larger moulding should be less likely to be pulled out of shape.
Plastic glass could be offered if worried about children, I usually have that conversation anyway when the glass size starts to become large.

[Roboframer]

Moulding is too lightweight for the job - doesn't really mattter what's making it bow, the fact that it is means it's not up to it.

I don't see why how it tastes would matter either

[prospero]

Could be the gumtape. Paper can exert tremendous pressure if it shrinks. When I used to stretch watercolour paper I used to soak it and fix it to a board with gumtape. When it dried it would sometimes bend the board slightly. That's without the tape giving. And I'm talking 1" blockboard.

[Jonny2morsos]

It was strange that the frames immediately went flat once the tape was cut between moulding and backboard. Everything was given the usual 2mm expansion gap.

I am going to hang them on the wall as they are now and see what happens. I do take the point about moulding size and certainly would not have used it for anything larger.

[Roboframer]

Maybe the reason the moulding straightened out a bit when the tape was cut is that it could not relax until that happened and, being flat, gravity wasn't an issue any more.

Was/is the cord fairly tight and were two hooks used or one?

If you lay the frame face down with just the glass in and gently tug the two long sides apart at the centre, what happens?

I'd say about 20x16 is the limit for that moulding, slightly larger if it was hung portrait maybe, it's not got much guts.

[Jonny2morsos]

Both frames portrait. I always double up the cord and tape them together to make sure the frame is hung on the hook(s) with the weight being taken by both cords but I did notice they had been pulled apart which suggests only one cord was on the hook.

I am tending to move away from cord to wire and am familiar with the chart I believe you have posted here on a number of occasions showing how the angle affects the load and your method of marking the hanging points.

I think a change to self adhesive tape, which I don't particularly like but will provide a little give and some customer education on hanging points is called for.

[Roboframer]

If you 'double up' the cord, what actually passes through each 'D' ring (or whatever), more cord or the same amount of cord if you had not?

When I used cord I'd double it too, but the fact was that it was only double on the wall hook; it went through the 'D' rings just as it would if I hadn't doubled it - not much point really. If you double it through the 'D' rings that would mean quadrupling it on the wall hooks.

I don't think the type of tape would affect anything regarding this problem, or whether wire or cord or whether either is slack with two hanging points or tight or slack with one, the problem is that the moulding isn't fit-for-purpose and that the rest, if not right, will make it obvious in less time than if it was right.

Econospace is 4.5mm wide; if you have 2mm of play in your glass/boards then the moulding only has to bow 2.5mm before the edge of the glass pops off the spacer, so you should be looking at a moulding that simply does not have any, or negligible, give over the required length - same would apply anyway, spacer, mount or neither.