Newbie Q - Frame Support

[RogerC]

Hi All,
We have a 'simple' job - it's for staff so a good opportunity for us to practise as we are new to the framing game...
We are framing a large world map poster - 1020x1380mm.
Cheap commercially produced print so no conservation concerns - easily replaceable. Purely being framed for cosmetic purposes (and practise ).

Using Wessex budget range moulding, WF524 - 7/8" square black.
3mm clear acrylic glazing. 3mm MDF backing.

Just a slight concern that the frame may need some additional support to prevent sagging, especially on the long lower length moulding.
Can I just glue a vertical support strip in the middle - in which case what is best glue to last?
Or is there some other trick others use to support the moulding (against the MDF backing perhaps?).

Thoughts and suggestions welcomed.

Thanks in advance
Roger

[prospero]

For something that size and with that moulding width you really need a subframe. That is a support frame
that goes behind and takes the weight of the entire inner package. Wessex do suitable sections, but for max
strength you can make your own from PSE timber. It should be the same size as the backing and the hangings
can be strung from it or better still incorporate a cleat system.
On drawback, you need an outer moulding that is deep enough to swallow the depth of the subframe. It doesn't
matter if it sticks out a bit, but not so much that you can see it from the side when hung. The outer frame then
only serves to hold the inner package together and supports no weight.

Here's one I made earlier....

This is made from 95mm x 8 mm tongue and groove cladding with the 'tongue' ripped off. This allowed me to form
half-lap joins by using two layers glued together. Very strong.

[RogerC]

Okay - makes sense.
Research sub-frames...

Appreciate the prompt response - thanks.

[JonathanB]

The method I frequently use for jobs like this is to use WF533 or MO1949, which look similar to WF524 from the front, and use the sub frame PW219 to give the whole thing strength. There’s a guide to using the subframe on Wessex’s website. You will find better selections of deep matt black profiles elsewhere. Lion, for example, have a good selection.

[RogerC]

Thanks for the reply Jonathan.
I had found PW219 - but I only have 10mm of space at the back of the frame.

But it's given me some ideas for a solution!

Regards

[Justintime]

Rose & Hollis do a 10mm deep subframe.

[prospero]

You can fix braces to the back to mitigate bowing of a thin moulding. I've used strips of 2.5 MDF in the past.
Also add steel 'L' mending plates on the corners. It works up to a point but it's a slightly half-arsed solution.

* The Wessex subframes have a neat bevel on the inside that allows you to do a 'French Cleat' hanging.

** I made myself a bathroom mirror from a full 4x3 sheet of 3mm mirror. It uses a subframe and an ½" beech deep moulding.
With a cleat system it's solid as a rock.

[RogerC]

@prospero
@JustinTime

Thanks for your input.
I'll take a look at the R&H solution.
Otherwise current thinking is to build a simple inner frame, with vertical supports to add the support for hanging and preventing sagging.

Appreciate the forum support - great resource!

[JKX]

If you could live with a slightly wider and/or a deeper frame, aluminium may work without any sub frame.

[RogerC]

Yes - thought of that. Just after building the frames!
Mind you, big enough to cut down and use elsewhere, so a possibility.

[pramsay13]

Centrado do a tulip wood subframe.
https://centrado.co/product/raw-tulip-subframe-3810tu/
This one is 10mm deep.

[RogerC]

Thanks pramsay13

We built our own sub frame in the end

It's all a learning experience!!