Fixing a canvas floater into a deep rebate

[Judders]

This is for a floater style frame in a white 30mm wide moulding. I am looking to use a deep rebate (Centrado CR63550) the rebate is 20mm deep and the canvas on the stretcher is 16mm deep, so not much to play with. I can't work out how to leave about 8-10mm gap round and fix the canvas in. The effect is like the Cubik L's mouldings that Lion do for these floater frames. However with a min order from Lion of £50 or chop for £30 it doesn't work out for this canvas on a stretcher 40cm by 20cm. Thinking of using a spacer between the canvas and the deep rebate and use shallow offsets to support. Is there a simple answer to this, using a deep rebate moulding?

[prospero]

If I'm getting the drift......

You are using an ordinary moulding upside-down?

To create the gap, drop in a board - MDF or something similar. You can paint it black around the edge to make the 'bottomless pit' effect. Tack it in with a few spots of glue. To get it just the right depth, a few shims of board behind.
Once you have done that you can screw the canvas to the board from behind. Use a few scraps of foamcore or whatever to hold the canvas in central position while you fix it.

[Judders]

Thanks for that reply. I like the simplicity of doing a floater frame with an upside-down deep rebate, however I still have a bit of a problem as the section which is then at the top is too narrow, my client wanted a 30mm wide frame, and there don't seem to be any mouldings that are wide upside down with a deep enough rebate to take the canvas. I shall try and persuade my customer to have a narrower frame as I think that would work out much better and be more practical and economical. Thanks for the advice it has been a topic of interest judging by the visits!

[prospero]

Right gotcha....

In this case you could just fix the MDF panel to the back of the frame. But I would not advise it as it could swell up and break the frame if it was placed in a humid atmos. Fixing strips that aren't joined at the corners is better.
Actually this is a nice method for floaters as the inside would be undercut. Paint it black and it would look more floaty than the usual L shape moulding.

[Judders]

Hi Prospero, many thanks for the reply. I'm getting the idea, I think fixing a board at the back of the frame is fairly straightforward. I must admit I don't quite understand the strips and the undercuts approach!! However one way or the other, you have given me some much appreciated guidance and I can now get on with the job. Thanks

[prospero]

Tricky trying to explain things with words.

Say you used a deep moulding, so that there was say, a 10mm gap between the inner edge of the frame and edge of canvas all round. The rebate of the frame would be set back a bit. It you painted it matt black it would almost disappear. A 'L' floater moulding has straight sides. So with the std deep moulding the floating effect would be more pronounced.

The strips just fill in the back and create a fixing point for the canvas. 2.5 MDF would be OK I think, but 3mm ply better. You just have to step it back from the outer edge so it's not visible. Bevelling the edge is better. The reason strips would be better is that you don't really need to cover the entire back. Fixing a board to the back of a frame in one piece is best avoided. If there is a bit of dampness about the board will either bow in or out or force the frame corners apart.

[Judders]

Hello again, many thanks that is much clearer now. Understand about setting strips in a bit, I did wonder about that, was concerned about them showing from the front. I shall keep these notes for future reference. Big thank you.