rebate depth, small mouldings

[Trinity]

I've come unstuck for depth recently trying to put a double mount + undermount into small moulding. To increase the depth slightly so I can get a decent fixing in I've added a small section peice of wood to the back, painted.

Any other ideas please?

[prospero]

It's a perennial problem. Most mouldings seem to be made to just about swallow glass/single mount/thin back. Use a double mount+ undermount and you start struggling with mouldings of <10mm depth.

You can get plastic extrusions (can't remember the proper name - never used them) that you screw to the back. You can use bendy tabs. All a bit of a lash up IMHO.

The best way is to phase out all the shallow rebate mouldings you stock. When the rep comes round, take a a ruler to the rebates on his samples and say, "That's a nice moulding! I would have bought 1000ft if it had had a rebate 3mm deeper. Shame. " To be fair, one reason they do this is because timber comes in set plank thicknesses and adding a couple of mms to the depth might involve jumping to the next size which would make the moulding a lot more expensive. But weigh this against all the embuggerance of shoe-horning something into a diddly rebate.

[Not your average framer]

Many smaller moulding can cause problems for you. Not only is there the issue of rebate depth, but also the problem of adequate width for inserting wedges and getting good solid mitred joints.

Sometimes the depth problem can be solved when fitting a double mount into the frame by not using an undermount and substituting a conservation type backing board. This will save you the thickness of one piece of mountboard.

Another possibility is the fact that some corrogated backing boards can be crushed at the edges to reduce the thickness a little. Not ideal, but it can be done if there is no other way.

However don't be fooled into thinking that these conservation backing boards will enable your framing to comply with FATG conservation standards. The FATG standards do not recognise a so called conservation backing board as a substitute for the use of a undermount.

I try to avoid mouldings which are so narrow that they cannot comfortably accommodate two wedges per corner. I can't always persuade customers to agree about this, but at least I try.

Another point to be aware of is that some really narrow mouldings are also lacking in rebate width, which means that the difference between the glass being too big and being too small is an extremely small amount. This becomes a significant issue on frames which are big enough for any variations in the straightness of the moulding to show the edge of the glass somewhere.

[Trinity]

Is this a possible solution?
Currently I cut the outer size of the bottom layer of a double mat the same size as the top. If there's a real issue with depth could this bottom mat be reduced in size significantly so that you retain the look of the double mount but at the edges (where depth of rebate is an issue) I'm then only wedging two layers - top and undermout - with the bottom mat trapped inside.

[Roboframer]

If you did that then the undermount and/or the backing would be bowed up from the centre of the artwork and the top mount - a bit like this II) and in time the artwork could bow away from the mount too.

[Ricky]

I use These Sometimes when all else fails

http://www.lionpic.co.uk/Catalog/Produc ... abbetspace

[framemaker]

so I can get a decent fixing in I've added a small section peice of wood to the back, painted. Any other ideas please?

If they are small mouldings and not very large sized frames, you could put the fixings in the backing board. You could also use a thinner barrier board as an undermount.

[Roboframer]

Another solution is to fix and seal the undermount as per a backing board and then cut the backing board to fit over the back of the frame.

But the best solution is to gather together all your moulding samples with less than a 9mm rebate and toss 'em! (2mm glass, 4 ply double mount, 4 ply undermount and 2mm backing is about 8.5mm.

[prospero]

I agree 100% with Robo about using minimal bottom layers for double mounts. I regard this as very poor practice. I've seen this lots of times on things I have re-framed and the whole thing looks like a dog's breakfast. Even seen it done on triple mounts. I like everything level. I think this is done mostly as a penny-pinching exercise where people think "why use a big bit when you are only going to see a narrow edge". Fair enough. Done it myself when I didn't have bit big enough, but it's easy enough to fill the gap with scraps.

When you come to using fillets in mounts, you need even more space. Recently did some double mounts+fillets and the total sandwich depth comes out about 12mm.

For mouldings 30mm or more across the back, Rose&Hollis do a handy little section (A293) which I use a lot for extensions. It's actually a slip with a beveled edge, but if you mitre it with the bevel outwards it can be quickly screwed to the back on the frame to give 7mm extra depth. You can go right up to the edge of the frame if necessary and black out the bevel with a marker pen. Looks very neat compared with using a square edged section. You could use it on narrower mouldings if you have a handy bandsaw to rip it to width.

[Trinity]

Well, thanks for the advice re best practice, which I prefer to adhere to, I just didn't know. I've sent off for a Rose and Hollis catalogue but your description of 30 x 8 brought to mind a tube full of parting beads I have for sash windows which I'll run through the router and give a try.
I've a fair bit of the micro stuff which look good (to me) for up to 8 x 10 as a stand up - nice and fine.

[prospero]

Ahaaaah! Just had a beautiful specimen in for reframing. A five-layer mount, one layer double thick + undermount. Only the top layer went right to the edge. The rest all held in place by parcel tape. All this jammed into a 8mm rebate. The back was bowing out about an inch and there was a gap between artwork and the inside of the mount that you could stick your finger in.

Film at 11. Maybe......