Joining mouldings cut on side

[Fellows Framing]

Hi All,

Am hoping you can help me with the following please:

I need to use a moulding like in the attached image but cut on its side with the rebate being on the bottom for backing board to be fixed in.

The cutting part is fine but how on earth do I join the mitres? The rebate lip is to thin to put many many nails in. Is there a special way of doing it? Can the underpinner be modified somehow???? I cant get my head round it.

Alternatively do I need to source timber with no rebates and then router a v small rebate which will leave enough space to put several nails in? If so any ideas where to get such timber from - I want to avoid batten from builders merchants due to greeness and twisting etc.

Thanks.
Sarah

[GeoSpectrum]

The gurus will no doubt have the correct answer but I'd be tempted to try placing a thin shim of wood in the rebate so to fill the void then pin through that, use an extra pin, pull the shim out and the last pin with it, leaving two in the moulding. Or something like that.....

[Not your average framer]

I have been making frames like this in batches on a regular basis for a regular customer for at least a couple of years now and I you chose the right moulding, it's not all that difficult. My customer only buys the frames from me and then paints them himself and gets me to staple his own 4mm handboard backs into the back and sells them with his own custom made minature paintings on his own ceramic tiles.

These frames are quite small and the moulding I am using is Simons PIN/28. The sight edge lip on this moulding is thick enough if you are careful to uderpin through the sight edge lip with a single 15mm wedge. Don't be tempted to stack more than one wedge, it won't work! I use plenty of glue and don't do anything else to hold the front of the frame together, it works fine as long as it's well glued, but it might be different with larger frames.

PIN/28 is a relatively knot free moulding and I can can get quite long lengths of moulding between the knots. I discard the few areas of the moulding which have knots. This not only means that the finished frame is much easier to paint, but the area immediately either side of the knot may be problematic to join on an underpinner without the wedge emerging out of the outside edge of the moulding.

It may be just me, but my impression is that it is a lot easier to find flat section bare wood mouldings with thicker sight edge lips, than with factory finished mouldings. I also use this moulding to fit into the back of other frames for box frames. I use a mount to hide the front edge behind the glass. This moulding is both a good consistent moulding and also quite an inexpensive moulding to buy.

There are other suitable flat mouldings with thicker than usual sight edge lips, but I like this one because it's such a good price. I hope that this is helpful to you.

[Roboframer]

Frame mouldings are simply not designed to be joined like that so you either have to adapt it and/or your underpinner or find something with a really wide rebate lip, but if you do then there will be a very big area you'll have to leave un-pinned unless you adapt.

However, there are plenty of mouldings that come with matching rebate spacers which will achieve the same result - i.e. - setting something right back, but with the added benefit of allowing glass if you need/want.

[prospero]

Various ways....

Using a sacrificial shim as previously suggested will do the job. You can stack though it if you hold everything very firmly.

Is there going to be a capping on the top side? If so pin from the top.

Or, you could use good old hammer and nails. This means a bit of filling, but if the frame is not under great stress you can just nail into the top and bottom leaving the visible sides unmarked.

[Fellows Framing]

Hi all,

Thanks for all the suggestions. I will try the shimmy method and failing that the old fashioned nails, it's going to be painted so with abit of sanding the filled holes no one will know.

So that leads me to ask, having always used a underpinned, what nails are best to use? I have some panel ones are these suitable?

Thanks
Sarah

[prospero]

I use the veneer pins from Lion. But any nails with a minimal head will do. Drill a pilot hole first, about half the length of the nails. You'll need a punch to knock the heads under the wood surface.

If you are painting the frame it's actually easier than underpinning. The main thing is to make sure the joint is clamped or held very firmly before nailing. My usual method with deep mouldings is to insert one v-nail and then cross nail near the top.

If you don't happen to have the right drill, snip the head off one of the nails and use that.

[Roboframer]

it's going to be painted so with abit of sanding the filled holes no one will know.

Why not just underpin the other side then?

[Fellows Framing]

Will the paint cover the nails then so you dont know that they are in there????

[Roboframer]

I'm assuming if, with a bit of sanding, no-one will know about nail holes on the side then nor would they about little "V" shapes on the front ???????

[Fellows Framing]

Thanks, thats the easiest way to do it so I shall try nailing and painting first....will let u know how goes
)

[Jamesnkr]

I've put v-nails right the way through barewood mouldings...

Dig them out, fill the hole with polyfilla, good as new.

[A3DFramer]

I used to do a joint similar to this but many years ago. It involved driving long wedges up into the back of the rebate, perhaps two spaced across the face, then using a pin punch to complete the insertion of the wedge into the moulding. I discovered that pin punches were counter sunk, having bought my first in the early 1960's. This actually locked onto the elbow of the wedge so the pin punch stayed in place whilst light, drumming taps drove the wedge into the back of the rebate. A couple of extra mm's depth is useful.

From this technique I developed a jig, this made it possible to drill into the face of the mitre a blind hole at right angles to the face of the mitre. This was before the ready availability of the 'Dremel' type hand drills, I had equipped my workshop with dental suspension drills. Using a drill that matched the diameter of a toothpick, mirror image holes were places in the moulding where the 15mm wedges could not reach. By using parts of tooth picks in a way that biscuit joints are effective it is possible to make a blind joint of considerable strength, using the flexibility of tooth-picks.

This may not help the OP, but if it is wanted I could spend some time making some images to show this technique.

[Fellows Framing]

Thanks ad3framer.

I remembered I had a push master tool that I used before
i had a underpinner which will do the same as a Your pin punch.

[Not your average framer]

I have just completed a batch of the frames I previously mentioned using Simons moulding PIN/29 and since they say a picture is worth a thousand words, here are two pictures.

Dscf0111.jpg (115.65 KiB) Viewed 5974 times

In and on the top of this box are a total of 59 frames using PIN/29 joined on it side. Two frames are arranged so you can see the front and rear views. This way round the moulding measures about 32mm deep and each corner is joined with just one 15mm wedge.

Dscf0112.jpg (113.35 KiB) Viewed 5974 times

This is a magnified veiw of where I am using my cameras close up, or macro setting. Here you can see that the wedge is fired into the edge of the sight edge lip. You can see with the apparently large looking wedge that this is a highly magnified veiw and in fact the thickness of the sight edge is in reality only about 4 or 5mm thick and it is still quite easy the insert a wedge into such a thin piece of wood. In practice this method works very well.

The customer paints these frames himself using a thick chalky emulsion paint. I had not noticed this before, but there is a slight misalignment on this corner, but the magnification of this image is so large that is shows a misalignment which is not visible to the naked eye and after painting this will not be visible even with so much magnification.

These frames are produced to a low price and this dictates using the cheapest possible moulding, if the customer allowed a better budget the the moulding would not have been in pine, but something much nicer. After painting the finished frames look great.

I also join the even thinner Simons K/262 on it's side using this same method. It may look difficult, but once you have got used to it, it's not difficult at all. All you need is a little bit of practice!

[A3DFramer]

Purely by coincidence I was researching a tutorial on Sketchup and these videos were close by;
https://www.youtube.com/watch?v=donBPcmhUMA
https://www.youtube.com/watch?v=oEgRWSqkoXI

How technology has advanced, had I had the benefit of the internet when I made the joint I described in my previous post, I might have used a much cruder punch that a pin punch, one a simple piece of 10 -12 mm mild steel bar with a right and ground on one side.

This would, it appears from the videos above have driven the wedges (or V nails as the google searches would have found) that bit further in, from where my underpinner left them protruding. At the time I did try to chase them in with a second wedge but this was not successful on a consistent basis. My needs were for a joint that was probably going to fail at the upper end of the moulding where the wedges could not reach, so hence the tooth pick/biscuit set up.

These corners never did fail to my knowledge. The drawing is to scale of 15mm wedges in a 1 7/8 moulding.

I described from memory that a jig was made to position the holes for the dowels/tootpicks, it is more accurate to say that two jigs are needed one for each face of the mitre, though they quite simple things to make.