How do you get flush mitres?

[Gillthepainter]

You've probably hit the nail on the head with the way I use the strap.
I tend to tighten the corners off centre to the top, rather than in the middle of the clamp. Making sure the mitre that will show from the front is tight. It is this practice that probably makes the join unstable for me when I try to put the v-nails in.

I did read your description on another recent thread too.

[Justintime]

If you're using bare woods then any tiny gap on the face can be filled before sanding the edges flush. Bare woods benefit from a sand over before finishing.
When I talk of top or bottom pressure, I'm referring to a standard underpinner which has the top bung/pad exerting pressure from above whilst the hammer drives in the wedge from below. Yours is reversed so ensure that the material that the face rests on is supportive enough.

[Gillthepainter]

I never do sand them before finishing. I shall take that on board, Justin.
My framer friend used to save up sanding dust for those corners.

The material I use to rest and protect the moulding face is one of those fashionable gelli plates. Or an ordinary harder rubber. I fancy making a batch of frames now.

[Justintime]

Sanding dust is quite old school. If you want some fuss free modern fillers, for obeche/ayous/Ash I use Ronseal Multi Purpose wood filler in natural or for Oak I use Brummer stopping interior wood filler in natural oak. If you want to venture into the world of sanding I can highly rcommend Abranet sand papers, start with a 180 grade and finish with a 320 grade.

[chaos]

I also think it is possible to over tighten band clamps and this pushes the corners up a bit making the upper edge uneven. I say think as I think this is what I am doing atm. Sigh

[Gillthepainter]

I've been asked so many times by other artists to show them how to make their own frames.
I'd love to help, or even do a workshop, but know that getting that mitre cut and join is a craft. I don't want to offer false hopes to people that they can make frames.
ie. on the cheap.

I don't get involved in making any frames for anyone else. If asked (regularly), I tell them to source their own wood and I'll do a chop service, and it never goes any further than that.

[Gillthepainter]

Brummer stopping interior wood filler in natural

I've just ordered a 250ml tin.
I find my regular filler can crack, or countersink and is sometimes visible a couple of weeks later. Whilst art buyers are looking at the picture, my eye is drawn to potential blemishes in the frame.

[South Holland Frames]

Always best to check mouldings for warping and twisting by casting your eye down the length.

I collected this batch last week from a major supplier - the lengths were wrapped.

But after I unwrapped them when I got back ..... !

[Ultima Thule]

I have had this problem with the current vogue for flat mouldings and agree with the findings of twisting and varying heights along the length of a piece. I solved this by buying two Masterclamps from the USA which have a positive grip and an adjustable fence which is very handy in wider mouldings and with a bit of attention when tightening the join the surfaces can be made flush. When dried I underpin as per usual, with the proviso that I use a venerable Euro foot operated model and apply pressure gently to avoid any stress on the glued faces. A lot slower than underpinning only but gives a far superior finish.