Mitered moldings - biscut, spline, spring clamps, other...?

Hi mate,

I am fairly familiar with large moldings; but while mine are composed of multiple pieces, averaging 4-9 sections, amounting to massive crowns I have not faced your problem directly.

Still the basic principle of regulating the location [ translates to determining a fixed point ] may be worth considering.

If I understand this aright the jig that you use limits forward/backward movement by use of some type of stop allowing you to pre- join the mitered sections.
I have never pre- assembled a crown in this mannor, but have come up with a system that works for me even for lenghts of 16”.

The trick amounts to a ” NO-GO ” gauge and requires nothing more than a rabbit cut into one member.
The rabbit itself can be a modest 1/8” to 3/16” deep but it still provides a positive point of reference that traps the applied molding from traveling even when little pressure is applied.
Having once determined the final location of the face or return pieces they can be pinned,etc.
Although I use titebond 3 almost always, they also make a heavy bodied , no run, no drip, molding glue that I found worked as advertised.

Holding the corners true at the miters if assembly dictates no nails/pins will require special spring clamps etc.; but I have never run across a job that rquired joinery that relied on glue alone.
I.e a good finish will well conceal any nail hole that I have ever seen.

If the work itself is square and you have taken the pains as is evident in your work I cannot see where the mold will not marry up just as you hope.

I wish that I had a picture of this but maybe someone else can provide one.

Ps.Generally speaking the simpler that you can keep any method the better.

I hope that this may be of some help, Norm.

I would rather put it together on the peice. This would allow the mold to set flush to the peice. Biscuits will work for the corners to help keep it together.