In the process of making some 2" thick exterior doors and wondering if anyone can see a problem with this method. I don't have shaper tooling that will allow me to cope rails beyond the stub tenons. One of these doors will be south-facing with no overhang and so dowels are out. It needs all the strength it can get.

Obviously, loose tenons is a way to get around that, but this got me thinking.

What about running the loose tenons all the way through like after the fact stave core?
The process would be
Cut to length and cope rails on the shaper
Run a dado 2.5" deep where the panel slot will be. 1" on this door.
Glue in staves that extend to the desired tenon length.
Then run edge profile, fit tenons, and Bob's your uncle.

Can anyone see a problem with this method? Other than a decent waste factor from milling out a lot of solid stock.

Hi Perry,

Don't know your geographical location but i think the south facing no overhang is you biggest problem.
For our exterior doors Sun and UV are hard on the finish worse if you got no overhang for shade. If you got a dark finish on them they basically heat up, the wood dries and checks. the finish cracks and glue joints will separate, panels will split.
this will happen regardless of your construction.
We had good results using Accoya on black south facing doors, but even they had a proper overhang.
No overhang we would not recommend wood.
We like to use Loctite PUR glue for anything exterior that gets heat.

I would avoid loose tenons at all costs.Right away, you double your joinery labor. And extra parts to make and fit. Tenons should be 3" long.
Do not use TB glue. 2 is not really waterproof, just water resistant. 3 will fail if the door gets warm, Looses more than half at 210 degrees.
Use epoxy for all your joints.

Yeah, it has all the "no no's". But it is a historic house, everything is period correct. The client is aware it will fail at some point. Couldn't talk them out of painting it black either.
But the real crime is how dark they want to stain this gorgeous 30 ring an inch heart pine that is the interior half.

Outside is all Sapele. Grandis stave core. All quartersawn.
Have been using epoxy for everything, and will peg the tenons as well.

Fred, on the panels- an idea I had this morning was to use PVC trim board to make the exterior floating panels since the outside is getting painted. I know it moves a lot more than wood, but I can account for that with panel slop.
The current door has failed primarily from the floating panels splitting. I figured using something that wouldn't split would give it a little longer lease on life.

So the panels would be heart pine on the interior side, 1/2" xps in the middle, and then PVC on the outside

Any reasons that would be a bad idea?

Thanks
PF

The panels should be a seven ply, all wood construction. Use 1/16" cross bands to stabilize the panel. Core of 1/2" man made wood stable - ply wood, MBO, etc. with solid wood, same thickness both sides, then crossbands, then faces.
Same species, balanced construction. Glued into the frame.

Exterior doors with one species on one side and a different species on the other will fail. Soon. They are done that way at the whim of a person that knows little about wood, and respects it even less. Usually a designer or similar. Your job as a professional is to speak responsibly about the respect for the craft, and that you don't wish to make work that will be unsightly and unusable. You are trading a small bit of your life for some money. Don't waste either.

Thanks for the input Dave,
I understand that the dual-species sandwich would fail. Especially in this application. Total exposure, south facing. And the outside must be painted black. In the south. This thing will get hot.

A spot all of us would professionally reccomend not putting a wood door. But the added constraints of the historic house and oddball size make it the logical solution.

But do you still see the different species interior and exterior as a problem with a stave core?
Again, the staves and veneers are all quarter sawn.

The current door is all heart pine and the exterior has been through many painter hack filler jobs since it first failed a number of years ago.

My respect for this 24 Karat heart pine that is the interior is why I am trying to figure out the best way to give it the longest lease on life.
While the interior must all be heart pine, I have the freedom to play around with the exterior and I'm always trying to make a new mouse trap. Hence the pvc idea for exterior raised panels since it machines well. It is a tall profile about 3/4, thicker than I would be comfortable veneering to something that won't move.

Hi Perry,

We had used this product in the past and it worked out well. For paint grade profiled exterior Panels.

https://packardforestproducts.com/products/wood-composites/extira/

I
t is prone to chipping on sharp corners and edges but it does not look like it takes on water.

Due to our Climate and heating requirement's we prefer to have an interior and an exterior panel.

There is also Tricoya for a higher price. I have never used it and at times it is hard to get in our region.