Thread: Plank door construction

Originally Posted by BowlingBall

They will be hinged in hardwood door frames – actual door size Height 2000 x Width 770 x Thick 60.

No one has responded yet so i'll give it a crack. First thought is...wow that will be one heavy door....especially for indoor use. Second thought is...it would be a shame to stain mahogany but i get that you're going for a look here.

In terms of how to do this my thoughts would be to get the colour variation by using different timbers, something with a similar grain. There are plenty of Australian hardwoods available with wildly varying shading. Then i would laminate as normal to about 250mm (or whatever works), run it through a planer/thicknesser and then slice it on a bandsaw and use the resulting pieces as a veneer. That way you get the look but you save on weight an material cost. Not sure about the core something lightweight like pine would probably work.

Not sure how you'd go if you want to use the same timber for every piece though since you won't be able to finish it after the stain is applied, even if you had pre finished pieces you would struggle to glue them up with precise joints.

Maybe some of the others here have a better idea...

Good Luck.

So are you planning on basically face to face gluing a bunch of boards and then flattening it and basically having a door which looks like a large chopping board?

If so, I would be very very wary of this. My understanding is that, while the frame and panel aesthetic is, in modern homes, mostly just that (aesthetic), its origin was a response to the shrinking and swelling of solid plank doors. Basically if you have on big piece of wood, it's hopeless as a door. You need to have opposing grain in a variety of panels in order to stop each board from expanding and contracting willy nilly and wrecking the whole thing.

If you do what I mentioned in my opening question, all of the grain will be running in the same direction and you will likely have problems with shrink/swell.

BUT

Another solution to this, which is frequently used on smaller work, is a plywood core surrounded by veneer. In this case, this may be a very good solution. It would make the project drastically less costly and would make the door much lighter. You could glue up all your boards and then somehow cut it into thin sheets and then put some solid, matching strips on the edges. As far as how to cut door-sized veneer sheets... I'm going to leave that ball in your court. But it can be done.

I believe another option is to create some kind of skeleton and then join a panel to either side. Basically create a core of air in the middle and then leave some holes in the bottom of the door or somewhere invisible so that the door can "breathe".

The book "The Essential Woodworker" has a section on the theory and construction of doors. Possibly worth a look.

If nothing else, it makes it obvious that door construction is not to be taken lightly, lest problems arise.

Hope that helps some.

Cheers,
Luke

Wow! I get about eighty kilograms per door in Mahogany. Mahogany ? It might have been popular in the eighteenth and nineteenth century but there isn't much used these days. And stained? Mahogany is a beautiful red-brown colour which will disappear when you apply stain. If you really want to make doors like this you might as well ask the glu-lam mob to make the blanks for you out of mixed hardwood and you will get something much better than stained 'mahogany'.

Gotta agree with Len on that.

So many better options which involve native timbers without stain on them that would have the same/better results.

And if you did use laminated stained mahogany or any other species after you laminate them you would have to sand them to achieve a flat surface what happens to the stained lamination's? = sand off stained surface no stain. I was contracted to make base and capitols for lift cars for one off top end Hotel on Gold coast in 2000 as specified by architect were rock maple and cherry and the rock maple had to be stained walnut (what the) why not use walnut?
Regards Rod.

Originally Posted by Rod Gilbert

And if you did use laminated stained mahogany or any other species after you laminate them you would have to sand them to achieve a flat surface what happens to the stained lamination's? = sand off stained surface no stain. I was contracted to make base and capitols for lift cars for one off top end Hotel on Gold coast in 2000 as specified by architect were rock maple and cherry and the rock maple had to be stained walnut (what the) why not use walnut?
Regards Rod.

BowlingBall... I believe that's checkmate.

Originally Posted by Luke Maddux

BowlingBall... I believe that's checkmate.

After reading up on this over the last few days it appears there are 4 construction methods worth considering::


1. Ladder core with Mahogany veneer ‘planks’ glued to both faces.
2. Individual Stave core planks with T&G or spline joints.
3. One piece engineered wood slab core with veneer pieces glued onto both faces.
4. 3 ply laminated solid wood planks – glued together with T&G or spline joints.


Annual humidity range here is 67% to 81%


Mahogany timber is at 12% MC


Given real Mahogany’s reputation for stability and minimal movement would the # 4 option be viable or will it move over the years quite a bit like other woods?

Originally Posted by BowlingBall

......Mahogany timber is at 12% MC.....

....Given real Mahogany’s reputation for stability and minimal movement would the # 4 option be viable or will it move over the years quite a bit like other woods?....

The idea is to start with MC equilibrated to about the middle of the annual moisture cycle for the site the object will live in. This gives you the best chance of things remaining where you want them (on average) to be. However, it doesn't matter what the MC is to some extent, as wood is continually giving off or absorbing moisture according to ambient humidity, it is never 'dry' unless you keep it in a totally dry atmosphere. If you were to assemble a door like you've shown in solid wood, it would be extremely difficult to predict future behaviour, even if yiu were meticulous in alternating growth-rings & all that sort of stuff.

As I see it, you would be tempting fate far too severely with solid, laminated doors of these proportions! Our climate is just too unpredictable - e.g., these last two years have been so dry in the latter half, I've noticed shrinkage & movement in my house I've not witnessed before in 40 odd years of living here. A 60mm solid-wood internal door is totally ott, imo, it's not necessary structurally, and as someone has already pointed out, it will be absurdly heavy! You will have to beef up the door frames for these things, and use some rather heavy-duty hinges! To get the look you're after, I reckon it would be far more practical to go with an engineered core, with thick veneers, either in pre-stained woods, or different woods applied to the core. If done at all well, noone could possibly pick the difference, but the saving in weight, and a more stable construction could mean the difference between doors that are still opening & closing nicely 20 years hence, and a bunch of nightmares that will have you back on site dealing with various problems 20 times in the next few years. There are several options for building a lighter core, each of which could give a durable door if done properly, and the finished door could still have a very 'solid' feel & be able to withstand anything short of a nuclear blast....

Cheers,

Thanks Ian W - some great points you mentioned including the fact we will need to seriously beef up the existing door frames and use extra heavy duty hinges.

Actually the colors in the image are exaggerated to make the design stand out but they will be toned down quite a bit in the finished doors. Agree it does look a tad scary.

It will all be one wood species - genuine Mahogany.

Going to go with a stile and rail "ladder" frame for the core, 20mm thick, and glue 20mm thick planks on to each face of the core which we believe will give them the stability needed
and reduce the expansion and contraction between the wet and dry seasons which a completely solid door would have. 1mm gap between T&G planks glued on with a decent glue which stays elastic should do the trick.

Pin the planks in place and run the doors through the belt sander - the planks can later be removed for staining then glued in place.

I certainly hope you're going to show us a picture of this one it's all done ?

Fairly unique project. I'm still baffled as to how you intend to glue up all the post-sanded/post-stained planks in such a manner that they don't need a final sanding (which will remove the stain, of course).

Cheers
Arron