I have to build approx 35 interior residential shaker doors, I am planning on using solid knotty alder for the stile and rails, but I am not sure about the panels? I am looking for recommendations, the doors will have 4 or 5 panels, so the panels will be short. The doors I am thinking will be 1 1/2 inches thick with 1/2 inch thick panels. The two options are glued up solid for the panels or particle core with veneer. I was thinking the veneer would be more stable. I don't do many doors so I could be wrong. I have build a ton of cabinet doors and a ton of residential mdf doors, but not many solid wood ones.

If they are are only 1/2" thick it would be very fast to do plywood if you can find it off the shelf. Having it layed up would still be more cost effective than using solid. I would use mdf core. I'm not a fan of particle board except for laminate counter tops.

Milling 1/2" solid takes a ton of time. Resawing is one more step that is very time consuming. (35) doors is a ton of panels.

Gluing up that many panels isn't a big deal, it all depends on your equipment. For me, no big deal, Taylor rotary glue rack with a jump saw and straight line rip and a 26 " planer. If you don't have things like that, that many panels would be a chore and not cost effective. Your hardwood supplier is another thing, is the Alder dry enough? Can the ply you get with Alder veneer close enough in grain texture on both sides mimic the solid stile and rails? Will it finish the same? Clear coat is one thing but stains sometime differ from solid to veneers due to backing or how thin they are and glue not allowing stains to penetrate and achieve the color needed.

Like Dustin asked, will the ply match the solid? The plywood we get in rustic grades has a lot of filler in the knot holes which does not match the natural knots in solid wood. Also the knots are obviously not as deep as in the solid wood.

For me it would be simpler in all regards to use veneered MDF for the panels. Cut, assemble, finish. You can fit the panels snug in the frames and don't have to prefinish them like with solid wood ones. As long as you can specify the grain orientation and grade you want I don't see a down side.

John

Some valid points and good information. The color May be different when finishing and I never thought about the filler in the knots. I am starting to wonder if maybe a different species is the way to go. They want something very nice looking, but not cherry.

We use Famowood solvent based filler and fill all knots and cracks. We use laquers as our top coats so solvent based filler is the way to go. It's way better in my opinion than the weird stuff they use to fill plywood that doesn't take stains. With the knots and voids filled it still has the rustic look with a high end feel since you won't loose skin when someone cleans it. All this depends on how your shop is setup though, low man power with no heavy wood processing equipment and this is all a moot point.

Dustin,

Thanks for the info, I am not set up like you for that kind of work, I don't have a good clamp rack or a straight line rip, as I have never really chased that kind of work.
I do have SCM jointer, planer, widebelt and shapers so can move through the material fairly quickly.

The other dilemma is what should the frames be made of, the original choice was paint grade frame and casing, but it is up in the air at the current time. I may regret this. :)

You can use poplar for the frames and casings. It paints well and is hard enough to resist dings and dents over time.

If you have the luxury of presenting wood species options to the customer then I would start the selection process with the panels. See what veneered MDF species are readily available from your suppliers. If any of those will work for your customer you've made your job easier right out of the gate.

I agree that MDF core is the way to go. Particle board is less stable and plywood will be typically 1/32" too thin for your 1/2" panel slots.

BH Davis

Hate to be devils advocate but the knotty alder door you describe is a commodity item at the local builders supply. However it will be built using engineered stiles to help stay straight. Tough to compete with.

If these are worth building, knotty alder is so cheap and the plywood's very expensive I would use solid wood. Use premium frame so the chance of through holes are less and being shaker sticking upping them to 5/8" thick is a nice addition.

I'm not a fan of "rustic' Alder and the veneer sheets are less than ideal. Unless there is something very special about the design you want, buy them out. With your equipment you could make the required stave cores but it will be slow going. I missed what kind of morticing you use. If you do much solid get yourself a SL ripsaw. Way faster than jointing and table saw ripping. I've got a Taiwan made Extrema that has been very good. Main draw back is it's top feed rate of 99'/min.

How do you make your veneer skins for the stile & rails? Standard veneer is too thin for doors. More than an 1/8" is probably too thick.

I think a better looking door would be either maple with a darker stain or walnut with a close to natural stain and clear coat or even quarter sawn oak with a darker stain. I have seen a few jobs with knotty alder where it looked good, but not that wow factor.
I definitely agree with others that I would look at getting a price on them first, I know the interior finish package company in my area can get those shaker doors in certain species like fir and knotty alder for somewhere between $200-280 per door.
As for building them a straight line rip is nice, but if you have a good sliding table saw and a good solid blade you can rip that way and go straight to gluing up. I am not sure of your overall door height, but I figured on a standard 80 inch residential door your panels would be about 10 inches, 5 per door so I would cut and glue up sections that are about 4’6” long and then cut the individual panels . Order some 9 ft stock and your off to the races.
Just my nickels worth.

I see. I'll keep that in mind. :)

Just some thoughts....
Are you set up to produce this quantity of doors? I'll guess you chose 'Shaker' (meaning square corners) because you think it will cost less to make without any profiling, much less cope and tick tooling. I'll also guess that you chose 1-1/2"thick since that is twice 3/4" and that is how thick lumber comes. Full size 8" x 84" or larger joiner? No? How will you flatten stock?

1/2" flat panels? Plywood? With 'rustic' grade Alder? Why 1/2" - cheap? What you are doing, as already stated, is building a perfect copy of an Asian produced Internet door. They sell 'em for $38.00 or something like that. You have been keeping your costs down, so you should be able to sell them for less. Hey, after all, you are not in China.

If that knotty Alder is too dear for you, look around behind motorcycle dealerships for large skids. They make skids out of stuff that can pass for Mahogany, and you can get it for free!! The knots in Alder are large enough that each door could use about $12-15 per door of Famowood. I like it, but not at that volume. There are alternatives.

And clamping. The 2- 3/4" boards can be clamped by stacking them up and driving your car on top of the stack. Tire tracks sand off easily. After the joints are made - biscuits, festool, dowels, fake mortise and tenon or loose tenons - how will you clamp the door?

Your end.... How long do you figure on building and sanding to finish each door? Are you pre-hanging and making a frame? What is your hourly rate? Overhead based or generated smoother way?

As you may have guessed by getting so many negatory comments, the ol dogs laying around here have their doubts as to your ability to pull this off according to your budgets.

Please prove us wrong with photos of excellent work, expertly completed.

Good grief.

John

David,
Are you talking to me?
I was planning on building some doors, not a space shuttle.
But thanks for the sarcasm.
Really appreciated.

Scott,
Let me quantify my response because I build tons of knotty alder doors, mouldings and other millwork. I've processed literally millions of bdft of alder over the years. Lots of pallets right!! Why the hell would I or you build a door out of maple or walnut when the customer wants rustic alder! Quality craftsmanship doesn't know wood species, and my alder door is built exactly the same as a maple or walnut, and yes I build lots of those too. Oh yeah, I don't work out of my garage.

I was trying to point out at standard 1-3/8" doors you can't compete, but value added at 1-3/4" thick or let's say a heavier panel, there is money to be made. If the wood snobs don't want the work I'll take it!

As a side note my dad was a car mechanic by trade but built beautiful furniture and cabinets.....FROM WOOD HE SALVAGED FROM PALLETS!

Scott,

I think you're on the right track, I build thousands of this kind of door. We build them like the "Asian internet door for $38" that doesn't exist, but with quality materials and craftsmanship. No they aren't solid Walnut but in 15 years I have only had 2 doors come back "Warped". We typically use a 1/2" veneered flat panel, I wouldn't go less than 3/4" using solid wood. Less then that becomes hard to clamp up and is very unstable. Cracking and shrinking causing problems after finishing. I sell mostly in Alberta and Saskatchewan which have harsh lost dry winters. We build our shaker doors like this in any species the customer wants. I run thousands of board feet of Premium Frame K Alder, if they don't like as many knots you can get a better grade or even superior alder which is clear of knots. We use to import these doors from a factory we ran in china. Yes they can build quality doors, but at times we had to shake our heads and send full containers back. After years of this we decided to bring production back to North America. No we can't produce them for as cheap but we had hopes that a better quality product for slightly more money would eventually pay off, and it did.

Here are some brief suggestions for the interior solid wood swing door you plan to build:

1. Panel material selection:
Solid plywood is more suitable for door panels, with stable structure and not easy to deform.
Particle board veneer is more suitable for cabinet doors, but it may deform or loosen when used in doors under stress or in a humid environment.

2. Panel thickness recommendation:
Panels usually do not need to be 1.5 inches thick. It is recommended to use 0.5-0.75 inches to reduce door weight, reduce pressure and reserve floating space.

3. Panel structure recommendation:
Panels should be installed in a "floating" style and should not be fixed to accommodate seasonal wood expansion and contraction.

In short, it is more appropriate to choose high-quality plywood panels, which are stable in structure and smooth in appearance, suitable for your solid wood door structure needs.