Message Thread:
What is the maximum size of a frame and panel door to join it with cope and
2/7/22
Hi everyone,
I am building two set of doors, each door is 29" x 95" x 1-3/4" thick. So they are big doors. I will be using poplar. They are paint grade. The styles are 5" and starting from the top the rails are 5", 6" and 8", so they carry two panels (mdf 1/2") each. And they also carry a molding hence the idea of using just a set of male and female shaper knives that give me a cope and stick joint. But being these doors so big I am almost convinced they need a big tenon, so I am having trouble deciding how to build them strongly.
One way would be to groove the pieces first for the panel, run the pieces on the shaper to get the profile with only one knife, (so flip the pieces to get the same profile on both sides. And enlarge the groove with a mortising machine ( that I don't have but that mmmaybe could borrow) where the rails go for a big tenon that I can indeed do at the table saw. Or maybe do this step first so the mortising machine doesn't deflect when enlarging the groove for the tenons.
They are closet doors so they won't get the same traffic that normal doors get. Would it be enough using the small tenon the cope and stick knives give me, knowing that I could perhaps glue the mdf panel to the doors?
Any advice would be really appreciated
Daniel
2/7/22 #2: What is the maximum size of a frame ...
Website: http://www.cougilldiversified.com
Hi Daniel,
Many ways to go about this. A simple mortise and tenon frame with applied panel moulding would be a simpler approach. You’ll want the shoulder of your tenon fitted into that plow where your panels will ride, and extending into that stile a good half its width at least. Lots of glue surface, can be done with table saw, drill press, and chisels. I’m not a dowel fan for doors, but they would even work for an interior occasional door, if you let that rail into your plow.
2/7/22 #3: What is the maximum size of a frame ...
I would mortise and tenon. 1/3 the thickness and half the stile width.
I agree with Nate. Applied molding will be easier, but you can stop miter the sticking if needed.
If you can't borrow a mortiser, then drill press and chisel will work. It's a pain, but only two doors is manageable.
For what it's worth, I typically mortise before grooving for panels etc.
2/7/22 #4: What is the maximum size of a frame ...
You can also reinforce the joints with good sized dowels, easy if you drill the holes before machining the rest. Good luck
2/7/22 #5: What is the maximum size of a frame ...
I have made a great number of doors that size. I use 1/2" dowels. 2 in the narrow cross rails. With 3 in the wider ones. Never had a problem.
2/7/22 #6: What is the maximum size of a frame ...
For budget grade doors like this, you can drill, install, and plug, GRK structural lags as needed. Will get you at least a decades worth of use if everything else is cut and fit well.
2/8/22 #7: What is the maximum size of a frame ...
Do not use poplar. The stiles will grow enough in width that it will jam the door. Then you will plane it. The next winter you will have 1/4” margins. Poplar is as much a weed as a wood. Not stable. It’s likely that the door will warp.
2/8/22 #8: What is the maximum size of a frame ...
I made all of my interior doors out of Tulip Poplar. 5” stiles and rails. Over a year old and no issues yet.
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2/9/22 #9: What is the maximum size of a frame ...
Website: http://acornwoodworks.com
There is no magic size where cope and stick is adequate for passage door construction. A tenon or some other member should also help the joint carry the load. It is all about glue surface. Calculate the glue surface for different possibilities to see which will give you the best surface area for the effort.
Poplar can be a good interior wood. Be sure you are buying from a good vendor that knows how to dry it and cares about your success. This is no place or time to try to save a few cents per foot. We use soft Maple for most of our interior work. 3
2/9/22 #10: What is the maximum size of a frame ...
Several ways to do it, all mentioned here are perfectly valid... another option (I've done tons of barn doors this way) is to use half-lap joints (with your "traditional joints" [between the rails and stiles] on the front and the "mess" on the back. If it's for a closet and paint grade, it'll disappear if the sanding is done properly. Mark out your pieces where your panels will go and drop them on a dado stack or use a slot cutter. With your rail/stile sizes, you'll have a LOT of surface area for glue.
I also think the lags/dowels through your stiles and plugged is a super strong connection, just make sure you clamp everything tight before you drill out for them!
2/9/22 #11: What is the maximum size of a frame ...
My belief is that if one is to go out in the world and make doors for fun and profit, one should do so using best traditional methods. I don't do surgery (other than splinters....) but I have some very sharp knives, and a book on anatomy.
Doors require mortise and tenon or dowel joinery.
Therefore, the correct machinery and/or tooling is necessary to engage in the professional trade of doors. Cope and stick is not enough to rely upon long term. Half lapping is the mark of an unprepared amateur or desperate professional (nothing personal). Drilling thru the stiles for dowels is fine for a hobbyist.
2/14/22 #12: What is the maximum size of a frame ...
Website: http://www.bhdavis.net
I'll second the comment not to use poplar. I did an entire house in poplar 4 panel doors once. 95% of them were fine. It was the 5% that moved that were the problem.
Soft maple is a much more stable wood for this purpose. That would be my suggestion. Stave core construction would be even better.
There is a bit of an end run around the dowel alignment issue without having to live with plugs on the edges of the doors. If you cut a 90° V-cut on the outer edges of your stiles before assembly you can glue the cope and bead doors up without the dowels. Then edge drill through the V-cut on the stiles and into the butt ends of the rails. Glue the dowels in place, and then glue in mating V-strips on the edges of the door. End result will be that you have a solid door edge with no hint of the process used to make the door. This works. I used the method on a large group of doors with good success.
BH Davis
2/14/22 #13: What is the maximum size of a frame ...
Website: http://www.bhdavis.net
Here's a sketch of what I described above.
BH Davis
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2/16/22 #14: What is the maximum size of a frame ...
Thanks for that BH. That's the first new thing I've learned today. Gotta love WoodWeb
2/16/22 #15: What is the maximum size of a frame ...
David, I am interested in why you would say doweled doors are on par with mortise and tenon doors? I was taught that the minimal amount of long grain in a doweled joint made for a poor connection. I’m my head, a structural lag has the benefit of the threads holdings tight, and the washer shaped head not slipping back down the hole. Set it epoxy, and it’s quite strong. Seems like a better set up to me, What am I missing?
2/17/22 #16: What is the maximum size of a frame ...
Inlaying 3/8" steel plates across the joint will hold better than a lag bolt or two. Once you add in a new material, you leave woodwork behind.
The beauty of a tenon is that it is right there in front of you. You make it to suit. No chasing this lag or that dowell. Dowels are far from a M &T, but adequate.
2/17/22 #17: What is the maximum size of a frame ...
Between poor machining tolerances and non round dowels there is an interference fit in a doweled door. (4) large dowels have plenty of glue surface area. End grain to long grain glue bonds are plenty strong. Stronger than the lignin.
2/18/22 #18: What is the maximum size of a frame ...
And the problem with lags (other than introducing another material) is that they are going into the end grain of the rails. Threads do not hold well in end grain. You can compensate by using a longer lag, but then the drilling becomes a problem.
2/18/22 #19: What is the maximum size of a frame ...
With lags, I put some epoxy in the hole and run them into it. The epoxy soaks into, and helps harden the end grain, making it much stronger. It also acts as a lubricant for the lag. Another benefit is you don’t have to leave the doors clamped up, the lags hold everything tight. I use GRK structural lags, the threads on them are deeper than a lot of other lags I have seen. Never had an issue drilling holes for them.
I don’t claim this is the best way to build doors, but if your on a budget, it’s not a bad way to go. As a small shop, I use either mortise and tenon, or lags. It fits the tooling available to me, in the space I have.
2/18/22 #20: What is the maximum size of a frame ...
Structurally there is nothing wrong with lags. If anything it’s overkill.
Just for your info. The epoxy will fill in the gaps between the wood fibers. That makes it a solid and increases the friction between the wood and screw. The West System guys tested it back in the 80’s. You can wax screws epoxy then in to wood. The pullout strength is massively increased. You are permanently bonding the bolt to the wood with epoxy. The limiting factor is the lignin adjacent to the epoxy.
David and I make doors for a living. M/T, slip tenons and dowels are the only options.
Personally, I would do a slip tenon if I were you. All you need is a plunge router and a quick shop made jig.
2/19/22 #21: What is the maximum size of a frame ...
Website: https://www.carpconn.com
Daniel,
Did you happen to purchase David's Book?
2/19/22 #22: What is the maximum size of a frame ...
Adam, if you wax the.screw, the epoxy will not bond to it. Is there a specific type of wax that you are referring to? I epoxy lots of stuff, I use wax paper and waxed cauls to keep the epoxy from sticking. To be clear, I put the epoxy in the lag hole and dip the lag in epoxy, then drive it in while its uncured. The wet epoxy acts as a lubricant, and as the lag screws in, it Hydraulically forces epoxy into the wood around the threads.
I sell doors for money, so I guess I make doors for a living also. There are many ways to skin a cat, but the circumstances around each job will dictate how you build them.
2/19/22 #23: What is the maximum size of a frame ...
Matt,
I have a ton of experience with epoxy as a boat guy.
We usually use paste wax like Butchers or Johnsons. Carrnuba car wax works as well.
I wasn’t encouraging you to use wax. I was explaining filing the grain/friction. Simply using PVA wood glue on regular construction screws increases pullout.
In your case the epoxy will bond to your lag. That’s a good thing.
If you are selling doors. You should be doing slip or dowel construction. You should not have to plug or fill holes. The construction should be completely blind.
We actually did a similar thing to screen doors with all thread & epoxy.
2/22/22 #24: What is the maximum size of a frame ...
I made some doors using cope and stick for the detail and 4" long X 1/2" dowels for the joints. I'd guess over kill but wanted to make sure it would stay together. Went together really hard, closing up that many dowels was tough. These were for a commercial fishing boat and are still working today.
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4/10/22 #25: What is the maximum size of a frame ...
As a production and custom shop we take on a lot of repairs, and moans come from the benches when doors come in that are warped or joints that are failing.
Laughter fills the shop with removal of 6” deck or landscape screws coming out of stiles, jokes resonate as to no matter how long the rod, satisfaction is null without proper use
Mortise and tenon is the way to go. No doubt about it.
Dowels do the job and need to be sized accordingly and placed with precision.
Most of our repairs come into the realm of refusal to use proper door sizing when built, butt joints, pockets screws, no bevels at strike, etc. not to mention materials that have warped over a short time.
In order to get them in and out on budget, (and we always make a small profit) is using dominos, dowels, and or lags/with dowels.
If the door is constructed well - rot repairs, weathering repairs, etc naturally get taken care of naturally quick.
If it’s garage shop quality we force the repair speed with 1/2” dowels into the rails and lags into the edge of the stile Thus giving the lag something to bite into
Perhaps the saddest thing is a door built by someone that didn’t build it square, used cheap materials, or was just in over their heads.
Not everyone has the precision equipment to build with dowels or motor rise and tenon in production quotas, but a good living can be made with good square parts, properly stored, dried and acclimated materials, and a few small jig clamped in the right place to land out a hand chiseled or machined tenon
There is a lot of great advice on this one thread.
Best advice I ever got was slow down enough to do it right the first time using the right materials and techniques allowing for expansion and contraction for the seasons.
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