Background
We’re building 8 identical pair of Paint Grade French exterior doors using solid stock VG Fir for an upstate NY project. 2 1/4 ” thick x 2′-10 x 8′-2 tall Doors. One piece 5/8″ insulated glass with simulated divided 8-lite applied muntin bars (silicon to glass) on both sides that overlay an internal glass SDL grid. Aim is to achieve TDL look and satisfy Owner demand for one-piece glass. Stiles and top rail are 4 1/2 ” wide plus 5/8″ sticking. Bottom rail is 11″ plus 5/8″ sticking. Baldwin lock box and extension flush bolts. Fantastic hinges. That’s about it.
My concern
My concern is using dowel joinery. We do a lot of high-end Bars, cabinetry, etc., but no Doors for years now. We use our CNC for all we can and dowel just about everything routinely. Thus, for these doors I’m planning to cope & stick plus use 3/4″ dia spiral dowels with Titebond III. Two (2) dowels in top rail. Five (5) dowels in bottom 11″ rail. Problem is, my CNC horizontal drilling travel is only 1 3/4 ” max and thus my “practical” dowel depth is only 1 1/2″. It just doesn’t seem 3 inch dowels will be sufficient. Plus, I was thinking I ought to go deeper for sure in cross grain stiles. I want these doors to last over time in extreme weather. I’m comfortable aligning dowels and the cope & stick. I’m not comfortable doing loose-tenon joinery or using epoxy only because I haven’t done it. I like dowels. What can I say !!
My Question
How deep should my dowels fit into rails ? How deep into stiles ? I would have to “deepen” my 1 1/2 ” deep holes by hand and try not to wallow them out. Or what else would you guys recommend from what I’ve described ? Thanks. OTWBob
Replies
Bob,
I would use at least a 6 inch dowel for this project 3 inches into both rail and stile. A good drill press with a brad point bit should deepen the hole from the CNC without a problem.
I would also look into A stave core product for the rails and stiles.
Charles
Thanks for input on dowel length. As for stave core stiles and rails, I already puchased 10/4 and 12/4 VG Fir. I thought sure folks would 'slam' me for using solid stock instead of a laminated glue-up for stiles and rails -- which I came close to doing. As for stave core .... thought about that too ... but came across this solid stock VG Fir and I'm going with it.
Just a note on the VG Fir, I found you REALLY have to look close for end checks and splits. Some of these boards just "split apart" looking at em. Other cutoff pieces I put in a vise and hit sideways with a sledge and the stuff wouldn't split. Scary.
OTWBob
Bob,
I would feel comfortable with 2 1/4 - 3" deep in each , I would drill them deeper with a hand held drill motor .
The stile and rail coupled with the dowels is a strong way to go imo.
just out of curiosity , why paint VG ? don't let any tree huggers find out .
good luck dusty
Hey there olddusty,
I'm a tree hugger and I have painted plenty of VG fir. In the old days it's what we built everything out of.
Now days I buy boat planking stock. It's beautiful, long, and sweet. Just like my wife!
Right this minute, while it's freezing outside, I'm sitting in front of a warm and toasty fire of Wenge, Teak, and Maple. Kiln dried, of course.
Hal
http://www.rivercitywoodworks.com
Hey Hal ,
Funny you mention the warm fire and wood used . I pack up my scraps and give the stuff I don't burn myself to a few seniors for kindling .
Over the years I've coined the phrase " designer kindling " kiln dried at that !
It's way cold down here south of you also , it will get into the teens tonight .
I'm well aware of the uses of VG fir , many supplies of the old growth are gone , as you know the secondary growth is not the same . I love the look of VG but hate the splinters .
Your website is very cool and your work is stunning
regards dusty
Thanks Dusty,
I wonder how many pounds of kindling I have given away over the years.
Sometimes I put it out on the highway in front of my shop in boxes and it dissappears within 10 minutes. Once I put probably 20 full apple boxes out there and it was gone when I got back from lunch.
Hal
http://www.rivercitywoodworks.com
Dusty,
Many tell us few woods are as stable as VG Fir for exterior use. Moreover, it was a job Specification. Yeah, the wood looks fantastic and yet they are painted. Our only other exterior door experience is with all finished mahogany entry systems, and that was years ago. The cost of this VG Fir was just under African Mahogany. Outrageous. I would have preferred using the Mahogany (who can like working with Fir) but most agree it doesn't paint well. Another subject.
OTWBob
Hi OTWBob,
I would think the loose tenons would be fine. And you should be able to do it on your CNC Router.
Seems that if they were 4 inches total length, you will have plenty of strength. I personally would make the lowest mortise in the stile a little wider than the tenon so that it will allow a little movement if it becomes necessary.
The thing I was saying about the dowels is that when you drill a dowel hole in your lower rail, then install the dowell which is tight in both holes, when something has to give, it is the weak spot that you have created with the dowel hole in the lower rail. Even using loose tenons spreads this force out a bit.
I also think that the Titebond Type III is just fine for what you are doing. If you haven't used epoxy, this would be a messy place to learn. I've been using it since I was in high school, so it just seems like another glue for me. It is easy to make a mess with it though.
Hal
http://www.rivercitywoodworks.com
Hi OTWBob,
DON'T USE DOWELS!!!!!!!!!
Sorry to shout, but, well, don't use dowels. Make mortise and tenon joints. It's the right thing to do and it isn't that hard. Sure dowels are quick and easy but if you go one step further, why not have them buy fiberglass doors?
Why would you use fake divided lites? I have photos on my web site of 12 French doors that I recently did doing everything the correct way. If I can do it you can too.
You can do it, and why would you want to fake it? You are just inviting misery for yourself and your customer. What will you tell them when the doors fail? That you knew better but did it the wrong way anyway? Yes, I know that door manufacturers use dowels, but they have one benefit you don't: They make millions of doors. A few sags now and then aren't too big a deal. Just send out another door.
Sorry to be so hard on you but I don't have a lot of sympathy for guys like you who are faking it. You might as well be building cabinets with all of the components premanufactured, then buy the doors, drawers, and drawer fronts, and hire someone else to install them, photograph it, then say you are a cabinetmaker.
You can buy the correct tooling for your CNC machine.
Okay Hal, breathe in, breathe out. Okay, I'm okay. Sorry about the rant. I guess if everyone did things like I do, I wouldn't get paid the extra bucks to do what I love doing. My favorite thing is making really nice mortise and tenon joints. They are the best!
So...back to your question: If I were you, I think I would make the dowel holes deeper by an inch both ways. Maybe 1 1/2" or even 2" in the stiles. You're going to be loosing at least 1/2" because of your glass rabbet and sticking. You should use brad point twist bits, by hand (in a drill motor of course), and your guys should be able to make the holes deeper without wallowing them out. They will follow the starter hole. Also, I would use fluted dowels, not spiral. I think the fluted ones are stronger.
You should really try epoxy. Titebond III works well, but epoxy will fill any gaps and never fail. Plus it gives you a little longer open time. I use West System. If you get the technical manual and follow it exactly, the stuff will work.
One problem you may have is that the wide bottom rail could split. It's unfortunate, but one of the side effects of using dowels. They don't allow for any crossgrain movement.
Hal
http://www.rivercitywoodworks.com
Hal,
To think I was almost comfortable with my dowels. I think the best I could do in our shop is a loose M&T . I would make the tenon from same VG Fir. Yes ? As for tenon size what do you think ? My bottom rail is 2 1/4 thick x 11" wide. It's a 2-piece glue-up with dowels (what else) to prevent horizontal shear splitting -- at least in my head ! Not sure meaning of your comment about side effect of dowels ... that wide bottom rail could split, and that dowels don't allow any cross grain movement.
Can ya help me out here when you get a minute ! Thanks. OTWBob
Hal
In the process of doing some research for two entry doors, each 3' wide x 8' tall. I was going for a net thicknes on door of 1 3/4", going to use 8/4 and mill down. I came accross your post and looked at your web site, and hense have some questions for you. You state on your door page that you are using 1/4" marine plywood between the inside panels and outside panels. Does this mean that you have a laminated panel?
I agree 100% with the mortice and tenon joint and will be doing that. I also agree with the West System Epoxy and will be using that. The doors that I will build will have insulated tempered glass, Low E. The glass panels will be about 25 1/2" wide by 48" tall. I am a little worried about the weight issue, should I be?
The owner I am building for would also like Oak and I was suggesting to him that we use QSWO for stability. Is this wood OK for an exterior door application? Any other tips-tricks would be appreciated.
Thanks........Steve
Hi Steve,
Glad to help, although it sounds like you already have it together. Here are answers to your questions:
No, I don't laminate the panels. I install 1/4" marine plywood, glued into a groove in the stiles and rails to keep the air from penetrating. I then caulk all around this ply panel. The solid wood surface panels are then installed and merely glued and tacked to the plywood panel in the center of the plywood panel's width. This way the panel can expand and contract. The raised moldings are then installed over the edges of the panels.
I do it this way so that as the outside panel is moving around with the weather changes going on outside the door, and the inside panel is doing the same except differently, they don't have any effect on each other. In the meantime, the 1/4" panel keeps out the air as well as helping to keep the door from sagging on its mortise and tenon joints. The surface panels never split if done correctly, and even if they did, the door would still be weather tight.
As far as Quarter Sawn White Oak goes, yes, it works well for this. White Oak has long been considered the strongest and most durable of North American hardwoods for furniture and boat building. It is commonly used in ship and boat building for the hull frames, knees, keel timbers, deadwood, etc. Water will not wick into white oak because of the tyloses, which make it fairly rot resistant. Red Oak doesn't have these, and is much softer. By using quarter sawn material, you are helping to cut down on the seasonal expansion and contraction, which also makes a better door.
Another thing that I have sometimes done is rather than using 8/4 for exterior door stiles, I use a wide piece of 5/4 lumber, rip it down the middle, flat joint the same side of both boards, the glue those two faces together. I think this is just the opposite of book matching panels since I am putting them back together rather than resawing them apart. I feel that by doing this, the door is much stronger and more stable. It's cool too that you can then make your door a full 2 inches thick.
I would advise you to seal the top and bottom of the door with epoxy if you can, at least two coats. It makes a big difference. Oh, and get some help to install it if you end up making it 2" thick!
Yes, the weight will be an issue, but you can deal with it. These won't be the heaviest doors ever built. You will need strong hinges, four butts. And after you install the doors, you should also screw the hinge jamb to the wall studs underneath the hinges.
Have you used West System epoxy before? If not, you will need to follow their directions exactly. Coat the joints with a thin coat first, then put thickened epoxy in the mortises and wiggle things around as you connect them to squish the glue around everything. White Oak doesn't glue really well with epoxy if you try to use it on finely planed wood, so it is actually best if you leave the wood with saw marks on it so the epoxy can bite in. I personally don't make my mortise and tenon joints very smooth anyway, which is better in this case. Also, wear gloves and don't get it on you. It is quite toxic and many people become sensitized to it easily. Whatever you do, don't wash it off of you with lacquer thinner or acetone. Wipe it off and wash with soap and water. The thinners just thin it, and then you will absorb it.
You may already know all of that about epoxy, and maybe some of the other info., but I thought I would give you as much as I could in this small space.
I hope I have helped you. I'd like to see a photo when you are finished.
Hal
http://www.rivercitywoodworks.com
Thanks Hal for your answers, I appericate it. One question did come up, when you say you are taking 5/4, ripping and planing and glueing, are you saying you are taking two 5/4 pieces and milling down to 1" net and then face glueing in order to get a net 2" thickness? And I assume you are doing this to stabilize the the piece?
Also great idea about the 1/4" glue in panel, I bet it adds a lot of stability to the door in so far as racking is concerened. Also would make it easier to trim out the panels.
I will post some pictures when I am done. Should be in Jan sometime (I am a hobbiest so I work on the weekends). Thanks again for the help.
Yes, that's what I was talking about with the 5/4. If I can, I try to use one wide board to start with though, so that whatever is going on with one side will be the opposing force on the other.
I personally don't plane them to 1" prior to gluing. I like to glue them, then flat joint again afterwards to insure that the stile is perfectly straight, then plane to final thickness.
Hal
Gotcha...thanks
Don't use dowels. Absolutely don't use dowels. Dowels are for aligning work. The amount of strength they add to an endgrain to side grain joint is small at best. A large door is the most severe test of joinery.
The racking forces on a door are enormous. Use mortise and tenon joinery. A haunched M&T joint is the one to use for a door. It's not that hard to do.
A large doweled door will fail eventually. First the fit will start to go. The doors will rub where they meet. They will become obviously out of line in the frame. If the doors are always left closed the joints may not open. But if the doors don't lean against each other, closed in the frame, the upper joints will eventually open.
Rich
Edited 11/30/2006 9:40 am ET by Rich14
Rich14
The responses I got on my doweled joinery for exterior French Doors is causing me to re-think things. As I said, I already purchased solid stock VG Fir but I still have time to final decide joinery. I personally believe loose M&T with West Epoxy is way to go but I've never done it. I do dowels and Titebond III all day long. Not that I'm totally frightened -- but I'd rather practice all this on a lesser project -- not these 8 pair of doors. Not sure what I'll do.
By the way, what's your thinking on lag bolt joinery. A guy in our shop swears by it but it sounds like junk to me. Just doesn't seen it would allow for seasonal wood expansions and contractions -- and thus stress out the cope and stick glue line and butt joint -- and then what ! Plus, without a sizeable washer under the head, it would have little bearing area and thus not be too tight for too long. Junk I say.
OTWBob
Bob, It's very obvious that you are not comfortable with making M&T joints. I think you need to practice on scrap pieces until there is no doubt in your mind you've got it right. Those doors aer going to hang there for all to see, and you're GOING to get called back if they're not right. Floating M&T construction is probably ok, although I would use the "real thing." Invest in a tenoning jig for your table saw. There are a half dozen ways to set up a router or a drill to make the mortise. You'll need an edge guide for the router. Or make them by hand. It is NOT that hard, really. It's a basic joint. Lag scews? Ugh. Yeah, they'll hold for a while, but that's really low-end. Stop being afraid of being able to make a M&T joint. Rich
Mortise-and-tenon joints on those doors will outlast you; dowel joints won't, and you'll have unhappy customers when the joints begin to fail.
Edited 11/30/2006 10:04 am ET by Bill Duckworth
Bill,
I'm re-thinking my dowels. Thanks for input.
OTWBob
If one more voice will help to sway you, I have to agree with most of the other posts. Dowels are no match for these doors. Use M&T.
As a rule, certain joints have become traditional practice not out of frivolity or fashion, but out of hard-earned experience. You can go against those traditions, but you'd better have a damned good reason.
best,
DR
Ring,
I'm re-thinking my dowels vs M&T. Thanks. OTWBob
The other major consideration is the type of glue. I say thumbs down to PVA. Use hot hide glue, polyurethane or epoxy.
Rich
Hey Rich14,
I have to dissagree with you about the use of hot hide glue. Aren't these are exterior doors?
Also, I don't think that Titebond Type III is PVA. It isn't my favorite glue, but it works well for certain applications.
Hal
http://www.rivercitywoodworks.com
OK,
Didn't catch that they are outdoor doors. Nix on the hot hide glue, then.
Titebond III insn't PVA? Didn't know that. Does it creep?
Rich
I'm somewhat ambivalent about the joinery here. M&T is undeniably stronger on doors, however, dowells have been used successfully for too long now to dismiss as being inadequate.
I'm really curious as to why your customer insists on a single pane of glass and applied "muntin" bars. It seems like an expensive repair if it ever breaks. Also the joinery of real muntin bars can help keep those stiles straight and true.
Thanks for comment. Actually, we would agree. TDL were first planned by us but the Architect wants SDL instead. One piece glass is his 'thing'. It's his call, but we did have discussions. Nevertheless, the 5/8" glass actually has an internal 3/8" thick x 1/2" wide "rubber grid" between the 1/8" tempered glass panes that align the outer applied muntin bars. I will say the sample he gave us doesn't look bad. Pella windows do this same SDL thing.
As for replacing broken glass -- can you imagine the total aggrevation !!! We agree.
Are you familiar with the Architectural Woodwork Institute?
Dowels are acceptable in low to high end doors in their standards guide. You need to be a member to get the book but it's very helpful.
http://www.awinet.org/
RickL,
The problem with using the Architectural Woodwork Institute guildlines is that even though they will allow some types of workmanship and tolerances, it is not always in the best interest of the end user or the manufacturer. I have seen it used as an excuse too many times by manufacturers for poor workmanship.
An example is the amount of warpage allowed in exterior doors.
Hal
http://www.rivercitywoodworks.com
The AWI is great for estiamting jobs and helps compare apples to apples so to speak. Quotes can vary thousands based on different construction methods.
I also used it to give some creedence to using dowels on the door otherwise it's just an opinion with nothing to back it up. FWW, years ago did a strength test on joints and dowels were up there with loose tenons and regular tenons for strength.
"FWW, years ago did a strength test on joints and dowels were up there with loose tenons and regular tenons for strength"
That "test" continues to get referenced as you have done. It was one of the most seriously flawed evaluations of joint strength I have ever seen. Nevertheless, it got reprinted in several Taunton publications as I have noted in this forum in other posts. One "finding" was that biscuit joints in a rail to stile joint were as strong as M&T construction. That alone is absurd. The methodology used was inconsistent, inconclusive, used far too few examples of each type of joint, and confused joint types.
Early in the article, the author stated that the testing used was not scientific, yet the article went on to present the innaccurate data in a way that led the reader to think that it was valid.
Nothing in that article should be used to justify any particular type of joint for any particular application.
Sure, examples of doors made with less than M&T construction can be shown to be prevalent. One can also walk into the Home Depot "tool" section and see abominations of pressed steel and black lacquer that are called "hand planes." Cheap products are everywhere.
Everyone who has recommended using M&T construction, including me, has recommended how to do it right. Not the only way, but the best way.
Rich
Edited 12/1/2006 12:47 pm ET by Rich14
They also said the biscuits failed immediately as opposed to the tenon joint faling progessively slower. There's not much "scientific" evidence on strength of joints in print. Forest Products Laboratories info is pretty old and doesn't include biscuits. Anyone got any documentation on other sources on joint strength????? That's why I also referenced the AWI info, otherwise it's just an opinion.....
Use of mortise and tenon construction in lasting, quality work by experienced workers is not simply opinion. It never hurts to do something right.
I knew you were going to receive some flak for referring to that FWW "test."
I also know that most manufacturers of doors use dowels rather than mortise and tenon joints. They are certainly better than nothing, and totally acceptable for mass production. But since OTWBob has been hired to build custom doors, and is probably not being paid for mass production doors, it seems he should use the best construction method he can.
I just hate to think about him having a callback later when a little head scratching now, figuring out how to make a better product, could save the day later. And with his CNC machine, it probably won't be a heck of a lot more work.
Hal
http://www.rivercitywoodworks.com
I'm curious--is there an architect involved in this project, or is it just between you and the homeowner? If there's an architect involved, there may be a specification--such as AWI or WDMA--you have to adhere to. If not you have to adhere to the best possible method that you and your shop are capable of.
I think that you're getting some pretty good advise here on this forum, and your concern about the joinery issue tells me that you will end up making doors that you will be proud of.
Hi Bob I just destroy, I mean make things in the garage but I just did two exterior doors one out of Poplar and the other out of Walnut and did loose tenons for both of them. I cut the mortises with a plunge router and a 1/2" x4" spiral bit and it seemed to work pretty well. I hand held the router and used a jig setup to keep everything square. If you have a cnc setup I am sure it will work great. For glue I used tite bond 3, the longer setup time is very helpful. Of course the doors are not installed yet so time will tell but if you do the loose tenons I am sure your doors will be very good.
To bad they can't be finished with clear coat instead of paint.
Good luck
Troy
So, how'd those door turn out? What dimension VG Fir did you buy to get 2 1/4 thickness? What joinery technique did you use? Glues?
I have 7 doors to build and would like to use insulated glass units with SDL. I am renovating a historical home built in 1916 designed by Julia Morgan (of Hearst Castle fame). I am currently building similar casement windows to replace aluminum windows that had been installed in the 1950's. The doors are 2'x8'6" and will replace doors damaged in a previous remodel.
I am considering using a 3 ply lamination inspired by Scott McBride's article in Fine Homebuilding Jan 2005 --Custom Doors Done Easy. Do you have any recommendations?
Thanks for your help,
Merry
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