I priced a job for some exterior doors 4' x 8' in poplar, and have since landed the job. Upon further research here at wood web's knowledge base, I understand poplar is a poor choice. I have been building custom furniture for decades, but am new to the exterior door business. Douglass fir, mahogany, spanish cedar are way to expensive for what I am being paid. So, here are my questions: Would western red cedar be a good choice for a paint grade door? How about alder, as I see many entry doors made from alder, though it is not rot resistant. Another option is to go ahead with poplar, and give it a borate treatment to prevent fungus, and then prime it to ensure it is fully sealed before leaving the shop. (even though primer was not included in the bid)
My plan was to construct rails and stiles with a three layer system... making the middle rails the full width of the door, thereby making them huge tenons to simplify and strengthen construction. Then wrapping the edges with veneer after outer layers are in place. Any advice from more seasoned pros would be appreciated.

Another option I am considering is using baltic birch plywood layers for the rails and stiles, due to its stability.
I have two pair french doors to do, as well as one front door with sidelights. Each rough opening is roughly 8 x 8.

Why bid on something so far out of your wheelhouse that you are asking such questions. Can you get out of this job? You are asking for trouble!
Rich

I wouldn’t use poplar for an interior door. I wouldn’t use poplar for a cabinet door. It grows like a weed. It’s not stable. Primarily used for trim.

You are going to lose a lot of money on the material alone. The customer is going to get a product that should last decades, but may never work properly.

People think making entrance doors is simple or easy. It’s not.

French exterior poplar doors. That’s the rainbow unicorn of door building.

Baltic birch isn't rot resistant either.

Same here Matt,
I would seriously go back to your customer and as tail-between-your-legs as possible tell them the construction you quoted is simply not going to last. It will be far better to walk away, or let them ask you to re-quote, than to try to salvage delivering a product based on a mis-quote that will haunt you for years and years.

You may well tell them that based on further research you realized you didnt want to ship them a bad item and they may give you a second chance or turn you loose open ended. OR they may just say thanks, and never deal with you again. Either option is better than delivering product that will be,... bad.

Any of the heroics, borate, blah blah, are not going to be a good solution to salvage your bid that is too low.

Would see the only options are, go back to them and tell them you need to re-bid.. go back to them and tell them you bid outside your capacity and dont want to screw them, OR.. you just eat this one and realize your going to build a batch of doors properly, for as long as it takes, and your going to pay 3-4X what you billed out of pocket for materials and learning curve to make it right.

Problem with the last option is they will run around telling everyone on the planet that they got these custom doors for 1/5 what they should have paid and youll spend all your time telling everyone else you'll not build them for that.

Just be honest with them and tell them you muffed it.

It's not just a bid that was too low. Most experienced door companies would only consider doors that large if they could be built with engineered stiles and 2 1/4 thick and then with no warranty. I saw your website and believe you are accomplished but you obviously are not a door builder. Take a loss but don't hurt your business by building doors to fail. With the details you have mentioned you probably won't even be able to deliver flat doors.Please have the courage to tell how this goes.

No disagreement RichP. But I dont have all the details. Maybe the doors are on the side of a barn or an outbuilding and the customer made it clear that they were just "simple doors". Or the default is to think the doors are on some multimillion dollar home and are supposed to be featured in the next issue of AD. Who knows. No speak to exposure, climate, client, etc..

I dont doubt that a crude door built 3 ply as he mentions with the center ply on the rail forming a deep tenon would not suffice for a bunch of the people in my uber rural area. I'd hope to be smart enough to non-warranty them.

No idea if this is a weatherstripped exterior front door on a home, or a door on a barn.

Regardless.. all good info. I too hope he keeps up with the post. Pretty honorable to ask with reference to boot.

If I had known what I was getting myself into at 23, I never would have started my own woodworking business. Learning by doing, mistakes and all, is how I roll.

I have located 1.5" douglas fir door stave panels at a reasonable cost. So I am thinking of skinning that with 3/8 to make a 2.25" door.

I found douglas fir timbers, NOT quartersawn, at a decent price but a long drive. I could skin with those.

However, I am intersted in feedback on what would be wrong with western red cedar, especially now that I have the stave core. It is decently priced, and closed grain. It is my ideal pick. Yes, it is easily dented, but any other drawbacks? I am leaning toward red cedar for at least all the framing and sidelights, but why not everything? (White oak thresholds were included in the quote)

I have one raised panel on the entrance door, planned on using 3/4" Extira, two panels with foam insulation panel between.

What about glue? Titebond 2, or 3; Unibond 800 or something else?

This is a house in East Texas, hot humid summers.

"...a decent price, but a long drive." This alone tells me that you should reconsider what you are about to do. The fact that you don't include the costs of a long drive as costs attributed to the materials shows you are not prepared business-wise to do that bit of work. I would say that if you don't charge $100 per hour (or your normal shop rate) plus gas, wear & tear, etc. then you are not charging enough.

Even a furniture guy knows not to use Poplar. Or Baltic Birch, or 3 ply with mock mortises ("...for extra strength" - tell me more).

All due respect, and as your furniture work shows , you are no newbie. Undoubtedly you have learned when to say no if the situation warrants. Puffing out the chest and proclaiming your willingness to teach yourself only means you have a blow hard for a teacher. Especially when you ignore seasoned pros cautioning your over-zealous approach.

Materials are easily 1/3 to 1/2 of of an exterior door unit price. Marked up, that is. Saving on material may make you think you can do the job, but all the other rough edges will conspire to make this mediocre at the very best.

You can make whatever rules you like, but that does not mean your methods, materials or project will obey your wishes. "Borate treated and primed" - indeed!!

I checked out your website. Very nice pieces. I am now confused. Obviously, you know what you are doing. The guy who made all of those projects would research every detail involved before throwing a number at a significant project.

You come looking for answers here without doing your basic homework. Most of your answers can be found in the WW Knowledge base. Guys like David has written chapters worth about door building there.

The fact that you have little knowledge of exterior woods or adhesives is surprising. Please don’t do the poplar was used for fences and also furniture in the Smithsonian. The tulip trees from a long time ago far far away are not the ones you buy today.

This whole thread would have gone differently if you asked your questions with more prior knowledge and before you took the project. The fly by the seat of your pants guys don’t get much help here.

Yep, your absolutely right, I failed to research before I quoted the project. My knowledge of exterior building is woefully inadequate. You have all repeatedly pointed that out. I get it. I knew that before I posted here. That is the only reason I posted here...I am in over my head. Pointing out the obvious does not help. I am not going to use poplar. I promise. Please read all my posts. Now, can we get on to solutions please? Is there anything wrong with western red cedar over stave core...please explain.

I'm sure that it was my post that opened the door to the responses that you have been enjoying,most of which you surely deserve, but here I go again. Western red cedar is way too soft for doors. titebond 2 and 3 are also bad choices. Titebond 3 creeps easily and loses much of it's strength at 120f. I bet that never happens in the Texas sun. You used the term french doors. Please describe french door and I will suggest a glue for painted ext doors subject to tough weather. I will repeat my first advice. Walk away from this job!

I have repaired an f-ton of doors. You name the species and I’m sure I’ve worked on it.

My favorite are junk stile and rail “dowelled” doors no tenon. (Yes for an entry no less !) I now just bore and glue in a 1/2” maple dowel into the rail and run a 1/4” x 8” or 5/16 lag bolt across the stile. Plug and paint or stain. Some are just junk. The end user just wants it to latch and lock.

Once had to take a couple of mahogany doors off a cape cod with 8 feet overhang, filet the astrigal/joining stiles and sandwich a straight piece of beech in there, as I had it for 6 years in the shop. 10 years later they still come together - flat

Any who, I’m not a joiner, but repaired, made and set my share of doors

East Texas ? Let it move

Floating panel, stile and rail with tenon/ not floating. Your pick of white oak or Douglass Fir. Oversized stops, let the end grain absorb the alkyd if painting. Gonna have to give it a decent bevel to keep from scraping the paint off in July or August hell I’d dry assemble, take apart tape off the tenon, cope and stick and paint it all, then assemble.

Have never really had to repair stave cores. Replaced a ton of white oak parts due to poor maint, termites etc.

Hope this helps. I’m sure I’ll hear it about Douglass isn’t god for paint. Or, I’m a hack. Whatever.

Repaired an 80 year old 12 beveled light front door. No overhang. Southern exposure, 1 1/2” stops ! Beveled relief stops at knob. Concrete porch falling into door. Fir. Tenons through stiles wedged
Didn’t stand a chance for 80 years. Um, ya

I have built a few hundred all cedar doors albeit for yurts. Clear dry Western red cedar. I have glued with type II pva and have had no glue failures in the joinery or floating panels. The doors are not protected from rain or sun and have had a minimal oil finish. So I feel confident in the glue.
The caveats are that these doors are not painted and I have read about extractive from cedar staining paint or messing with adhesion. Also my doors have no fine details or mouldings. I would be wary of making fine mullions of cedar because it is not strong. Lastly, it is soft so fine mouldings will get bruised

Richard, there are no mullions on these french doors, just one window panel. I planned to make the top and bottom rails about 12" wide, side rails about 6" wide. I have wondered if I should go wider..... Raised Panel moulding around perimeter of glass is all to be resin for outdoor use.

Cabinetmaker, that is encouraging to hear that you have never repaired stave core. That is definitely the route I am going. But what did you mean about oversize stops? Are you referring to the wood on the frame that the door will seal up against, where weatherstripping is installed? Standard factory doors are at 1/2" thick, so your saying much thicker to allow for seasonal wood movement?

Tom, there are no fine mouldings, so that is good to hear about your experience with cedar.

Just for arguments sake, why couldn’t you build up three layers of 3/4” exterior grade mdf and epoxy them together? I wouldn’t do the fake mortise and tenon, rather a full sheet with cut outs? The inside and middle sheet cutouts would be larger than out side Sheet to form a rabbit. After it’s glued up, but in your panels, insulated glass, and hold them in with wood stop. You might have to epoxy some wood into the hinge side to hold the hinge screws better, and a strip of wood on the strike side would also be good. Problem solved, I’m a genius

I would not use yellow poplar or western red cedar. At 4' wide and 8' tall there is going to be lots of opportunity for movement, hinge stress/sag (use ball bearing ones) and the latches going out of alignment. All these issues are doubled with French doors.

I think you should be honest with the customer and back out of this job. The resulting cost of doing it will far exceed your time and materials.

If you do go ahead, for sure use a truly water proof, structural glue. Resorcinol has always been my choice, exterior doors or boats. Good luck.

I just ordered spanish cedar for the structural components. Extira for other

Matt the First - Spanish Cedar will be a good wood in the weather. I'll leave you alone except for one thing - make the moldings out of Spanish Cedar - not Extira. Never.

Respect for the craft, if it means anything, means to use the best methods, materials and process one bring together. Door building and stairbuilding are two high points of our chosen craft, and that carries a responsibility to do well. To treat it with respect instead of using ticky tacky resin moldings or similar.

As for being self-taught, the inhernet problem is that you do bnot know what you don't know. You can ask here, as you did, but when all is done, you still don't know what you don't know. And, you may never find out what you are missing. Self taught doesn't work except in limited areas and processes.

And there is no engineering in engineered stiles (if you disagree, please show me the calculations done for the engineering), so please do not use the term. It was invented to mislead.

I was wondering when Dave would show up.

Good post, something the OP should consider.

Spanish cedar, like a lot of other tropical hardwoods, can be contributing to deforestation, depending on the source. If it’s from Central America, it’s possibly second-growth and possibly from well-managed logging. But if it’s from S. America, well, it’s the Wild West of old-growth logging, which is the main precipitator of deforestation. Clear Western redcedar will soon go the way of the dodo, since the ‘good stuff’ is pretty much all coming from the last of the coastal rainforests of British Columbia.
Mahogany is available from second-growth logging in Central America, but one has to due the work of tracking down truly good management. Costa Rica might be a good source, for instance, but there are also other species they call mahogany that aren’t Sweitenia.
Anyone ever try Southern live oak for exterior doors? They used to build ships out of it. And I’ve often wondered if well-dried black locust would be stable enough for exterior doors.

Apropos of Tim's post I am surprised that torrified or thermally modified poplar or soft maple has not taken over the exterior wood market.
It's main benefits are that it is dimensionally stable, and rot and bug resistant. The species are renewable and plentiful.
I have pleaded with my suppliersto carry 8/4 stock but haven't had any luck. I would love to reduce my cedar use not only for the harm to the BC coastal forests but also for my health. I know that I'm playing with fire the longer I work with it.

Southern Live Oak was prized for its branching. The huge branches, low on the trees, made for superior brackets under gun decks for their ships. As guns got larger, the ships had to be built more heavily to cary the weight. Those huge branches we naturally strong in the curve.

When the Constitution was renovated, there were some articles about searching for suitable Live Oak trees.

I cannot get my suppliers to take the thermally modified woods seriously. One manufacturer/supplier I contacted twice and never heard back from them. One vendor just laughs if I ask for it.

If 75% of what I hear is true, T M wood (what is the short cut name gonna be?) will be a real game changer. Imagine 12" wide 2" thick 16' Poplar boards, clean clear and straight, that will not rot! Could it be?

How about an 8" wide mitre that will not gape open even on exterior work or a 36" wide panel with no expansion.
I hear of containers of ash and SYP being sent to Latvia to be torrified and milled into decking and sold through Europe and N America.

Is there somewhere where people who build doors from scratch test the doors? Or are there small companies out there that make doors that trial new materials, and have a way to test them? If so, I’d like to supply that person some material to test.

Matt,
Building doors is not a lot different than building furniture. I live in a climate where we have weeks at a time at -30 Celsius and it is really dry. The same piece of wood will react differently here than it would in a warm humid climate. One type of adhesive might work well here where it wouldn’t work in that same warm humid climate.
I can name a long list of companies who successfully build doors in my area, I bet everyone on that same list has lost money or learned something by a door failing.
I would do your research and take a shot at what you think is best. This website is just full of people who are no different than you.

You are going to lose a lot of money on the material alone. The customer is going to get a product that should last decades, but may never work properly.