Building laminated veneered doors

[Malcolm Schweizer]

This week we milled all the lumber for 10 doors. We have already made 20 for rooms at a historic hotel restoration. Now we are making all the entry doors. The entry doors will have glass top lights and raised panel bottoms.

We use Torrified Ash for the core, which is stable and has less movement. We lip the ash with Yellow Birch to match the existing doors in the hotel. We veneer it with 2mm thick yellow birch veneers. Center panel is yellow birch veneered ply.

Once done, it is almost impossible to tell these are not solid birch rails and stiles. Finished door is a door for one of the hotel rooms. Of course the horns get cut off last. We leave them on until delivery day to keep the veneer from getting damaged moving around the shop. To help this customer, we agreed to hold them until they were ready for them; normally we make them take delivery immediately.

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[Ron Selzer]

very nice,
clean shop also
Ron

[Richard Coers]

That is a ton of cross grain construction in that bottom rail! Sure hope it's as stable as plywood.

[John TenEyck]

Nice work, Malcolm. Didn't you recently buy a new Grizzly bandsaw? If so, how's it working out for you?

John

[Malcolm Schweizer]

Nice work, Malcolm. Didn't you recently buy a new Grizzly bandsaw? If so, how's it working out for you?

John

Yes, we did get a Grizzly 24” 3 phase bandsaw. The new carbide tipped blade arrived, and it cuts smooth and straight. We made over 100 yellow birch veneers in a mix of 88” and 20”. Some of those were a foot wide. The minimum was 7.5” wide.

[Malcolm Schweizer]

That is a ton of cross grain construction in that bottom rail! Sure hope it's as stable as plywood.

The torrification process basically creates a closed cell structure. We soaked a test piece in a bucket of water. The moisture content read zero. (It’s actually around 0.3%, but it isn’t enough for a low-end moisture meter to read.) It makes a gorgeous door by itself, as it finishes to a color similar to a dark walnut.

[John TenEyck]

Yes, we did get a Grizzly 24” 3 phase bandsaw. The new carbide tipped blade arrived, and it cuts smooth and straight. We made over 100 yellow birch veneers in a mix of 88” and 20”. Some of those were a foot wide. The minimum was 7.5” wide.

Thanks for the feedback, Malcolm. Glad to hear the new saw is meeting your needs. I sure love my 17" one. I cut some 12" walnut veneer with it the other day and have some 13" wide mahogany to cut this week. It's such a pleasure to use a machine that makes the task easy.

John

[Dan Chouinard]

Yes, we did get a Grizzly 24” 3 phase bandsaw. The new carbide tipped blade arrived, and it cuts smooth and straight. We made over 100 yellow birch veneers in a mix of 88” and 20”. Some of those were a foot wide. The minimum was 7.5” wide.

I would love to get a new carbide blade for our 36" Northfield. What brand blade did you buy and where?
I just might make a half dozen pine interior doors for my basement remodel. Nice job building yours and thanks for the inspiration.

[Carroll Courtney]

Being a hobbyist, I love reading how professionals do their woodworking. Please keep your post coming and other projects

[Joe Calhoon]

Malcolm, how did you assemble and join those wide bottom rails? I’ve run into this occasionally repoducing historic store doors. The originals are always cracked right down the center. When I build these I usually do a double tenon with the top tenon having a little side clearance to allow for movement and only glue the bottom tenon. So far seems to be working but 100 years will be the true test.

[Kevin Jenness]

Here's an assessment of torrefied wood by Rob Cosman describing its stability. https://robcosman.com/pages/newslett...torrefied-wood The material losses some strength from the treatment process but it would seem to be a good product for this application, allowing for a wide solid wood door rail unlikely to crack over time. Malcolm, how much experience do you have with torrefied wood, and would you mind sharing your supplier?

[John TenEyck]

I would love to get a new carbide blade for our 36" Northfield. What brand blade did you buy and where?
I just might make a half dozen pine interior doors for my basement remodel. Nice job building yours and thanks for the inspiration.

I believe Malcolm is using a Woodmaster CT, 1" x 1.3 tpi, like several others here do, including me. I buy them from Spectrum Supply. Much lower pricing than other places, but their order/accounting system often is problematic.

John

[Malcolm Schweizer]

Good evening all:

Well, I do apologize for the delayed response. Yes, we are very busy at the shop. The doors are only a small part of a historic restoration project that we are very involved in. The Hotel Petersburg, in Petersburg, VA, is a 100+ year old building that is being renovated into a Hilton hotel. We started out fixing laminated doors that were damaged when a fire set off the sprinkler (years ago). The damage wasn't from the fire; it was from water. The veneer started to peel off. We fixed those doors, and that led to making new doors for rooms where the doors could not be fixed, or rooms where additional doors were added. We also are building the bar, and many furnishings for the project. So, let me try to answer some questions now that I am in front of a computer where it's easier to type as opposed to on the phone.

Yes- we have the Woodmaster CT Carbon Tipped blade for the new saw. It is amazing. We took the job veneering the doors knowing good and well that our 3HP Rikon Professional 14" saw was not really cut out for the job, but agreed to do the first set of doors, get paid, and then get a bigger saw. *** EDIT*** The Rikon is and AMAZING saw, and we made veneers for over 30 doors with it!!!! It bogged down a few times, but it did very well, and I have no problem recommending the Rikon 3hp saw- it's just that we have literally hundreds more veneers to make, and it's very evident veneers are going to be a regular thing for us, so we got a bigger saw, but we are keeping BOTH Rikon saws. We have a 3hp and a smaller 1.5 hp that we reserve for small curved cuts. For the new saw, we landed on the Grizzly 7.5hp 24" 3 Phase saw. It is a beast, and it is very well made. I'm very impressed with the quality of the construction. The machining of the top is perfect. All the adjustments are precise and so far the only issue is it came with the absolute worst blade I have ever seen- and I used to own a Ridgid Home Depot special. Literally the blade in that was better than the one Grizzly sent with the new saw. I immediately got a better blade- the Woodmaster CT with 2 TPI. It works beautifully, and it resaws a 12" wide piece of yellow birch with no issues.

An important note about the doors: Historic Preservation required that we kept any wood that we could keep on the doors we fixed. I would have preferred to just strip ALL the wood and replaced it, but we were required to keep any wood we could and replace only what was damaged. The rest got sanded. The doors will be stained, so the match should be fine once stained. *someone else is doing the staining, which I'm glad-because I didn't want to stain that many doors! For the NEW doors, we had to use the same construction as the old ones, which were Stave Core- which meanse the core is glued up from a bunch of small pieces of wood. Folks, I am amazed that these doors lasted as long as they did. Removing the veneers, we found huge gaps, tons of butt joins, and a lot of poor glue lines. The veneer seems to have held it all together. Although we technically aren't doing a stave core, as there are no butt joins in the glue-up, it is a glue-up with multiple pieces glued up to make the core, and then laminated with a veneer.

The veneers are 2mm thick. (*When possible, we prefer to use metric, although most contractors give dimensions in standard US Inches.) The core is 40.4mm, so veneering both sides makes them 44.5mm, or close enough to 1 3/4". The center panel on the door I showed is 1/2" plywood. I had cutters made to match the profile of the old doors, which also had 1/2" plywood center panels. The profile has a groove 1/2" deep and wide, and the panel is cut to leave a small gap all the way around for expansion.

Okay, the torrified wood I get from Northland Forrest Products in Troy, VA, but they also have a yard (*I THINK) in Pennsylvania. It's somehwere north. Look them up to verify. They don't deliver- I have to drive there to pick up. It's the most convoluted lumber stack. The heavy torrified ash and yellow birch are on the second floor of the stack, and I have to walk them down two by two. It's crazy! I literally have a bruise on my shoulder a week old from carrying wood from the top level. That said, I get to pick every board, so I get all usable wood. I did order some of the birch from another place because I needed 400 board feet, and I didn't want to lug 400 board feet two by two down stairs!!!

The torrified ash is beautiful, and we are going to be using it a lot. I did a lot of tests with different glues- epoxy, PVA, and Cascophen (resoursinol). I was pleased that they all worked fine. I was worried about how the wood would glue up since the pores are hardened in the torrification process. The process is basically this: They take the wood and kiln dry it like any other wood, but then they put it in an autoclave and suck out the oxygen. They then bring it to high temperatures that would normally burn the wood, but since they suck the oxygen out of the furnace, it doesn't burn. Instead, it cooks the sugars and lignin and hardens them and basically makes it nearly impervious to water. It is about 0.3% moisture, and it doesn't change. It doesn't move (by any amount that matters- even steel will move some), and it makes solid doors. I did a lot of research and met with some other makers who have used it longer than I and all have said it makes solid doors that don't swell (again- any amount that would matter). It takes an oil finish or a varnish or even a french polish very well. We tried them all. It darkens when finished to look similar to Peruvian Walnut, but has a little bit of a purple hue- only to my trained artist eye- I'm not saying it looks real purple, but having taken a course in color where the final exam was to match 1600 color chips- I notice these small color differences. My shop partner also said it has a bit of a purple hue to it when finished- so I guess it isn't just me, but it is very subtle.

We also tried torrified Poplar, maple, and oak. The maple and oak were just too hard to get, so they were out due to supply issues. The poplar to be honest just has that negative stigma in the woodworking world, and we thought the customer might hear "poplar" and think, "Oh, poplar is the cheap stuff." I'm sorry- but that's really a main reason we didn't use poplar. I have worked with ash a lot in boatbuilding, and so I felt confident with using it. I also wanted to play with it for other projects, so we went with the torrified ash over the other torrified options.

One thing to note: For sure without a doubt, the torrification process does make the wood a little more brittle. For example, I needed a test piece for an intricate dovetail I wanted to make, so I used a scrap of the torrified ash for practice. It blew out very easily- much more easily than the ash I used for my Roubo workbench. Also, the dust is very fine. WEAR A MASK!!!! It's really fine dust. So- yes, the brittle aspect was a concern for the doors, but you will notice that we lipped the rails and stiles on either side, so the screws for the hinges and lock hardware are going into solid yellow birch. We used cope and stick rails and stiles and added 10mm wide by 60mm tenons using the Festool D700 (the larger of the two domino machines). We also use the D500 with 5mm dominoes in the glue up process, mainly to keep them aligned when gluing. It also adds a little structure.

We used Titebond III for the interior doors. It's strong, water resistant, and it works really well for veneering in the vacuum bag. WE have a 4'x8' vacuum bag. For the exterior doors we are now making, we are using epoxy just as overkill since these doors get all the weather, and literally every person coming in or out of the hotel will use one of the four sets of double entry doors, so we want them extra strong. We tried Resourcinol, which I have used extensively, but my business partner has not. I didn't care either way for epoxy versus resourcinol, although I felt resourcinol would have been easier due to forgiving mix ratios and favorable cure times. We went with epoxy since we both had experience with it. YES- it's overkill, but as I said, these doors will get a lot of use and abuse.

So, the process is first we mill all the parts, and all the veneers. Currently we are using a helical head planer with a sled to bring the veneers down to 2mm and it works amazingly well. We are putting aside money from every project to pay for a wide belt sander, but right now we have to make do with what we have. Wide belt sanders are $$$$ for a 37" that we would want for door making. It's also more $$$ for wiring up the 3-phase, and it requires a dedicated dust collector of fairly large CFM. I used to work at a shop making doors and we had a massive 44" wide belt sander that would have made this project so much easier, but now that I have my own shop, I have to use what I currently can afford. It's working very well with the helical head planer, but we do lose a few on the last couple of passes. The yellow birch has a lot of variations in the grain. Honduran mahogany works much better, but that's not an option for this project.

Once we have all the parts milled down, we glue up the rails and stiles, and glue on the birch lipping on the outer edges. Once cured, they get jointed and planed to final dimension and to ensure sides are parallel. Next, they go to the vacuum press, where the parts are veneered on both sides. Once that is done, they go to the shaper to mill the edge profiles. I do cope cuts first, because any blow-out might be correctable on the stick cut. This requires a test piece to be sure what my final dimension will be AFTER the pass through the shaper. I have gotten pretty good at setting the shaper up to take only a sliver of length (cope) or width (stick) with the final pass. That said, before running all the coping cuts, I do a test piece. I measure it before and after the cut, and determine with the current setup how much length I am going to lose (usually it's only between 1/32 and 1/16" overall). THEN I cut all the rails to size and then do the coping cut. The stiles I make just a little wider than final dimension because once the doors are all glued up, I put them on the slider and take the horns off the top and bottom, and then I like to take a sliver off each side to ensure they are square. WARNING!!!!! If you do this, your saw has to be set up absolutely perfect, because if you're off just a tiny bit, over an 80" door it can end up taking 1/8" too much off on one end!!!! We check our setup every time before we run final cuts on doors. Even the finest sliding saw can go out of whack with vibration and use. A fraction of a degree off will cause your door to be way off if you cut the long side of it.

Seems I missed the glue-up. Pretty basic. We put two dominoes in each end of the top rail, three in the bottom, and if there is a middle rail, it gets two as well. We do a test fit and double-check the panel dimension before cutting the panel, just to be sure. With glass doors and doors with glass lights, you have to order the tempered safety glass first, so You just have to really double- check your measurements before ordering, and when you get the glass, make sure it's what you ordered. There is no trimming safety glass!!! You have to just ensure your measurements are right, and it all comes together. If the glass were to be off maybe 1/8" or so from the supplier, you can always take 1/16" off either side of the door to keep your dimension. That shouldn't happen with a good supplier.

Well, let's see- I'm just kind of rambling off the top of my head trying to go through the process for you. I hope that answered all the questions.

Oh, another thing with the torrified woods. We also tried a fairly new product called Accoya. This is a wood that goes through a process that has a similar result to torrification, but my understanding is that instead of a heat treating process, it is a chemical treatment. The down sides of Accoya for us were (1) it is VERY expensive, and (2) the chemical treatment process requires that you ONLY use stainless steel fasteners, as others will corrode. Well, thanks but no thanks! That said, we soaked a test piece in a bucket of water overnight, and it still read 0% moisture. Very impressive results, but the torrified wood did just as well. I am paying around $5.40/bft for the torrified wood. Very economical. I do not remember the price of the Accoya, but it was more than double what the torrified wood was.

I very much recommend trying torrified woods, not just for the resistance to moisture and the effects of humidity, but for the beauty of the wood. You will get a nice dark color without having to use stain, and the color goes all the way through the wood.

[Malcolm Schweizer]

Reading through what I wrote, I realize that I need to clarify the glue-up. There are two glue-ups: One is gluing the pieces of wood together to make the rails and stiles. That is where we use the 5mm dominoes to keep them from shifting during glue-up, and to add a bit of strength to the joint. The other glue-up is once the rails and stiles are milled, and that's where we use 10mm x 60mm dominoes to strengthen the joints where the rails and stiles meet, although there is also a cope and stick route to the rails and stiles. I would never make a door without either an actual through tenon or a loose tenon (domino). Making this many doors, the dominoes simplify the process. I find the 10mm dominoes to be fine for doors. I used to make doors using a huge heavy floor model machine that ultimately was no different than a floor mounted version of a domino machine, but with pneumatic hold-downs. I find the D700 is a great alternative to a $5000 floor mounted machine, and currently I plan to just stick with that.

Actually, there is also a glue-up where we laminate the veneer to the rails and stiles, so I guess it is actually 3 glue-ups.

[Kevin Jenness]

Macolm, thanks for the detailed writeup. I typically build doors in a similar fashion using a stationary slot mortiser and longer spline tenons (125mm). The Domino does a great job. The stationary mortiser does have some advantage in capacity for larger bits and for boring but If I were starting out now I might well opt for the Domino.

I am about to build an exterior reproduction door using integral m&t at the client's request, doing the copes with a custom router bit. I will be using accoya because a stash was was readily available locally but it is good to know there is a less costly alternative. I will be looking for a closer supplier if a similar project comes up in future.

Thanks also for documenting your new shop. You seem to be going about it very sensibly, keeping debt to a minimum and acquiring good quality equipment as the need arises. Keep it coming!