Interior door construction

[Dave Squires]

I'm looking to build some interior doors for my house. These are 3'x8' single shaker style. I was planning on using 1 3/4" poplar for the stiles and rails and dado 1/2" MDF for the inside panel. I was going to attach the rails/stiles with a Domino 700.

My concerns are whether the poplar will be stable enough. The other idea is to still use poplar, but to laminate two pieces of 7/8" to help with any movement. Would really appreciate any suggestions for this style of door to help ensure stability over time. Thank you!

To add, these will be painted.


door.jpg

[Jim Becker]

Properly dried tulip poplar is just as stable as any other hardwood, so IMHO, no worries there if you use quality materials. Soft maple is an option that's similar in cost (in my area at least) if you need to compare and choose an alternative.

1.75" is pretty thick for an interior door. If it's replacing existing, the stops and hinge accomodations in the opening will have to be rejiggered.

As to your build methodology, I'd be doing it similar to you with the DF-700 and 14mm Dominos. As an alternative, working with three layers of .5" material laminated permits easy full depth M&T without chopping out the holes while also making it easy to do the half-inch panel. That's how I did the door for our basement stairway in the kitchen (pre-Domino in my shop), although I used .5" BB for the panels. I made moldings to match other doors in the house and applied them inside the panel openings after the door was glued up and fully assembled. (I had to make this door because it was an odd size and not, um...square. The one for the powder room will be similar...odd side and not even close to square. I have to match the openings as they cannot be adjusted. Old house fun)

[Dave Squires]

Thank you Jim, I like the idea of doing .5", could just hold back on the center for the dado. I was considering also using an LVL (https://www.menards.com/main/buildin...4438528942.htm) for the frame, with it being painted, maybe this could be a good cost effective way and maintain stability.

[Jim Becker]

LVL is going to be darn tough compared to poplar or maple...it's also murder on tooling and heavier than all get-out.

[John TenEyck]

Poplar is fine but soft maple is better as it won't dent as easily and paints great. Use quarter or rift sawn wood for the greatest stability. I would glue the MDF panel in the frame. The Dominos will hold the frame together, but the glued in panel will make the whole assembly incredibly strong. An alternative to MDF is PlumaPly It's 2 or 3 mm of HDF on both sides of a plywood core. Just as flat as MDF but much stronger and paints great.

John

[Richard Coers]

I'm looking to build some interior doors for my house. These are 3'x8' single shaker style. I was planning on using 1 3/4" poplar for the stiles and rails and dado 1/2" MDF for the inside panel. I was going to attach the rails/stiles with a Domino 700.

My concerns are whether the poplar will be stable enough. The other idea is to still use poplar, but to laminate two pieces of 7/8" to help with any movement. Would really appreciate any suggestions for this style of door to help ensure stability over time. Thank you!

To add, these will be painted.


door.jpg

Why so thick? The door is really 8'? You have 10' ceilings? Width of the rails and stiles will be a concern for the stability. Go too wide and you'll get boards that may be closer to the pith and those will move more.

[Jim Dwight]

1 3/4 is normal for exterior doors, 1 3/8 is the most typical thickness of interior doors. As has been mentioned, if you hang a 1 3/4 inch door in a jamb made for a 1 3/8 you will at least have to move the stops (if they are not intergral, if they are you have to change the jamb).

I made one door like you describe and illustrate. It was the interior door to my shop. I made the rails and stiles from construction lumber planned down to 1 3/8. I did not have a domino so I used traditional mortise and tenon joints. The mdf panel was in a dado as you plan but I also put a shop made molding around the panels that dressed them up. Construction lumber if frowned on by many but it worked fine for me. It is often not as stable as good hardwood, however.

[David Kumm]

I'm in the minority but I prefer 1.75" interior doors. The feel and heft on ball bearing hinges is hard to beat. If you keep your house reasonably temp and humidity controlled, solid wood should be a non issue, laminated or not. I'm looking at 3-8 doors I made 20 years ago for my office and they still look new in spite of peoples best efforts to screw them up. I would go with maple. you can dent poplar with a finger nail. I would also make sure you are happy with the 1/2" panel vs the 1.75" frame. I like more panel thickness but that is because all doors you buy cut costs by making panels thinner. Anything thicker than 1/2" might be too a lot of weight though. You also want to size the width so it looks appropriate to the hardware. I think a 3.75" backset looks better on that size door but you need5-5.5" frame to make it look right. I also use 4-4" ball bearing hinges on doors that size. They don't need to be as good as Hagar but at least similar to Emtek in quality. Dave

[David Zaret]

i agree with dave on 1.75" doors - that's my go-to, i like the heft and feel. for construction, i've had really good success with LVL cores, i use Timberstrand, edge it with solid stock, and veneer it with shop-sawn veneers. the doors are incredibly stable - they don't move at all. construction can be either domino 700s if i'm covering the edges with a moulding, or doing a straight shaker, or cope and stick with the Zuani set (or freeborn set). i cannot speak highly enough of the end result of doors made with timberstrand - they never, ever move.

-- dz


C5944D8E-34CD-4BA5-894B-8D1E9AC1B52D.jpg

[David Kumm]

Beautiful David. What do you buy, the framing 2x6 or headers with 1/8" veneer? How thick to you band the edges, depending on profile? I've got some Hickory doors to make and they get so heavy I usually cut them down to 1.5". this might be an alternative unless I get some really nice 8/4 Hickory but that is getting hard to source locally. Do you run into issues with the solid edges telegraphing through the sides and seeing it under the veneer? Is the LVL hard on a WB or planer? I'm assuming you glue the edges, run the LVL through either machine to get flush, put on the veneer after that? Dave

[Dave Squires]

i agree with dave on 1.75" doors - that's my go-to, i like the heft and feel. for construction, i've had really good success with LVL cores, i use Timberstrand, edge it with solid stock, and veneer it with shop-sawn veneers. the doors are incredibly stable - they don't move at all. construction can be either domino 700s if i'm covering the edges with a moulding, or doing a straight shaker, or cope and stick with the Zuani set (or freeborn set). i cannot speak highly enough of the end result of doors made with timberstrand - they never, ever move.

-- dz


C5944D8E-34CD-4BA5-894B-8D1E9AC1B52D.jpg

That sounds good. Another idea I was considering is LSL (https://www.menards.com/main/buildin...4438204228.htm). Could just go 1.5", but this would be pretty cost effective and I can't imagine any deflection at 8' with these as the frame. I was planning on going with soss hinges (3x 218). This would end up being about a 75lb door, which should have a pretty good feel to it.

[David Zaret]

dave - i buy the 2x6 timberstrand and hack it up as needed to make cores the size i need. if i need wider pieces, i just glue it together.

to machine the timberstrand, i take it raw, rip off the factory edge on the slider, clean up the other edge... and glue on some solid stock - this is rough at this point, just get it glued on. once dry, i slip a nasty set of tersas in the jointer and face joint the whole sandwich flat, then plane it down, again with nasty tersas that i hold back for precisely this type of thing. it machines just fine.

i run it through the wide belt with 60 grit just to open up the surfaces to get a solid glue bond... then i vacuum press on my shop-sawn veneers. then, either cope and stick on the shaper, or size and 14mm dominos, typically with thickened epoxy. the doors are solid, heavy, stable, flat. the edges are all solid wood, the timberstrand is buried in the cores. i've made... 20(?) this way with great success.

here's a shot of the joinery of one of the cherry doors i made with the zuani set - i think this was 1 3/8":

E600437A-FE91-44BB-9EE0-CD79AA8875D3.jpg

[David Kumm]

I probably wouldn't want to run my Porter jointer over it but the ESTA in my 8" jointer would be OK. I've never had a door warp but worry that the wide rail is the weak joint. I've never had one fail but the TS or laminated core idea has tempted me. Do you make the loose tenons from TS or hardwood if not using Dominos? I run a Bacci and would guess a carbide end mill is better than HSS in that stuff.

What glue to you like for the veneer. I've used Resorcinol ( SP ) powder from Woodcraft and it likes to curl up the veneer vs even a slightly thinned slow set yellow glue. I also use epoxy for most doors unless I'm assembling the center rails and stiles and have more time. The outer with the loose tenons works best with epoxy. Dave

[David Zaret]

i think that any carbide tooling is fine. the timberstrand is rough, but probably easier on tooling than particle board. i haven't seen an issue with carbide hitting it. for glue, i really like two-part urea resin for doors, a great solution. better than epoxy for the veneering. but sometimes i use thickened epoxy for the loose tenon part of it because i can easily mix a small amount without measuring.

specifically, the two-part from vac-u-press (unibond 800, with the thickener) is my go-to. it''s wonderful stuff. if you keep it refrigerated it lasts a long time.

for the tenon stock, i use the largest dominos (14mm thick) and they are incredibly strong. i think that any comparable hardwood tenon would be just fine. these doors will absolutely outlive me, my kids, their kids.. unless somebody proactively rips them out. those joints aren't failing.

[mreza Salav]

I made 31 doors and jambs for them for our house (documented in threads here) out of Maple at 1.75" thick with 3/4" thick plywood panels gluing. These were stained. After 6 years of use I still love the end result. I would use plywood instead of MDF and wood add a middle rail.