Exterior door

[Jim Becker]

Jim,
Thanks for the information. As I said earlier I have never used epoxy with the exception of the small tubes available at Lowe's, Home Depot etc. I am little concerned but will give it a shot. I think I may go the laminate route it may make the mortises easier since I may actually cut the mortise slot prior to glue up. I was thinking mortises 3" deep and difficult to do with a router setup. I have never cut mortises this big by hand and if I can measure and align properly I think I can allow for the mortises prior to glue up. Do you recommend a respirator while using epoxy.

It's handy to have a little of the structural epoxy around, not just for situations like your exterior door, but it's great for complex assemblies that you need a very long open time to get things together and properly clamped. PVA is great, but even the longest open time versions start to get beyond "the point" too quickly when you only have two hands to do eight hands worth of work. It doesn't "go bad", per se, very quickly being a two-part product and I just keep it in my "special adhesives" drawer. Mixing is generally one to one so it's simple to use, too.

[Richard Coers]

1 3/4" thick exterior door is quite common in the commercial industry. While oak is incredibly hard to dry and if you could find it, that kiln operator better be a genius. Highly likely to have a wetter core and that means movement as it dries after machining. More of a worry to me is setting panels in dadoes. With a direct driving rain, the water has a good chance of wicking between the panel and rails. White oak can handle that pretty well, but a clear finish can not. The water will wick into the end grain, or just under the finish and it will soon wick up. I like to angle drill a couple 1/8" holes in the rails to let any moisture run out. I'd also use ball bearing hinges that will last a lifetime on the heavy door.

[David Zaret]

as others stated, i would stick to standard dimensions - especially thickness. build a 1 3/4" thick door so your hardware works. i've done a lot of doors, and i certainly wouldn't use solid lumber - at least do a glue-up, ideally three layers so you get a couple of glue lines. personally, i use a stable core material such as timber strand and veneer it with shop-sawn veneer. i've never seen any door built this way move a millimeter. for glue, my go-to is urea resin, you get long open time and exceptional strength and rigidity when cured.

[John TenEyck]

I highly recommend you don’t use Gorilla glue. We do wide belt sanding for other shops and when I see panels coming in glued with Gorilla they are usually failing coming out of the sander. Long time user of TB3 here and never any problems. It is a very inconsistent product for viscosity though. I always stir up the pails before using and any panel joints are reinforced when used on exterior.

Why do you suppose that is, Joe? Maybe the people who made the panels didn't wet one side of the joint, and where you are with such low RH that's probably a must. I've used GG for all kinds of applications, many exterior ones, and it has held up very well.

John

[John TenEyck]

Jim,
Thanks for the information. As I said earlier I have never used epoxy with the exception of the small tubes available at Lowe's, Home Depot etc. I am little concerned but will give it a shot. I think I may go the laminate route it may make the mortises easier since I may actually cut the mortise slot prior to glue up. I was thinking mortises 3" deep and difficult to do with a router setup. I have never cut mortises this big by hand and if I can measure and align properly I think I can allow for the mortises prior to glue up. Do you recommend a respirator while using epoxy.

I'm pretty sure Dominos don't go 3" deep and they work fine for exterior doors. But if you want 3" deep mortises you can cut them with a plunge router. Use a shorter bit to cut as deep as it goes, and then switch to a longer bit for the remainder.

I've never felt a need for a respirator with T-88, the one I've used to make exterior doors. Check the SDS to decide for yourself.

John

[Jim Becker]

Max depth for the DF700 is 70mm which is just under 3"...more than adequate for doors, especially when using multiple 14mm Dominos per joint as one should for the application.

[jack dempsey]

I decided to go the Epoxy route. After discussing with a customer service person at Jamestown Distributors I am awaiting the UPS delivery of Total Boat FlexEpox. For those experienced with this method can you give advice as to proper clamping. My plan is to laminate two thicknesses of 4/4". They should be easy to clamp as they are 4 1/2" wide. I want to be sure that I do not over tighten the clamps and starve the joint. Any practical suggestions. Am I over thinking this? I have done a fair amount of woodworking but an exterior door is something different. At this point I believe I may be over thinking this. Thanks for your help and advice.

[Jim Becker]

I really like Total Boat resin products, Jack. I will likely be increasing my "collection" of their products.

[Kevin Jenness]

Don't worry about over-tightening the clamps as long as you have a rough gluing surface, either sawn or abraded with 80#. A rough surface is needed for good adhesion. Mill your staves flat and use flat cauls set up on a flat surface to spread out the clamping pressure. You can use cellulose filler if concerned about filling gaps, but in this case there should be none. I rarely use filler.

I like 2 1/4" thick doors as it allows for some insulation between the panels, but I have 1 3/4" doors on my own house. Properly dried, carefully selected solid wood is fine for doors but as others have said well dried thick white oak is hard to find. Let your stave sit for a day after milling in case they twist, and oppose any bowed pieces. 2 1/4" is easy to achieve with 3 layers of 4/4. You may struggle to get 1 3/4" with two 4/4 layers.

Ideally the doors will be protected from the weather. If not you might want to consider vertical planks laminated to a central ladder core with insulation in the ladder voids for better moisture resistance.

[John TenEyck]

Don't worry about over-tightening the clamps as long as you have a rough gluing surface, either sawn or abraded with 80#. A rough surface is needed for good adhesion. Mill your staves flat and use flat cauls set up on a flat surface to spread out the clamping pressure. You can use cellulose filler if concerned about filling gaps, but in this case there should be none. I rarely use filler.

I like 2 1/4" thick doors as it allows for some insulation between the panels, but I have 1 3/4" doors on my own house. 2 1/4" is easy to achieve with 3 layers of 4/4. You may struggle to get 1 3/4" with two 4/4 layers.

Ideally the doors will be protected from the weather. If not you might want to consider vertical planks laminated to a central ladder core with insulation in the ladder voids for better moisture resistance.

Kevin, could you please explain more about the vertical planks laminated to a ladder core? I have used a ladder core with HDF sheets for a couple of painted interior doors, so I know how it works. But I'm curious about how you attach solid wood planks to it and avoid expansion/contraction issues. Are you using a tongue and groove? A curious mind would like to know. Thanks.

John

[Kevin Jenness]

T&G planks. Best to leave expansion gaps between them and glue only half their width. I have made several in Spanish Cedar that have held up well in exposed situations.

[John TenEyck]

Thanks Kevin. That makes sense, both the wood and the technique. So the outside boards get glued to the outside stiles of the ladder core, and the others in the middle? Or you nail the tongues and glue that half?

John

[Kevin Jenness]

Well, it's probably best to glue down one edge of each plank and over to the middle. Nailing the tongues wouldn't be a bad idea either. I have to admit that the first one I did I laid up all the planks glued full width in a vacuum bag with epoxy. Of course the glue wicked up through the joints and I had to clean it out with an azebiki. I wouldn't recommend that, but the door has stayed flat for over 10 years with no surface checking. That's probably due to using Spanish Cedar, a pretty stable and forgiving species.

I had a disaster once when I made a garage door with t&g planks glued full width to one side of an x-braced frame. Despite the fact that I left spaces between the planks they swelled when exposed to the weather and curled the door badly enough that it had to be remade. One of those lessons one doesn't soon forget.

Getting pressure on the planks in the center of this style of door requires the use of cambered cauls or a press of some sort so it is a bit more time consuming to glue up than a paneled door, but it does avoid the problem of water getting into horizontal panel grooves.

Here's one ready for installation.

Miles' door.jpg

[John TenEyck]

Thanks for the added info. Kevin. Much appreciated.

John

[jack dempsey]

Kevin,
Thanks for the information and your helpful insights. As I mentioned I will use epoxy for the first time. I understand the logic concerning a rough or textured surface for the adhesion of the epoxy for the laminated pieces. I am leaning toward using a router to get the first 2 1/2" inches of material out for the mortise then finishing with a drill to get an additional 1/2". Do you believe the walls in the mortise will be sufficiently rough to allow good adhesion for the epoxy? Thanks, Jack