Veneer over solid wood panel for exterior door

[Aaron Petersen]

I'm building a new exterior entry door for my house and I'd like to veneer the panels with some figured grain, but I wanted to pass the situation by some others to see if I'm asking for trouble. The door is sheltered under a porch, so it takes a minimum of direct weather or sun exposure. I want to use solid wood as a substrate because the panels are rabbeted, so you may see the substrate peeking out at the corners.

Here's the situation:
- Each of the panels will be about 30 wide x 20 long with the grain running the length.
- The substrate will be 1.25" thick and made out of qtr sawn white oak. I've got a bunch of 4/4 flat sawn that I'm going to cut into strips and turn on their side - essentially making a butcher block substrate with very qtr sawn grain.
- The veneer is 1/42" qtr sawn white oak with a lot of curl to it.
- I'm planning to press in a vacuum with epoxy as the adhesive. The panel will be glued up with either TB3 or epoxy.
- Panels will be finished with Waterlox marine.

My questions are:
- Am I asking for a lot of delamination problems having veneer on the exterior of the house?
- Should I cross band the substrate? My thought is no because I'll have the same wood species in the same grain orientation for both substrate and veneer so any movement should be consistent between the plys. In other words, both layers should move in tandem making splits and delams a non-issue.
- Are there better glue or finish choices?

Thanks for the help. I appreciate your opinions.

Aaron

[jack forsberg]

i would no cross band but i sure would like a thicker veneer. stave core is suited to exterior but with the thicker veneers. I have a door made that way on the shop facing south and stained dark red . holding up well With TB3

[Peter Quinn]

Every time Ive seen veneer that thin on exterior it's been for a call to the extent of "Can you fix this", it's always a mess, and I always say no. Stave core doors usually run much heavier veneers, like 1/8" or a bit more, and the widest parts are maybe 12"? Any fractional movement in the substrate and the veneer will crack and split, especially open grain woods like oak. Careful using epoxy to veneer that thin, it will bleed through bad and you don't have much room for sanding. If probably lay up a substrate of MDO, miter a band of QSWO around that. To create the panel raise or rabbit area, then veneer that, you might stand a fighting chance, better also to do two thin panels back to back with a break between them so the panel is not so tense from vastly different environmental conditions.

[Larry Edgerton]

I've got some veneered doors out there built like you are suggesting except I use an Appleply core. I used epoxy as well, West 207 hardener and applied it liberally so it would soak through everywhere, then applied a coat of West/207 before sanding so I was just sanding out epoxy. I think I did one more coat of West and then applied a few coats of automotive clearcoat as it stretches a bit and has a UV inhibitor.

If you have not started I have done entry doors with a sandwich of 1/2 Appleply with a sheet of 1/2" urethane foam in between. Did one that was bulletproof with a layer of some high tech Kevlar in the sandwich just in case you have someone mad at you.

A lot of people think a plywood core is cheating, I think of it as zero callbacks.

[Aaron Petersen]

I'm having a bit of a "duh" moment here. For some reason the mdo with a mitered oak band never came to mind. I've done it similarly in other interior projects. I like that idea much better than the stave core, so I think I'm going to go with (2) 1/2" panels separated by a thin layer of foam. Do you think I could get away with the thin veneer using MDO? If bleed through is going to be such a problem with epoxy, is there a better choice?

Thanks for all the help. Having others to bounce ideas off of is why sawmillcreek is great.

Aaron

[Peter Quinn]

I would do a test piece, or do as Larry sAys and use the 207 clear hardener, then use it again as your prime/seal coat. You may have to thicken the epoxy you use to glue down the veneer to avoid bleed through. Alternatives are titebond III or polyurethane glue, the poly will almost definetly push through any gaps in the veneer. I've had the problem laminating shop sawn 1/16" rift oak veneer. Just realize the potential for problems and test before committing a large glue up. When it comes to epoxy and doors, the two best sources I know for info are Larry, and the west systems technical info on their site. Lots of very real world info from both. I am not an expert on exterior veneers, most of my experience comes from laying up curved jamb heads or laminating sash parts. I have done thicker veneers on MDO to simulate v groove paneled doors with good success.

[John TenEyck]

Peter, what's the advantage of MDO over BB Plywood?

John

[Larry Edgerton]

If you go with MDO, coat both side first with West, sand out flat with 80 grit lightly for bondage, then use the 207 to bond the veneer to the core, and do the 207 coat after as discussed. Epoxy is a mechanical bond so the 80 grit it critical. Precoating will keep the MDO from starving the MDO/Veneer interface of epoxy. At the thickness of veneer you are using it will bleed through, but thats good, can't get any better bond than that. I skip the precoat with Appleply, but I am getting $5-7,000 a door so the cost is negligible for me.

Make sure you have a absolutely flat surface, and check for twist with winding sticks. Once bonded in a twist, etc, with epoxy it is always going to want to go that way.

You are going to laugh at my press, but I use three 12" I beams shimmed to perfection, a sheet of MDF covered in plastic with the core laid on that. I spread the West, lay on the veneer, cover in plastic, and then take my tractor and dump about three buckets of sand on the whole thing.
I have a vacuum pump and controller, just never got around to making a table and bag..........

[Chris Padilla]

The polyurethane glue, even if it bleeds through, will not interfere with any finishing. It is quite a remarkable glue.

I did a veneer on panel glue-up with Better Bonds and was experimenting with using canvas on the platens. The substrate was some 1/8" plywood from one of the borgs and some commercial (1/42"?) thin African Cedar veneer. Well, it came out wavy and bubbly here and there. A real mess to be honest. I rescued it with GG. All I did was smear it on the veneer and spread it with a roller and then put plastic over it and sandwiched it between two MDF platens and back in the vacuum press bag.

I pulled it out the next day and it looked much worse as the GG had dried to a pale yellow/brownish, opaque in most places coating. I then took a scraper and ROS and went to town to see what it looked like under the glue. It came out shockingly perfect. No more waves and bubbles...dead flat...and the finish took just fine. I was and am still amazed that it turned out so nicely. You don't even need to pierce any of the bubbles...the glue soaks through and will adhere.

[Peter Quinn]

Peter, what's the advantage of MDO over BB Plywood?

John

Its available at my local building yard and is a bit cheaper, but otherwise, not much IMO. The BB at my next nearest source is highly water resistant, so that's a fine choice too. As long as the substrate is very flat relative to its grain and rated for exposure it should work. There are marine grade fir plys that would probably work if available. I'm thinking you don't want anything whose grain might telegraph through the very thin veneers over time, and MDO sure fits that bill, but BB is not bad either.

[Kevin Jenness]

Aaron, our shop has done a number of doors with veneered panels as well as veneered slab doors. We typically use shopsawn veneers of 1/16-1/8" for durability. Keep in mind that a door exposed to the weather is going to need continual upkeep, and if the finish is not well maintained repeated sanding to bare wood over time for refinishng will jeopardize a thin sliced decorative veneer.

We typically use Extira as a substrate, but mdo would be a good choice as well and perhaps more available at local yards.

For adhesive, West system 105/205 is our standard, but it will bleed through thin veneer, and will also bleed through thicker veneer with steep angled fibers like the curly oak you are planning on. That should not be a problem if you follow up with an epoxy primer coat like West 207. Otherwise, you will be faced with a fair amount of sanding to reduce the bleedthrough prior to finishing.

Epifanes has proved to be the most durable marine varnish for us. It's not inexpensive, but the labor cost of maintaining a clear finished exterior door far exceeds the material cost, especially if the finish is not kept up meticulously. They offer a matte finish option if that interests you. Sikkens Cetol finishes are also worth looking into, as they are less laborious to refinish.

[Kelly Humphries]

I have a similar issue, but slightly different details and would appreciate any insight.

I have flat double entry doors, original to 1963 house. Interiors are in fantastic shape, but exteriors are sun facing and deteriorating. Have refinished several times but running out of good veneer, and it is splitting and opening. The doors are sun facing much of the time, but are protected from water with a large overhang except in cases of horizontal driving rain. I've been planning to re-veneer the doors with some mahogany veneer I picked up, but want to make sure I do this right.

A) Is this a good plan?
B) If yes, what type of adhesive would be best for this application? I've seen a lot of discussion that seems to center on either a good wood glue like Titebond III vs. epoxy.

New to the forum, so apologies for any missteps.

[lowell holmes]

See this link.

https://www.google.com/search?q=wood...hrome&ie=UTF-8