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Engineered Stiles out of Accoya3/1/20
Has anyone made engineered exterior door stiles & rails out of Accoya ? I have had great results using it for gates and exterior balustrades.
Whats engineered mean?
"Engineered" is a meaningless marketing term invented by the plastic/metal door industry to denigrate wood doors while elevating the fake wood doors with buzzwords like 'engineered". Add it up over the years, and I'll guarantee there is far more "engineering" in solid wood door stiles than there is in composite wood stiles.
Tell me, who is the engineer? What calculations did he do to make the stiles? How do those calculations help make a better door?
I have wanted to try Accoya, but can't seem to find a wholesaler/retailer to sell it to me. I can't even get pricing.
If I could, I'd build 3 doors - one in pattern grade Honduras, one in Accoya and one in Thermally Modified wood. Then, I'd watch.
I picked up the term "Engineered" from this forum; not sure of its origin. Stave core is more accurate but I thought most people would be more familiar with engineered. I build my gates out of solid Accoya which is flatsawn. I would prefer to have the flatsawn turned 90 degrees so it becomes more ridgid lengthwise ( as in V/G Fir) Thus the desire for the stave core application. Doors have been built this way starting in England around 1911. The only difference was that they would mill teeth into the stave faces and also corresponding teeth into the backside of the skin faces so they would interlock when glued and clamped. They considered them to be of Premium quality.
I've built a few exterior doors with stave core construction. I see why you would consider Accoya for the core because of it's very low seasonal expansion. I used LVL for a couple of stave cores for the same reason.. They worked fine for the stiles but the outside veneer on two of them with 12" bottom rails split right in the middle. I think it's because the LVL has so much lower seasonal expansion/contraction than the 3/16 - 1/4" veneer glued to it. The split in one with Sapele is so small that I didn't need to repair it. That door faces West and gets direct sun, rain, etc. The other with white oak veneer was very noticeable so I replaced it (not an easy task) with a poplar core and have had no further trouble with it. It didn't help that the door faces directly south and gets direct sun on the lower half.
From then on I've used wood stave cores, white oak, poplar, white ash. I finger joint a piece of whatever the outside species is to the ends of the staves. The exposed edges of the core get a 7/8" thick piece of show wood, too. No more troubles but the oldest is only about 5 years, not 5 centuries.
I typically stay away from LVL for exterior doors; they just don't like moisture. I had a similar experience with cracking and cupping. I always make my stave cores out of the same species as the face veneer to keep the potential movement the same. David: are you finding Pattern/Genuine Mahogany easy to find where you are ?
Gary - Yes, stave core is the better term, I feel. With those older English door stiles, how thick were the faces with the milled teeth on the back? I can see how that would increase glue surface. Always a desirable result.
I have used pattern grade Honduras from the same vendor, my favorite, for 50 years - Charles F Shiels & Co. Not many of their customers are still using it, but they still buy on the docks in Louisiana and dry it themselves. It is expensive and still not coming from Brazil. Most of what we see now is from Peru. The drawback is a wider palette of 'normal' color.
I have found that South facing doors do not get the same intensity of solar radiation that West and East facing doors get. This is due to the angle of the sun in the Southern sky. It hits the door at an angle, and this angle is not as detrimental as when the sun strikes the door directly, close to 90 degrees from the surface. We have replaced panels in East and West facing doors, but none on the South exposure. The replacements were necessitated by TBIII glue failure.
engineered: skillfully and deliberately arranged rather than arising naturally or spontaneously.
You can engineer a good meal, you can engineer a coup d'etat, you can engineer a door stile. Just saying!
LVL is compressed under extreme pressure, any slight humidity change will cause those fibers to expand and result in split veneers. Many production companies using lvl will have a small thin layer of a melamine product between that and the veneer to prevent splitting. Also most of those doors are narrow stile patio type doors. We have access to accoya but have yet tried to glue up one in a stave or engineered type core, on the list to do. Makes great exterior soffit material!!
Theoretically, LVL manufactured perfectly with the correct amount of force would have exactly the same coefficient of contraction/expansion due to moisture as the same piece of solid wood. Pine will move way more than your saeple.
As Gary & Am noted itís been compressed and isnít some perfect piece of lumber. Go on a job site and look at an LVL. Itís not the same as the stock we buy for doors, but itís not really different.
Was your comment to me Adam? Sapele has a dimensional change of 4.8% radially, exactly the same as white ash. Yellow poplar is 4.6%, white oak is 5.6%, eastern white pine is 2.1%, while Ponderosa pine is 3.9%. I'm not sure what LVL is at the moment, but since I switched to yellow poplar and white ash I've had no more problems with Sapele in stave core construction.
The times we've used Accoya for exterior door/facade applications, we've never applied a face ply. We laminate, mill and use Klima or Milesi for tinting and top-coating.
The attached photo is a job we completed about nine months ago: 150 folding doors, 1m wide x 3m tall. The stiles were of three laminations, finished to 60x90mm. Adhesive was Aerodux resorcinol.
Re adhesive, we've since gone to a Franklin product: Advantage EP-950A as it's more user friendly.