Kiln Dried Timber: Is It A Failure?

[@thomo74]

Thank you for taking the time to explain this. There is a lot of science behind drying I never knew.

[@DTJoinery]

Not a problem. Thanks for watching😊

[@justcruisin109]

I prefer air dried timber as well although I’ve had that pretzel on me as well but generally it’s a better product. Thanks for sharing your thoughts. Cheers

[@DTJoinery]

Yeah, it's not perfect, but I believe it to be superior. It is also better on the lungs, the kiln dried timber, the dust is so fine.

[@brycecomerwoodworks]

Hi Gary, Interesting you are having the same issues as i am. I'm inland Western Canada. Our humidity levels are all over the place depending on the season. I typically get my KD timber at about 7-8%. I do have the same issues with Doug fir splintering, and hate working with it for that reason. Oak is another one i have issues with checking throughout the boards. I have had material come in where most of it has this issue. I'm not sure if this is simply a trait of oak from North America, but i just don't remember seeing this until fairly recently. I am very out of touch with drying procedures, but it would seem to me they're doing things differently to what used to be done. I don't remember having this many issues even just 20 or 30 years ago. Are they even seasoning it anymore before starting the drying process? Like i said, something has changed. Oh and don't even get me started on how much things move when resawing, i'd be lucky to get one board out of 10 actually remain straight if i have to resaw a bunch of boards! Thanks for the video.

[@DTJoinery]

Totally agree. It sounds like it is pretty universal. It does seem to be a lot worse than it used to be. Perhaps, as another person mentioned, it's the age of the trees being cut. It's hard to say for certain, but kiln drying certainly is a big part of it.

[@brycecomerwoodworks]

@@DTJoinery Hmm, the age of the trees may well play a part in it. The old growth trees, tend to have tighter growth rings, & maybe the way it dries so fast in a kiln results in stresses between the summer and winter growth? Cancel Reply

[@DTJoinery]

@brycecomerwoodworks There is definitely a huge difference between old growth and modern timber. I have a lot of very old timber here that was cut in the 60's-70's and it is vastly superior timber. It may well just be a combination of all these things combined. Funny enough, the laminated timbers are much more stable.

[@brycecomerwoodworks]

@@DTJoinery Yeah, i don't build exterior doors any more without at least laminating boards together. I don't usually go to a full stave core, as i find 2 or 3 laminations works very well and stays dead straight. We are still cutting old growth Douglas fir here in BC, but a lot of it still moves a lot when resawing, so it just has to be the way it's dried.

[@Dazza19746]

All the time, it’s a nightmare. Even in accoya it can happen 🤷 I usually get a ‘feel’ for how it’s moving and over cut based off that , ie. skim face and edge and leave a bit of time .. then repeat… and if it seems to have settled down I’ll thickness. Even then sometimes I’ll pop it on a pile on jointer over night‘weighted’ Worst I ever had was a couple of cube of ‘thermally modified hemlock’. At least 60 percent was shot to shit inside / totally unusable from about 3 mm in the whole way, it was shocking. Some you could pick the cell collapse just looking at it in the rough!! But some caught you out. The most annoying thing was the ‘good stuff’ was fantastic !

[@DTJoinery]

@Dazza19746 So irritating, so much good timber ruined. They need to come up with a better drying method, or at least slow it down.

[@eggsoups]

East Coast of US here. Our kiln dried hardwoods are usually around 12% moisture content and rarely are there any major issues if the wood is allowed time to acclimate in the shop or on the job site (if used as trim/flooring for example). Not all kilns are the same but timber can be ruined in any type of kiln. 🤷‍♂️ I do prefer air dried timber and most people will agree air dried timber behaves better when steam bending. We have very humid summers here and very dry winters indoors with heating so a lot of seasonal movement to account for with panel doors etc. I wouldn’t be surprised if timber meant for export is processed differently

[@DTJoinery]

@eggsoups That is interesting, as all the US species that come here are around 5-6%. I wonder who it's dried for at that level? Thanks for sharing.

[@verymadmango]

What do you mean by dressing the wood at 4:15? I haven't got a lot of experience with resawing 😄

[@DTJoinery]

@madmango6705 We buy our timber in rough sawn and size and mill it to the sectional sizes we need. During the process of doing this, we can and do experience the material bowing, twisting, etc, after we have straightened it. Hope that answers your question.

[@verymadmango]

Thank you!

[@DTJoinery]

@@verymadmango No problem.

[@johnsykes5464]

Kiln dried is shocking Gary, Ive experienced problems a few times now when machining timber thats been kiln dried. Ive had a similar situation when i was once ripping some 'kiln dried' sycamore, soon as it hit the riving knife it went all over the place, 3 lengths of timber shot to shit and unusable. Where i work now ive had the same problem with the steamed beech we use, wants to go back in on itself and hardly ever straightens out. I jump for joy when i get straight lengths! 😅

[@DTJoinery]

It's frustrating, so much timber goes to waste as its just too crooked to use.

[@brycecomerwoodworks]

Just another thought. With kiln drying, you pretty much guarantee that any bugs and borers will be killed off. This is likely a huge part of why you can't buy exotics that are air dried.

[@DTJoinery]

Had never really thought about that, good point.

[@joshuahayes1272]

I’m in Florida which has a fairly similar climate to what you’re describing and I do experience some of the issues you’re having but it seems like it’s less frequent. The KD process in the states actually produces lumber to 10-12%, however, the European standards are closer to 5-8%. When you you get your American white oak, is there any chance it’s going through Europe or is it straight from the states?

[@DTJoinery]

@joshuahayes1272 I'm not really sure about that. It's certainly possible given the distance.

[@kimjohnston417]

I wonder how much is due to the timber coming out of plantations or regrowth. Looking at the growth rings on a lot of stuff, it’s not going to respond well to kiln drying.

[@DTJoinery]

Yes, certainly would have some degree of effect. some very young trees being cut.