Whats best Air dried or Kiln wood

[OneEyedBint]

I am a new member hello everyone. I am wanting to know before i start any building work is there anything wrong with using air dried timber.  I have some beach wood planks that have been air dried for about 18 months. My Question is is there any reason why i should not use this wood ? I also have air dried castillo wood.

 

My concerns are you have experience and will know the risks of timber twisting or bending and as i am wanting to build my first ship please tell me your opinions and advice on your experience of  Air dried or Kiln dried wood ??

 

Thank you.

[Charter33]

Hi and welcome to this highly informative and supportive site!

It's been my experience that there is little difference in working with wood that has been kiln dried or air dried as long as it has been done sufficiently in the case of air dried. As a rule of thumb it takes about a year per inch of thickness. Poorly seasoned wood will very likely warp, twist or split. Kiln dried tends to be more expensive because of the higher energy costs involved (plus all the possible associated environmental impacts). There is more control over the final moisture content however, and the process is much quicker - months rather than years. Producers often use a combination of the two forms of seasoning to balance cost against time.

Just one other point to consider - kiln dried timber can have a different appearance to air dried. Beech in particular can take on a 'pinker' colour when kiln dried compared to a 'creamier' finish of air dried. This has something to do with the steam that is pumped into the kiln initially to deal with any insect or fungal issues prior to the main heating to reduce the moisture content I think.

Hope this helps.

Graham.

[Bob Cleek]

Air dried is preferred, actually, particularly for steam bending, although sometimes with some species there's little or no difference between the two. That's especially true for the small sizes used in modeling. If wood moves when drying, you'll know it.! Keep mind, though, that dried wood will also sometimes move after it is cut, owing to stresses that are released when the parts are cut. The general rule of thumb for air drying wood is one year of drying for each inch of thickness of the thinnest dimension. Thus, a one inch thick plank should air-dry for at least a year. It sounds like you're probably good to go with what you've got.

 

 

[Griphos]

All wood will twist and bend under the right conditions.  Kiln dried lumber can be egregious about twisting and bending.  

 

This varies, in part, by the kind of wood and the conditions in which it has been dried, the moisture content to which it has been dried at its driest, and the consistency of that moisture content throughout the board.  Some wood, like mesquite, hardly moves at all with changes in humidity or temperature.  Other woods move a fair bit (like soft maples, and even some hard maples).  Depending on how you stored it and the environmental conditions, 18 months may or may not be enough time for it to become as stable as possible.  A good moisture meter will help you assess that.  But, if it hasn't moved much (no real twisting or bending) so far, that's a very good sign.  

 

However, as Bob mentioned, stored stresses in a given board can create some twist or bend when released by recutting, so milling your boards into sizes you plan to use will tell you a great deal also.

 

At 1:1 scale, for making furniture, I much prefer the air dried wood I have harvested myself (walnut, cherry, mesquite, maple, etc) over kiln dried wood.  The air dried wood simply works differently, and better.  I am tempted to use the word "alive" to describe it.  Both the way it responds to tools and its surface after tooling is clearly superior.  Kiln dried wood has been steamed, and that definitely changes the composition of the wood, I believe.  

 

At model scales, I'm not sure there would be as much difference in workability, but others with more experience will surely chime in.  

 

 

Edited March 27, 2019 by Griphos

[OneEyedBint]

Well I have spent a few days just trying to find this out and have had very little success. I should have asked people on this forum much earlier. Yes you have answered what I was wanting to know.  

 

Thank you

[grsjax]

Air dried or kiln dried wood should be allowed to sit in your work area for several months to acclimate to the humidity in your area.  If you use wood that is to dry it will absorb moisture from the air and if it is to wet it will lose moisture.  In either case you can get movement.  Let is sit for awhile to adjust to your local conditions and you will have fewer problems.

[vossiewulf]

Improperly kiln-dried wood (lumber yards will dry boards too fast) is the type of wood most likely to have stored internal stresses that will manifest as reaction wood, i.e. wood that visibly bends as it is ripped, frequently binding the saw blade being used. The other source of reaction wood are trees that grew on steep slopes, so one side of the trunk is under significant tension while the other side is under compression. That kind of reaction wood can have boards hugely sweeping as they are ripped.

 

If you've never had the wonderful opportunity to rip some reaction wood on a 5HP table saw, you've missed a chance to be at least scared to death, if not had that fear justified by having the whole board thrown back at you at high velocity. I had a case of the latter and have a nice scar on my hip as a result.

[OneEyedBint]

I have not even thought about that. The conditions the tree was growing in in the first place. Thanks

[mtaylor]

An excellent warning, Vossiewolf.  Kickbacks are very frightening and very dangerous.  Even standing off the side when one kicks can miss you but punch holes in walls which I had happen once.  

[Roger Pellett]

Standing to one side of a table saw ripping lumber has its own problems.  If by doing so you can’t use a push stick and the wood kicks back there can be nothing keeping your hand out of the blade .  I have severe nerve damage in an index finger and a scar on the middle finger from such an incident.

 

Roger

[mtaylor]

Push sticks, in my opinion are mandatory.   I also use feather boards.   I got lucky and had one kick back early on and it embedded itself in the wall about 10 feet from the saw.  Note that this is a MicroMark table saw.  The full size ones I left the anti-kick assembly on the saw and still stood off one side. 

[vossiewulf]

The only safer table saw is the Sawstop. And it's expensive, and you can't cut anything but fully seasoned wood on it without risking the wood's moisture tripping the electrical resistance detection mechanism for bits of human bumping into the blade. When that happens you have to buy a whole new safety mechanism as it's destroyed in stopping the blade near instantly.

 

And it doesn't stop kickbacks at all.

 

Real table saws are just damned dangerous devices and when they get up into multi HP you should have giant heaping heaploads of respect for the machine before trying to operate it. I always force myself (ditto with shaper/jointer/any serious machine) to take a deep breath and look around and confirm again I know what the hell I am about to do before turning on a table saw. I worked for 5 years building custom furniture and had more than a few close calls and bad events. I still have occasional nightmares about the time I was tapering a table leg and the wedge-shaped cutoff dropped into the tiny slot next to the blade and bent it toward the work, and suddenly I had a 5hp saw trying to throw the whole taper jig at my face and only my full weight on it was barely stopping that from happening, and I couldn't remove a hand to reach the emergency cutoff. I don't know how long it really lasted but to me it was a very long time before a guy on the other side of the shop recognized the sound of the saw binding and came running to shut it off for me.

[OneEyedBint]

Thank you everyone for your advice i will take heed to your warnings on using saws.

I am a 1st time builder of any ship and i am going to scratch build the Harold Underhill brigantine leon. I have not even built a kit ship before.

I would like to then build a scratcjlh built 60 gun or 74 gun ship of course depending how i go with tlthe brigantine leon. I have both of underhills books and a set of his ship plans.

 

Thank you