Wood questions.

[lcm1947]

I am just getting into working with hardwood so am not real knowledgable about this topic so bear with me if it's real basic info that everybody should know. I plan on buying some boards for a project and will stow them for however long and worried about them warping or whatever boards do. Now that I've started thinking about it I don't know that I've ever never ever seen a truely straight board. Course now I've never seen anything other then what the big box stores carry so may have a very limited experience but never the less I am worried about buying all this wood and it warping on me. Any advice, suggestions or even comments would be welcome. My gar age is full of tools so don't have room to build racks and such so thought I'd put the load in the spare bedroom but then would I have a problem when I use it. Questions, questions and questions.

[kwgeorge]

The issue with wood warping is due to the woods cell structure collapsing and changing as the wood loses water while drying. Without going into great detail you can think of the internal structure of wood to be something like that of a sponge. End grain will absorb and release water much faster than the long grain and that is why you will notice that a lot of the rougher saw wood you may buy has coated ends.

Now I know that most people who purchase wood from the big box stores expects that it is dry but this is not necessarily a good assumption as the wood may have spent some time in the elements. Locally we have a company that receives construction grade wood shipped in from trains and it is nothing to see these huge stacks sitting outside unprotected awaiting trucking to their final destination. Even though this wood was kiln dried originally after being exposed to the elements it is again wet and subject to warping as it dries. A couple years ago I knew of a custom home builder that built a house with such wood. In a matter of months some of the walls bowed out to the point of breaking brick and sheetrock. They ended up being sued over it by the new homeowner.

I think it is very important that everyone own a moister meter of some kind. They are relatively cheap now and easily obtainable. You should always check the moister content of your wood prior to using it. I store most of my wood in my garage as my shop is separate and too small for storage. Most of my wood is stored standing up on end and is pretty safe from the elements. If I get wood that still has a high moister content I will store it flat and use stickers between the boards until it dries to a level of moister relative to its surrounding humidity. I think you will be fine storing yours in the house and again the amount of warping will depend on the surrounding moister levels and by what degree that changes and how wet it was when you originally purchased it.

Ken

[lcm1947]

Thanks for the reply Ken and hopefully if you are still watching this post I'd like to ask you a couple specific questions. I just bought this 6' pine board 1x4 and at the store. It was fairly straight ( no bow ) so thought it good enough to practice on. Well got it home, cut it in two and the very next night noticed one of the two pieces bowed. I guess you call it bowed if the board raises up on the ends. Anyway I was just practicing and being Pine not a lot of money but I can just see my assortment of lumber I'm fixin to buy doing that and it scares me. So you just take your chances whether boards will warp or bow etc then? This particular board was actually lying flat on my work table and still did it. I know a lot of people store lumber and surely it doesn't all warp or bow?

[kwgeorge]

You have another issue to contend with in wood and that is internal tension. It has been discussed a few times around here but simply put this happens typically when a board has a section of highly figured grain or grain inconsistencies. Basically these areas have a tighter more dense grain than the area surrounding them. I see this quite a bit in Walnut so normally I cut my pieces oversized and then let them stabilize awhile and finally cut them to what I desire.

A lot of people here have probably experienced a board either bowing away from the kerf or closing at the kerf while cutting on the table saw. If you look closely at the board you will often notice that this happens to the board on the left of the blade much more that the piece closest to the fence. This can be caused by many factors such as tension in the wood, the wood not being sufficiently dried or even having various moister contents throughout the length of the board.

Wood does some strange things and that is all part of working with it. Many people have made quite the studies of wood trying to understand it. One of the best books I have ever read about wood is by Bruce Hoadley and called “Understanding Wood: A Craftsmen’s Guide to Wood Technology”. This book is really helpful in the pursuit of woodworking and understanding why it does what it does.

Things that will help you are 1) Use a sharp blade when making final cuts. 2) Get your feed speed right. If you feed to slow you will burn the wood and heat will be your enemy but if you feed to fast you will have issues controlling the cut and other problems. 3) Learn to read the grain a bit. If you have a board that the grain seems to be tight on one side but not of the other then try and adjust your cut accordingly. 4) Try rough cutting a bit oversized and then let the wood sit for a bit. I have several pieces I cut earlier today awaiting my attentions tomorrow.

Hope that help a bit.

Ken

[Knottscott]

Even "straight" boards aren't often truly flat...that's where a jointer comes in. A handplane, or a planer sled can help flatten boards too, but nothing is more efficient or effective than jointer for flattening a face and squaring an edge.

[lcm1947]

Thanks for the replies. I'll try finding that book by Bruce Hoadley. Sounds like something I need to learn a lot more about. Thanks. Dustmight I know I need a jointer but it's just not in the near future so I am trying to get by by learning to route an edge joint but what I'm really asking is is it possible to buy S4S wood without it warping, bowing or cupping once you get it home and stored waiting for a project. I assume it has to be but this incident with this Pine board I bought and it bowing over night has got me concerned about buying $100.00 worth and it doing the same thing. Now what I'll be buying is Red Oak and maybe it doesn't act like Pine so just wondering.