Need some help with wood movement

[Rich Bybee]

Hi all,
I'm trying to find online or book resources to learn how to deal with the expansion of natural hardwoods while designing projects.

I'm sure this has come up a dozen times, but I'm not sure of how to phrase the search request. Very sorry if this has come up repeatedly.

I'm new to woodworking, since a long ago woodshop class in high school, and I need to re-learn how to design around the natural expansion and contraction of hardwoods.

I have a new Powermatic 2000 tablesaw on order, along with a PM 15" planer and a PM 8" jointer and have MANY new projects that I'm all set to get busy on. I'm SO looking forward to getting started!!

One of the very big things I'm worried about is having my craftwork self destruct because I didn't factor in expansion of the wood while crafting my projects!!

OK, I'm a NOOB!

Most of my first pieces will be tables (sofa tables, end tables, coffee tables, dining room tables eventually)

Can anyone recommend a web site or books that can educate me about where I should worry about expansion and where it is not a problem?

Are there certain hardwoods that are more prone to expansion than others? I think most of my first pieces will be white oak, but it will expand after that to cedar and other woods.

Thanks so much for any responses!! :-)

Rich

[Micah Carter]

your biggest enemy is solid wood table tops... and the solution is table top mounting clamps. Rip a kerf in the the side skirts and install these guys instead of using pocket screws or other means of tabletop attachment...

http://www.leevalley.com/hardware/pa...586,43588&ap=1

[Gary Keedwell]

Hi there....If you go to a book store or library or maybe magazines...the plans that you find will more then likely be designed to allow for wood movement. Almost all plans have been proofed by wood worthy experts.
By the way...welcome to the best hobby and best site around.
Gary

[Rich Bybee]

Micah and Gary, thanks so much for the quick responses!! I already know this is the best site around, as I've been surfing for quite a while! You folks are so friendly!!

Micah, I'm kinda already sold on the figure 8 attachments, those look really nice!

My concern is when do I need to use them..... I kinda know I need them for solid tabletops.... Do I need to worry about them for table legs? Cabinet faces? Chair legs with a Mortice & tennon joints?

Thanks BUNCHES for the replies though!!!!!

[John Thompson]

Probably the best book on the market currently is Bruce Hoadley's "Understanding Wood". Richard Jones is currently working on a book that will deal more specifically with movement. He is a professional that had a custom furniture bussiness in Houston for years, but moved back to England to accept a WW teaching job at one of the English colleges.

Movement will vary depending on species used and the climate conditions in your area. I live in Atlanta and we have very humid summers with very mild winters. My experiences over the last 35 years would not be valid for say, someone in Seattle with the monsoon season or northern states with the much colder climates.

A good example is a bed about to be finished. We have had a basic drought in the deep south this summer. It rained Sunday and I saw a 2% increase in my stock just before I was to apply finish yesterday. I will wait a few days as we expect no rain and it will most likely be back to the 10% moisture mark tommorrow. And that's where I personally like to seal it at as it is a medium between 8% and 12%. Anything more or less.. I simply wait till it goes to that range.

Sarge..

[Rich Bybee]

Thanks for your input John, I'll try to find that book at the library and check it out! My main concern is that I don't build something SO tight that it self destructs the next time the weather changes!

Are there any general tips dealing with movement? Maybe leaving a 1/16" gap in joints?

I don't know.............As I said... I'm new to this.

Thanks so much for the info though!!

[Rob Will]

There are some very nice woodworking schools around the country that offer classes from one day, one weekend on up. Marc Adams has a school near Indy. Alan Turner has the Philadelphia Furniture Woorkshop (PFW).


Rob

[Jim Knishka]

Rich, "Understanding Wood" is a very useful book and I consult it regularly but it's focus is on wood characteristics and not so much joinery. The Taunton Complete Illustrated Guide series has two books I find especially useful - "Joinery" and "Furniture and Cabinet Construction". I also get use of "Tage Frid Teaches Woodworking" - especially volume 1 - Joinery.

You're investing a lot of money in tools - I'd recommend purchasing some books. You'll go to them often.

[John Thompson]

Thanks for your input John, I'll try to find that book at the library and check it out! My main concern is that I don't build something SO tight that it self destructs the next time the weather changes!

Are there any general tips dealing with movement? Maybe leaving a 1/16" gap in joints?

I don't know.............As I said... I'm new to this.

Thanks so much for the info though!!

Morning Rich.. The old adage I picked up in 1972 has some merit, but again depending on your local climate and species. "Summer.. build it tight-Winter build it loose", which in general is referring to having more moisture content in summer than the dryer winter months especially with heat running.

I use and find moisture meters helpful.. A Timber-check pin type when purchasing at my hard-wood suppliers and a non pin for shop and home in my case. They take some getting use to at first as you will always find end stock with more moisture than the stock when you read moving to the center. Most moisture enters through the end grain. You have to average.

I wouldn't be overly concerned with joinery with just the adage I mentioned above. Tenons won't move that much so tigth in more humid months to allow for loss latter in dryer cold months and vice-versa. Table tops or bread-board ends are more critical.

I usually make my own cleats. I just use a biscuit joiner and cut a series of slots in a 1" wide strip of hard-wood. Then cross-cut between the spaced slots in the series I ran the lenght of that strip. Glue an appropiate biscuit size in that slot and just cut a slot in the strechers latter that I will use them for.

I will make about 50 at one time... if you don't use them in the quantities I do, probably easier just to puchase the metal ones from LV or just simple L shaped brackets from the BORG will suffice. By no means major "rocket science".

Good luck and enjoy your new journey as pretty soon you will know how tight or loose from experience. Not too tight and not too loose.. Ya want it just right and eventually you will just know what "just right" is from sensing.

Sarge..

[Rich Bybee]

Morning Rich.. The old adage I picked up in 1972 has some merit, but again depending on your local climate and species. "Summer.. build it tight-Winter build it loose", which in general is referring to having more moisture content in summer than the dryer winter months especially with heat running.

Thanks John, that quote is exactly the sort of thing I was looking for!

I think I'll be ordering all three books from amazon tonight!!
"Understanding Wood" and the Taunton "Joinery" and "Furniture and Cabinet Construction" guides. Jim, thanks for the recommendations!

Rob, I don't have much in the way of woodworkers schools in my area (at least according to the yellow pages). I'll be winging it for a little while at least.

Thanks guys!

[Dave MacArthur]

Welcome Rich!
Building with white oak, you might consider using quartersawn wood (perpendicular to the rings)--it will expand/contract only 50% as much as flatsawn (tangent to the rings), and this is also the "mission style" look which is kind of the big white oak design.

When you build your pieces, you should be MOST CONCERNED when you ATTACH two pieces of wood together: look at it and say, does the grain on both pieces go the same way? Imagine a table top that was glued down (BIG no no!) to a 4-sided framework. The rails for two sides, probably the long sides of the table, would have the grain running the same way as the table top, right? Therefore they will expand/contract along with the top at about the same rate, and a glue joint would probably not cause problems. HOWEVER, what about the two cross supports at the ends? Can you imagine how the long grain of the supports would run ACROSS the grain of the table top? Wood doesn't stretch along the grain! That is, a tree stump doesnt get TALLER when wet. It stretches ACROSS the grain, so a board gets wider not longer. Therefore, if you were to screw/nail/glue the table top down at it's ends to a support, the table top would widen/shrink, but the support rail wouldn't. THAT is the thing you are looking for and trying to avoid. So, you don't attach it solidly, you use figure 8s, or pin one side and let the other float (a screw in a slot), or you use cleats as folks said up above.

MOST of the projects on New Yankee Workshop will actually have some wood movement techniques built into them, and you can learn from there also.

good luck!