How To Insure Wood Movement Doesn't Ruin Your Project

I place each species of wood into one of four wood movement categories, they are minute, small, average and great.

Woods should be glued {laminated} whether edge to edge, face to face or edge to face only to other woods within the movement category they are in. Then if the piece is moved to a different environment the woods will expand and contract at approximately the same amount insuring that there will be no unnecessary stress and tension on the glue joint or either piece of wood, which could cause damage {cracks} to the weaker wood. The exception to this would be if using very small pieces of wood. Take for example cigar humidors they are normally lined with Spanish Cedar, which is in the minute wood movement category. When wood from one of the other movement categories is used for the box the Spanish Cedar lining should be left floating or be slotted and stainless steel screws used to affix it. In this way the two woods can slide along one another resulting in no damage to the humidor when it expands and contracts.

You should make a project {all parts} from one length of lumber, larger projects from wood that comes from the same bundle and same business. Even within a species pieces of wood will vary in specific gravity {from different areas of country or world} causing them to expand and contract at different rates.

When gluing wood together {especially oily exotics} you should blow the piece off with compressed air {100 PSI} first {safety note: be sure to wear a high quality respirator mask.} This works especially well with opened pored woods to get the dust out of the pores. Then wipe the surfaces to be glued with a cleaner for better adhesion. I have found Acetone to be excellent for this, as it leaves no residue, evaporates rapidly and does not harm the wood. In fact I also put it on a lint free cloth and use it as a tack cloth after I have blown the piece off with compressed air and before putting the first finish coat on.

All glues have cons; it depends on what cons you want to live with. I have found polyurethane glues work exceptionally well especially on oily exotics. They are very flexible and expand and contract well with joints.

The Four Wood Movement Categories With Some Woods Listed Follows:

Woods In Minute Wood Movement Category

Alder {Red}
Aniegre
Antiaris
Balsa
Bamboo
Basswood
Camphorwood {East African}
Cedar {Spanish}
Cuchi
Curupay
IPE
Jequitiba
Maracaibo Boxwood
Padauk {African}
Pear
Pine {Yellow}
Rengas
Rosewood {Indian}
Sen
Tatajuba

Woods In Small Wood Movement Category

AppleAsh
Aspen
Arariba
Balau
Blackwood {African}
Ben Se
Chechem
Curunai
Curupixa
Cuta
Cypress
Ebony {African}
Flamewood
Fang DengFreijo
Goncalo Alves
Guatambu
Honey Locust
Hug Lon
Jelutong
Kaki
Kauvula
KOA
Makore
Maple
Mesquite
Muhuhu
Nontsia
Ochoo
Pecan
Prima Vera
Purpleheart
Rosewood {Brazilian}
Rosewood {Cocobolo}
Rosewood {Honduras}
Sarari
Sassafras
Satine {Bloodwood}
Satinwood {Ceylon}
Redwood
Ta Baek
Tarara Canarywood
Teak
Tulipwood {Brazilian]
Walnut {American}
Wenge
Willow
Xang SeakYew
Zebrawood

Woods In Average Wood Movement Category

Akossika
Andiroba
Bayo
Beech
Berkung
Blackbean
Butternut
Cancharana
Chakte Kok
Chakte Vega
Cherry
China Berry
Chinkapin
Ebony {Gaboon}
Elm
Hackberry
Indian Laurel
Jabin
Katalox
Kapur
Lacewood {Australian}
Lam Nhai
Leng Man
Lignum Vitae
Maple {Hard}
Machiche
Morado
Oak {Red}
Oak {White}
Paela
Paldao
Palm {Black}
Peroba Rosa
Poplar
Pyinkado
Rimu
Sapele
Snakewood
Sycamore
Taun
Tchitola
Walnut {South American}
Yom Hom

Woods In Great Wood Movement Category

Beli
Birch {Yellow}
Ekki
Esia
Gum {American Red}
Holly
Hornbeam {European}
Pink Ivory
Karri
Keruing
Olive {East African}
Ramin
Rata
Stinkwood

The information in this article is taken from my notes of 18 years of woodworking experience {mistakes included} and working over 350 different species of wood.