How To Insure Wood Movement Doesn't Ruin Your Project Author Johnny W. Morlan 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 the 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 make a sort of tack cloth by applying cleaner to a lint free cloth. Wipe the surfaces to be glued for better glue adhesion. I have found Acetone to be excellent for this, as it leaves no residue, does not raise the grain of the wood, evaporates rapidly and does no harm to the wood. I also use it in the same way, aforementioned above, before applying the first finish coat for better coating adhesion. 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} Aningeria 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 Apple Ash Aspen Arariba Balau Blackwood {African} Ben Se Chechem Curunai Curupixa Cuta Cypress Ebony {African} Flamewood Fang Deng Freijo 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 Seak Yew 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 21 years of woodworking experience {mistakes included} and working over 350 different species of wood. .