Mahogany ” South America “
- Trade Names: Swietania Mahogany Crotch, Caoba
- Uses: Veneer, solely as face veneer in the furniture industry (main markets GB, USA), used for architectural woodwork and in the piano industry. Lengths generally up to 1,50 m.
- Properties: obtained from the forks of trees & produced on the slicer. Very often the crotches are open in the middle which makes them impossible to use. The coloring becomes beautiful with age.
- Seasoning: Drying causes considerable problems so Crotch must be dried slowly and carefully.it is essential to avoid direct sunlight & high velocity windows.
- Finishing: The wood stains, varnishes and polishes well but the resin exudation must be considered and washed out if necessary.
- Machining: Due to the growth form of the crotch the interlocking grain is still more pronounced which means additional problems when machining. Smooth surfaces can only be achieved at slow feed speeds
- Jointing: Mahogany Crotch is easy to glue and takes nails and screws well.
Ash Crotch ” Europe “
- Trade Names: Ash Curl, Ash Crotch, European Ash
- Range: Crotches from Ash trunks are very rare.
- Uses: Architectural woodwork and single projects.
- Properties: The frequently occurring brown heartwood in Ash is generally found in the crotch. It is more or less distinctly developed & leads to very expressive patterns and textures in the veneers
- Machining: Mechanical machining of Ash can be carried out easily and well with all tools. Coarse grown trunks tend to split at planed edges. Surfaces can be made very smooth.
- Seasoning: Due to tension caused by its crotch growth, drying in particular involves a greater risk of degrading through splitting. Only slow and careful drying can reduce this risk.
- Finishing: Ash is suitable for all kinds of treatments and especially colored stains are used. Easy application.
- Jointing: Ash takes glue well and provides very durable joints. Pre-drilled screw joints hold well.
Cerejeir Cotch ” South America “
- Range: Limited to Argentine and Brazil, particularly in the Amazon basin. Logs as such are unknown in Europe, crotch wood is imported in small quantities, however.
- Uses: Architectural woodwork, more popular in the USA than in Europe.
- Properties: Diffucult to slice. Some rough patches are almost impossible to avoid.
- Machining: Due to the interlocking grain machining calls for a slow feed speed. Planed surfaces are slightly rough and have to be sanded down.
- Seasoning: The tendency to check is particularly apparent with this species of wood and can only be reduced by careful drying.
- Finishing: It is easy to treat the surface of this wood with all finishes. For external use open pore varnishes are used, for the interior, varnishes and mat finishes are applied.
- Jointing: Glue joints hold firmly, screw and nail joints are very durable.
Oak Crotch ” Europe “
- Similar woods: Cerejeira Crotch
- Range: Oak log crotches are very rare.
- Uses: Architectural woodwork.
- Properties: Very difficult to slice, very often with open crotch.
- Machining: Despite its hardness Oak can be worked well with all tools. Planed surfaces are very smooth. Molding and turning produce good results.
- Seasoning: The growth form of the crotch is most problematic for drying. Splitting due to tension is almost not to be prevented.
- Finishing: Oak takes all surface finishes well and treatment presents no problems.
- Jointing: Glue joints are durable. Screw and nail joints hold firmly but can cause wood staining under the influence of moisture.
Sycamore Crotch ” Europe “
- Trade Names: Sycamore Crotch, English Sycamore Crotch
- Similar woods: Beech Curl, Beech Crotch
- Range: Branch crotches of Sycamore logs, extraordinarily rare in pieces suitable for veneer, very often the crotch is open.
- Uses: Architectural woodwork. Since this wood is only available in small (max. 1,20 meter) lengths and very rare, only usable for single projects. No mass-produced furniture possible.
- Properties: The wood is almost white. The veneer has to be dried quickly after slicing, otherwise it yellows when exposed to light and air.
- Machining: The various directions of growth must be observed when machining.
- Seasoning: Great attention should be paid to the figuring when drying. Only extremely careful drying can obviate tension checking, caused by the different directions in shrinkage.
- Finishing: Sycamore Crotch is excellently suited for polishing and staining. To prevent premature yellowing, UV-resistant varnishes are recomended.
- Jointing: Wood joints are easy to produce with glue, screws and nails and hold well. Pre-drilling is to be recommended when using screws.
Walnut Crotch ” North America “
- Trade Names: Walnut Crotch
- Origin: North America (Juglans nigra) and very seldom in Europe (Juglans regio).
- Range: Branch forks of Walnut trunks.
- Uses: Architectural woodwork, upright and grand piano production, gunstocks.
- Properties: Lengths over 1 m very seldom, often open in the crotch.
- Machining: The wood is easy to work with all hand and machine tools. Walnut is excellent to mold. The direction of growth must be observed to prevent fibre pick-up.
- Seasoning: Drying has to be carried out with particular care where the Walnut Crotch is concerned so that no tension checking occurs in the crotchy part.
- Finishing: The very smooth wood takes all stains well particularly water and nitro stains. The wood polishes well when fillers are used.
- Jointing: Joints using screws, nails and glue are easy to produce and are of normal tensile strength. However, alkaline glues can cause reaction stains.