Acclimation: The best way to protect your investment

(This is a reprint of an article posted last June. It bears repeating, as it's the primary insurance of a quality installation.) Too often in the contracting field, unnecessary and easily avoidable errors are made due to deadlines and impatience. I’ve been a culprit of this myself. Needing to have a job done by date X, corners are occasionally cut, and it almost always shows.

When a commitment is made to a high-end decking material such as Ipe, Cumaru, or Tigerwood, it’s essential to remember that with the solid durability and resilience of these species come a few concessions. The most important allowance any contractor or homeowner can make to assure the highest quality installation is proper acclimation of the building materials.

If I were contracting an exterior siding or decking job, I would certainly allow the delivered wood to be sorted, spaced, and stacked with adequate spacing to assure proper air-drying for all four surfaces of the material. Cover it, forget about it for a week or two. Catch up on some other projects. It’s so easy to get anxious for delivery of the stock and immediately start pounding through the inventory to finish the contract. Sooner than later, this oversight will show up.

It doesn’t always necessarily happen. But I wouldn’t want to assume the risk of anything but the highest-quality installation. If the homeowner/project manager is already investing several dollars per square foot for a high-end material, the project should likely be budgeted to allow for this crucial acclimation of the lumber. Especially in the instance of finish boards, risers, skirt boards, and other applications which require direct fastening and/or plugging, having as close to a fully acclimated lumber member will prevent splitting from shrinkage or swelling of the stock when it has not yet fully adapted to the local climate.

Less splitting, a truer feel of the finish presentation of the product, and a happier customer are what can be gained by simply exercising just a bit of prudence, and sometimes allowing a job a week or two allowance providing the stock, the builder, the architect, and the homeowner a proper chance at the highest-quality overall installation.

Know your wood: African Rosewood

African Rosewood

This is a pretty good image showing the coloration and complexity of African Rosewood. Lots of color and interesting features in this species.

Trade Names: African Rosewood.

Taxonomy:
Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Rosidae
Order: Fabales
Family: Fabaceae – Pea family
Genus: Guibourtia
Species: coleosperma

Janka Hardness (pounds-force): 2090

Description: Grain is anything from straight to highly distinct and rippled. African Rosewood can have some very interesting featuring, depending on the tree and the cut. Generally speaking, however, African Rosewood is less figured than Bubinga.

Location: Southern Africa, namely: Angola, Botswana, Cameroon, Swaziland, Zambia, Zimbabwe, Namibia.

The seed pods and foliage of an African Rosewood are featured on this Namibian stamp. Follow this link if you are fluent in Japanese and collect stamps for presumably much more information.

Common Aliases: Bastermopane, False mopane, M’chibi, Machibi, Mtjibi, Mucibe, Muxibe, Muzauri, Rhodesian copalwood, Rhodesian mahogany, Rhodesian teak.

Performance: African Rosewood generally saws without difficulty. It is a very durable wood, and is better than average in resistance to insects.

Affordability: $$$$ Cheaper in Europe than in the United States. Deals can be had in purchasing African rosewood, but timing is everything with this import.

Common Uses: Tools, agricultural implements, boats, cabinetry, veneers, flooring, fine furnishings, heavy construction, plywood, railroad ties, turnings, wheels.

From: The Wood Explorer:
Common Name(s): African Rosewood
Scientific Name: Guibourtia coleosperma
Distribution: Central and southern Africa
Tree Size: 35-70 ft tall, 1-3 ft trunk diameter
Average Dried Weight: 46-52 lbs/ft3
Basic Specific Gravity: .66
Hardness: 2,090 lbf
Rupture Strength: 14629 lbf/in2
Elastic Strength: 1,326,000 lbf/in2
Crushing Strength: 7,260 lbf/in2
Shrinkage: Radial: 3%, Tangential: 7%, T/R Ratio: 2.33

Know your wood: Purpleheart

Purpleheart

There is a good pictorial detailing this purpleheart guitar’s construction here. I imagine there might be a candle maker’s tutorial, as well?



Trade Names: Purpleheart , Amaranth

Taxonomy:

Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Liliopsida – Magnoliopsida - Dicotyledons
Subclass: Rosidae
Order: Fabales
Family: Fabaceae - Pea family
Genus: Peltogyne
Species: porphyrocardia, venosa, paniculata, and others.

Janka Hardness (pounds-force): 2390

For all you botanists out there, Peltogyne paniculata, according to Wikipedia.

Description: Purpleheart refers to many of the species from the Genus Peltogyne. When this dense tropical hardwood is sawn, the heartwood appears dull gray/purple-brown, but when exposed a bit, turns into a vibrant hue of purple. Over time, this color can fade, but the striking violets can be somewhat retained using a high-quality UV inhibitor. Purpleheart has generally straight grain, but irregularities are common. Texture is medium, pores are tight.

Location: Central and South America, namely: Bolivia, Brazil, Colombia, French Guiana, Guyana, Mexico, Venezuela, Suriname

Further information on Purpleheart found here, as seen in the Wood Explorer database.

Common Aliases: Amarante, Amaranth, Barabu, Bois violet, Ellongrypho, Kooroobovelli, Koroborelli, Lastan, Morado, Palo morado, Pao violeta, Pau roxo, Pelo morado, Saka, Sakavalli, Violetwood.

Performance: Purple is very durable against rot and insect infestation. Keep your tools sharp when working purpleheart, as the wood becomes gummy when it becomes too hot. Like I said before, it’s an interesting wood…

Affordability: $$$ Purpleheart is a relatively affordable and widely available specialty wood in the United States.

Common Uses: Audio equipment, billiard cues, bridges, millwork, skis, sporting goods, wharf construction, specialty guitars, veneers, furnishings, cabinetry, small wooden craft items.

From: The Wood Database:
Common Name(s): Purpleheart, Amaranth
Scientific Name: Peltogyne spp.
Distribution: Central and South America (from Mexico down to southern Brazil)
Tree Size: 100-170 ft (30-50 m) tall, 3-5 ft (1-1.5 m) trunk diameter
Average Dried Weight: 61 lbs/ft3 (980 kg/m3)
Basic Specific Gravity: .79
Hardness: 2,390 lbf (10,630 N)
Rupture Strength: 22,000 lbf/in2 (151,700 kPa)
Elastic Strength: 2,586,000 lbf/in2 (17,830 MPa)
Crushing Strength: 13,350 lbf/in2 (92.1 MPa)
Shrinkage: Radial: 3.2%, Tangential: 6.1%, Volumetric: 9.9%, T/R Ratio: 1.9