Humidity and its effect on various species of wood
The materials required for this science fair project:
- 1 redwood block (20mm x 10mm x 50mm)
- 1 teak wood block (20mm x 10mm x 50mm)
- 1 black oak wood block (20mm x 10mm x 50mm)
- 1 red maple block (20mm x 10mm x 50mm). You can purchase the wood from hardware stores such as Lowes and Home Depot
- 1 caliper
- 1 oven
- 1 pair of gloves
- 1 black marker pen
1. For this science fair project, the independent variable is the type of wood used – redwood, teak, black oak and red maple. The dependent variable is the change in each block of wood’s dimensions when exposed to room humidity and after they have been dried in the oven. This is determined by measuring the dimensions of the wooden blocks with a caliper. The constants (control variables) are the size of the wooden blocks, the surrounding air humidity and the humidity inside the oven.
2. The preparation for the experiment is done by cutting the redwood, teak, black oak and red maple wood into wooden blocks measuring 20mm x 10mm x 50mm. The growth rings should be along the 20mm side. The dimensions of the wood are measured and recorded in the table given below.
3. The black marker is used to indicate the type of the wood on the wooden blocks.
4. The temperature of the oven is set to 100°C and the 4 types of wooden blocks are placed inside the oven. The wooden blocks are left in the oven for the next 24 hours and during this time all of the moisture in the wooden block should evaporate and the wood should dry.
5. Gloves are used to remove the hot wooden blocks from the oven after 24 hours. The dimensions of each of the dried wooden blocks are measured once more using the caliper and the results are recorded in the table given below.
The oven should not be left unattended when the pieces of wood are left to dry in the oven for 24 hours. There is a possibility of the wood catching fire (although it is unlikely, if a proper temperature setting is used). Have fire safety equipment on standby. Be careful when removing the hot wooden blocks from the oven. Use gloves for protection.