Best Wood for Steambending, Rot Resistant, and Low Weight
Unfortunately, there probably isn't a way to get all three of those with the style of trailer that I'm building. I'm going to compromise on weight to get the look that I want. I've done some testing after reading about steam bending on the internet, and tried a few different pieces of wood: Poplar, Red Oak, White Oak, and Cedar.
I knew immediately that cedar wasn't going to work, but for the sake of science, I tried it anyway. I first need to disclose that all of the wood that I tried was kiln dried, and bought from a big box store. In the final version of my testing, I plan on purchasing some green wood, and possibly soaking overnight before bending. I went to Menard's yesterday and picked up a 4'x8' sheet of particle board to use as the backbone for my CNC'd templates. I can fit all four template molds on the sheet so that I'll have 4 different pieces of wood drying at any give time.
The Hatch template has one of the biggest bends, which snapped 2 pieces of cedar before getting anywhere close to being clamped in. The next piece was a 3"x1/4"x 6 foot section of Red Oak. This was a kiln dried piece that I used a planer to get down to 1/4". I also went with a piece that was longer on each end to help with leverage. Seemed to bend with difficulty, as the board was in the steambox for almost an hour.
Here are those pieces after they are removed from the templates after being clamped for a week. I'm using a bungee to help the red oak maintain its shape until the hatch frame is built.
I'd also like to point out that I've snapped a few more pieces of wood after removing from the steam box. I plan on soaking my wood for this next weekend's test pieces. I am also going to a hardwood shop in a couple of weeks to purchase some green lumber to see how well that bends in comparison to the kiln dried wood that I've purchased at the "big box" stores. I'm sure that breaking perfectly good lumber is all part of the steam bending process, just sad to know the money is wasted to get a specific look on the teardrop.
I made the trip today to a hardwood supplier near Monroe, Wisconsin today to order the "green" white oak for the teardrop. I also picked out an 8 foot green plank to take home with me to test bending. I sent the rough cut board through the planer, and then used the table saw to cut a 1" x 1/4" x 8' strip. I put this in the steamer for about 40 minutes, and it was like rubber when I pulled it out. It bent around the tongue box frame template very easily. Looks like I've got a winner, and making the choice to go with white oak that has not been dried in any fashion is the way to go. I will probably still try and add accent pieces to the tear, but will be mostly white oak. Very pleased with the results today.
Click the play button on the image below to watch high speed video of me bending a 1/4" x 3" piece of white oak on the hatch template.
Did I mention that you need clamps? Lots and lots of clamps. Harbor freight is my friend when I comes to cheap clamps. I always seem to pick up more when I'm there.
Here is an updated mold for the tongue-box trim and door gutter.