|Home » Forums » Professional Furniture Making » Message||Login|
You are not logged in. Consider these WOODWEB Member advantages:
Alaskan Yellow Cedar2/2
I am building curved benches for a 250-seat outdoor venue and would like to use Alaskan Yellow Cedar. The front row bench is 14 feet long and has a radius of 16 feet. Does anyone know if AYC is a good product for curved outdoor furniture? Does anyone have a suggested method for construction? Attached is a plan and section. Thank you, Jim
Click the link below to download the file included with this post.
Jim, AYC gets pretty high ratings for durability, but I'm sure you already know that NO SAPWOOD has any decay resistance.
Aside from that, there are only a couple of things that show up on my radar. First, is on the back side where the Nylock nut and washers are countersunk, will only leave about 1/4" of wood under the washer on a board which is trying to spring away, especially on the ends.
The other thing, is that you can't bend a board all the way to the end. I seem to recall that eight times the thickness of the plys will remain straight. Adding to that, is the fact that the leg which would help hold the shape is 30" over from the end, so there is nothing out there to help counter the combined springback of all the 10 slats.
You might want to bend a single board to that radius, then multiply it x 10 to see what the force will be, might be a good idea. Plus you can see how far from the end stays straight.
Definitely use stainless steel. A cut piece of galvanized all thread rod will rust on the ends where no coating remains. I don't like the 1x4 spacers. They will hold water in the seams and shorten the life of the bench. With only the single piece of all thread, what keeps them from rotating? I'd use short pieces of stainless steel tubing. Don't use 3/8" lag bolts through the angle irons into the 1x4s. Too likely to split out. No experience with that cedar. Does it splinter easily? I'd round over all the edges on the top of the bench.
Just a few more thoughts,
Back to the all-thread and washers. If this lumber comes wet like Western Red Cedar does here, it will bend easier while wet than dry. Not that it would be very hard to bend to 16'R, but when it all dries, there will be enough shrinkage that those through bolts will be left sticking out. Then when someone tightens them back down to the narrower dimension, which will be temporary until the next rain, when the expansion will crush the wood under the washer. This would allow the ends to spring loose.
I'm thinking that it might make more sense to not use the bolts at all, but rather screw and bond each of the spacer blocks in with something that will keep the water out, plus about 6 screws in the end blocks and 3 for the in between, which can be about 3" long., with bungs over the outside heads.
You have some good advice above, especially about the ends not bending properly.
But, I think I see a big steam box in your future. I am not experienced with large scale bending, or with YAC, but it is the only way I can see a fair curve without building in a whole bunch of tension into the benches.
Why not just use trex? Or Alcoa brand trex which is nicer.