Question on using conduit to build greenhouse?

I searched for threads on building your own greenhouse using metal electrical conduit. Did not find anything with these answers. What size conduit? Thin wall - thick wall? How to bend uniformly? Any plans? I have plans for PVC greenhouse, but I want to go wider. I would also consider using treated lumber to build.

All of my grhouses are built with 1" electrical conduit. You have to make/borrow a jig that is a rounded piece of wood (plywood) that you fasten the metal conduits to and bend so you get a uniform shape for the bows. I connect 3 of the 10' pieces to get one bow. I also use them for the purlins. They have held up well over the years.
I use treated lumber at the base and at the gable ends and for all the tables/shelves. I cover with two layers of treated grhouse plastic. My largest grhouse is 100' long x 20 (?)' wide and about 8 ' at the tallest in the middle of the house.

The electrical conduit, was it thin wall? You don't happen to have a picture of the jig? or of the way you join the conduit? I'm not afraid to experiment, but I'd rather borrow someones experience if I can. I had thought of taking plywood and cutting it in a radius at two points then taking 2x4s cut to 3" lengths to join the plywood sides, then put a conduit clamp on one end and bending it that way. Does it spring back?

I will try to take pictures of the grhouse for you tomorrow. I am not sure if it is thinwall-but I can take a picture of an open end of one of the pipes and maybe you can tell from the picture. I will take pictures of how it connects to each other and how it is fastened to the wood base .

Unfortunately I lent my jig out and he lost it. It was a nice one that my brother made from tracing the curve from someone elses. After he cut the plywood to get the curve, he put a clamp at the bottom of the start of the curve, where you insert the pipe and then you bend it over the curve and it bends/holds the shape easily. It doesn't spring back. Its a simple, but effective design. It is just one piece of plywood, no need to join any pieces. I think that it is doable for you to come up with the curve and draw it on the plywood and then cut the plywood. Maybe I will try to draw a picture of it and scan it into the comp tomorrow as well. If you can come up with an idea thats doable of me somehow tracing the curve of the pipe on a large piece of paper and mail it to you,or some other way, I can try that.

I'm wanting to do a 20' greenhouse, I'll have to try to figure out the radius. I want to do 20x30 this fall and expand it to 60 or 90 next summer. I plan to do personal growing on one end and try to do some commercial growing on the other. Do you heat your greenhouse?

Yes I heat all the grhouses, I use them for commercial use.

When you say that you want a 20' grhouse-is that the length? and then a 20'x30'-is the 30' the width? Meaning the width if you lay a measuring tape on the ground and get 30' or using 30' of pipe and getting a 20' width? The reason I am asking is because my curve, I don't think, would be useful for you if you are trying to get a 30' wide grhouse. Your curve would be less severe than what I have, if so.

You can buy a conduit bender at HD for around thirty bucks. You will need a length of black pipe for the handle. Takes a few tries to master, but I can bend it like the pro's now. I would think that thin wall would be adequate. The size depends on number of conductors, and the gauge. By yourself a copy of Ugly's little yellow book. It has all the specs you will need.

thats good to know, since I will eventually have to make repairs-say if a tree lands on a house etc. You can adjust the bender to the arc that you need?

The one I have only provides one radius. Of course you can get any degree you want. The hardest bends are the out and back to run around an obstacle. I just adjust my design to the bend. I sure save on having to buy those expensive nineties. When I get around to re- wiring my GH I plan on running a bead of silicone around each fitting. I have seen conduit benders that have different tubes that can be placed for different arc's. Bet they are pricey. I love running conduit, and did a much better job at it then the electrical contractor that installed my generator! If I lived closer, it would only take a six p[ack to get me over there to help out:-)

20' wide by 30' long, sorry. thanks for the reference on Ugly's Little Yellow Book, I'll try to get my hands on one in the next couple weeks. I eventually want 2, 20x90 greenhouses. But I'll start slow and build as I can pay.