1/2 emt Conduit Arches

[bblumka]

I am planning/was planning on make arches out of 1/2 emt Conduit. The arch will be over a double sidewalk so it will have to span 7 ft and be around 7 ft tall in the middle so ppl can walk under it. I was reading in the thread "Heavy Arches" that they were stable with no tag lines before the lights were added, but after the lights got added they became unstable.

First off would like to know how to attach the segements of the arch together that will allow a 3/4" pvc to slide over the conduit (sleeved arch).

Secondly, without tag lines or increasing size of the conduit, what would make this stable?

Has anyone done this? or have successful expirence with it?

[dunnsr]

first off... i dont think you will be able to get 3/4 pvc over 1/2 pvc... regardless of the types
i use the electrical pvc (grey) because its a bit more flexible for my arches.. and i use 1 inch waterline for my sleeves... they are just rigid enough and slide over fairly tight... still not enough room to run the cables under the sleeves... but...

as far as strenght... i am running just 10 ft lengths of pvc which makes about a 5 ft by 5 ft arch... and they are completely stable both ways

much bigger would get wobbly up top... as far as stability without tag lines, i dont think you will accomplish this... if you use a more rigid material it will be less flexible and break... the only other thing i suggest, is that they sell whats called

pencil stick or 1/4 inch rebar... which is fairly flexible, and you can put your lights on a 1/2 or 3/4 piece of pvc and that would be more stable depending on how you anchor it in the ground...

hope i helped.

seth

[bblumka]

You are burstin my bubble dunnsr. I understand what you are saying and that is why I thought I should put that question up before I actually started building the big arch. I already have the conduit bent for some smaller arches, so I will try and put a sleeve on one of those to see how it goes.

As far as the big arch, there are alot of people here, a little brain storming and I'm sure there would be an answer.

. . . or am I just beating my head against a wall.

[bblumka]

Belzona for holding the 1/2 conduit together.

[dunnsr]

You are burstin my bubble dunnsr. I understand what you are saying and that is why I thought I should put that question up before I actually started building the big arch. I already have the conduit bent for some smaller arches, so I will try and put a sleeve on one of those to see how it goes.

As far as the big arch, there are alot of people here, a little brain storming and I'm sure there would be an answer.

. . . or am I just beating my head against a wall.

OK... here is an IDEA... i dont know if you weld... but the pencil stick i was talking about... its metal... they come in 20 ft lenghts... so that should be just about right for your arches...

buy two... they are like 4 dollars a piece... and then take and spot weld them together... so that you have one long 20 ft rod... that is 1/2 inch in the center as long as they are snug... and a 3/4 pice of conduit should slide over nicely... and since your doing two rebar they will be flat when you bend the arch... that should be stable... and I would take a piece of small conduit and drive it a couple feet in the ground and push these inside it... i would do the galvanized conduit for that... still very cheap... paint it because if you dont it will rust... anyway... once you got all your pvc sections wound, (i would use one inch waterline so i could run the wires inside the pipes..) but if your dead set on 3/4 then you can just tack the wires up with some zip ties.

that will be one hellova arch... but i think the double rebar method will give you the strenghth to hold the weight without the sway, as long as your anchors on the bottom are secure...

just my idea... no clue if it will work.. .and if you get struck by lightning, its not my fault!

[Skunberg]

I've read of people using 1/2 rebar 8ft long, pound 4ft into the ground then slide the arch onto the remaining 4ft slightly angled piece. Lots of work to pound 4ft into the ground but this gave lots of stability. I haven't done anything this large to need some support like this but it's in a thread somewhere.

Brian

[JackFrost]

first off... i dont think you will be able to get 3/4 pvc over 1/2 pvc... regardless of the types

Yes .. you CAN slide 3/4 inch PVC over EMT conduit ( pipe/tube/metal )
And as far as how to join them so the PVC can slip over without getting hung up .. use an inside sleeve .. NOT an outer one . And when putting it together , take one of the 1/2 tubing and when you put the sleeve in , make sure to hold it from slipping thru and drill thru BOTH the tube and sleeve and then add a small nut/bolt to hold it in place then do the same for the other pipe for the opposite side of the same sleeve .

[bblumka]

Inside Sleeve . . . Yes . . . but do they make them?

And what about stablity? Arch will be have a 42" radius so it will span 84". If I just put this arch it would only be 3.5 feet tall, so I will put this arch on 3.5 feet extension. (here's were the inside sleeve comes in). What would I need to support this? Trying to stir away from pounding two 8 ft pieces of rebar 4 ft into the ground. I don't think I'd be able to get them out.

[bblumka]

Ok, just ran a test. Wrapped my first sleeve (prolly wrapped it wrong, but sleeve is made out of 3/4" thin wall pvc) with 100ct string. Tried slippin it over 1/2" conduit arch. Didn't work out so well. Way too tight. Hmmm Looks like Dunnsr was right. Will have to re-think what I will be using for sleeves. Also anyone know were there is a you good you tube to show how to wrap the sleeves.

[bblumka]

Got a old piece of 1.5" pvc schld 40, but that is too rigid to bend.