jeepguy553

Looked around in the interweb for an answer to this question and really didn't find one.
I am considering building some stuff out of 2" rigid conduit and wondered mow much weight an 8' section of this stuff would hold without excessive deflection or deformation. Anyone out there in JK Land have an idea? Specifically, I want to build a VERY lightweight roof cargo rack because the one I originally made out of 1" square tubing and expanded steel mesh was DAMN heavy. I figure that using conduit as a frame and some of that seat belt webbing I got would be a good way to start up a roof rack that doesn't weigh in at 300+ pounds.

Xodius

Not sure how much it can hold but know of several jeepers that have made racks out of it without any problems. You can check on L.O.S.T. Jeeps. There are several there. If memory serves me, I believe one guy even said it held him one time while he was messing around and he was around 250-260#. It is an older post though so it might take a little digging.

jeepguy553

That sounds good enough for me. I appreciate the help. Just didn't want to repeat the mistake I made with that damned square tubing fiasco. I definitely want a roof rack of some kind but don't want something that weighs 300 pounds by itself over my head (soft top) when it is holding a couple of hundred pounds of gear and assorted kid-related stuff. Having 500+ pounds crashing down through the soft top at 75mph might just be a bad thing. Besides, I might want to have the ability to remove the rack by myself to lower said soft top.
The project design right now includes:
1.) Roof rack made of rigid conduit welded in a rectangular shape with round elbows at each corner
2.) 6000-pound test nylon seat belt webbing sewn together in a cargo net fashion
3.) Mount points for e-tool, hi-lift jack, etc
4.) Mount frame with integrated windshield light bar
5.) POSSIBLE swivel point on one side or in the back to be able to fold the thing over for use as a shade or shelter
6.) Rear facing lights
Any other suggestions?
EDIT: Looked on L.O.S.T Jeeps and found exactly what I was looking for. Looks like one guy made one out of 1" EMT conduit and apparently hasn't had any problems with it up to now. HMMMMM

Inko

Curious as to why you would choose EMT? Why would you not look at standard tubing in the .120" thickness? It would be lighter then steel EMT as EMT is usually SCH40 pipe so depending on your diameter, your wall thickness could be from .133 -.145".

Apostle

Work with conduit alot. the stuff is thin. recommend you add in support structure every 8-12 inches. straight its pretty solid, sideways it is really flimsy.

jeepguy553

I mentioned EMT because it's cheap and easy to get. Hadn't thought about the tubing though. I'll have to look into prices around here to see what I can find. The rigid conduit is some expensive stuff!

feuerdog

Conduit is galvanized, and welding galvanized is dangerous.
I used some for a modified bicycle frame, but i used a fan, a respirator, and alot of careful prep to minimize my exposure. The burned off-gases can cause nervous system damage. Google search for details.
Other than that its thin and easy to burn though, so you'll want to know how to weld at low power levels too, or just very carefully spot weld it up.

I won't use conduit anymore for welding projects, I use local metal supplies for regular weldable steel/alloy now.
With a good design the weight can be kept in check and it's be far safer to work with.

jeepguy553

I used 3/4" galvanized conduit to make my dash dock/organizer. I knocked the zinc coating off of the outside with a grinder. You aren't kidding about it being thin. I had to turn the MIG all the way down and basically do what you said and weld a bunch of little tacks around it to keep from making a mess. I think I am gonna look into the steel 0.120" wall tubing today to see if there is a significant price difference. If not, I may go that route instead of the conduit even if the tubing turns out to be $1.00 or so more per foot than the conduit. I definitely agree that it is safer to work with.

Inko

Also when they galvanize something it penetrates the surface up to .050" so removing the surface zinc wont get rid of it all and the evaporating zinc will still blow your puddle around inceasing difficulty of welding the joint. Galvanized isbest left to threaded applications or,getting hot dippedpost welding.

And ERW tubing is good you can spend more on DOM but it would be overkill.

jeepguy553

I found a supplier of the ERW here in Shreveport but they (of course) don't post any pricing per foot or per joint. Go figure. I sent them an email yesterday about another piece of 3/16" plate and they still haven't gotten back with me. I guess they don't want my business. I have a 10' length of 1/2" conduit and some elbows I am gonna play around with this weekend. Don't have a respirator but I can definitely see the need to get one. If I can get some time to mess with this stuff, I am gonna put together a frame for a folding rear cargo shelf for the back of my JKU. I think the roof rack will be put together out of the ERW if I can find a decent supplier here that wants my business.