How to fasten galvanized pipes?

Hi there, I have a lot of galvanized conduit of various diameters that I found in a dumpster. I would very much like to know how to fasten one pipe to another so I can make stuff with it.

Welding: I've read on instructables and elsewhere that you will become quite ill if you weld galvanized materials due to the evolved zinc fumes. Are respirators an option?

Lap Joints: I thought of trying to make a lap joint by cutting out matching "half rings" from the pipes, overlaying them, and then bolting them through. I'm stuck as to how to make that cut though. I could do it in wood, it seems like metal would be trickier. Any thoughts?

I'm being forced to move the pipe in a week or so; any off-the-cuff ideas would be fantastic, thanks!

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post.haste (author) 8 years ago
Excellent, thanks everyone for the variety and depth of ideas.
skunkbait8 years ago
A short pipe slightly smaller or larger would make a sturdy joint with bolts through both ends. You could wrap the joints in rubber to minimalize vibration (and the likelyhood of anything getting snagged on the bolts).
LinuxH4x0r8 years ago
Yes, respirators are an option. The best way would be to cut them and then thread them using a tap and die set.
110100101108 years ago
if its not used really as pipes or ducts i'd go for solution with bolts and connections like this if you can find square pipe that the pipes just stick in it and dont move then it + bolts can make good connector
chiok8 years ago
Welding galvanized steel is possible, but you have to be extra careful about everything. Lots and lots of ventilation to get rid of the zinc particles. If the weather is nice, weld outside. You'll need a proper respirator with a filter too which you wear underneath your welding helmet. And then keep a short arc to try and use the weld pool for catching the zinc. It's possible, but not easy, and there's more splatter too. Also suggest a full set of overalls that you can change out of outside so you don't drag the zinc particles inside. Are you thinking of a 90 degree cross lap joint or a 180 degree straight lap joint? You'll have to drill some holes for the saw blade to turn in when cutting parallel to the pipe. If it's a straight join, could do a sort of spline join. Or epoxy a smaller tube inside the ends. Fixtures and fittings would be better, but then it's not as neat.
. Yep. Welding galvanized is not for most DIYers. Breathing the fumes will make you sick (and could kill you) and you're liable to pollute your whole house if you don't cleanup properly. . Plus, welding burns off the galvanizing on both sides of the weld - you'll need to re-galvanize the weld areas if you want to maintain the protection it provides.
caitlinsdad8 years ago
I guess you are not Joe the plumber, but there are various threaded pipe joints/connectors in various shapes like L-shaped elbows, T connectors, size adapters, flanges to tie one end to the wall or floor, etc. They have pipe die kits where you can cut standard pipe threads on the ends of various diameters of pipe. You clamp the pipe in something like a vise and then take the thread cutting tool to cut the thread on the ends. You may be able to rent from a tool shop or else make an investment in one if you plan on doing a lot with pipe. Good luck.
Oh, if you plan on trying the lap method, use a jig saw or reciprocating power saw with a fine tooth metal blade. Find a v-shaped groove to clamp your pipe in so it doesn't slip when it cuts. Doing by hand with a hacksaw will take a lot of work. You might want to get a filler wood dowel or smaller plastic pipe the size of the inside diameter to place inside the joint when you fasten it to keep it from slipping.