1/2 galvanized conduit

[fishpick]

OK - I have done the tables, I have tried different rod - I'm just gonna ask the people that do this all the time. What's the right setting (AC/DC and EP/EN) and what rod and how hot - to weld 1/2 EMT conduit with blowing through - OR - not just spitting it on the surface... YES - I know - I need to "work on it" - but I'm looking for a ballpark set of setting here! Just something to get me NEAR where I should be - cause the pile of scraps and half spent rods says - I'm WAY off

 

[flusher]

OK - I have done the tables, I have tried different rod - I'm just gonna ask the people that do this all the time. What's the right setting (AC/DC and EP/EN) and what rod and how hot - to weld 1/2 EMT conduit with blowing through - OR - not just spitting it on the surface... YES - I know - I need to "work on it" - but I'm looking for a ballpark set of setting here! Just something to get me NEAR where I should be - cause the pile of scraps and half spent rods says - I'm WAY off

I don't do this often, but I'd carefully grind the galvanize coating off first.
Then I'd use 3/32" 7014 rod, DC+, 80 amps and see what happens.

 

[brandoro]

Like flusher said, get rid of the galvanized coating. That stuff is bad for you.
Not being too proficient with the arc welder on light stuff myself, I have done a lot better sticking thinwall together with the O/A torch and brazing rod. It makes a joint that is about as strong as the tubing.
What are you making? Knowing that might make the responses to you get more applicable.

 

[AlanB]

Can I start with a question please? What joint are you doing? I am assuming you are not fishmouthing and I am assuming you are doing a T joining an end to a middle section?

If that is the joint I am assuming you are squishing the end flat a bit so they sit together well.

Assuming that is what you are doing, I am sure you are aware that is the happy place for a 110 v mig with .023 wire? And I am guessing you have a small stick welder and need to accomplish this task with that?

If I was sticking it, as Flusher said, I would use a 7014 which is a fast fill, fast freeze rod.

I would differ in that I would use AC as in my opinion as the wave travels from + to - of nueteral then you recive a small additional benefit of cooling the puddle. (I also think most 7014 is optimised for AC.

I would also go 80 amps or so, lower if your machine will go down further. If I could start about 50 then come up I would. A better more experienced welder will weld hotter then a less experienced welder with more travel speed generally. Start low, and raise as needed.

In the what is possible. My dad repaired soccor goals that had rusted in several places that were made from exhaust tubing on the field one time for a freind of his. We showed up unprepared as we were told they were made from water pipe. (black pipe) When we saw the guy moving them around and they were 2.5" diameter or so we realized there was some miscommunication somewhere.

Dad welded those together with 6011 1/8" about 75 amps, AC. I could not make it work, and he did it beautifully.

 

[MikeD74T]

Years ago I made a sidecar frame for my son's bicycle out of 3/4 EMT. Used 3/32 6011 & a Sears colormatic AC welder set on the lowest setting that would hold an arc. I was welding full time then and had a steadier hand & much better eyesight than today. Worked outside with a fan to keep the galv fumes at bay. MikeD74T

 

[Hooked_on_HP]

First, Dont weld galvanized unless you have to. If you have to, do it in a well ventalated area. They also claim drinking milk will help. I spent 2 days in the hospital from the fumes from welding galvanized pipe in a closed garage.
Bill

 

[wroughtn_harv]

I learned to weld welding galvanized thin wall. 3/32 6011 and an old Forney buzz box that jumped ten amps every plug. So it wasn't dialed in like you could with a Miller and you just moved faster.

The secret is to not try to weld it and you can weld it. By that I mean you forget all the stuff about working a puddle etc. Because if you're looking for a puddle all you're going to see is a hole. It's about as close to a faith thing as you'll ever do. It's almost like welding with your eyes closed but it works once you learn to get the arc going and then start moving. My dad could lay it around a pieced of fifteen gauge hot dip galvanized and the welds would be beautiful. I got okay but never as good as he was, dads being dads and sons being sons and all.

As for the galvanized fumes. I've welded it all my life and only got zinc sick a couple of times. Knocked me in the dirt for a couple of hours and that was that. But I had friends who came by while I welding galvanized that got sick for days afterwards from just being around some fumes. It's an individual thing that I figure depends entirely upon the person and their body and how it handles it.

That's why I don't recommend people who haven't done it doing it. You don't know how your body is going to deal with it. It might not bother you but then it might wreck your life. If you have to do it anyways you can get face masks at your welding supply that will remove most of the fumes. The one hitch in the get along with those is they're not designed to work around a beard. I haven't shaved in over twenty something years and ain't about to start now.

If you're using the emt because it's available then I suggest you find a good steel supply store. You can get good tubing that's not galvanized that will work better and be easier to work with. It just won't be as cheap, unless you consider the price of lost work if the fumes do to you what I've seen it do to others.

 

[firefighter jim]

First, Dont weld galvanized unless you have to. If you have to, do it in a well ventalated area. They also claim drinking milk will help. I spent 2 days in the hospital from the fumes from welding galvanized pipe in a closed garage.
Bill

Agree with Bill, I would not weld galvanized steel.

 

[fishpick]

Thanks for all the replies... Here's some info about the "plan":
1) never had an issue with zinc fumes - so I'm a lucky one... but I always weld with the barn doors open - fans on - and charcoal filter under the face shield.
2) Really want to use the EMT because of the galvanized factor... why?
3) I have a "nice" Hobart AC/DC EP/EN buzz box. It's got lots of settings and I can do the job of fixing tractor parts / implements when I need to... small stuff - that's tough because you can't just "crank it up and spray metal on the problem."
4) in relation to #3 - I run a really mean grinder

Now - what am I doing?

Making a pasture chicken coop - at least I'd like to. I have several of these built out of wood - How was this animal raised? Chicken Thistle Farm - they work fine, are nice, but are also HEAVY! The same design with EMT would be about 1/2 the weight and about as strong... the issue is - if I build it with special fittings and don't weld it up - it's nutty expensive.

What I have been trying is mashing the end of a tube flat and then trying to weld that onto the adjecent tube where the joint would be made. Nothing fancy (chickens don't care about the look) but it does need to hold.

Will take some of these tips to task later this week...

 

[Craig Clayton]

Dear fishpick
I am electrician which has nothing to do with the welding trade, except I welder 1/2" EMT on a toothed rake as a handle and it lasted for years. 6013 on AC and a small rod. Try to direct most of the heat to the base metal.
Craig Clayton

 

[yomax4]

Also, If the voltage is still too high and you continue to burn through, Get some 6013 1/16, turn it down, Remove some of the Galv. Weld her up AC or DC. Pick up a can of Rustoleum Cold Gave to re-galv your welds or Gal-Vis is a stick that you rub on to re galv after heating.

Good Luck..

 

[2manyrocks]

Agree that zinc poisoning from welding galvanized matierial is a concern, but I weld this material outside to reduce the risk.

I think it's harder to mash it flat and then line it up and hold it all together than it is to birds mouth one piece with a hole sale in a drill press and then weld it. Now that I think about it, it's not hard to cut a V in the end with a grinder that will allow a birdsmouth fit. Probably faster anyway

A little grinding does a lot to help when it comes time to weld.

I've done the same sort of thing repairing my dog kennel using galvanized top rail which is larger than 1/2 EMT, but I used a mig. You guys that use stick welders for this are better welders than I am.

I just used aluminum colored paint to paint the welded areas.

 

[AlanB]

I will try and go grab some pictures, and we may be saying the same thing.

I would not "smash it flat" I "squeeze it a bit" Not sure how to say the difference but for me it works best when there is a 1/4" gap or so between the two sides.

I use an Arbor press now, but a hammer, one good lick on either side, or big vice work pretty well.

I struggle with the fishmouths in this instance.

The best guy I ever saw did fishmouths with a 4.5 grinder and brazed it all together. Made camera mounts for the film industry. Could whip those things out, were strong enough and cost little.

I like your chicken coop deal, ours are free ranging at the moment but we have been thinking about something along those lines.

 

[kidr]

I know this is a welding thread, but really PVC might be a better choice for this project. You could use 2 or 3" for the base and 3/4 plastic elec. conduit to form hoops to attach fencing. If it's all glued up adding water in the base will make it more stable. Just an alternative to think about,and maybe a little easier to do.

 

[Redneck in training]

I would just smash the ends flat and bolt the corner together. Might not be as ridgid as welded joint but since it would give some it will not break when dragged around.

 

[2manyrocks]

If he has a bottom rail in contact with the ground and flares the ends up like the end of a ski, then it ought to drag fairly decently. Some of these coops have wheels on one end, too.

But bolting the ends together is another way of doing it and definitely no burn through issues with it, either.

Sometime in the OP tells me that he is determined to successfully weld this EMT or bust. We all get projects like that.

 

[fishpick]

@AlanB - I think your thoughts and mine are on the same page... smash, squish, mush... all the same - make the gap less - but something to fill. Although I may mess with the grinder too to see about fishy work too...
@kidr - I have used PVC in the past - it stinks for a variety of reasons. One pen - maybe - but a fleet of them - PITA.
@Redneck in training - that's plan B Welding will be faster if I can "get it" right as opposed to drilling and bolting... plus it will be more rigid.
@2manyrocks - I have a system I dreamt up where the wheels move with the pen so I don't need to form skis... I used to do the dolly thing but that resulted in lots of run over and unhappy birds! Ohh - it's not weld or bust - it just would be the fastest and strongest approach... one rod and 2-3 joints is a heck of a lot cheaper than bolts, nuts and washers... plus drill and tighten time

 

[pat32rf]

Over my years as an electrician I have found that there are two types of EMT, both galvanized, but one is easier to weld than the other.
I will use a very low setting and often build up the pipe with a quick pass of weld BEFORE I try to make my joint. This just gives a little bit more steel to act as a heat sink for the final weld. Don't try to do the job quickly, IE-stick it together, then let it cool a bit rather than trying to weld it solid in one pass. Use short runs and maybe alternate between two joints at once so they can cool .....
It can be done, with small rod, a low setting and patience

 

[JPinnell]

I made these tree guards using 1/2" EMT 4' high and roughly 4' in diameter. The T-Joints for the center supports were easy. The butt weld of the top half to bottom at the start gave me fits using fluxcore on my MIG. As has been said grind or sand as much of the zinc off as you can, do it outdoors, etc. I stitched them together with a series of spot/tack welds. Easy to do with the MIG, but would be hard to keep from sticking the rod on your welder. You won't be able to lay a bead, but doing a series of overlapping tacks they didn't look too boogered.

Given the limitations of your welder on the thin stuff maybe rethinking the design a bit is in order? I'm not sure what you're design is, but instead of going square framed would a hoop house style chicken tractor work? Some treated 2x4 for the bottom skid frame and then arched EMT for the top to hold the netting. Bends real easy with an old tractor rim, large propane tank, etc. Drill a couple holes in the bottom of the EMT on each end and screw right to the bottom skid. A 10' stick would give you a little more than 6' wide and 3' high arc. Should still be much lighter weight than a complete wood framed unit.

If you needed wider you could go 2 sticks of EMT and do a butt weld in the center. Maybe find some 1/2" OD tubing that would slip inside the 1/2" EMT (with a little sanding down) so you could do a butt weld and not blow through with your stick welder.

 

[lostcause]

i see a lot of panic about health issues from welding galvanized metals. while i'm not a physician or ever had any training in welding galvanized, i have been told a few things over the years by people who have done it a lot. i've also decided to look on the internet, and i found the following:

http://www.sperkoengineering.com/html/articles/WeldingGalvanized.pdf

before you run out to put a deposit down on the cemetery plot, read the third section: zinc fumes -- a safety hazard? i've done a lot of small projects over the years with old galvanized pipe, and while i try to keep my head out of the fumes, i'm sure i've breathed some in, but never felt any effects from it.