OK, I know I suck at welding...but

[terravista]

I needed to space two RHS sections apart parallel by 1200mm to make a roof over a hay feeder, so lacking pipe RHS or SHS I cut up a couple of star pickets.
The zinc plated RHS was ground back to steel, and the black paint and surface rust was also ground back to shiny metal on the pickets.
I welded the frame together with a stick welder, and it all held together to chip the slag off and then coat the welds with gal paint.
On lifting it up into position one weld broke instantly quickly followed by the other three.
The welded material stayed on the RHS and the pickets only had burn marks.
Are star pickets made of some weird metal that does not take welds well, or has my limited skills hit a new low?
If it is me, I guess I need a few rolls of duct tape to make the new frame.
Cheers
Ian

[muzza01]

Maybe your weld didn't penetrate. Possibly you welded on top of the stare picket rather than to the star picket if that makes sense.

[Footy Shorts Shane]

Did you grind back a spot for the earth clamp?

[terravista]

Maybe your weld didn't penetrate. Possibly you welded on top of the stare picket rather than to the star picket if that makes sense.

Sort of makes sense, but with full perimeter welding around four joints I would have expected some of it to hold.

[terravista]

Did you grind back a spot for the earth clamp?

No, but doesn't electricity go through the zincalume? I had a good arc which doesn't seem to happen when I have a bad earth normally, it fizzles and splutters more.

[macca]

You have to up the amps and really burn into the star picket. Concentrate more heat on the picket and not so much on the RHS

[terravista]

You have to up the amps and really burn into the star picket. Concentrate more heat on the picket and not so much on the RHS

Sounds like a plan, but with a cheap arse welder that only has two settings for two different diameter rods, is it feasible to use the smaller rods and the setting for the larger rods?

[macca]

Sounds like a plan, but with a cheap arse welder that only has two settings for two different diameter rods, is it feasible to use the smaller rods and the setting for the larger rods?

That's what I would do

[terravista]

That's what I would do

Well that is what I will do on the weekend.
Hopefully by then my head will stop hurting from having a broken steel frame fall on me, and the pieces of star picket that were hurled after the hissy fit are found.
Thanks

[oldmate]

And if that doesn't work this time, at least have a video of it falling on your head again for our viewing pleasure. 

[terravista]

And if that doesn't work this time, at least have a video of it falling on your head again for our viewing pleasure. 

I could do a re-enactment, but apparently Abbott and Costello won't travel here. And I mean the real ones, not the bozo's that spent their lives in Canberra.

[Green rv]

cut and paste from a site
don't know if low carbon is hard to weld or not

Star picket  which is made of low carbon steel, or sometimes rail steel.

 
Adam

[DaveR]

I'm thinking you'll have trouble welding a star picket due to the metal content.
Do you have lengths of gal pipe you can use?
The pipe can be welded easier. No need to grind of the gal coating 1st, it will burn off, the fumes are a concern if you breath a lot of them that why it is said to grind 1st.
Was the weld a big round lump sitting on top of the material?
If so, not enough heat, slightly more amps, or small size rod needed.

[terravista]

I'm thinking you'll have trouble welding a star picket due to the metal content.
Do you have lengths of gal pipe you can use?
The pipe can be welded easier. No need to grind of the gal coating 1st, it will burn off, the fumes are a concern if you breath a lot of them that why it is said to grind 1st.
Was the weld a big round lump sitting on top of the material?
If so, not enough heat, slightly more amps, or small size rod needed.

I can get pipe or RHS, it's just I had none yesterday (Aussie Day) and I used what I had available.
The weld wasn't a huge lump, it was a one of the nicest looking welds I have done, but by the look of the star pickets after they fell off, there was no distortion in the steel.
So, in the words of Tim The Toolman....More Power.

[Bad Scott]

You have to up the amps and really burn into the star picket. Concentrate more heat on the picket and not so much on the RHS

Turn and burn

[terravista]

After all this, anyone would think that star pickets should be used for some purpose other than welding.
Next time, I think I will try using them as fence posts. Less drama.
At least if I break something out bush and I rig the batteries to make a welder, I won't knock off Farmer Browns picket fence. His cows can remain fenced in.
Thanks for your help folks.
Cheers
Ian

[macca]

After all this, anyone would think that star pickets should be used for some purpose other than welding.
Next time, I think I will try using them as fence posts. Less drama.
At least if I break something out bush and I rig the batteries to make a welder, I won't knock off Farmer Browns picket fence. His cows can remain fenced in.
Thanks for your help folks.
Cheers
Ian

Yeah knock off his gal pipe from his water tanks

[Liege]

I really enjoyed this thread, makes me feel better to know there are other people that share my questionable talent when it comes to joining a couple of pieces of steel together...

[cassgazz]

Make sure the polarity is correct. Hand piece should be positive, and earth should be negative. If it is the wrong way around, you won't get as much fusion.

[glenm64]

I reckon I'm a pretty good welder normally. The other week at work I had to do a small welding job, but couldn't work out why I couldn't weld properly, then I realised I didn't have my glasses on.
Doh!

Cheers Glen

[Homerj]

cut and paste from a site
don't know if low carbon is hard to weld or not

Star picket  which is made of low carbon steel, or sometimes rail steel.

 
Adam

Low carbon steel is generally the easiest type of steel to weld, but if the two pieces you're trying to weld together are not very similar it will still be difficult.  Can you leave a gap of at least 1mm when you fit it up next time?  It will help with getting better penetration on both surfaces.

[DaveR]

I can't remember steel spec stuff. But the fence picket would be similar to shipping container steel, a right pain to weld.

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[denidoug]

Star picket steel has a high content of copper and chromium ,unless your using low hydrogen rods and your amps are set correctly,forget it,this is a major problem world wide in the structural steel fabrication ind,welds cracking and steel failing. and where is this steel manufactured???CHINA.and what else is made of their steel???CAMPER TRAILERS

[Andy_Q]

Chromium is used to make stainless steel. I doubly there is a lot of it in star pickets. Shipping containers may well be a corrosion resistant grade that is hard to weld.

I'm guessing that the lack of fusion to the star pocket would be due to the difference in wall thickness of the materials. More heat is required to melt the thicker section.  If all of the amps are travelling to the earth on the gal tube you may need to move the earth to the picket. By directing more of the rod to the picket you can also control the heat on each part to some extent.



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[glenm64]

All this technical talk.
Maybe it was just a Shit weld??

Cheers Glen