Post by: terravista on January 27, 2016, 01:36:31 PM
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
Post by: muzza01 on January 27, 2016, 01:53:56 PM
Post by: Footy Shorts Shane on January 27, 2016, 01:58:18 PM
Post by: terravista on January 27, 2016, 02:03:50 PM
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.
Post by: terravista on January 27, 2016, 02:05:43 PM
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.
Post by: macca on January 27, 2016, 02:11:16 PM
Post by: terravista on January 27, 2016, 02:20:19 PM
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?
Post by: macca on January 27, 2016, 02:28:21 PM
That's what I would do
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?
Post by: terravista on January 27, 2016, 02:34:04 PM
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
Post by: oldmate on January 27, 2016, 02:49:10 PM
Post by: terravista on January 27, 2016, 02:54:22 PM
And if that doesn't work this time, at least have a video of it falling on your head again for our viewing pleasure. ;D :cheers:
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.
Post by: Green rv on January 27, 2016, 03:04:17 PM
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.
:cheers:
Adam
Post by: DaveR on January 27, 2016, 03:28:39 PM
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.
Post by: terravista on January 27, 2016, 03:42:02 PM
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.
Post by: Bad Scott on January 27, 2016, 03:42:19 PM
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 RHSTurn and burn :D
Post by: terravista on January 27, 2016, 03:56:04 PM
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
Post by: macca on January 27, 2016, 04:03:39 PM
After all this, anyone would think that star pickets should be used for some purpose other than welding.Yeah knock off his gal pipe from his water tanks
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
Post by: Liege on January 27, 2016, 04:54:05 PM
Post by: cassgazz on January 27, 2016, 08:19:14 PM
Post by: glenm64 on January 27, 2016, 08:30:10 PM
Doh!
Cheers Glen
Post by: Homerj on January 27, 2016, 09:16:53 PM
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.
:cheers:
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.
Post by: DaveR on January 27, 2016, 09:31:21 PM
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Post by: denidoug on January 27, 2016, 10:33:58 PM
Post by: Andy_Q on January 27, 2016, 10:49:48 PM
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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Post by: glenm64 on January 27, 2016, 11:03:56 PM
Maybe it was just a Shit weld??
Cheers Glen
Post by: denidoug on January 27, 2016, 11:46:49 PM
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.
It is well known through out the structural steel industry that ALL Chinese manufactured steel contains excessive amounts of Boron,chromium and copper,earth position and amp direction??? Have got nothing to do with it,the steel in the star picket failed, not the weld
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Post by: Footy Shorts Shane on January 28, 2016, 05:51:36 AM
All this technical talk.
Maybe it was just a Shit weld??
Cheers Glen
:cup:
Post by: terravista on January 28, 2016, 06:43:23 AM
All this technical talk.
Maybe it was just a Shit weld??
Cheers Glen
Well the heading did say I sucked at welding so that would generally be true. But in this case the four welds actually looked half OK. I would have hoped that at least one of them held enough to have to use metal fatigue to break it off.
Maybe that was the problem, looks like a supermodel, as poorly efficient as my second wife.
Post by: glenm64 on January 28, 2016, 09:28:18 AM
Maybe that was the problem, looks like a supermodel, as poorly efficient as my second wife.
PMSL
Cheers Glen
Post by: truck on January 29, 2016, 04:40:49 AM
I am trying to remember when welding disimilair metals use 308 or 309 electrodes. Also sometimes you may actually need to change the polarity ie earth positive electrode negative, move the earth to a different location on the job to stop arc wander. Consider the angle of the electrode also as previous mentioned.
Finally - nothing worthwhile comes easy :D
Post by: Troopy_03 on January 29, 2016, 08:51:02 AM