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Old 17 March 2008, 15:39   #101
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Oh ye of little faith.
But how brittle will it be ? Looks good enough, but wont bits of zinc be entrapped in the weld, usually by way of a gaseous state as the arc or gas melts it ?
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Old 17 March 2008, 17:08   #102
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But how brittle will it be ? Looks good enough, but wont bits of zinc be entrapped in the weld, usually by way of a gaseous state as the arc or gas melts it ?
Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide. I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?
I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.

I'm not recommending the use of stainless welding of mild steel in general but it's a way of welding galvanised steel and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.

As usual, it's what I've found to be successful.
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Old 17 March 2008, 18:23   #103
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Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide.
Some of it does , but some of it gets in the weld and forms an alloy which is weaker than the weld

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I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?
Because the zinc and the process of oxidisation end up being in a gaseous state within the weld.

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I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.
Yep I can see that, but a lot of peeps forget to remove the zinc from inside the joint of either piece, which is very hard to do, especially in square section, and it doesnt take a lot of contamination to weaken the joint

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and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.
I've found the rust resistence to be very variable, and tbh never found out accurately why, I suppose the metal content of the welding anode has a lot to play here, as I dont know what make up of fluxes are used (in Sticks... MIG's just get thrown off Galvy stuff), this is even after properly treating the welds for protection after the weld
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Old 17 March 2008, 19:29   #104
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.... MIG's just get thrown off Galvy stuff), this is even after properly treating the welds for protection after the weld
We must weld differently then cos that's mig welding. I haven't used stick welding for years. MIG or TIG for me. I was going to suggest you go and try it before judging it but if you can't even make a MIG weld on galvanised stuff then there would be no point.

And it isn't full of bubbles as I think you are suggesting...I know, cos Angle Grinder is me middle name.


PS. analysed. It's strange what one doesn't notice after a bottle of Newcy Brown before ya evening meal. Hic.
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Old 18 March 2008, 03:45   #105
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MIG's just get thrown off Galvy stuff
I meant that this as a consequence if you dont remove all the zinc
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Old 18 March 2008, 04:35   #106
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Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide. I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?
I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.

I'm not recommending the use of stainless welding of mild steel in general but it's a way of welding galvanised steel and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.

As usual, it's what I've found to be successful.
JW, I think we're going to have to agree to differ on this
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Old 18 March 2008, 13:06   #107
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JW, I think we're going to have to agree to differ on this
Fine; but first, go and get a couple of bits of 6mm galvanised steel, bevel their edges for about half the thickness, take back the zinc for about 2-3mm along the edges, lay in a stainless weld, grind a bit of it to check whether it's porous (If you can weld, it won't be.), test it with the sledge hammer and then come back and apologise.

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Old 18 March 2008, 13:37   #108
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Fine; but first, go and get a couple of bits of 6mm galvanised steel, bevel their edges for about half the thickness, take back the zinc for about 2-3mm along the edges, lay in a stainless weld, grind a bit of it to check whether it's porous (If you can weld, it won't be.), test it with the sledge hammer and then come back and apologise.



Jeff, since my livelihood and that of the forty odd people I employ depends on me knowing a thing or two about stainless steel welding and fabricating ……of which we produce hundreds of tons a year all of it in very severe service conditions… I think you’d agree that I do a little more research into things than hitting it with a hammer to see if it breaks.
I agreed to differ rather than bore everyone else to tears with the technical explanation of traces of zinc and the effects on the granular structure of the weldment…that’s for two reasons…the first is as a humble Fabricator, I take guidance from the more technically qualified, especially when they back it up with evidence…….and secondly they lose me as soon as they start using words of more than two syllables…
If you really must argue, I suggest you look at some of the excellent papers written by the Engineers at The Chiyoda Company of Japan, or Mitsubishi Heavy Industries. Companies that have a great deal riding on the integrity of their equipment. Their work on all forms of cracking in S/Steel in service is most informative

…..as to your experience in this matter….don’t confuse being lucky with being right.

I don’t think I’ll be apologising anytime soon….
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Old 18 March 2008, 13:48   #109
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Gold old Ribnet. 11 pages on how to repair a trailer and no one has yet suggested bracing it with pieces of wood lashed on with tie wraps. I'm certain it would work
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Old 18 March 2008, 14:06   #110
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….don’t confuse being lucky with being right.
That's a good one. I'll keep it in mind. It's lucky I've been lucky often.

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I don’t think I’ll be apologising anytime soon….
I didn't expect you would be.

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I agreed to differ rather than bore everyone else to tears with the technical explanation of traces of zinc and the effects on the granular structure of the weldment…
I wouldn't be bored with that. Better than reading again how to clean tubes or how to enter an MMSI.

Argue, I thought this was a discussion.
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