why wont my stainless welding shine???

[hotrodder]

Does the nipping of the rod in the pool happen due to freezing rate or something along those lines.

Dunno

Sorry another Q.
Surly we select ss for it's corrosion resistance and we remove oxides and heat tint etc to aid with those characteristics. I cannot think of a case scenario where sugaring/coking is ok. Yeah I suppose a dull weld can soon be brightened back up but the underside is knackered surely if you create coking.

I agree in principle but the service environment plays a huge role. There's various architectural/decorative applications that aren't gonna challenge the corrosion resistance of stainless where burnt/coked welds are more of a cosmetic/time wasting deal when partial pen and/or fillet welds are acceptable.

Not a coked example but FWIW just taken this pic of a stainless tailpipe welded to what's left of an (origionally aluminised) mild steel exhaust



I made that at least 8 or 9 years ago, might well have used 316L wire as i'm more likely to have had some in 1mm than with 309L etc. Definately wasn't purged and never been cleaned until 10 mins ago when i wiped it with a rag (it wasn't about having a shiney tailpipe, just a convenient bend offcut kicking about)

Didn't know about the horses yesterday, manure/pee is presumably gonna be more corrosive than the conditions a car exhaust sees but probably not as corrosive as being submerged in brackish water? http://www.mig-welding.co.uk/forum/threads/crevice-corrosion.15360/

 

[wheresmejumper]

Theres always a lot of talk about accurate amps for stainless welds,but i find its easier to vary your rate of travel and amount/frequency of filler than worrying too much about whats on the display.closed butts or fillets im talking about

 

[Tinbasherdan]

Theres always a lot of talk about accurate amps for stainless welds,but i find its easier to vary your rate of travel and amount/frequency of filler than worrying too much about whats on the display.closed butts or fillets im talking about

But the correct way would be to put the right amount of heat in and adjust your travel speed to that rather than vice versa. Once you can do something properly, then you can take shortcuts from time to time

 

[wheresmejumper]

Correct heat can be got many ways,not just the pot on the panel

 

[wheresmejumper]

You mightnt have the luxury of walking back to change the amps by 2/3 every time its a little hot or cold.or changing from vertical to overhead.sometimes you have to pick a setting and weld what comes at you

 

[Richard.]

I prioritise with fusion/pentitration but I've always aimed for bright welds in SS not grey or dull. I then polish the heat tint and If I'm going through I'll always protect the back side either with a backing bar (tip from Tigpaul) or a purge. I also keep some pickling paste on the shelf which really brings the life back to it and I do use it on some things (not always). I'm a stickler for detail and probably a bit OTT when it's not nessecary.

 

[Richard.]

You mightnt have the luxury of walking back to change the amps by 2/3 every time its a little hot or cold.or changing from vertical to overhead.sometimes you have to pick a setting and weld what comes at you

Very true mate and I've been there and like you say gotta make the best of it with technique alone. In the comfort of my own little workshop though I'm lucky enough to be able to set exactly what I need and adjust.

 

[Tinbasherdan]

Very true mate and I've been there and like you say gotta make the best of it with technique alone. In the comfort of my own little workshop though I'm lucky enough to be able to set exactly what I need and adjust.

But surely when advising someone that's starting out, and presumably has the luxury of adjusting Amps on the panel, teaching him to get all the right settings in place should be the first thing? It's certainly how is teach an apprentice. After that he knows what he's looking for in the weld and I don't dispute there's times where you just make do and mend, but there is definitely call to show someone the correct settings before telling them how to work around bad settings

 

[Richard.]

But surely when advising someone that's starting out, and presumably has the luxury of adjusting Amps on the panel, teaching him to get all the right settings in place should be the first thing? It's certainly how is teach an apprentice. After that he knows what he's looking for in the weld and I don't dispute there's times where you just make do and mend, but there is definitely call to show someone the correct settings before telling them how to work around bad settings

Yeah controlling heat input is key with ss to avoid the dull appearance and distortion. Travel speed is really the key for this over amperage settings mind. I do tend to run a little hotter so that I can travel a little faster.

 

[wheresmejumper]

Yeah controlling heat input is key with ss to avoid the dull appearance and distortion. Travel speed is really the key for this over amperage settings mind. I do tend to run a little hotter so that I can travel a little faster.

Thats it.with stick (and mig) you are burning a rod more than taking into account the depth of material (to a certain extent)
You can more confidently tell someone at what amps a particular brand and type of rod burns well at.rate of travel is more constant.
tig welding has no real hard numbers that apply to everyone,as you are managing a weld pool with more variables.slightly more arc length,slightly faster travel,slightly less filler slightly less often will radically change the amps required.
someone isnt 'wrong' because they are running 5 or 8 amps more than you.they could very well be putting less heat into the workpiece

 

[Tinbasherdan]

Thats it.with stick (and mig) you are burning a rod more than taking into account the depth of material (to a certain extent)
You can more confidently tell someone at what amps a particular brand and type of rod burns well at.rate of travel is more constant.
tig welding has no real hard numbers that apply to everyone,as you are managing a weld pool with more variables.slightly more arc length,slightly faster travel,slightly less filler slightly less often will radically change the amps required.
someone isnt 'wrong' because they are running 5 or 8 amps more than you.they could very well be putting less heat into the workpiece

Fair enough but there's a ball park figure of amps which the op wasn't in to begin with , as stated I think it's better to teach someone to set a machine up somewhere close than to teach them to just work round bad settings from the get go, I k ow that travel speed is important but no travel speed in the world is going to help if you are stupidly over the odds on amps

 

[Richard.]

Thats it.with stick (and mig) you are burning a rod more than taking into account the depth of material (to a certain extent)
You can more confidently tell someone at what amps a particular brand and type of rod burns well at.rate of travel is more constant.
tig welding has no real hard numbers that apply to everyone,as you are managing a weld pool with more variables.slightly more arc length,slightly faster travel,slightly less filler slightly less often will radically change the amps required.
someone isnt 'wrong' because they are running 5 or 8 amps more than you.they could very well be putting less heat into the workpiece

Of course. You can only give guidelines. The end result is the important thing.
As above I usually run hotter than I'd advise but it's my Alu tig background that puts my comfort zone on the speedy side with travel so I reduce heat input that way.

 

[Richard.]

Fair enough but there's a ball park figure of amps which the op wasn't in to begin with , as stated I think it's better to teach someone to set a machine up somewhere close than to teach them to just work round bad settings from the get go, I k ow that travel speed is important but no travel speed in the world is going to help if you are stupidly over the odds on amps

Your right mate I agree advise should be given on a guideline basis as I did in the earlier posts (20-25 amp per 1mm) (30 for mild) (40 for cold Alu ) these are the guidelines I advise. Technique, position and general preference will change them from person to person.

 

[wheresmejumper]

Fair enough but there's a ball park figure of amps which the op wasn't in to begin with , as stated I think it's better to teach someone to set a machine up somewhere close than to teach them to just work round bad settings from the get go, I k ow that travel speed is important but no travel speed in the world is going to help if you are stupidly over the odds on amps

Ive done a bit of stainless and would find his 60-65 amps bang on the money for me.3mm 90 amps and up to 110 if in a rush.
you would be equally correct in saying its way too hot,turn it down.youre not wrong im not wrong.
someone learning needs to keep the dulux chart in the back bedroom and aim for adequate penetration and weld form/shape.and buy a stainless bristled brush

 

[Richard.]

Ive done a bit of stainless and would find his 60-65 amps bang on the money for me.3mm 90 amps and up to 110 if in a rush.
you would be equally correct in saying its way too hot,turn it down.youre not wrong im not wrong.
someone learning needs to keep the dulux chart in the back bedroom and aim for adequate penetration and weld form/shape.and buy a stainless bristled brush

I thought I run it hot and fast. Those numbers (especially 100 plus on 3mm) don't work unless your dials are well out. The stainless must be completely cooked at that surely.

 

[Tinbasherdan]

That's my thoughts, I've done quite a lot of stainless and those numbers are waaaay out for me.

 

[Richard.]

An inside corner fillet joint with good fit up I might go close to 90amps (3mm to 3mm)
Butt/lap/outside I'm a way off that .

 

[wheresmejumper]

Over 100 would definitely be an inside fillet.on something critical like heavy wall pipe you wouldnt push it to keep the mechanical properties of the metal,but you could easily ruin the structure of the metal without visible evidence from either side,root or cap.nor would an xray show it up for that matter.jesus you can weld something with wrong filler and it could look right to most tests

generally,the 'fancier' the base metal the more susceptible it is to overheating and losing whatever properties the alloying elements were added to provide.this i cant say with much conviction as it is something i think ive picked up somewhere but not taught.its hazy at best

 

[Richard.]

Mechanical property with regard to material/joint toughness is more likely to be compromised with lower current and slower travel pace. Your figures may be a little hot for my liking and I don't hang about but if it is mechanicals we are looking for your on the right track of cranking things high and getting the travel moving. (Less heat input this way than low current in the same spot over a longer period. This again really depends on what is desired. Weaving and cup walking is another one. Pipe welders often adopt it as you would all to well know. Productivity and the amount of weld you can cover by walking is very high especially if we'll skilled. But mechanicals are more effected by this meathod particularly if it's a wide walk as heat input goes up. Wmj you are totally right it's about trade off and what you need over what you can sacrifice etc.