When to start trusting your welds .

[PSweeney]

Being self taught in mig and tig I weld to a reasonable standard, struggle welding out of position but I compensate by moving work as best I can. I've cut and etched welds and beat them in the vice and got plenty of my welding on previous projects still going strong however I'm still hesitant to do critical strength welds despite not one of my welds ever having failed, so the questions to pros and hobby welders alike is at what point do you start trusting your welds ?

 

[Tinbasherdan]

i don't really know, I'm confident that my welds are strong, but that's come from experience over a few years. I'm not going to say I've never had a weld fail ndt, I don't think any of those on here that do it for a living have either, but most of us would be happy enough to do most welds

 

[God mode restorations]

I use me trusted old man method. If he can't brake it no f@@ker can

 

[cocker]

You whack hot welds with your "old man" ??

 

[Barking Mat]

Cocker, maybe not helpful, but that is a quality response.

 

[God mode restorations]

Right right right...old man as in father..not as a part of one's anatomy ...

 

[Bill Edwards]

When you are reliably consistent with your welding. We can all have good and bad days, but the difference between the two shouldn't be too major - you can't start welding things if you judge yourself by the good days!
Also, particularly with MIG, you should ideally do some testing that shows you the results obtained by different welding techniques and to be able to judge a weld by the noise and watching the puddle so you know how the weld is turning out based on experience.

Not having welds break isn't actually that good, because until you see them break you can't really judge the strength - has it not broken because it is several times stronger than it needs to be, or is it right on the edge but hasn't quite gone yet.

Have you tried some nick break tests?
What sort of welding are you considering to be critical, could it be dangerous if it fails, or expensive, or just embarrassing?

It's not a bad idea to post photo's up on here. You can't tell much from a photo, but people are then able to make some basic judgment and offer advice.

 

[Richard.]

Bill I couldn't of put that better my self.
You should be trying to understand what your welding can take to distruction. As Bill rightly said not having one fail isn't always a good thing as you have no reference point regards to how much it takes before it does. There are a number of basic dt's you can carry out at home with basic equip. Don't go and smash it with a hammer as again it's not giving you any indication of force.
Bend tests across faces and roots are good, cut polish and etch for macros to see fusion/pen levels , nick breaks are another. You'll soon get a feel for how good they are with some basic home distructive testing.

 

[jinjahbiscuit]

You whack hot welds with your "old man" ??

Grief, that one caught me off guard, I'm going to have the giggles all day now

 

[Dee J]

When to trust your welds? Its a sliding scale isn't it. Trust to hold a gate hinge? Trust to hold a chair up or trust to hold your motorcycle together? Design comes in to play too... Design to limit the stress on welds, or so that a weld fail isn't lethal....

 

[ms08]

Cocker, maybe not helpful, but that is a quality response.

Think I would think twice before whacking welds with that!

 

[Richard.]

I wouldn't need to think twice. Poor welds wouldn't stand a chance

 

[whompa73]

I think realy its an intuative thing. I welded for a living (mig) and with doing it day in day out on everything from jig work to mechenery and structural for an architectural engineering firm. The confidence comes with experience and for me atleast I always said I weld by ear as I knew what the welder was doing by the sound it was making (well the sound of the weld being laid). However having not been in the game for a while and only just getting back into it as a hobby I think it will be a while before I trust my ear like I used to . However I would still feel comfortable taking on most welding that my 210a single phase professional welder is capable of. If I thought that either I or my welder were not up to the job in hand then I'd have it done by someone with the right kit & experience. If you have a " critical" and you have conserns wether you are up to the job. Then may be you should be taking it somewhere to be done even if its just for peace of mine. You could alternativly either do the job or an identical test pice and then have it checked by a reputable welding firm.

 

[dannyp]

you get a feel for how much abuse a weld will take, if your welding ok its rarely the weld that gives even if it's not perfect usally whatever it is gets torn off and the material tears in the heat affected zone. usally the only time i get weld failing where they crack through is where there is massive amounts of vibration. but in those situations its not a safety critical weld as it is know that at some point the welds will fail, they allways do

 

[PSweeney]

Thanks for the input guys. I try to design in as much mechanical strength as possible but There's just certain welds which end up being critical to the integrity of something, for example the bearing headstock on a bike frame etc. Yes it can be gusset but when the surface area of the adjoining pieces is limited, obviously the weld is critical. I'm self taught but the learning curve has been over the last 10 years and fundamentally the biggest thing was to buy a proper mig instead of the hobby **** and to put some proper seat time into learning tig. I'm fine with both mig and tig to the limit of the machines capabilities and I've taken measures to ensure I have enough amps and proper 32a power supply available to properly burn in big stuff but there's always that little doubt in the back of my mind on critical stuff.

 

[whompa73]

Thanks for the input guys. I try to design in as much mechanical strength as possible but There's just certain welds which end up being critical to the integrity of something, for example the bearing headstock on a bike frame etc. Yes it can be gusset but when the surface area of the adjoining pieces is limited, obviously the weld is critical. I'm self taught but the learning curve has been over the last 10 years and fundamentally the biggest thing was to buy a proper mig instead of the hobby **** and to put some proper seat time into learning tig. I'm fine with both mig and tig to the limit of the machines capabilities and I've taken measures to ensure I have enough amps and proper 32a power supply available to properly burn in big stuff but there's always that little doubt in the back of my mind on critical stuff.

I take it your a biker. I too am into my bikes and have photographed for bsh several times and even writen for them on occasion ( heavaly edited as im dyslexic ). To be honest it sounds like you have things well in hand and maybe your intrepidation is more down to tackling a job you have held as being in asteam for a long time and now its time to tackle those jobs its natural to feel slightly intimidated by them but i think you will do fine and once you have compleated it you will know/feel if its ok or not. It sounds like you know your capabilities and your welder. I am still in the get to know you stage with mine she is an older modle but very well built probably the best single phase i have used but no 2 welders weld the same. Just go for it coz you can always cut it off and start again. But if you are doing a motorcycle frame especially a headstock then I'd look at making a jig and you'll need to be carefull about it warping out of true with the heat. good luck!!