poor standard welding in 'flagship' industries?

[hotrodder]

Porsche 917s were (mostly at least) MIG welded i believe and they pressurised the entire thing(?) so they'd know if when a fatigue crack appeared. Even with modern synergic MIGs i doubt (m)any would be able to nail a chassis like that together out of small dia ally tube and have all the welds pretty enough for their twitface page

While the different works teams (and companies they subcontract things like exhausts and radiators out to) may be able to afford to employ the 'best welder in the world' i bet they don't. Finding someone that wants the 'prestige' enough to work for less £££££ = more to spend elsewhere. Or more profit in the case of subcontractors. I don't really follow F1 but i only can think of one instance where a car retired due to a broken exhaust and none where a radiator has let go? The only nasty failure that comes to mind was the tragic death of Senna whose steering column had been cut and shut to provide him with the different driving position he requested AIUI? It's still not known for certain if it broke and caused the crash or broke as a result of the crash?

Metal shaping rather than welding but Geoff Moss' comments about piecework and origional race cars versus restorations/replicas from around 5 mins in seem relevant...

 

[PhillipM]

Some of the F1 stuff there looks like it's the demo/show exhausts - they'll be knocked up out on the cheap out of stainless by a trainee rather than the rather fragile inconel ones usually used. Half of that is just knocked together with seam welded pipe in the earlier pictures for example.
Show spec racecars are often oddly cobbled together from various years spares and demo/shipping pieces, often in a config that never actually raced because of it.

Most of the F1 stuff from the past few decades you can tell if it's a race manifold because all the welds are planished out inside and out so they can take the stress risers out (IIRC at one point Mclaren were making the headers out of 0.4mm inconel, so I guess pretty crack prone!) - Mac's current manifold for example:

 

[hotrodder]

Inconel or stainless they often/usually start as sheet due to the sizes and wall thicknesses used not exisiting as commercially drawn tube. Let alone seamless tube. It was years ago (i did post a pic somewhere on the forum) when i last got to play with an F1 exhaust and while the welding wasn't "worthy of twitface" i was pretty damn impressed by the overall quality of the thing

 

[Maker]

inconel ones usually used

Chris said they don't get used long before they're replaced, so why would the go the expense of using inconel?

 

[PhillipM]

Weight, you can use a thinner section with less risk of cracking compared to more common stainless options.

 

[whm_fab]

Inconel or stainless they often/usually start as sheet due to the sizes and wall thicknesses used not exisiting as commercially drawn tube. Let alone seamless tube. It was years ago (i did post a pic somewhere on the forum) when i last got to play with an F1 exhaust and while the welding wasn't "worthy of twitface" i was pretty damn impressed by the overall quality of the thing

100% correct!its all made from sheet - it always amuses me when i see the guys making F1 exhausts cutting the tube with a scissors, instead of battling with stainless and and a bandsaw

im not taking away at all from the craftsmanship btw, they are absolutely fantastic fabricators etc.

i love the bit in this program (at 30.07) its a few moments of film that inspired me to so what i do.

 

[whm_fab]

Chris said they don't get used long before they're replaced, so why would the go the expense of using inconel?

weight saving and incredible stability at insane temeratures for 2+ hours.stainless or Ti cannot handle that

edit: phillipbeat me to it

 

[PhillipM]

Great, I was going to bed and now I HAVE to watch 5 video's on english wheeling and one on F1. Thanks guys.

 

[hotrodder]

Found it http://www.mig-welding.co.uk/forum/threads/f1-engine-pics.10577/#post-127623 Didn't realise they'd started planishing welds out for fatigue reasons, i thought they were just shotpeening the finished parts. Too long ago to remember now but the exhausts in the link were definately sub 1mm wall thickness before they got bent so probably closer to 0.6mm at the outside of bends

 

[whm_fab]

you wouldnt want any air gaps tacking that

 

[PhillipM]

I wouldn't even want to pick the torch up, I'd probably trip over and flatten the whole thing

 

[hotrodder]

i love the bit in this program (at 30.07) its a few moments of film that inspired me to so what i do.

Good vid that, i remember watching that when it was on and screaming at the TV 'cause they only gave Steve and his exhausts a few mins.
Another good one to keep Phillip up is Equinoxs qualifying boost which follows Cosworths development of what would become the GBA

 

[Chris Stevens]

F1 exhausts are not generally made in house, and are bought in. They have a finite lifespan and as such I cant see any of the teams choosing to pay higher unit cost for pretty welds? Guy I know used to build and restore historic F1 cars, which were often used for show and promotional purposes, and I would guess the cosmetic final finishing work on those, is a good deal better than those which are actually raced.

 

[whm_fab]

Good vid that, i remember watching that when it was on and screaming at the TV 'cause they only gave Steve and his exhausts a few mins.
Another good one to keep Phillip up is Equinoxs qualifying boost which follows Cosworths development of what would become the GBA

me too! you'll like this so, another piece on him, skip to 12.50, you can see them here cutting the tubes with a snips

F1 exhausts are not generally made in house, and are bought in. They have a finite lifespan and as such I cant see any of the teams choosing to pay higher unit cost for pretty welds? Guy I know used to build and restore historic F1 cars, which were often used for show and promotional purposes, and I would guess the cosmetic final finishing work on those, is a good deal better than those which are actually raced.

my point is, at that level, all welds should be "pretty" regardless of their lifespan, it takes no more time to do a pretty one! why would someone at that level be happy with their welds?
I know if i was in a position like that, with all the best equpiment and raw material, id be damn sure my welds were as close to perfection as possible. This is supposed to be thee yardstick for engineering perfection - i dont think incosistent beads, tungsten dips and blobs have a place there.

 

[daleyd]

I wonder how much of it also comes down to time pressure, I imagine (And it is only a guess, it could well be completely different....) that most of the time/effort is spent in design and development and at the last minute the things actually get thrown together, in the expectation that they will last 1 maybe 2 races, after which the design will probably change again.

 

[Chris Stevens]

Not sure that pretty looking welds, are truly reflective of engineering perfection? Is there any evidence to suggest stack of dimes welds are any better than a full pen weld which doesnt appear quite as good?

 

[Maker]

Not sure that pretty looking welds, are truly reflective of engineering perfection? Is there any evidence to suggest stack of dimes welds are any better than a full pen weld which doesnt appear quite as good?

I think any inconsistencys in a weld will be more Likely to initiate a crack?

 

[daleyd]

From what I've seen in motorsport in general, form really does take second best to function. Not just in welding, but in castings, bodywork etc

Ferrari F40s were renowned for being completely unfinished inside, with glue and sealant everywhere, as well as having wafer thin paint on the outside.

 

[Mick B]

Hi Folks, I said id post this here to see what others thoughts are on the subject.

Naturally, as welders, im sure we all (well I do) inspect every weld I ever see, from hand railings in shopping centres to structural stuff etc, everywhere I turn in day to day life I look for welds if im bored

<<<<<<<<<<<<<<<<<<<<SNIP>>>>>>>>>>>>>>>>>>>>>>>>>

As a builder I know exactly what you mean ! Whenever I'm in a church (not very often !!) I am always looking towards heaven as one should and wondering how the hell they managed to get that big beam up there or how they managed to set that part of the roof out etc etc. Next minute my wife is tapping me on the shoulder and telling me I'm supposed to be kneeling now, not looking around !!.
Even when I'm in a new house I compare how the builders have done something and how it should have be done......... little things like the gap around a door, whether the architraves have been arrissed (sharp edges planed off) and many more things.
Now days everyone seems to have to get every job done as quickly as possible to make more money instead of doing it properly. Who me ............ old fashioned ? You bet I am and proud of it !

 

[whm_fab]

Not sure that pretty looking welds, are truly reflective of engineering perfection? Is there any evidence to suggest stack of dimes welds are any better than a full pen weld which doesnt appear quite as good?

Well for a start, 'stack of dimes' never suggests anything about penetration? my welds are 'stack of dimes' as im in the motorsport industry, and while i would never compromise structure for looks, asthetics is an important part of it. but to keep me on point i still do all the certification tests for stainless dairy tube, which as you know are xray tested etc. and still look pretty from the outside.
Its funny when i turn up to the exams with these guys that just do it 'as a job' with all the run of the mill stuff, and i show up with my fancy miller lid, gas lens, nice gloves, my little bottle of acentone and scotchbrite, they think im a weirdo!

As Maker suggests below, not always, but more times than not inconsistencies will point to a weak link in the weld run.
i find when i look at welds 90% of the time its the start point after a stop where the welder will continue on at the speed he was travelling at after a restart instead of waiting for full penetration before moving again. you'll normally see a cold 3 or 4mm before full penetration resumes.

I think any inconsistencys in a weld will be more Likely to initiate a crack?

more times than not!