Mig or Tig for rollcage

[PhillipM]

Reading through i feel my statement "mig is stronger than tig" was an uneducated one .... and you have made me realise my mistake, (total rookie here)

Yes, so long as it's welded to a decent standard the weakest point on a cage is usually the HAZ, not the weld (MIG or TIG) because the thin wall open section means the heat gets sucked away quickly - I've seen plenty of cages/spaceframes that have cracked from impacts and shock loads and it's always been in the HAZ rather than at the toe or body of the weld - so long as the welder wasn't a monkey in a suit.

 

[langy]

I've been building and fitting cages for more years than i care to remember,
first off mig welding is not a fix for poor tube notching and general fitment,
the fit should be good with whatever process you choose,
i tig all my cages and tube chassis items nowadays as thats what my customers all want,
Saying that theres nothing wrong with a well designed mig welded cage so long as its correctly done,
however i will mig base plates if its going onto a factory floor pan due to all the contaminants, zinc etc so its more forgiving,
yeah its more time consuming and with tig a poor fit will usually result in a poor weld,
the SFI rule book in drag racing classes specifies that all 4130 cages must be tig welded,

think about it, its a safety device, do it properly or dont bother.

Same as for me

 

[Dubdecks]

Are you having a cage made up or buying an of the shelf kit?

Ive been looking at off the self kits, but I'm still undecided

 

[Richard.]

the weakest point on a cage is usually the HAZ,

The weakest point on a welded joint in general is the heat effect zone unless it's a very badly welded joint of course.

 

[chevy2]

Not all cage builders are equal

 

[PhillipM]

The scary thing is, that's not even the worst cage I've seen...

 

[langy]

Not all cage builders are equal

Scary !!! Gary there was a truck at the Supernats a few years ago with lovely looking tig welds and nobody could fathom out how the managed to get into the awkward places, turned out it was PU sealant in the hard to reach bits

 

[Richard.]

Not all cage builders are equal

Hey you said you liked it when I bought it round

 

[chevy2]

Scary !!! Gary there was a truck at the Supernats a few years ago with lovely looking tig welds and nobody could fathom out how the managed to get into the awkward places, turned out it was PU sealant in the hard to reach bits

Dont remember that one but i have unfortuneately seen it done before and cut cages out where the "welds" were shaped from filler.

 

[Robotstar5]

Not all cage builders are equal

Nice to see you taking pride in your work

 

[chevy2]

Nice to see you taking pride in your work

I like to show off my best work to an audience

 

[NickyEng]

Not all cage builders are equal

Jesus, that welding is atrocious. I don't fancy that holding up in a major roof impact....

 

[milk]

i've just put a custom cages one into my m3 and tbh wish i'd made one up myself as the fit on it was shocking

 

[chevy2]

Many years back i had some pre-bent cages from Safety devices, they fitted real nice.

 

[dannyp]

i've seen worse cages as well, tho scaryest weldin on a tube was a trike headstock i was askd to repair as the "welds had cacked" moe accuratly would have been the fillers cracked the grinder found a lot of filler before the whole thing went and sat in the skip of shame.

done a few emergency rollcage repairs after cars had failed scrutineering, there are some good arguments to be had about stick welding on cages

 

[PhillipM]

i've just put a custom cages one into my m3 and tbh wish i'd made one up myself as the fit on it was shocking

I refuse to fit CC cages any more. More hassle than just making one from scratch.

 

[Kent]

Not all cage builders are equal

Finding it hard to believe that is for real. I have seen nothing as bad on safety critical stuff.

 

[chevy2]

Finding it hard to believe that is for real. I have seen nothing as bad on safety critical stuff.

Its from a race car in the USA,
Theres plenty of shoddy work out there also,
the problem of it being such a huge country that theres more of it

 

[Turbo]

A few weeks ago I got a look inside the cab of one of the Paris - Dakar support trucks similar to this.

The roll cage in that was very impressive, looked like it was made in 100mm tubing. The rear was well kitted out too, would put many a good workshop to shame and enough spare parts to nearly rebuild a Bowler Wildcat!

 

[Kent]

Its from a race car in the USA,
Theres plenty of shoddy work out there also,
the problem of it being such a huge country that theres more of it

I often wonder about that as there are so many guys n gals over thier with the backwoods I can fix anything approach

All great until you realise that an accountant from baltimor is not the best guy to work on s cage - no matter how many u- tube clips they might have watched

And I thought I had seen some farmer rubbish