welding an exhaust procedure

[d c]

i am soon to butt weld some 57mm (2.25") stainless T304 pipe sections for an exhaust. 1.5mm thickness. i'm presuming tacking the sections together first is the way to go, if so how many tacks and is it best to run a weld between the tacks or use the stop start technique to avoid blow through?
i'll be using a clarke 90 with argon/co2 gas and have a bit of welding experience.

 

[briannerd]

I use the same technique as in this video:
http://www.youtube.com/watch?v=JohBHzhOyPg

I use a cheap gasless welder and it seems perfect, very little inclusion in the pipe and a very clean smooth weld on the outside.

 

[d c]

lol i just found that clip after posting my question. looks like the way to go.
thanks for your reply

 

[alogaparaloga]

nice find mate. unfortunately the clarke mig like 90 or 151 will not have all that adjustability.
I don't have welding experience and I am learning the hard way though.
Are you going to use disposable gas botles or a refillable ones? what is going to be your Argon to CO2 ratio?

BTW iam welding 57mm pipe that has 2.0mm thickness. http://www.mig-welding.co.uk/forum/showthread.php?t=25086

I ll try to follow advice i got from the members here when I get a chance to continue welding and I ll see how it goes.

 

[briannerd]

same technique, just click on, off, on, off, as you move it round the pipe, tack it in three places to keep it in the right shape

The gasless one i use doesnt have any adjustability, high/low and wire speed fast/slow lol

Thickness doesnt matter, just adjust the timing of the tack to prevent burn through

 

[d c]

nice find mate. unfortunately the clarke mig like 90 or 151 will not have all that adjustability.
I don't have welding experience and I am learning the hard way though.
Are you going to use disposable gas botles or a refillable ones? what is going to be your Argon to CO2 ratio?

BTW iam welding 57mm pipe that has 2.0mm thickness. http://www.mig-welding.co.uk/forum/showthread.php?t=25086

I ll try to follow advice i got from the members here when I get a chance to continue welding and I ll see how it goes.

i only have the disposble type, got a job lot cheap. its 86% argon 14% co2, not ideal from what i've read but i'm only welding a 45 degree bend on the end of the 57mm pipe for a side exit job. where the new pipe joins the silencer outlet i'll be using a u-bolt in case i need to fit another silencer as its a bit fruity sounding at the moment.