tips for effective preperation of the pipe joint

[Richard.]

When i did the 6g on the heavy pipe (oh what larks pip) the gap between the pipes was the same as the diameter of the rod used for the root run. Someone more experienced with mig might be able to tell you if this is what you should be doing with the mig.

With stick this is common. With tig I go slightly bigger than the filler as with GMAW/FCAW.
0.8 wire at 100 amps I'd be looking at a 2-2.5 gap 1mm face.


I'm not the most gifted mig/mag welder but I've done enough to get by. 6G tig roots I've done plenty and as Jim rightly said it's easier to make adjustments with fully manual processes to suit prep variation.

 

[Scotland90]

any advice is good advice man. so wat if im welding a thick pipe like 25mm where does my wire size and gap come into it. still the same or go up in proportion?

 

[lionleg]

No it wouldn't go up in proportion for the root. They would be the same as thinner pipe , you would use thicker rods to fill though.

 

[Richard.]

Makes no difference
You need pen in the root and fusion on the fill.
Once multi passing on joints the thickness doesn't tend to change much else apart from the no of runs you throw in.

 

[henry Kadzielski]

Good morning Scotland90.
I have been told to weld to the prep. Get your prep right and consistent and get used to doing that. As the boys have said previously Mig Mag is a semi auto process and is much less tolerant of variations. Once you get very familiar with what you are doing, you can see and understand what is actually happening during the weld process you can make small changes whilst you are welding. This however takes time to see and recognise. Practice, practice and then some more practice with also good instruction is what it is all about

 

[Scotland90]

im taking these tips back to the college with me on tuesday cheers lads its put alot into perspective

 

[Scotland90]

all u guys that gave me advice cheers i made some headway today my roots are beautiful and i also discovered that my helmet needed a battery that also haha but cheery because the advice wee a file came in handy