tips for effective preperation of the pipe joint

[Scotland90]

i need advice because i feel like im preparing the pipe but feel like im doing something wrong whether it be prep and set up which is most likely the case my setups alright but i kept loosing my puddle and keyholing my root pass

 

[Richard.]

You should see a keyhole on the root pass. If you can't keep control over it and are either burning through or not getting pen then you need to start playing with root gaps and root faces.

 

[Scotland90]

yea makes total sense, im doing a 6mm pipe fixed using .8 diameter and have just been hammering flux off a 6010 electrode for a gap i used a tig rod 2mm and that actually went so much smoother felt as if i was in control of the arc. 16.5V and 2.5 m/min in the last quarter of the pipe i got full penetration about 1-2mm constant. Kinda used a weave for a second then just started a stringer bead when my pool was hot and kept it mostly bang on the middle and on the leading edge and it wasnt burning the metal ahead of my pool.
so iv got the right machine setting its all down to my prep, i use a hand grinder, tape and chalk to measure out my bevel

 

[Kent]

Prep is important on such things. You will struggle to get perfection with a hand grinder
Once you have struck an arc you won't see the changes that effect
If it's not an odd job get a beveling tool on it

 

[Scotland90]

im a student i wish i had a pipe beveling tool but all i got is a grinder

 

[Kent]

im a student i wish i had a pipe beveling tool but all i got is a grinder

Ok so your learning! Great chance to improve and practice your prep.
Good better best never let it rest till your good is better and your better is the best

Oh
Correct little grinding errors with a file! Invariably when you correct with a grinder on small areas it gets worse not better as you bite off too much in the wrong darn place

 

[Scotland90]

haha i must say its definately a learning curve atm. I tried to cut time by beveling with no face then polishing the root face on a belt sander to get a consistent gap that fitted without rocking back and forward. The belt sander still leaves, like u said, uneven sizes of my root face. So a file is an easy way to quickly even this out. Iv been ****hot at plate and testing. pipe is somewhat totally different

 

[Richard.]

I'll second that. A good set of files for dressing up will make all the difference to your face and gap consistancy. Absolutely essential

 

[Scotland90]

sweet because apart from filing to perfection i had no other options, my college makes everybody do stuff the hard way. i had to make a drill drift with a hacksaw, file, scriber and a square right down to polishing it for the finish. Had buffers and stuff but we werent allowed to use them for these tasks. will doing things manually better my skills on how to do things for when i get a job?

 

[Kent]

Still prefer to pick up hand tools over power - time constraints are the reason to use power!
Poor preparation leads to #### poor performance. So I'd speed isn't an issue.
...

 

[Scotland90]

very true, i mean..if i had power tools id use them all the time for alot of reasons. it cant be a bad thing to know how to do something when i dont have much around me lol

 

[Jim Davey]

Open rood MIG welding is very intolerant of variables in fitup. If at all possible you must get your gap consistent. Its easier to compensate for changes in gap/prep when manually welding with TIG or stick as you have the option to speed up, add more or less filler, pull the rod push the out etc, but MIG just keeps chucking wire in as long as the trigger is pressed, so if it closes or opens up on you, you have very few options but to stick with it and hope it comes back to you, or stop, adjust settings and go again. So try try try to get the prep as near on perfect as you can. What exactly is your gap and face?

 

[Scotland90]

yea iv tried things like a slight weave it just adds heat and opens up. i had it set at apx 3.2 i used a 6010 electrode and hammered aff the flux but my good root was when i used a 2mm tig rod. seems like i had full control of my puddle and penetration. i got a good result with a stringer type bead which was excellent for the reduced gap. had it hard trying to root 3.2 using .8 wire haha it felt like my puddle wasnt going anywhere no matter the angle and technique i was using. My face was around 1-3mm equivelant to like 3/32 to 1/8 i think

 

[Scotland90]

and thanks for the tips you dont get this #### on youtube

 

[Jim Davey]

Maybe a 2.5 rod would be a better compromise, or a 3mm face on a 3.25mm gap if you are struggling to stop the keyhole running away. Are you putting on good strong tacks to keep it from moving?

 

[Scotland90]

why with a 2.5 gap? is there some sort of equation for gap to filler size quick calc?

well when im suspecting a blow through coming up and its feeling out of control i tried to weave and that made it worse everytime. i tried a smaller gap '2mm' it worked fine but only at 16.5V with lower wire speed. iv not had a chance to try a bigger gap with bigger face on it yet. Erm i thought i was but relised reading up that im supposed to give the tack a tiny run 10-20mm so it can be ground but strong. Wen tacking if its #### will that effect my other tacks?

 

[Jim Davey]

If a tack opposite your weld breaks the gap will close. As long as they are not failing and you aren't getting defects (lack of penetration) running over them, then you must be tacking them up about right.

 

[Brad93]

 

[ronan]

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.

 

[Scotland90]

yea and wat did u do ur 6G in? Stick?