Hi guys,

I currently working on my Tig. I've just got a few questions.

I'm welding up my collector for my ramhorn at the moment. The first pass I get a nice shiny weld and looks pretty good. I wanted to make another pass but the welds turn out undefined and grey, almost like a mig weld.

The first pass I use 60amps with 10lpm gas flow. I haven't got a pedal so I pretty much do a few welds and wait for it to cool before I continue.

On the second Pass I find I need to use more heat so I bump it up to about 90amps with the gas flow on 15lpm.

This is all on sch10 316l stainless pipe.

Any advice would be much appreciated.

thanks


Modified by vtec_lude at 7:40 PM 1/4/2008


Modified by vtec_lude at 10:44 PM 1/4/2008

 

No need to double pass sch 10.

 

Thanks... that just made my day!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">No need to double pass sch 10.</TD></TR></TABLE>

don't alot of guys do two passes when welding manifolds? first time just a fusion weld and second time with filler? or maybe i'm thinking of something else.

 

I think on the welding info thread they were talking about making a first pass to fuse the root face and then making a cover pass. someone even posted up a diagram of it on the 2nd page.

So for schedule 10 single pass is enough? Are you walking the cup and the putting filler in the middle where the bevel is the lowest or are you just pointing the electrode at the root face the whole time?

 

These aren't xray certified welds by any means, and double pass on such thin material for the application is just a waste of consumables and time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">No need to double pass sch 10.</TD></TR></TABLE>

Thats pretty narrow.

What about if its undercut.


Modified by RCautoworks at 10:31 PM 1/4/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RCautoworks &raquo;</TD></TR><TR><TD CLASS="quote">

Thats pretty narrow.

What about if its undercut.


Modified by RCautoworks at 10:31 PM 1/4/2008</TD></TR></TABLE>

Then you need to do something different, lol

 

Well my first pass has good penetration and isn't undercut, so I won't need another pass right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec_lude &raquo;</TD></TR><TR><TD CLASS="quote">Well my first pass has good penetration and isn't undercut, so I won't need another pass right?</TD></TR></TABLE>

Shouldn't have to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec_lude &raquo;</TD></TR><TR><TD CLASS="quote">Well my first pass has good penetration and isn't undercut, so I won't need another pass right?</TD></TR></TABLE>

Are you beveling the pipe any more then what it comes ? I don't see how your getting full penetration, and a solid ( no undercut ) weld in one pass.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by k24em2 &raquo;</TD></TR><TR><TD CLASS="quote">

Then you need to do something different, lol</TD></TR></TABLE>

Explain to me how your getting full penetration, and a solid weld in one pass on sch10 ? You using 1/4 filler or something ? How are you not over heating the pipe if you in that position long enough to build up the puddle.

I can see maybe a more advance tig person doing something like this, but its not something really noobs should come in and think 1 pass is ok.


I will mention this cause I reread the thread, collector welds can be done with one pass.

If you ever make a second pass you gotta clean off the haz or else you will over heat that weld.


Modified by RCautoworks at 4:12 PM 1/5/2008