tig root,stick fill and cap pipe question

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when you put in your tig root and you put to much heat on during your hot pass it frosts the root. any one have any tricks to avoiding this. i can put a stick hot pass in really quick and not frost it but i would rather put down a nice thick hot pass and then just cap the pipe(2 inch pipe) what problem is caused from frosting your root and why does it only do it on your hot pass? i can lay the heat on while capping over a quick hot pass and it doest frost the root.
Reply:stainless? keep your purge on at about 10
Reply:carbon steel pipe tig root, no purge, no stainless. 7018 fill and cap
Reply:what is a frosted root...?
Reply:he's oxidizing his root, or almost repenetrating causes unacceptable oxidation on the back side.If it's from excessive penetration you can change your torch angle, If it's from too much heat, you're out of luck, can't beat the laws of physics, unless you want to put in a really cold fill pass.Welding EngineerCertified Scrap Producer
Reply:Work that peddle and work that angle, I keep my angle at about %5 - %10 for the root and the hot pass and work the peddle based on my hey hole and puddle.  I also run my amps at 90 and have a 3/32 root face to avoid blowing out the key hole.
Reply:Are you free-handing or walking the cup? It sound like you need to speed up some. try focusing on the sides a little more than the center. Sometimes turning up the amps a little will let you run faster so you dont get so much heat soak.
Reply:i have been laying in my hot pass with a fast stick pass to avoid frosting it. i guess i just need to take the time and practice more
Reply:He's putting in a smaw hot pass guys. Half of the responses are addressing his question as if he were putting in tig fill passes. you're just trying to get out of the pipe in 3 passes instead of 4 right? You aren't frosting the root when you run a hot cap pass over your quick fill because there is more material layed into the joint to absorb the heat.  Can you possibly experiment with adding more filler on your root pass to give you a little more grace on the hot pass repenetration issue?As long as this is acceptable for the code you are working to I'm all for finding ways to get **** done faster. btw i'm not a certified pipe welder. just a plate/sheet/uncertified pipe guy hahaha. Yes I know that makes me uncool.