Struggling on Carbon TIG Roots in Horizontal Position

[tatiepot]

Hi guys,

I’m currently struggling getting my roots to look nice on Carbon steel butts in the horizontal position. I’m using 70S-6 2.4mm wire and have experimented with different root gaps/amperages/travel speed/feeding technique with no success. What i’m getting is concave roots with internal undercut. I’ve been trying to feed the wire into the back side of the pool to try and get a bit of meat in but it’s still an issue. Tried different wall thicknesses too. All butts have been single vee and single bevel to plate preps. Landing edges are under 1mm.

Any help would be much appreciated, cheers.

 

[Tigman]

A few pics may help !
Are you concave when you finish the root , or after you cap the root ?

 

[Brad93]

Is your pipe nice and clean i.e ground back clean

 

[tatiepot]

A few pics may help !
Are you concave when you finish the root , or after you cap the root ?

Concave when I finish the root. I’ll try to upload a few pictures

 

[Brad93]

Is it actually undercut or is it suckback?

 

[tatiepot]

Is your pipe nice and clean i.e ground back clean

I’ve been removing the mill scale both external and internal with flap discs and wheels approx an inch and a half away from the joint down to bright metal. I’ve noticed on the back side the steel really scales up and goes flaky around the toes of the root bead creating an undercut appearance. Is this normal? Perhaps it’s poor quality material?

 

[Brad93]

I’ve been removing the mill scale both external and internal with flap discs and wheels approx an inch and a half away from the joint down to bright metal. I’ve noticed on the back side the steel really scales up and goes flaky around the toes of the root bead creating an undercut appearance. Is this normal? Perhaps it’s poor quality material?

I'd suspect the material.

ER70S6 is commonly used for pipework, Filarc PZ63 something it's been too long since i was involved.

Whilst ER70-S6 has better wetting/flow capabilities it's only double de-oxidised and not as good as taking out impurities.

try some standard Tig rod ER70-s2 and see if it's any better. Triple de-oxidised will remove impurities and oxides better.

 

[tatiepot]

I'd suspect the material.

ER70S6 is commonly used for pipework, Filarc PZ63 something it's been too long since i was involved.

Whilst ER70-S6 has better wetting/flow capabilities it's only double de-oxidised and not as good as taking out impurities.

try some standard Tig rod ER70-s2 and see if it's any better. Triple de-oxidised will remove impurities and oxides better.

Yeah PZ6500 is what i’ve been using Brad. I haven’t thought of trying S-2 wire - i’ll give it a go for sure. Thanks for the advice

 

[Brad93]

Yeah PZ6500 is what i’ve been using Brad. I haven’t thought of trying S-2 wire - i’ll give it a go for sure. Thanks for the advice

That's the one PZ6500

Have you the ability to back purge a small area of the pipe. You can use masking tape to close up the rest of the root leaving 2 inch of weld exposed.

That will tell you if it's the material reacting with the atmospher e

 

[chrismac]

Yeah PZ6500 is what i’ve been using Brad. I haven’t thought of trying S-2 wire - i’ll give it a go for sure. Thanks for the advice

we used to use that too, felt it was pretty good, as mentioned earlier pictures would help, are you keeping the filler wire in there and nearly pushing the root run in or dabbing,

Hi guys,

I’m currently struggling getting my roots to look nice on Carbon steel butts in the horizontal position. I’m using 70S-6 2.4mm wire and have experimented with different root gaps/amperages/travel speed/feeding technique with no success. What i’m getting is concave roots with internal undercut. I’ve been trying to feed the wire into the back side of the pool to try and get a bit of meat in but it’s still an issue. Tried different wall thicknesses too. All butts have been single vee and single bevel to plate preps. Landing edges are under 1mm.

Any help would be much appreciated, cheers.

After reading the first post again , what size of pipe? 1mm landing is pretty light, is the prep key holing, I would think it would be. see how you get on with Brads suggestion's, its quite a bit different once you purge a carbon butt. good luck.

 

[Brad93]

we used to use that too, felt it was pretty good, as mentioned earlier pictures would help, are you keeping the filler wire in there and nearly pushing the root run in or dabbing,


After reading the first post again , what size of pipe? 1mm landing is pretty light, is the prep key holing, I would think it would be. see how you get on with Brads suggestion's, its quite a bit different once you purge a carbon butt. good luck.

Should weld beautifully with a purge

 

[tatiepot]

Well it’s safe to say the roots are looking a hell of a lot better with 70S-2 wire. Thanks Brad

 

[Brad93]

Well it’s safe to say the roots are looking a hell of a lot better with 70S-2 wire. Thanks Brad

No problem. Just needed a bit more deoxidising then.