SMAW hot pass?

[Avram]

Hello,

A quick question for all you stick welders out there. When welding pipe with the SMAW process which electrode do you prefer for the hot pass, 6010 or 7018? I know it can be done with both, just curious to see what your insight is...

[MAC702]

I'm not a pipeliner, by any means, but I use 7018 for the hot and cap passes.

[lotechman]

The objective of a "hot pass" is to burn out an cold lap at the edges of your root pass and ensure that you have a flat surface down in the vee before adding your fill passes.
Normally it is done with a cellulose electrode ( E 6010 or E 6011)
E 7018 does not take kindly to any highly crowned beads or cold laps and will simply cover them over unless the flaw is ground out beforehand. I have never heard of a "hot pass" cleaning up a root using '18. Too much flux and no allowance to whip or manipulate.
Though last time I did a pipe test was in '83.

[MAC702]

You know, I totally wasn't even thinking about the question. HOT pass is what I saw, but what I read/thought was FILL. I agree that 6010 is the better for a HOT pass.

[TxRedneck]

6010 all the way on hot pass for me. I like a good sized root and a hot pass to verify Ive got no risk of blowing a hole when I run my 7018. Hasnt failed me yet

[zapster]

i guess we have our own methods but i do alot of cooling drums and water filled rollers all with 7018 from start to finish...

granted theres a .010-.015 shrink fit (double heads) before hand but i never had one fail in all these years...

...zap!

[Avram]

Thanks for all of your advice and opinions. I really appreciate it! I know some people don't use a "hot pass" and go strait to the filling with 7018. While others swear by the "hot pass" with 6010. TxRedneck and others -when you put in the hot pass with 6010 what kind of manipulation do you use, weave, side to side, or whip forward and back? Thanks so very much, you all are very insightful.

[TxRedneck]

Avram,
I will say, I dont use hotpass in theory with 7018, but Ive laid lots of full laid 7018 fills. Never open root, open root reservedfor the venerable 6010. Without 6010, I dont find the problems associated with wagon tracks thats commonly repaired with a hotpass. Now the question posed was the manipulation, I use a whipping t. This means I whip up come back down, do a side to side and whip up do a side to side and whip up and do a side to side. Fast, hot and proud. Thats what I do.

[wirehunt]

It's a personnal thing a hot pass For me a straight whip with plenty of heat.

Stephen

[toons310]

For pipe, 7018 rod is correct for your hot pass. The 6010 root should be ground down flat.

[structweld1]

I agree with toons, if you are welding pipe for asme sec.IX, then 7018 is the choice for the hot, fill, and caps. If you are welding cross country pipe then you would use a XX10 series electrode for all of the passes.

[wirehunt]

My last 6010 root pipe test was welded with all ten series rods and it was viewed to ASME IX. The only time I fill and cap with 7018 is if it's specified, otherwise 10 series all the way as it's a lot faster.

Stephen