Welding Tips and Tricks

RMD root, pulse fill and cap

Looks pretty damn good from this quarterback's armchair!

Steve S

hardhatdiver wrote:RMD root, pulse fill and cap

What gas are you using for RMD?

C10

hardhatdiver wrote:C10

That's interesting, our Miller rep told me we should use 75/25 or straight CO2 for RMD. I have not had a lot of time to mess with the Pipeworx but I did run a 2g 60 deg included angle with a feather edge and a 3/32" root opening. I finished the entire joint with RMD and it bent just fine. Root passes with RMD and CO2 are really easy, I had a student watch me and who had never run bevel, he tried it and his root was pretty good, never blew it out once. If i'm not mistaken we were running about 17V, don't recall the wfs.
Looks great, what setting and joint prep were you using?

John

C10 for rmd root and pulse. One gas is all you need. You can run rmd with c25 but then you can't run pulse. Gave myself a 1/6 land and 5/32 gap. After tacks its a 1/8 opening. Once you start using c10 for your pipe welding you'll stay away from c25. Much cleaner.

hardhatdiver wrote:C10 for rmd root and pulse. One gas is all you need. You can run rmd with c25 but then you can't run pulse. Gave myself a 1/6 land and 5/32 gap. After tacks its a 1/8 opening. Once you start using c10 for your pipe welding you'll stay away from c25. Much cleaner.

Thanks for the tip I'll give it a try.
John

John,
I only have experience with STT and RMD and they can use CO2, 75/25, 90/10 or to a degree whatever has you want. Supposedly, some I these processes were designed around CO2 but work with other gas mixes. Fronius brags that their machines will work with any mixture. So far I believe them.
-Jonathan

Straight from Miller when they set-up the perimeters for the pipeworx machine they used c10.

hardhatdiver wrote:Straight from Miller when they set-up the perimeters for the pipeworx machine they used c10.

Straight from Miller, did you read this somewhere? Not trying to be argumentative I appreciate the information, just curious. Since you can change the gas type on the front panel https://www.millerwelds.com/pdf/spec_sheets/PWS2-0.pdf and they list different gases for RMD I would assume there are different internal settings for the different gases. Maybe Miller feels 90/10 gives the best results?

Check out this etch, kinda scary when you look at the penetration on the right side at the top of the weld.

Talked with one of the engineers. So yes you can use c25 for rmd but not for pulse. C10 can do rmd and pulse. No need to change gas and get the full potential out of the machine. They have those options for other gases because every shop and procedure is different. C25 works great for normal mig but if you are going to do spray transfer or pulse it will not work. And yes every time you change the gas setting on the machine it changes the amps and volts. The other great thing with rmd. Kicks a$$ on thin sheet metal. You can weld 18ga horizontal or down and have a smooth bead inside and out. Even with .035" wire.