Rookie in need of a tip.

jones318 · Fri May 02, 2014 4:49 pm

New to welding.In school now trying to stop getting undercut on my last pass on a fillet t-joint,flat position,1/8 7018,3/8' plate.Bout 100 amp's.I've been told to angle up a little more on my last pass and slow down but it doesn't seem to be helping or maybe I'm just not doing it right.Yes,I know this is supposed to be an easy joint but I can't seem to prevent the undercut.Any advice would be appreciated.Thanks.

jones318 · Fri May 02, 2014 4:54 pm

jones318 wrote:New to welding.In school now trying to stop getting undercut on my last pass on a fillet t-joint,flat position,1/8 7018,1/4' plate.Bout 100 amp's.I've been told to angle up a little more on my last pass and slow down but it doesn't seem to be helping or maybe I'm just not doing it right.Yes,I know this is supposed to be an easy joint but I can't seem to prevent the undercut.Any advice would be appreciated.Thanks.

AKweldshop · Fri May 02, 2014 4:55 pm

A 100 amps with a 1/8 7018???!!!

Who's teaching you that garbage??

Watch these videos.

https://www.youtube.com/watch?v=8VKkIH3e4os

https://www.youtube.com/watch?v=nq2LgmThpP8

MinnesotaDave · Fri May 02, 2014 5:02 pm

You have to watch the undercut fill in. That's how fast you go.

Yes, angle the rod more towards the verticle plate.

I question 100 amps with that rod - I'm around 120 or higher depending on the situation, flux lightly dragging on pass number 2 and sometimes the verticle plate, (making the arc length about 1/16") if this is a three pass weld.

jones318 · Fri May 02, 2014 5:48 pm

Thank's guy's.Yea,I asked if I should try turning my heat up since I keep wanting to go too fast thinking it would make up for it but was advised not to.I'm going to try 115-120.

Fri May 02, 2014 6:36 pm

More heat will "likely" help. How much heat depends on your technique.

I personally like 105A, but it takes practice. The reason I use 105, is because I also do 1/8" 6010 root at 105A, using "bury-rod" technique. When I can do both at the same setting, I don't need to run (or send a helper) to the machine to change the setting when I switch rods.

When I'm not doing 6010 roots, just 7018 on plate or similar, I like about 115A, because it's a bit faster and smoother.

Keep in mind, these amp settings are only consistent on digitally controlled machines. On old-school machines, the actual output will change with input voltage, which varies from market to market. Your 220V service in your home, for example, may actually measure 220, 230, or 240 volts.

Steve S

Wes917 · Fri May 02, 2014 7:21 pm

When running that rod I'm usually in the 110-115 range, but I like moving a bit faster as well, though there was one machine in the shop I'd set to 125. It just seemed to run better there, so experiment a little and find what works best for you

AKweldshop · Fri May 02, 2014 7:40 pm

Steve,
I don't know how you can hold an arc at that low of amperage!!

Seems like you would get a lot of cold lap and lack of wetting in.

Just me,

~John

DylanWelds · Fri May 02, 2014 7:52 pm

When I was in school we were instructed to run 1/8 7018 at 100 amps. Since I started working in the field I've learned to run 135 flat and overhead and about 115 for horizontal or vert.

To avoid undercut experiment with rod angle and heat ad also make sure you are not getting ahead of your puddle to quick. Stay in it and allow the material to fill into what the arc is chewing out.

AKweldshop · Fri May 02, 2014 7:56 pm

DylanWelds wrote:When I was in school we were instructed to run 1/8 7018 at 100 amps. Since I started working in the field I've learned to run 135 flat and overhead and about 115 for horizontal or vert.

To avoid undercut experiment with rod angle and heat ad also make sure you are not getting ahead of your puddle to quick. Stay in it and allow the material to fill into what the arc is chewing out.

That's exactualy what I've found.

Rod angle and travel speed are a big thing, more important than amperage.

IMO

jones318 · Fri May 02, 2014 9:38 pm

Thank's again for the responses guy's.I really need to start visiting this site daily.Lot's of knowledge.I heard 7018 was alot better/easier than 6010 but I haven't quite got the speed and consistency down with it.Didn't have any problems with 6010 fillet in the flat position but I'm stuck with the 7018.Ready to get back to school on monday and try again.

kermdawg · Sat May 03, 2014 8:39 am

jones318 wrote:Thank's again for the responses guy's.I really need to start visiting this site daily.Lot's of knowledge.I heard 7018 was alot better/easier than 6010 but I haven't quite got the speed and consistency down with it.Didn't have any problems with 6010 fillet in the flat position but I'm stuck with the 7018.Ready to get back to school on monday and try again.

It's not that 7018 is "better", its just a differant rod for differant applications. Apparently in some parts of the world they actually use 7018 for pipe root passes...so it CAN be done. But in the states thats pretty much unheard of.

Just remember every rod is it's own skill. And every pass it's own challenge. Gotta practice em all, but some will probably come easier than others. I remember it took me FOREVER to figure out how to keyhole with 6010 and not burn a huge hole in the groove. It's not quite second nature yet but it's getting there.

Watch all the videos you can...it WILL make you better. You'll probably get taught one way to do something in school, but in reality there's 10 ways to do it, and you might find something that works better for you. It's good to know a couple ways to do everything, cause sometimes the one way you know how to do it wont work for you for whatever reason.

Take some pictures and post em up. Its easier to see the problem with welding than describing it alot of times.