Please Help! I failed my 6g pipe test.

Date 09-12-2009 00:11

Hi Weisel! Welcome to the forum!
Short answer here, cause I gotta leave, is I believe you are dragging TOO slowly to the crater, causing slag and deposits that 7018 simply wont burn through.

By Shane Feder (****)

Date 09-12-2009 01:05

Weisel,
I will have to give a quick response as well but I think Rick is spot on.
6 o'clock is dead bottom of your pipe.
Start your electrode at 7 o'clock and move quickly to 6 o'clock.
From 6 o'clock start welding over the top of the "chicken scratchings" you have made between 6 and 7 and continue up to 9 o'clock.
For the other side grind out your stop/start, start at 5 o'clock, quickly back to 6 o'clock and then weld all the way to 3 o'clock.
Hope that helps,
Regards,
Shane

By Tyler1970 (***)

Date 09-14-2009 00:00

shane, this pipe is a 2 inch .625. if he struck ac at 7 oclock, he would only be about 1/4 in away from 6 being that this pipe is so small. im not saying that thats not right or anything, but i do belive he should try to start from say 9 or 3 oclock. now also he can be long arcing it to as he brings it down to the bottom. he can also be getting to close to the weld as he starts to weld from the bottom. another thing is if the rods are coming out of an oven, depends on who has them and what they perfer to bake them at, that could be baking way to hot, and as you strik arc the flux is just breaking of at the ends. anyother tactic i like to use when taking a up hill test is not to stringer it. on heavy wayy 6 in, like in the 600+ range i only use 3 weave cap. its more like a small lace but only 3 of them. and it comes out really nice. you should try this aslo on the 2 in. if you get good at it you can get away with 2 and have it looking slick. but its what ever they perfer. i wish i had some pics to show you this.

By dbigkahunna (****)

Date 09-12-2009 01:06

Rods are not hot enough or wind. IF you are welding inside then look at the rods. Use fresh from a new can or HOT from the rod oven

By RatherBHuntin (**)

Date 09-12-2009 01:10

Hey Eli, Don't know much about the tig part but the 7018, I am pretty familiar with. Been doing a lot of ethanol projects most 6010 bead and hot, 7018 fill and cap. One of the biggest things I noticed is first have the 7018's in the rod heater, they run a lot smoother that way. Also, wind will kill you with these rods. You are exactly right about dragging the rod to where you want to start. Keep the rod at about a sixty degree angle, towards you. Then start running it up. If the end of the rod's not glowing beet red, your heat isn't right. Grind your start; when you are grinding if you see black specks, that's porosity and you need to get it all out.
Just my 2 cents. It's what I've been doing and it's working well. No problems on any tests so far. Good luck!

By low_hydrogen (**)

Date 09-12-2009 01:14

I don't start that far away on lh for the same reason rick mentioned going to trap slag. I like to light it just a hair in front of the direction of travel and travel back across were i started before it has a chance to cool..you maybe doing it this way and just using to much motion, if someone was to watch me while i got started they probabley wouldn't catch what i was doing especially on a small diameter pipe (it's a quik action but not don't over exerate the motion) let the rod do most of the work for you. On a 6g I always overlap more than I do in the field and I don't start the cap dead center of the bottom of the pipe I'm usaully of to one side a little. I've never had the porosity issue with 7018 but i would assume you are trapping slag or not moving fast enough or possibly not holding your rod tight to your pipe...If you have the option try the excalibur rod by lincoln I really like the ex 3/32

how that helps! I'm sure you'll get it down

p.s. I always clean the weld zone out after grinding wire brush etc the grit from a grinding wheel trapped in your weld can get ya to!

By makeithot (***)

Date 09-12-2009 03:07

grinding can work agianst you try to grind as little as possible. When I strike an arc I always start just forward of the crater then back up into it with 7018 so as to get the puddle established before you fill the crater and do the tie-in. If it was 6010 or 11 I will start just back of the crter to get it hot then do the tie-in, that little bit of trapped slack will br taken out with the grinder before you start the fill and cap. In your case with a tig root if you have porosity in the root it is most likely caused by inadeqaute shielding gas inside the pipe. Keep your arc length short and you also will have less trouble with porosity. when doing the fill and cap do not let one side get to cold before you come back to it have your heat set so you can move fast enough to keep it red with out creating under-cut it's a fine line etween to much and not enough. thats my 2-bits hope it helps.

By rick harnish (***)

Date 09-12-2009 06:10 Edited 09-12-2009 06:38

Hey Weisel! Im home and ready to give a full explaination, but these fine hands on this site got er done! Knew as much, so again, welcome to the site, and the treasure chest of info! Doesnt stop at "How to" welding questions. Ask about anything in this field, the answer is on this site.
Excuse the edit, I had misspelled the word welcome.
Good night!

By Cumminsguy71 (*****)

Date 09-12-2009 12:03

When you strike your arc on the bottom you need to get the 7018 arc to the proper length quickly. You go to long arcing while dragging an inch across the bottom and porosity is a given. Not a super 'perienced welder but have learned the 7018 ain't much for the long arc. I was doing the same thing on the 6g 7018 after running 6010 for so long downhill. We had a guy at school who was having the same problem on a 3g, porosity in the restarts, told him what I'm telling you and he has not had a problem since.....actually neither have I.

Good luck!

Shawn

By KFab

Date 09-13-2009 06:19

hi weisel all i do all day are 2 inch heavy wall pipe and here is what works for me. For test i always grind all my starts and stops with low hi.. period... so there goes your porisity on starts and stops. Second is i run hoooot... then turn it down on your cap..hell u got the hardest part down.. and thats the tig root. i suck at tig. and take as much time as u need i believe its 4 hours per test. ... if the job is 10 grand a month and its a year long then that little test is 120k test.. so take your time.

By weisel Date 09-15-2009 01:51

Ok, lots of good ideas to try out. Thanks guys.

One thing isn't clear to me still though. When I transition from long arcing to a shorter arc to weld, how fast is the movement of the rod upwards to the pipe? Should I slowly (like 1 or 1.5 seconds) bring the rod up ? Or more like half a second?

I am using excalaber rods, I really like them. Have the rods in a hot box at 300 deg. F, is that too hot? Never thought of wire brushing the grinding dust off the pipe, sounds like a good idea. And after that it seems that I am just not doing the long arcing correctly, time to try it out more.

Thanks much for all the advice. I'll post up how practice went.
Eli

By rick harnish (***)

Date 09-15-2009 02:34

upwards to the pipe? Explain that further, please.

By low_hydrogen (**)

Date 09-15-2009 04:28

If I understand what your asking? I'd say Fast get that rod in their quik if by long arcing you mean, getting the rod lit and than gettin closer to your pipe you need to get in their quik.. I personally don't do it that way...lets say I'm going to weld to the left ...I would start a little left scratch to the right and weld back to the left (sorta) Your basically covering up were you first made contact with the work piece but you don't want to start so far away that you can't get back over it before it cools...if that makes sense? Thats how i do it anyway kinda harder to explain than it is to visualize

maybe that your just spending to much time on your starts? Its really just a get it lit cover your tracks and get to moving uphill

hope that helps?!

By F-17

Date 09-15-2009 05:21

I've been at this awhile but not as long as others,coming up on 20 years and will just say that murex rod to me is the absolute best for welding pipe,apparantly murex is out of business according to the local weld supplier.We have excalibur in our shop now and both the lead man and I do not particularly care for it because it has the porosity issues on the starts,the lead man likes to "restart" a rod that's partially been burnt but I NEVER restart a rod unless it's murex and even then if it's important I start with a fresh one.I've welded alot of joints with excalibur and haven't had a bad shot but,I don't get the warm fuzzy feeling from it because YOU HAVE TO CHECK the starts,murex I never worried about.I've found the 3/32 excalibur and atom arc to be about the same,porosity and it spits off more will nots.1/8 inch in both is better than 3/32 I think.

Since it sounds like your somewhat new to the game I'll give you a tip.Load your stinger with the rod pointing down toward the handle in the 45 degree slot(unless your using a worthless shortstub,then bend it down),coil up with elbow high ,strike your arc and drag down to the start point,you'll start kind of uncomfortable but as the rod is consumed you have the perfect rod angle(almost automatic) and it will get real comfortable about a half inch into the travel.With not much practice it is easy to achieve a complete bottom to top(6-12) bead without stopping,same goes for the other side of your coupon if your ambidextrious.Welding is a whole lot like burning with a torch the more comfortable you are the better the end product will be.

Make sure to get it filled out to about 1/16th from being full,perhaps your porosity if coming from trying to fill to much with not enough heat,get it full and burn a slick one on there with the width bead you want,grinding dust should be a non issue on a test coupon,something like t bar stiffners on a flat floor plate,or floor plate butt welds yes an issue where the dust is concentrated and thick.But an in position coupon I'd say no way,anything there is of no consequence and should burn to smithereens.

By low_hydrogen (**)

Date 09-15-2009 17:00 Edited 09-15-2009 17:28

lincoln bought murex out several years ago, part of the deal was they had to use the murex name for a while. If you been burning murex it was lincoln rod in the box. Thats according to our local supply house?

And on a test I would clean after grinding I would assume that your going for the best weld possible and I wouldn't take a chance that i trapped a piece of grit in my weld that shows up in x-ray. Of course you wouldn't need to do it all the time in the field after you get more experience and it does have a lot to do with position and what style grinding wheel and it's make up. When I test even tho I've taken a few and could have passed with less effort I take no chances and I do everything I can to attempt to achieve the best weld possible. just my to cents