Help me settle a disagreement (welding related)

Hey me and one of the guys in my shop are having a disagreement about what the definition of a fully penetrated weld is on thicker metal. We cant agree between whether a weld bead has penetrated based on a) if the weld bead has protruded to the back side of the joint (meaning you can visibly see that the back side started to melt) or b) proper penetration means that both pieces have completely fused and as long as the bead is as wide as the combined thickness of the material and they both melted together its fused and penetrated. We both agree on a cold weld being one that is just sitting on top of the work or barely bit into the metal but its more of how deep does the weld have to go for it to be considered properly penetrated? Help me out because one of us owes the other lunch and no one else wants to get involved in our little dispute.

 

If you go at least halfway in from both sides, that's full penetration to me.

That's what she said.

 

haha I was wondering how long it was going to take for someone to make a joke like that.

 

Blown...pushed...burnt...melted all the way through the back side its by the book.

 

all the way through was how i was taught

 

3/8" plate I leave a gap the thickness of a penny so I can push the rod/wire through. Run a root pass grind it out then lay the filler passes then close it off with a nice cap.

 

Im the one that said it needs to start burning through the back but between two of you I got different opinions. Ive actually pulled out my old welding 101 school book trying to find the answer but all it talks about is welding fkn pipe with a root pass and cover passes. Havent found anything related to tee joints in particular.

More or less I think on a tee joint filet weld that you should see the weld just start to burn through the back side of both pieces of metal, the other guy claims as long as you got it burned in deep enough and the weld bead is wide enough then its should be strong and good to go. I didnt agree and figured if your only gonna weld half way through then use metal half as thick cause thats all the strength your getting.

 

Yep, What you said...

 

sounds like jimboys for me!! Ill take the special lol thanks

 

Ignore the different terms for the cracks but this is what a full penitration weld should look like with a small bead on the backside.

 

thats for a butt joint and I definitely agree with that pic but is there anything conclusive about a tee joint? Thats why we were arguing about it, he claims that on that particular joint even if its done proper you wont see it melting the back of the base metal. I said all joints should penetrate to the backside on the parent material of both pieces. Im worried we are both right SORTA but Im not for sure.

 

As long as both of the weld toes are not rolled over I would think you have good penetration.... now if it looks like a catepillar or bubble gum... grind it out and turn the heat up!

here's a quick pic from google...

 

damn maybe I do owe lunch.... If that is in fact a properly penetrated tee joint then Im wrong. I kept arguing the issue because of what a properly burned in butt joint should be. oh well time to eat some crow

 

If its T joint the bevel the piece that goes vertical to insure max penitration.

 

chaddilac posted a good picture. Full penitration on a typical t joint should be half the material thickness with the weld bead from each side meeting in the middle.

 

ok so he was wrong about how wide the bead should be but he was definitely right about the rest so Ill still buy him a burrito tomorrow. I hate being wrong, its my biggest problem and annoys me even more than it annoys other people. thanks guys

 

On thicker material, there is no such thing as a properly penetrated t joint in my opinion. That is why we bevel, to get proper penetraion all the way through the material.

 

ok one last time for lunch.... a properly penetrated tee joint is melted clear through the whole joint.. regardless if you had to bevel to get it. That is my contention, I think every last micro meter of metal in the joint needs to be welded to be correct. The weld may work fine forever with less than that in a car application but we were arguing whats right and whats wrong and I shook on lunch thinking I was right. My thoughts were with a roll cage, that tube needs to be melted clear though to the next one if someones life depends on it. Granted we arent prfessional welders unless youre talking soldering wires then everyone in the shop can do it flat, vertical and overhead lol. We weld on our own projects and this was something that came up at lunch time.

 

This is a picture of a standard fillet weld.
A complete joint penetration groove weld of the same configuration would have a 45 or 30 degree bevel on one side of the vertical piece with a root opening of 1/4" for 45 or 3/8" for 30 degree with a back-up bar. The joint desigination per AWS D1.1 would be TC-U4a

 

ok so the weld can be cosindered good as a filet weld as shown in the picture but I guess depending on the application where full joint penetration is neccesary then it needs to be welded all the way through... Im glad I dont do this for a living. Is it safe to say we were both right? Id rather pay for my own lunch than his and like I said I was unsure if we were both right. It sounds like thats the case where depending on application the necessary weld will be different for the same joint

 

ok thats what I needed to hear thanks Ill be eating free tomorrow.

 

Bloody Australians .always gotta make a joke!....root crack indeed!

 

thanks guys theres nothing that taste better than a free lunch

 

Well, at this point I'm not sure who's buying.

But I LOVES me a big ol' stack of crow burritos!

 

That T joint pic'd on page one sure looks pretty........But I highly doubt it would pass the Fillet Fracture test. Full penetration means all the way through & if it's not ...then it sure better be enough to make the weldment material TEAR before the weldment material pulls away from the weld itself.

Word mumbojumbo is what alot of this stuff is, but when you fold the material over the weld, something has to break & it Better be the material itself tearing......and not just pop off the fillet weld like a candy stick.

That weld pic'd looks very nice, don't get me wrong.....and the legs of the fillet look to be equal too or greater than the thickness of the base material ....which is the AWS rule......so.......different types of testing for different reasons......

Some of the groove test I run are cut in half in a wet saw & then folded over to see what gives first........anyway.......Carl Hagan

 

wtf cares

 

[QUOTE wtf cares [/QUOTE]

burritos are at stake! we should all care!

i always like to see the weld coming thru the other side. if it doesn't, you really have no way of knowing 100 percent how deep it did go.

 

wtf asked you?

 

well at first I thought I was wrong because of that damn pic, then it was revealed that the weld was correct but needed to be finished on the other side so I was right. Im stoked, got the special of the day and didnt even have to leave the shop to get it!!

 

Full pen welds are gapped 3/32 to1/8 apart both pieces have to beveled with a small landing. The root has to COMPLETY tie in both the top and bottom. Then needs to be filled and capped above flush. I just did 3 steel pipes that passes x ray 100%