Welding class pics for your critique

[zardoz]

Thought i'd better throw in a few of my own welding pictures, and see what the more experienced guys think of my efforts. I am doing City & guilds level 2 at the moment. (there isn't a level 3 yet, so next year its back to level one with the TIG)

The metal used was, (I think) 22 gauge steel plates (0.7mm), and 200mm long but as it is 4.30AM I am disinclined to go out to the shed to check

They are both Vertical Butt welds. The Vertical welding was done from top to bottom. The first is done with a copper backing plate, with a channel behind the weld to allow for weld metal. The second is done with no backing plate, just tacked to the bench. 0.8mm wire was used in both instances. Before welding I tacked top & bottom & middle.

The last two pics are the rear of the welds.

 

[TonyWilk]

Hi,
Whilst I'm no expert, that looks pretty damn neat to me - well done!

Yours,
Tony Wilk

 

[malcolm]

Looking lovely and neat. I'm curious about the line down the middle of the one done without a backing plate. Looks almost like aluminium done without cleaning the oxide off the edge but I've never managed that sort of thing on steel before. What causes that? I'm guessing you are running argoshield and don't have a gap between the thin sheets.

 

[zardoz]

Looking lovely and neat. I'm curious about the line down the middle of the one done without a backing plate. Looks almost like aluminium done without cleaning the oxide off the edge but I've never managed that sort of thing on steel before. What causes that? I'm guessing you are running argoshield and don't have a gap between the thin sheets.

I wondered about that myself Malcom. I guess i should have said, that both plates have a 2 - 3 mm gap which I held in place with 3 or 4 tacks, but I am running on Argosheld. I was wondering if the line down the middle was caused by me not weaving (I'd been told to try not to) I just got the initial weld pool going by starting on top of the top tack and concentrating on pulling down a straight weld, from top to bottom, as the gap was small enough for me to not have to "pick up" either side with a weave. So i asume the line was caused by the weld pool in the mid point, sort of collapsing, as maybe i was going a tad too fast. As the bottom few inches, where i either slowed down, or moved slightly over to one side, does not seem to have it ?

 

[vanagon nut]

Looking good!

I'll bet welding vertically is a challenge.

One of these days, I'll give it a whirl.

Neil.

 

[shenion]

Looking good!

I'll bet welding vertically is a challenge.

One of these days, I'll give it a whirl.

Neil.

Actually, it is easiest on thin metal to do vertical down. The weld pool groes faster in the direction you are going so there is less penetration sideways. Since you move faster, there is lest heat input and distortion.

Always did welds flat until I did my utility trailer/cart. Lots of 20Ga steel seam welds. Found out it was a lot easier doing vertical.

And yes, very nice job zardoz

 

[zardoz]

Thanks for the comments guys. As Shenion says, Vertical down is not difficult once you get the hang of it, certainly a lot easier than vertical up, which is something of a challenge to say the least!

 

[English Steve]

Zardoz, nice looking welds. The line down the middle is caused by the weld contracting into the gap as it cools - we have come across this when making long (2.9m) vertical down welds on 3mm plate with a 3mm gap. Close up the gap a little and it will disappear.

 

[snowcat]

Just to point out, vertical down should only be used on very thin meterials, only the most skiled of welders can get a properperly welded joint, I can only achive it with stick running fleetwelds, otherwise its little more than a "wash", your going the right route zardox by practiceing the more difficult welds.....

 

[English Steve]

Yes, I agree with Snowcat a vertical down should not be considered as a structural weld. The 2.9m long efforts I mentioned above are purely cosmetic and to prevent corrosion on the inside of an articulated semi-trailer body.

Steve

 

[zardoz]

It did take a bit of practice, but once i'd "got my eye in" as it were. I could knock them out no problem. Fortunately as it was only a bit of small plate, I could get to the back of it to look at the weld and make sure it was done properly. Also as part of the City & Guilds assessment, you have to make sure the test piece has:

1) Penetration must be visible for a minimum of 75% of the joint and both edges must be fully fused. (As this is level 2, our lecturer though, likes you to try and get 95% or 100% if you can)
2) Total undercutting does not exceed 25% of the weld, with no single length more than 15mm. (Again, we are pressed for much higher quality than the minimum)
3) Destructive testing, done by the 'cupping test' to put the weld root in tension to a depth of 10mm without splitting

I will put the other 4 pieces on the forum over the next month or so, with close ups of the before and after tests. So people can see the level to which we weld at on our C&G level 2. I will be interested in what people think of the things we do on the course. Especially comments from the more experienced welders.
The other 4 test welds are: 1. Butt weld in flat position. 2. Lap fillet weld in the vertical position. 3. Tee fillet in the vertical. 4. Tube to plate tee fillet in Horizontal/Vertical position.

With destructive testing done, such as cupping, nick break fracture, macro section examination.

I look forward to all your comments.

 

[zardoz]

Here are some pics of the welds after being subjected to the Cupping test. The idea is to try and split the weld and see if it fails. first pic is from the front, second the rear of the weld. The weld had to be stopped in the middle then re-started.
(10 gauge/3mm sheet steel)
I did take more pics of the other welds but my camera has threw a wobbler, so they didnt come out right. Will try again.

 

[matt1978]

Looks good mate........keep it up

 

[bigdavesproule]

is the test not bending it along the weld not across it??????? i might be wrong but that is the way we were tested

 

[runnach]

Hi Zardoz,

Looking good with the welds, I am curious on this "cupping" test of the welds, I have never heard of such a test. Testing and inspecting to BS 4872, requires (talking butts on 3mm) stop start 50mm around the central area of butt. Two coupons cut for root and bend test, both faces ground flush, coupon one, root bend test, two face bend test, matl should show no signs of tears or fractures proving lack of root pene or lack of side wall fusion ect. Again just curious, not stating at all this is incorrect.

 

[snowcat]

Yep bend, cuts and etch were always the norm, with a crush test on pipe, back in the day, when I was learning.......

BTW thin was welded with gas then, so we did lots of arc on decent sections hence the etching....

 

[runnach]

I assume you mean nick break when you mention "cuts". Care to elaborate on what is involved with "crush test on pipe" please. When I am examining pipefitter welders, I work to the procedures contained within this link http://www.summitskills.org.uk/businesses/244#startcontent, click on Download the Guidance Notes page 6>9>10 are the relevant pages. No crush test required, I suppose it is relatively thin wall matl.

 

[zardoz]

The "cupping test" is a proper city & guilds (MIG 3267/23) test for weld strength.
the exact wording being:

(Assessment No.1 Butt Weld in the flat position)
The weld is to be further examined using destructive tests:
a. two root tests through 90 degrees
b. one macro section at 5x magnification
c. one nick break fracture test from the centre 50mm to include stop/start position
d. OR as a substitute for items b. to c. above, where 0.8 to 3mm thick metal is used, a cupping test to a depth of 10mm, with the root in tension, should be used.

With this C&G test the metal is low carbon steel either 5 to 10mm thick or 0.8 to 3mm thick, for all five pieces. We used 3mm for our test as we though it would better teach weld control.

 

[snowcat]

By meaning cuts I meant physically cutting and polishing the side face (across the weld) then etching it for inclusions and faults........

The crush was simple but I'm sure bore little relevance to what we were supposed to be on, but the guy who taught us "Bob" welded for the military all his working life, which he didn't mention what he made, we would split large section pipe longitude to create two half's, prep, weld, cut into sections and crush to half its overall diamiter......No falure good weld, but as I said he insisted we learned gas for 3 months, something iv not used since

I have no idea if this has any relevance today or if it did 15 years ago.........

 

[matt1978]

I am not 100% sure as it was almost 14 yrs ago when I was at college, but I think that the cup test, relates to the ductility of the weld. It is definitely a recognised test, but not one which is used nowadays so much.

I think what you describe Snowy, was 'Big Bobs' take on a bend test, may not of been text book but certainly would of told if the weld was sound.