My TIG efforts

zardoz · Apr 12, 2009

Here are some pics of my efforts at TIG at my evening class city & guilds level 2. I appologize for the pics i made the rookie mistake of taking them in bright sunlight1 (You wouldnt think i actually have an A level in photography !) If you cant see them properly let me know and i will take some others.

They are numbered 1 to 9. Over the period of 6 weeks I did them, these are a representation of my progress. The steel was 1.6mm plate. The flat welds had purge gas to rear, welded on a jig. The vertical welds had no purge and were just done clamped to a vice.

First here is the machine I do all my work on. A Miller synchcrowave 300

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Here is effort 1 front and back.Pretty rubbish and no penetration on the rear of weld.

Weld 2, slightly better weld but no penetration whatsoever, in other words worthless!

Weld 3, slightly better weld though a bit wobbly. penetration a bit better but still way off.

Weld 4 is a better less messy weld with again better pen to the rear. (This is what the tutor laughingly calls "A mechanics weld") :laughing:

Weld 5, again a small improvement, but still a way to go.

Weld 6. By now i was getting well peed off. I could do a reasonable weld though I could not seem to get constant penetration all the way along.

Weld 7. Could it be true? I nearly had a good weld of an entire 8 inch run ?

Weld 8. The welds were now, Vertical up butts. I was much better on these for some unfathomable reason ?

Weld 9 Again a small improvement.

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I have to do five weld pieces for the exam. So far i have done a flat butt, and a verticle butt. Both have passed the cupping test. I have also done a flat verticle lap weld. This is being sawn in half and tested next week. I will try and remember to photograph these for you to see, so anyone who is thinking of taking up the C&G TIG can see what is done. I will also continue to take pics untill the course is finished.

hotrodder · Apr 12, 2009

Have you tried gapping the coupons? Not a huge root gap but around 1mm so that you can see the edges melting away rather than having to judge pen from the puddle alone

dutchman · Apr 21, 2009

Thanks for the pics, Zardoz. It is interesting to see the progress that you have made. :cool:

Would love to see a similar post about fillet and lap joints. My fillet tig-welds can use some improvement. On thin stuff the weld pool doesn't seem to spread nicely and I suspect it may cause lack of fusion. Hope to find some more clues for improvement in your post

rswinburne · Apr 21, 2009

Some really good welds there. wish I could weld like that first time.. I was dipping the wolfram all over the place and blowing holes.. Can't wait to get my own tig welder to practice :P

patreusch · Apr 21, 2009

looking nice definitely showing signs of improvement better than my tig welds

dutchman · May 8, 2009

How is the fillet and lap tigging going, Zardoz?

Got any advice for someone hoping to achieve perfection? :laughing:

I know that torch angle, arc length (see Hotrodder thread), watching the notch (centre of v shaped weld pool) and travel speed are hugely important. And, allegedly, if you manage to control those things properly and feed in the appropriate amount of filler, good welds should be the result.

Is there anything that I have missed, or do I just need to practice more and more, and more and more and.... more :welder:

patreusch · May 8, 2009

practice and it helps if you can get someone better then you to see your welds and give you tips

runnach · May 8, 2009

If gapping, I would suggest at least three good root tacks, even then, with 1.6mm matl, the chances of closing up is great. If this does happen, not all is lost, slow your speed of travel, pay good attention to weld being deposited, give it time to slump right through (giving good pene) at the same time, deposit a fair amount of filler into weld pool, do not "dab" wire into pool, you want suffice for pene and, to bring face of weld past the flush.

Best way of describing wire deposit is if I was pushing my finger into your chest, not a poke, a push......

HTH????

mv_tig · May 8, 2009

nice welds , what filler are you using ?

arcequip · May 8, 2009

Getting there, tig welding is an art... Number 9 is looking good..

Jaeger_S2k · May 8, 2009

First thanks to Zardoz for posting his first and subsequent welds. Good on ya' man! Even I can see you're getting better.
Thanks

Hi rannach,
Can I ask you to expand on parts of your post, it would help me understand more.

runnach said:
If gapping, I would suggest at least three good root tacks, even then, with 1.6mm matl, the chances of closing up is great.

Am I right in thinking, you would try to avoid the closing of the gap as the intention is to close it with 3 passes of root?
But closure from 1 of the passes will reduce pen?

runnach said:
If this does happen, not all is lost, slow your speed of travel, pay good attention to weld being deposited, give it time to slump right through (giving good pene) at the same time, deposit a fair amount of filler into weld pool, do not "dab" wire into pool, you want suffice for pene and, to bring face of weld past the flush.

This seams almost a contradiction, but that could be from my 1. Lack of experience (none). 2. Lack of experience.
If you were to fill the weld pool will this not encourage spillage and cause closure? Or is the dabbing more likely to cause it because of the 'splash' shock of dabbing.

I can see a better image in my head if I imagine the 2 sides of the weld as 2 separate work pieces, working 1 to build up and close the gap with the final weld being the 2nd work piece.

Finally would this be finished off with 3 top/cap (not sure of the terminology) welds or would that be reduced to 2 with a larger pool depending on the roots?

dutchman · May 11, 2009

runnach said:
....slow your speed of travel, pay good attention to weld being deposited, give it time to slump right through (giving good pene)...

Thanks for the description, Runnach.

I am still uncertain on how to judge whether penetration and fusion are adequate while welding 1.6mm mild steel (single run, multi pass welds on 1.6 are a bit out of my league I'm afraid :ashamed:

).
Since there is a blob of filler metal on top of the parent metal, it is hard to tell what is going on underneath. I don't see the occasional bit of parent metal melting away and getting sucked into the pool. Am I perhaps using too much filler, or is judging penetration while welding an experience/gut thing that you derive indirectly from the behaviour of the filler/weldpool blobbie and speed of travel? The welds look ok when I check the back etc after I stopped.

runnach · May 11, 2009

Gents, first of all if I were welding 1.6 s/s sheet I would expect to complete joint/test piece with one pass only.

With joint gapped, you are hoping to achieve destroying the edge of each piece of tacked together sheet, create a keyhole, from there you direct filler into the keyhole, I tend to aim for middle/bottom of keyhole, at same time, not just a dab of filler, more a little-ish push into keyhole, with this, one is achieving good root penetration, also face build up above the flush, is this clear and make sense guys, of course much easier to demonstrate in real than discuss?

Tacks: amount of tacks will be dependant on length of joint, I would reckon Zardoz test piece would be around 150mm long, for 1.6mm s/s I would have at least 3 sound tacks in place prior to welding. Of course with s/s creep is always a problem, if gap does close, what I was trying to put over is the fact that an experienced hand can still achieve penetration, it is not ideal, but achievable all the same, again give weld pool time to slump through, at same time PUSH filler to achieve root pene, also face side will be above the flush.

One other point, if one can keep gap without closing, this allows for a nice clean root face, argon seeps through to welders advantage. If joint closes, coking can/may occur.

Mr D, a lot of how a welder achieves a sound weld is purely down to experience, and yes, gut feeling comes into the equation too!! You making good progress with boat project?

I hope the above helps?

Cheers..........

dutchman · May 11, 2009

Cheers Runnach!

That makes a lot of sense. Sounds like we are getting into the higher realm of welding here :cool:

(boat not going as fast as I wish, but we'll get there...)

Regards, D

zardoz · May 14, 2009

here are a few more recent TIG welds from my C&G class.
these are Fillet T welds in the vertical up posistion.
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heres another go slightly better
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Here is another better one that i have cut into three pieces for testing. the middle bit is nick bends tested, and one of the second end bits is filed and emery clothed to a perfect level shine, then cleaned with acetone and finaly has a 10% solution of hydrochloric acid on it to better see the weld itself, and whether or not the rod has properly melted in with the parent metals, and is not just sitting on the top of it.
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I forgot to take a snap of this acid etch test, :doh:

so will take my camera in next week again.

mv_tig said:
nice welds , what filler are you using ?

I am using ordinary Copper coated deoxidised steel 1.6mm rods. i will try and remember to look at the trade name next week, but we only seem to use good stuff at college (i spose they can afford it?)

weldingscotty803 · May 14, 2009

did you have to cut them with a hacksaw?
i had to on all my test pieces. took ages
hopefully i will be going back to do level 3 in september but with the amount of work we've got on at the minute its looking doubtful. oh well

welds are looking good
keep us posted on how your getting on

zardoz · May 14, 2009

A hacksaw! no way

We have a huge Meddings mechanical bandsaw for that sort of thing, takes about 10 seconds

TheJoker · May 14, 2009

zardoz said:
A hacksaw! no way We have a huge Meddings mechanical bandsaw for that sort of thing, takes about 10 seconds

*drooool*

zardoz · May 19, 2009

Here are some more City & Guild welding level 2, TIG course pieces.
The steel welding rods are Murex safire 1.6mm copper coated. Dunno what the stainless rods were.

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first here is a lap weld cut into 3 for inspection and testing

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next here is the middle section sawn and given the nick break test. A 1mm nick is sawn along the weld and the weld is bend back and forth with a hammer till it breaks. If the weld has broken cleanly along the nick, all is ok. A fail is when the weld breaks off away from the parent metal and has obviously not melted into each other properly.
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