Day 1 of self teaching MIG welding

[Robotstar5]

However, I recently learned soldering and didn't realise that my gun was still on. picked it up by the shaft.....nearly went through the roof you woulda thought I'd have learned. Nope did it twice more that day

Get yourself a cheap soldering iron stand

 

[Richard.]

If your on the max heat for the machine and as it stands you have your wfs set nice with that heat increasing the wfs a little will help with penetration but only a little if you increase it a lot you will find it stutters and splutters because your forcing too much wire in for the arc to burn.
A 130 amp mig is good for 3 maybe 4 at a push. But realistically inside its duty cycle you'll be looking 2-3 mm happily

 

[Welding Bear]

Thanks Richard, appreciate that!

In that case I will try the 5mm on the same settings as I use for the 2.5mm.

If I find it cant do the 5mm what are the actual symptoms? A normal looking weld with lack of penetration?

 

[Welding Bear]

Ps, soz for all the questions but I just keep thinking of stuff... the more I know the more I can understand and all replies are really appreciated!

 

[Richard.]

Thanks Richard, appreciate that!

In that case I will try the 5mm on the same settings as I use for the 2.5mm.

If I find it cant do the 5mm what are the actual symptoms? A normal looking weld with lack of penetration?

Laying beads on top of it should be fine. Joining 5mm IMO is going to be out of its range but other owners may not agree. Ask away as often as you like. If I know the answer I'll help if I don't I'm sure others will.

 

[Welding Bear]

Got ya!!! Incidentally laying beads vs. joining together is something I think I may have somewhat overlooked lol

I thought I was going real well but then the subject of penetration was brought to my attention.

I have been reading about this and when ''butt'' welding (joining two pieces pushed up to each other) the MIG forum guide says the following is poor, ok and over penetration for butt welding.....


SO.

Just as a reminder here's my first proper butt weld which I think looks ok (once I've grinded it down

)...


But as you can see from this piccie of t'other side I just took I have poor penetration for a butt joint...


The forum guide states that you definitely shouldn't see the two joins.

So. Bearing in mind this weld was done at the Max setting..... will leaving a gap of around 1/2 the thickness of the metal solve this problem as the forum guides suggests? Or is there summat fundamental I'm getting wrong.

Cheers for all your help

 

[Richard.]

Yeah do exactly that
Tack the two plates together with a gap of about 1-1.5mm

 

[Welding Bear]

Cheers mate, will do. thanks for the input!

 

[Welding Bear]

Hi guys, another question if you don't mind. . . .

As per my first butt welds you could see the heat discolouration but you could also see the two joins and no weld coming through. This was easily resolved. . . I simply added a root gap as suggested by the forum and am now getting the exact penetration I need. However. . . I do my first steel tube weld next week and I'm unable to up the settings on the welder as I'm already at the max. setting. So as I can't have a root gap is the only option to grind bevels to leave a 'v'? This will be a table so good penetration is essential.

Well, actually I could have a root gap if I laid it on its side.

What do you think?

Cheers

 

[Richard.]

How thick is the tube wall?
It sounds like you know exactly what you need to do to resolve your problems . Root gaps and plate preps as you suggest are the best way to ensure penetration if you have no further adjustment on the unit.
Nice one

 

[Welding Bear]

Thanks again Richard. To be honest I feel like I am getting a real feel for it cos of huge info you guys and you in particular have provided and I'm really appreciative of that

The steel tube is 2.5mm so exactly the same as the metal I been practising on... And getting no penetration with them butted right up.

I'll play about with the bevels on the steel tube and see what results I get

Ps, slightly off topic. . how long do you guys find your grinding and cutting discs last? When I chopped my car door up (which I am stil yet to retry and weld) the cutting disc went from new 4.5 inch disc to about 3 inches in diameter in about 5 minutes haha! Grinding discs have lasted ages in fact but obviously they don't get used as aggressively.

 

[Richard.]

If your tube is been welded to a plate (fillet weld) seen as it is only 2.5mm thick there is no need to prep or gap ( I would only do this if it's tube to tube or if the tube wall was thicker I'd prep it for a fillet. Put some picks or sketches up of what you want to do

 

[norlander]

if you find you are not happy with the penetration, then I'd prep the tube as Richard says -ie for a fillet.You can also try "pulling" the gun, this is said by some to increase pen, and I have found it to be true for my machine.You can also try (and this is a thorny subject as some lads are adamant you should not do it) weaving, ie, walking the puddle left n right,
Have a gander at this if you have not already seen it

and this:

.
The thing is with penetration (according to me that is) if you really watch the puddle, you usually judge the penetration, I never used to call it penetration as I thought it was rude and anyway, I cud not spel penatatashun.So I called it burn in.
Btw, I think when I were an apprentice,I think it was called the weld pool, puddle might have become the word imported from the USA.IIRC, one of my reports from Tech college said sumthin like "he needs to pay more attention to the weld pool and less time looking into the typing pool-(cos there were typewriters then-the only processors were meat processors).
Put some pics up of what you want to do so Richard can advise cos I am learning from wot he sez as well.
Try some flap discs for grinding and cleaning up-the hard discs have their place but the flap discs are nicer to use and more verasatile, and when a flap disc is worn, you can use it for poilish prep.
Cutting discs do go quickly but they last longer if-and I gonna jump on me soapbox here- you don't force or put pressure on em, let the disc cut its way, keep your force for holding the machine.
When I have mates "helping" me, I can hear the grinder bogging when they lean on the bleeding thing.

 

[Jan]

IMHO the cheaper/cheapest cutting discs are nothing of the sort. All too many of them are 2-4mm thick which is way too fat for a decent cut. Good discs are no more than 1mm thick and can cut through car bodywork gauge metal quickly and easily. They also tend to be made of better materials so they last much longer.

 

[Welding Bear]

Thanks boyos, really appreciate your input

My next welding session is Wednesday now, so going to play with the root gaps and bevels (''V'' shapes) and see what works best. I've also got a little notebook with which I am noting down the correct settings for the different thicknesses of steel so I can easily refer to it as the settings given in the inst. booklet were, frankly, well wrong! lol I am of course aware that angle of tip and proximity to work piece etc. makes a difference so best I get settings to suit myself in my opinion

As for ''pulling'' the pool / puddle.... i'll be honest...that's what I do already! lol it just feels more natural. And for this thicker stuff if it improves penetration then that's got to be good. For thinner stuff that has a tendency to blow through then i'll attempt the ''push''.

Re weaving.... why would that be a bad thing? Cos of the look of the weld? As I've said before I don't really care what it looks like as i'll be grinding it down anyway (although it would be ''nice'' to have good looking welds...but defo for me not essential at all)

 

[Richard.]

A weave is slow hot weld and does not have the strength that a set of stringer beads does.
The problem is if a weld is produced with a high heat input the grains in the micro structure are no longer small and fine but large and course
This is called "grain growth" and the effect is simply poor properties from a mechanical point of view.
The toughness of the weld will be effected the worst. I only ever manipulated the torch if I'm welding out of position (particularly V up ) where weaving helps prevent weld metal running back over.

 

[Welding Bear]

Afternoon guys, I hope you're all well I apologise in advance as this is going to be a pic heavy and long post lol

Got the week off as had to use up some hol. Although only today could I get round to welding as was with the mrs yesterday and Monday. anyways I digress lol

Firstly, I used the ''pee shooter'' that recently arrived...... was indoors on max ''6'' on the regulator and only got 5LPM. this is clearly the reason why my welds look not that great lol is there a known problem with this Clarke welder and its gas distribution? im sure ive heard someone moan about it also on my car forum...

So anyways, today's exercise was to weld some beads on all different thicknesses of steel and actually get the settings written down so that I can simply refer to my notebook for the correct setting / wire speed. Then once that was all noted down I would try the methods we've discussed to get this good penetration on some butt welds.

Ok, so some 4mm. I only laid a couple of beads cos quite honestly I'm not convinced this welder will join 4mm that easily and in honesty I probably wont be focusing on this sort of thickness. anyways I noted the best setting for a nice sizzle was MAX 2 - W/S - 6.5


Some 3mm beads... setting MAX 2 - W/S 6


Some 2mm beads.... setting MAX 2 - W/S 5


And some 1.5mm beads... setting MAX 2 - W/S 5


The interesting thing about these is that I found I could weld the 1.5mm on the max heat setting. I did notice that the metal easily distorted though so I'm thinking that I either dial the heat down or when welding I will attack it in short bursts so as not to distort it.

As per the videos posted by norlander i think, I also found that doing loops with the puddle / pool got that classic weld look lol so will do that from now on too

So as of now I'm totally comfortable laying beads on top of steel. check point 1 made lol

So miving on to some butt welds...

3.5mm...with a root gap of about 1.5mm....

you can see in the pic that the inner most weld is a bit fat. I noticed this and then did the smaller weld closest to the bottom of the pic. the reason it was fat initially was cos I was experimenting with travel speed:the fat one was very slow.

as you can see even with a root gap the penetration is still showing the two joins...


A 2mm butt weld....

really not pretty and I think I really suffered from gas distribution issues here. but hey ho.

This 2mm join was a tad better...


my camera died so couldn't get any other shots of penetetration but theyre all the same and all are showing the gap still. where to go from here?

is it something I should be worrying about bearing in mind I beat the living crap out of it and the first thing to bend was the centre of the steel and not my weld lol....


around all the butt welds im getting a real nice ''heat leach'' but as said no weld filtering through the gap.

anyway to end on a high. I did a 1.5mm lap weld and its prob my best looking weld so far....



What do you think guys? and any help with the gap still showing issue would be awesome

 

[Jan]

Indoors with no draughts 5lpm will usually be sufficient, but even a slight movement in the air could breach the shield resulting in poor penetration and some contamination of the molten pool.
'Looping' the weld puddle will usually weaken any joint by overheating the metal being joined unless you're working at the very top of the machine's capabilities. any stressed structural metals should be welded with a straight joint/bead to avoid this.
As said: Thin metals warp a lot if care isn't taken to avoid it. In practice it's a bit like doing a series of half inch disjointed tack welds a couple of inches apart and then going back to slowly fill in the gaps in the same manner. If each subsequent 'tack' slightly overlaps the previous ones then the effect will be the same as a single, continuous weld.
The learning curve may not be steep, but there is still one to be overcome. Time and practice are the key, along with requesting the critique of more experienced hands.

 

[Welding Bear]

Thanks Jan. I've been told by a few people that it should be at least 10LPM. I dunno, ill check the gas flow coming out of the regulator directly to see if its a problem with that or elsewhere up the line i.e. in my hose to the gun. im convinced I should be using more and if the reg. isn't allowing that im going to get a new one. I just want some nice welds to post up like everyone else does

I've so far used the maximum setting for the machine down to 1.5mm steel.

i'll stop the loop welds lol and do some stitch welds (loads of tacks) so it doesn't distort.

I didn't get a chance to weld today but I did get a chance to make some bevels on some 1.5mm spare plates with my grinder so ill give it a bash tomorrow to see if that helps.

 

[Cobbler]

I only ever used 5lpm with my Clarke 100, you will have a job to get much more out of it than that due to the resistance of the small diameter of the tubing. To get 10lpm you will have to turn the pressure up ridiculously high. From what I remember the instructions say use 5lpm

Edit I've just checked the instructions & Clarke say 2-3 lpm. If you haven't got the instructions they are available on here at the top of the Clarke section