Learning to weld

[yotaonrocks]

Hello everyone. I found this website on accident and now I am glad I did. I just bought a millermatic 252 and am trying to learn how to weld with it. Here are some pics of some welding I did this afternoon. Please tell me how they look and what I should do to better them. Thank you for your help. The steel is 1/4 mild steel Im using .035 wire and 75/25 argon co2 mix.

 

[malcolm]

Hi, sorry for such a lenghtly wait for a reply. Isn't even going to be a good one as I tend to spend more time on thinner stuff and rarely get involved in fillets.

Weld looks tidy, so welder is working fine. Gas coverage looks a little low, but enough. I thing I'd have gone for more amps - if you were working off a calculator or manual the recommendations are generally for steel - when working in to a corner there's more metal to heat up.

Though I'm hopeful that someone used to welding thicker stuff might give a better reply.

 

[Sparkey]

Yes, i must agree with Malcolm: a bit more power!
Except for the few "blobs" (must been when you shifted your hand eh?)
it really looks very good!!!!! Is this really your first attempt???

 

[yotaonrocks]

yes it is my first time. I run a laser cutting machine for a living and I am around welding all day and have been taught some techniques by some welders but never actually mig welded. I was going by the parameter chart in the front of the welder for the heat setting. And I was welding on the floor so I had a hard time keeping from jerking my hand around when shifting. I have arc welded some in past but this is first attempt at mig welding. I bought the welder because I am building an off road buggy and am going to be needing to weld up an entire chassis and thought I could buy a welder and do it myself and have a welder from now on for same amount of money that I could pay someone to do it and then would have to take to them to fix it. I will try some more heat. This may sound stupid but how can you tell if you have good penetration? I will be welding alot of 3/8 on my buggy and want to make sure I have good penetration. And I have the gas set at 22 the book said set between 20 and 25. Thanks for the input I look forward to talking to you guys some more.

Matt

 

[Wozzaaah]

Whoops, 4 days without a reply . Agree with the others, a tad more gas and a tad more power but superb for a first attempt .

 

[arkangel06]

great first try , i think you have all the advice you need

 

[yotaonrocks]

thanks fellas

 

[peterd51]

Hi,

your 'penetration' question seems to have been missed...

basically you'd grind back one side of each piece so that when there's a small gap on the back there's a slightly wider gap on the front. I tend to go to about 70 degrees angle on the face of each piece. Then you can push the weld right through to the root.

3/8 is three eighths of an inch? That's about 10mm!

If it's possible to do it you may be better welding from both sides with the faces ground off to both sides with a ridge down the middle. The other guys may be able to give a better idea (I don't go above 6mm or 1/4") but I'd have thought that putting that much weld on one side would tend to bend everything as it cools.

Regards
Peter

 

[Drains]

While you can prep the joint, it is not normally deemed necessary except for thicker steels, and it's unlikely you will be going thicker, I reckon (over 3/8", for sure). It is a good idea to prep if you are welding a fillet from the outside of the joint though. There may however be an issue if you have an underpowered welder, then follow Peter's advice and give the joint all the prep it needs to get full fusion.

Normally, with standard technique on a standard fillet you wouldn't expect the weld to go right through the joint. It should penetrate evenly into both pieces of metal and have enough leg length to provide the reenforcing to give the weld the equivalent strength of the parent metals. Hope that's clear...

For a bit more info, you could download the manuals here (mig) and here (SMAW)

both from the Miller Resources
pages.

Well worth a look!