T Joint woes

[aametalmaster]

Your getting quite a bit of splatter, If I remember right you need to turn the volts down a touch or up the wire speed a smidgeon (or its the other way round lol).

Yup its the other way around Speed down for less splatter..Bob

 

[Paul G]

Anth, are you left handed?


Paul G

 

[Leedsutd]

Just a quick questio, no hi jack. What dhould you be looking for on the underside to show you have penetration? Noticed on anths underside views just a little discoloration. only ask as I am new to this as well and want to get it right, On butt joints its easy to see the reverse but what should I look for on a T?

 

[hotrodder]

^^ With fillet welds you're only looking to achieve fusion at/beyond the root (where the two plates meet). You need to 'look inside' the weld which is where destructive testing and macro etching comes into play... http://www.mig-welding.co.uk/wiki/Weld_Testing. The 'nick break' test is just an evolution/better version of the BFH test in that instead of beating the living daylights out of the coupon you encourage it to break 'through' the weld metal. Any voids/lack of fusion at the root is usually fairly obvious along with porosity etc. Macro etching is even more useful but the acid complicate things... you can get a very crude result using some acid from a car battery, nowhere near the detail but will highlight the weld some

 

[anth510]

Anth, are you left handed?


Paul G

Nope, right handed. I tend to go left-to-right when I weld (is that pulling or pushing?), not for any reason but it just feels natural. Why's that?

 

[Engineer1964]

^^ With fillet welds you're only looking to achieve fusion at/beyond the root (where the two plates meet). You need to 'look inside' the weld which is where destructive testing and macro etching comes into play... http://www.mig-welding.co.uk/wiki/Weld_Testing. The 'nick break' test is just an evolution/better version of the BFH test in that instead of beating the living daylights out of the coupon you encourage it to break 'through' the weld metal. Any voids/lack of fusion at the root is usually fairly obvious along with porosity etc. Macro etching is even more useful but the acid complicate things... you can get a very crude result using some acid from a car battery, nowhere near the detail but will highlight the weld some

When i did my coding i did a few etch tests on some test pieces to test for penatration

its a good way to check your welds and how much penatration your getting

 

[anth510]

Holy ****, those look perfect!

 

[Paul G]

Nope, right handed. I tend to go left-to-right when I weld (is that pulling or pushing?), not for any reason but it just feels natural. Why's that?

Well it would be natural if you were stick (MMA) welding.

You should be pushing with MIG. The weld should be disapearing under the gas shroud and you should have a clear view of the unwelded joint.

This could explain the convex profile of your weld. What you can't see will be less penetration into the corner.
If you "push" (weld right to left) the wire will be pointing at, and therefore heating, the root of the joint.
This will result in better weld profile (see Gerry's weld, post 17) and better root penetration.

HTH
Paul G

 

[anth510]

cheers Paul, I'll try pushing on my next practice run

 

[Leedsutd]

Pushing/pulling

Thanks for the tip, noticed on all the vids in the tutorials they are pulling so thats what I was doing too.

 

[Engineer1964]

Thanks for the tip, noticed on all the vids in the tutorials they are pulling so thats what I was doing too.

There are different ways to weld, When you pull your not seeing what your doing and cannot see if your laying the weld pool in the right place, normally you pull with Flux core, Dual Sheilded, but when your doing general mig work would would be better advised to push go from right to left.

Don't try pulling when your learning as you'll make an awful mess

 

[anth510]

Had a shot going from right to left, happy with the results, let me know what you all think. I did two passes to try and keep distortion down and just to see if I could do it neatly. I had an issue with lack of gas at the very beginning of the run as you'll be able to see. I had the regulator too low, didn't do a trigger test to check the levels properly.

 

[backpurge]

Looking a lot better, well done, great progress.

Now for the "fine tuning", you need to try and keep the leg lengths along each plane about the same.

Just ploughing one run on top of another is of no benefit whatsoever and only wastes wire and gas

 

[anth510]

Not quite sure what you mean, backpurge? Do you mean the length of the welds, try to keep them the same? So on the above piece for example I should try to make it exactly half and half?

edit: and thanks for the kind words!

 

[backpurge]

The weld needs to be evenly distributed between the horizontal and vertical pieces of metal, most of your's appears to be on the horizontal piece. Use Gerry's example to guide you