weld size?

[kibodwin]

I have just had a blast in the garage and something came to me.
How big is the weld bump supposed to be? I have .8 mm flux core wire.
I ask as I move faster across and got much smaller and thinner weld
lines. I dont think I got as much penetration though. Being a novice I find
the weld pool much smaller than I expected. How flat should the weld be,
on youtube it is difficult to judge the size the welds.
Any tips on judging penetration?
K.

 

[DuncanM]

Pictures of your work would really help us see what's going on.
I've been working on the basis that if you look at the back, and you can't see the line where the 2 panels but up against each other, then there's probably enough penetration.
Someone who knows their stuff will be along in a minute no doubt!

 

[kibodwin]

I have a photo but is is not really useful.
I suppose what I want to ask is when mig welding as opposed to tig welding
in there a difference in the look of the weld. I feel like my welds sit on the metal
as opposed to mix in with the metal I am welding. I do not know if this is a problem with welder
setting or technique.
Here are some photos, it is of the inside of a wheel rim so it did not turn out very good.

 

[gavuk]

Have you looked here mig tutorial sectioned welds at bottom of the page

 

[kibodwin]

Hi Gav,
Thanks for the heads up, it looks to me like I am getting some penetration. My worry was that I might not
as it looked to me like the weld was just sitting on top of the steel.
I will have to grind these horrid welds back and start over, again.....
It is not easy as it is a bit tight.
Thanks for all the advise,
K.
=)

 

[keith19]

You are just using this old wheel to practice beads on, aren't you? You're not going to fit it to anything...mobile? Just a slight H&S worry...

A steel wheel is a pretty big thing, and it will tend to draw the heat out of your little mig welds very quickly, so they will tend to sit on top.

Power settings need to be quite high to penetrate metal of around 3 - 4mm properly.

 

[kibodwin]

Dont worry it wont get used, not at speed anyhow. Its future might be on a wheelbarrow
I did think I did not penetrate enough but I did not want to blow through.
I might try a higher power setting and see the result.
thanks for the pointer....
K.

 

[gavuk]

Much better to get some practise on steel sheet and plate and get used to the settings .....what welder are you using?

 

[mike 109444]

Kibodwin I was trying to workout if that wheel still has the tyre on it as in one shot the valve is shown. There was a post on here somewhere about NOT welding wheels with the tyre still on them due to something about them blowing the tyre (even many hours later!!) hopefuly some one will point it out.... Also the hight of the weld would depend on the gas you are using (I see you are using gas less) but when you use gas then CO2 will give a higher bead than argon mix. Thats why argon mix is prefered but is a pain in the a** to get hold of. ps did you sort a sorce for gas ?

 

[kibodwin]

I have a cheap 2nd hand chinese mig welder, i think it is called something like mighty mig 130.
I am still learning so it is fine for now. I am gas-less with flux core wire.
Looking at some youtube videos I think this is where I am having trouble, the flux core wire
does not give as nice a weld as gas welding with solid core wire. The splatter is awful!
I will be getting a tank of Co2 soon I hope. I did finally find a very nice chap and his prices
seem honest for here. Only the other side of town, shame he is only open during normal
working hours (meaning I will have to take time off work to go..)
Mike, thanks for the info, I did not know that Co2 would give a higher bead, I thought the bead I have
is already quite big but I have no real reference to compare to.
The tire is flat and I think the only real danger is burning the rubber something I am not really bothered
about.
K.