another weldin thread... help needed !

[voucht]

Hi everybody.
I made a small break on my building as I am still waiting for my chassis plates and suspension brackets . But good occasion to practice my welding !
But I have a problem, and some questions. Sorry for the long post, but I need to be very specific
My welder is a MIG Easycraft 145A with external shield gaz source : http://www.awelco.com/fra/prodotto.php?IDprodotto=62
I have 2 switches with 2 position on each, which means I have 4 different power set ups : 1-3 (min), 1-4, 2-3, 2-4(max). Then, I have the wire speed I can adjust with a button from 0 to 10. I'm aware increasing the wire speed also increases the amp.
The shield gas I use is Ar(18%)/CO2, and after many tries, I set up my gas flow on 13l/min.
This 145A welder should be OK to weld 2mm plates with good penetration, no ? OK, I'm aware 145A in the name does not mean it can weld with 145A, as the maximum welding power is only 120A. But still, it should be OK, no ?
But when I'm welding, before I reach the limit where I blow holes, I have to set up the welder on maximum power (2-4), and the wire speed at 9.5 ! Then, I have to stay quite while on the starting point to make the weld start to penetrate the joint. Of course, during this time, there is an accumulation of melted electrode on this point, and when the weld starts to penetrate, this big blob falls down in the joint. If I don't wait until this instant, the weld does not penetrate the joint, and manly stays on the surface (or 1 to 1,5mm deep max.). And this is with a 90° v-cut, 1 to 1,5mm deep ! Without v-cut, I can't get any penetration at all.
When I weld 3mm plates together (T-joint), even with a 45° v-cut on one of the plates, I have to set up the welder on maximum power and maximum wire speed to get a start of penetration. Of course, in this conditions, the bead is very high, very big, and a there is a lot of melted electrode on the surface of the joint. It does not look right, and I think it is not supposed to be like that, isn't it ?
Last detail : pulling or pushing the welds does not make any difference in my penetration problem.
I used to have a 115A with flux core, and on 2mm plates, non v-cut prepared, and set up on the 3rd power level, the welds were much more penetrating than with this 145A.
My question is : could it be something wrong with the welder ? It looks to work normally, but... Is there a way to make it check by a professional to be sure it can weld with the maximum power it is supposed to ? Or is it a way to test it myself ? Or do you think it is just not powerful enough for what I want to do ?
Thank you very much for having read this post until the end and any help will be very appreciated.
Regards.
Sylvain

[K4KEV]

I think you might be mis-interpretating the term "penetration" it does not mean all the way through the weld so that molten metal is coming out the other side on thin metal the likes of what we are using "penetration will be sufficient when there is some outer discolouration with a little roughness in the centreline of the weld....that roughness shows the fusion process has reached through the metal and penetration is good without that part of the metal literally melting.
I'm sure some one on here will show you a piccy of the back of a weld that has good "penetration" hope this helps dude.

ps I use a similar machine with the 4 switches and I use 2-3 and a feed rate of 6-7

[voucht]

Thank you Kev. Ok, I thought you actually should see the metal go through the joint, a bit like on the weld B of Bonzo's pictures of his excellent thread treating of welding.
I can easily get a penetration up to at least half of the thickness of the metal. Tomorrow, I'll practice, make pictures, and post them, so you can comment on them if you don't mind.
Thanks for the help.
Regards.

[brainbug007]

When I use mine I find it tends to work better on 1/2 power rating and a wire speed around 3.5-4 of 10. I think when its working right you should almost get a drop of weld constantly at the end of the wire that kind of drips in a controlled way onto the workpiece. I also keep the nozzle about 5mm away at a 45 degree angle and push the weld pool along so the gas keeps the pool shielded. To avoid blowing holes I was also told to just keep moving quickly along so to speak and not stay in one place for too long.

[K4KEV]

BB ....your feed rate is too slow if you are producing a "blob" on the end ...it should look like it is "spraying" like disappearing from the end of the wire and re-appearing at the pool surface..... welding the way you are at the moment will not be precise and vertical/overhead welds will just "drop off".....just my 2 penneth.
K4

[AshG]

voucht. drop the wire speed a little and move slower, that will allow you to get more heat into the beginning of the weld. also make sure you start right on the very edge of the metal as it will heat up much more quickly than somewhere in the middle.

[voucht]

Thank you so much for your comments. here are personal answers and a link to my blog where I show pictures of my today's welding.

brainbug007 : thanks you for the tip. You are right, lowering the power was not worse, especially as I also lowered the gas flow (see my link to my blog for the details). I think it was one of the bad parameters.

K4KEV : thanks for coming back to me for this details. I definitely was wrong with these high settings and metal melting through the joint (I' too ashamed to show you the pictures of the blobs, you figured out it was bad anyway !)

AshG thanks also. It is more or less what I did today, but if I'm slow, there is a lot of metal on the surface of the joint, the bead is too big, as you can see on the link to my blog with the tests and pictures.

To all of you and anybody else : I've been practising with different settings and according to your advices today. I don't want to invade the forum with my pictures, so I published them on my blog, the link is :
http://vouchtroadster.blogspot.com/2...g-welding.html
If you can take the time to look at it and feed me with more backups and comments, it would be great.

On this thread of my blog, there is also a link to my introduction page if you want to know me a little bit more, and know where I come from, my background and so on, as I'm quite new on the forum.
http://vouchtroadster.blogspot.com/2...-about-me.html
(bilingual : in French and English)

Thanks to all of you.
Regards.
Sylvain

[voucht]

Hi there,
I practised more today, and published new pictures on my blog. The good news is I got rid of the horrible big bubbly bead I had yesterday, so welds look much nicer.

http://vouchtroadster.blogspot.com/2...ing-there.html

All comments, advises, help are welcome.
Thanks a lot.

[ozzy1]

To me your beads still seem high.I think that the wire speed is still a bit too high and also you are moving a bit too slow doing the run.

[K4KEV]

Looks like you have the penetration side of things sorted now .....I think like ozzy said ,your feed rate still seems high, drop the rate until it starts to "bobble"
at the end of the wire and then turn it back up till it stops "bobbling" (usually 1 to 1.5) and looks like it is just disappearing instead.