Welding Question

[matt69]

I bought a miller 210 a few months ago and am teaching myself to weld. It is set up with mix gas and .035 wire. AirGas said this was the best set up. Her is my problem, I am getting little pin holes in my weld at times. Any ideas? I don't have a digital camera, but will try to borrow one if that will help.

thanks
matt

 

[Dave]

Make sure the surface is free of oil dirt and rust. Too high of a gas flow can actually introdued oxygen into the weld via turbulance. A breaze can do the same.

 

[1owner66]

This is called porosity and is caused by air getting into your gas shield. Like Dave said it could be too much gas pressure or a breeze blowing your gas shield away. Or not enough gas as well. How much pressure you putting through your flowmeter? If you are welding relatively clean oil free metal and get your gas right you should be fine. How do the welds look otherwise?

 

[SaddleUp]

Also be sure your distance from the metal is right. If your too far away it can also do this. If you are welding too far away then you will need to turn down the amperage when you move closer.

 

[matt69]

I have it set at about 15psi. The welds look fairly decent just has the porosity in them. I think I am close enough, I try to stay within 1/4 inch of the metal. I am going to go out to the shop tonight and mess around again.

Matt

 

[Dave]

I have it set at about 15psi. The welds look fairly decent just has the porosity in them. I think I am close enough, I try to stay within 1/4 inch of the metal. I am going to go out to the shop tonight and mess around again.

Matt

PSI depends on the size and length of the gas tube. 15 PSI through a culvert would be a lot more gas flow than through a straw. A flow meter in cubic feet per minute is a number that can be used in reference material. So PSI between machines is kind of hard to compare. Start with a lower gas pressure and increase it until gives a nice clean weld. Then go higher and see if you get bubble or poping. Playing around at the extreams can give you a good idea of cause and effect. You can use the best PSI settings as future references for your machine. It just takes some practice to get things dailed in.

 

[matt69]

Cool, I am going to try some more tonight.

matt

 

[fordtrucks4ever]

Just out of curiousity, what are you welding on? Most anything auto related, 0.035 wire is too big for really good results on thin material. I wouldnt go with that large of wire with gas shield, unless I was doing major frame repairs, building heavy bumpers, modifying axles housings, or trailers.

 

[302fix]

Most anything anto related, 0.035 wire is too big for a really good results on thin material.

I got my outfit from airgas also and they set me up with .028 wire. Works great.

 

[Gummi Bear]

I use .030 wire for almost everything, .023 for the thin stuff.

Clean your work areas. MIG likes it nice and clean.

Wirewheel, flap disc or whatever to your work to knock off the rust and scale, then wipe the clean metal down with a rag sprayed with brake cleaner to remove any oils. This will give you a nice clean workpiece for best penetration, and a nicer looking weld.

 

[RedLeg0811]

Just out of curiousity, what are you welding on? Most anything anto related, 0.035 wire is too big for a really good results on thin material. I wouldnt go with that large of wire with gas shield, unless I was doing major frame repairs, building heavy bumpers, modifying axles housings, or trailers.

To tell you the truth I would not use hard wire for heavy duty welding. Hard wire is not structural. You should use flux core or even better dual shield.

As to the gas you are not running enough 15 is too low. I would put it around 25.

And to clean it I would use Acitone, keytone, or MDK as they will clean and then not leave a residue. When using any of these products make sure you wear chem resitant gloves, the correct resperator, and saftey glasses.

Regards
Martin

 

[matt69]

25psi was the magic number. Also, I was running .030 not .035. I still don't have a camera, but would like to put some pictures up for you guys to tell me if I am on the right track. The welds do not have any porosity that I can see now. Thanks for all the help.

matt