Penetration

Why 100% argon? That will give you almost no penetration. Put them in a vise and bend/smash them till the metal breaks. Examine where it breaks.

Are you welding aluminum? If not, you should double-check the chart on the inside cover of your welder, and see what it says about doing 1/4" steel with 100% argon.

You don't need 1/4 inch penetration just because your tube is quarter wall. Your weld material is always stronger than the parent metal. If you are welding a Tee joint the fillet weld on each side need only have a leg length of 2/3 of the thickness of the standing plate. In most cases if you are welding tube in a Tee connection a quarter inch leg length on each side is adequate. For the sides where the weld joint is a flare bevel you have very close to full penetration because of the natural preparation. If you are doing mitre cuts for 90 degree connections it is wise to grind a bevel on the sides of the tubes so that you have a 1/8th deep vee. Grind the pointed end of your joint also so that when your bead goes on that outside corner is forms a nice radius. Pure argon is not normally used for mild steel welding. Argon is an inert gas and penetration is limited if it is used alone. Bevel preparation of your edges is more important. Randy

"larry_kruzan" wrote in message news:uZKlf.627345$xm3.623711@attbi_s21... Hi Gang,

I normally weld 1/8" or thinner material so penetration has not been much of an issue. Now I am putting together a large project that has lots of welds that need 1/4" penetration. I am not a pro welder - just your average weekend hacker with a Miller Matic 210. Since most of the welds are 2" box tubing, 1/4" wall, I really cannot see the results I am getting. My settings are feed rate. 55, temp 5 and .035 wire, 100% Argon. What do you think?

Larry

-- Sometimes we just need to remember what the rules of life really are... You need only two tools: WD-40 and duct tape. If it doesn't move and it should, use WD-40. If it moves and shouldn't, use the duct tape.

See advice already given R. Zimmerman, Tom Lawrence, ATP and further contributors.

To look at how you are doing at the inside corner of a fillet weld you do a "nick-break". Cut out (or simply weld) about 50mm / 2inches of joint. Obviously, take a couple of offcuts and do a weld immitating your actual ones. Saw a nick in the fillet face aiming in at the fillet corner - usually the "45deg" direction. Go about a third of the way through the thickness. Then break the weld with a hammer. If It won't go easily having hammered it over and the nick has closed-up, work it backwards and forwards the few times until it does break.

The nick guarantees that the break will really focus into the fillet corner.

Have you fused deeply into the corner? - or do you reveal something less good? With stick (SMA) you can have slag lurking down the corner. With MIG you can find the metal is loosely lying on the metal but is not fused.

There is also macro-etch, but you need an etchant like 15%Nitric acid in alcohol, which you are not likely to have lying around. Nick-break is more probing, looking along a length of joint.

best wishes

Richard Smith