How Do I Deepen Weld Fusion?

[Franko]

They'll hold. And paint hides a lot of ugly, just kidding, The technique, with mig, is to move forward and backward, forward gets to the toe of the fillet weld, then back up a little to fill the weld, this gives the pleasing ripples. Most gun motion with mig is forward and back, no side to side. The roots may need a little side to side, if that is the case then on the next root lower your voltage and wfs . After the roots are in turn the welder bach up to the proper settings for the fill passes.

Oh, now you tell me, Chuck. I moved the torch slightly side to side on the T-welds in hopes to be sure it melded to both pieces.

I have a very hard time seeing what I'm welding after the arc starts. This causes me to veer off course and never be sure when I am at the end of the material.

I have the shade on my lens set to 12. I have a cheater lens on my hood which works very well, except in the glare of the arc. I get absolutely no flash with the auto darkening helmet I have.

Is there a trick to seeing what you are welding? I know a couple other guys who say they have this problem, too.

Question #2: Is there any special technique to welding vertically that's different from a horizontal weld?
If I push the weld, it will be easier for me to see if I run the bead up.

Jody (welding tips and tricks.com) says to use a triangular weave on vertical welds, basically tracing the edge of the puddle.

 

[E350]

I have a very hard time seeing what I'm welding after the arc starts. This causes me to veer off course and never be sure when I am at the end of the material. ... Is there a trick to seeing what you are welding? I know a couple other guys who say they have this problem, too.

Count me in that group Franko. Any suggestions would be appreciated.

 

[markknx]

Yes a triangular weave works most of the time. Keep it tight wait for the puddle to flow in at one side then move to the next and let the puddle flow in then move up to center of the joint holding long enough to fuse the joint drop back down just above the start and repeat.

The issue from last weak looks like you tried to fill the whole joint in one pass. Never do that on a weld where you need good pen. always run a nice root pass to keep the heat focused on the joint. If you want full pen bevel the steel more. make sure you are burning in good as you weld.

Turn the hood down to 10 shade and see how that works. if you can see there then you can try 11. Also it help to wear dark color shirt/sleeves. this will keep light from reflecting into the inside of the hood, the more light in there the harder it is to see the puddle.

Mark

 

[Franko]

Thanks Mark. I'll give that a try. The revised tests were a root pass and then covered with a single pass fillet weld. I purchased a spool of S3 wire for those welds.

I may need more practice on the vertical triangular weave. I attempted the first corner and It was eating it up from all the heat. I had turned my volts and feed down a notch. I did the rest of the vertical root weaves with a slight zig-zag to keep the hot part of the weld from poking through the gap.

I attempted one fillet weld with the assembly vertical. It was a tragedy. Large glumps of molten metal dripped and sagged. I ground it off and turned the stand so I could weld down on the fillet welds. I tried the push pull torch movement, but it looked very bad, so I ground it off and re-welded it with my familiar oval weave that turned out pretty good.

I learned a lesson. Don't try something new on something you can't throw away.

A weird thing happened on the last fillet weld. The last third of it was pitted, like it wasn't shielded. I ground off the pitted part and ran another pass which looked fine.

Clamping it straight and square was a long process, but It is very square and level.

So after all the excitement, I'm done with the big welds. Tomorrow, I'll cut the box support angles and drill a bunch of holes so I can pocket weld them in place. Once that's done, I can put the wheels on it and roll it around and play with it. Then I have to disassemble and prepare it and paint it.

 

[markknx]

some times one pattern works well for a join and others it don't even for the same guy. machine settings ground location. If there is much of a gap then you have to just pause real quick at the center and stay right on top of the puddle. Yes good idea not to try something new on a keeper part. vertical welds are the hardest to do but with a little practice you can get it. when you watch videos like Jody's keep your eye on what his puddle is doing. He does some great videos
Mark

 

[Pcbye]

Unfortunately I didn't have time to read all the responses, but from lots and lost of welding over the years and a good machine -- Miller Invision 352Mpa -- here are some rules of thumb. I suspect most charts will give you setting using 100% CO2. If you are using C20, or C10, like I do, you need to crank up the parameters as much as 20% for each reduction in CO2 you have if you don't have a chart to tell you. When welding two pieces of dissimilar thickness you might go up as much as one thickness in parameters to the heaviest material and wash towards the heavy side down into the bottom then just touch up the thin edge until it just breaks down. If you are welding on a heavy plate, table or Jig, take that into account as it will pull the heat away quite fast from where you are clamped or have extra heat sink. Use the push technique always unless you are welding really thin sections or just can't get in there to do it. Have about 10-degree lead at most. A slight uphill run will increase penetration at the expense of the visual quality of the weld. As was mentioned, on real thick sections with a smaller machine, you may want to make a root pass. Run Hot, Run Fast and clean it up, then make a cap pass -- think Pipe Welding. Small Transformer machines break down quickly at high amperages. You can hear it in the arc after a bit where is just looses the grunt. Big transformers or inverters just keep going like the whole power company is behind it. A good thing is to spend some time welding different things and keep a not book of settings. Try some parameters that are way off -- voltage / wire speed -- and take some notes so when you see or hear something good or bad you can check you notes and make a correction. Always write down that perfect weld / setting for reference too.

 

[shawn]

after turning it all the way up, the way to get more out of a mig is pure co2. I prefer 75/25 though. It welds purdy

 

[TheFenceGuy]

In order to get more penetration with your MIG use flux core wire. You have to reverse the polarity on your welder, too. Your ground will be positive and your trigger negative. This puts most of the heat on your welding surface and not on your welding tip. Also, shut your gas off. You don't need gas when using flux core. Practice a little bit to get used to the difference because the welder will weld differently. This setup will also allow you to weld galvanized metal with ease (outside in a breezy area though, smoke will kill you) and you will be better able to weld metal that is not perfectly clean.

 

[Franko]

Thanks for the comments, pcbye, Shawn, FenceGuy.

I'm using CO2 argon mix gas. Even though my rigs are small, I've never experienced them losing power or taking a nap. That's probably because I've never made a weld over 4" long. Even when I have long welds to do, I usually take them about 2" - 3" at a time and skip around to minimize warping. Another reason for the short welds is I'm more likely to get off line on a longer pass.

Both my machines have good welding charts on them, with good info on wire size, gas type, metal type and polarity. I do keep notes on anything that varies from the recommended settings.

 

[scroggin]

more heat transferred to the material you are welding gives better fusion, less allows you to weld finer material mig welding give low heat transfer. For some jobs you just shouldn't use a mig.

Most of the ways to get better fusion have been mentioned. One that hasn't is pre-heating the material you want to weld. I would definitely avoid using a large weave, it allows more cooling of the metal the others are high voltage, low wire speed and heavier wire. When welding steel I use pure CO2 gas it gives a hot weld but a lot of splatter, it's also more difficult to get the welder running right with CO2.