There is more to it than pretty welds, right? Or is there?

[e9999]

well, so as you can tell, I'm a total beginner at welding but getting into it.

The good welder I was hoping would mentor me just retired, but I have a better resource still: MUD! Yes, You!


So, after this little motivational speech , here is the question:

Being a total newb at this, my welds look mostly like road kill caterpillars with the rare exception. Naturally, my main goal right now is to make welds like these beautiful smooth ones we see here all the time. I guess it's a natural goal, a very quantifiable one at that. They look good, they look pro, they're cool to show off.

But what I'm wondering, though, is whether this is actually a good goal to go by for a beginner and whether one could get sidetracked that way.

After all, you could have the most beautiful welds but if they're surface only with no penetration they may not do much good. But then, how do you practice on getting good penetration? Is it by appearance? Trial and error with breaking and sawing open stuff afterward? Wet pools? What?

More concretely, let's say I'm a beginner and I can do decent looking welds. I have one part to work on for the truck. So no way to cut and test after the fact cuz it's the one. Do I just go ahead and weld it and get a nice looking weld and hope for the best inside or what? (Of course, would not do it myself for critical stuff.)

Or -one can hope despite long odds- is a good looking weld usually an indication of a good weld?

 

[cheap 40]

I've seen some pretty welds that were junk. I've seen ugly welds hold for decades. As a general rule, pretty welds are indicative of a more uniform weld that will be stronger. Not enough heat will lead to a lack of penetration as well as cold lap, lack of fusion, and a host of other things that will make the weld look bad. It's just one of those things that you have to do to learn. You can read about welding all day long, but until you strike an arc, you've learned nothing. Spend some time under the hood, and you will become one with the weld

I'm assuming that you are running a Mig welder?

Tony

 

[e9999]

but how can you tell while doing it that you do have good penetration? If I have a really liquidy big pool, is that enough?

 

[cheap 40]

You don't want the pool to be too big - that will cause cold lap at the toe of the weld because you just can't get the heat out that far to create good fusion. If you have one of those little mig welders that plug into a 110v outlet, I wouldn't go more than about a 1/4" wide weld (measured at the leg). If you need more than that, you will have to run multiple passes. Even with spray transfer, we are not allowed to run more than a 9mm single pass weld at work (John Deere). At 10mm, it turns into a 3 pass weld.

The liquid pool needs to be of a reasonable size, and when it's just right, you can watch the parent material melt and flow into the pool. When that happens, you are seeing the fusion.

Tony

 

[Dirtsquirt]

Watch the videos

At Tonywelding.com
If you choose the right amperage for the material
maintain the proper gaps. Standoff and Burn distance.
accompanied by the proper angle
I guess what I am saying if are doing everything by the book
you have to rely on faith at that point.

Mig is only intended for light to medium penetration.
you increase your penetration if you go flux core.

When I attended stick welding class we would cut our welds
to see how the penetration was.

In short. I still use the stick welder when I know it has to be
strong with good penetration. For things like bumper mounts and
recovery points.

I am and ameba on the welding knowledge and skill chain of evolution. The more you know the least likely you will be to get yourself in trouble.

 

[cheap 40]

In short. I still use the stick welder when I know it has to be strong with good penetration. For things like bumper mounts and recovery points.

I use a 225 Lincoln AC buzz box exclusively at home. It's all I have and all Dad and Grandpa had for years.

When it really counts, I'll bevel the joint with a grinder first and possibly weld the backside as well. Most of my bumpers are welded front and back, mainly because I ground the front side smooth. Probably didn't need it, but I build overkill anyway.

I will have to respectably disagree with one thing though - Mig can most definitely provide plenty of penetration. Often times, though, it needs to be spray transfer, and most home welders are not capable of that for very long. Almost everything in industry is Mig welded. It is rare as hen's teeth that we see a warranty claim at work for a poorly welded frame. But, we have the industrial welders that can spray all day long........

Tony

 

[Pin_Head]

but how can you tell while doing it that you do have good penetration? If I have a really liquidy big pool, is that enough?

With experience, you get better at reading the shape of the puddle, the machine settings and the speed of travel for a particular type of joint and thickness. Joint design is critical to getting the right results, so you need to know about beveling and root gap, especially for thicker material. For example, with pipe welding, you want to see the puddle look like a "key hole" for the root pass. This is a sign of full penetration, but you won't see it if you don't have the joint beveled with the proper root gap.

Until you get that experience, you test the weld destructively to verify the fusion. If it is a small piece, bend it backwards 180 degrees until it breaks. If it doesn't break in the weld, it is a good one. If the weldment is too large, you cut a 2 inch wide strip or "coupon" and test it. If you take a welding class, you will spend more time testing than welding.

 

[e9999]

snip
If you take a welding class, you will spend more time testing than welding.

ah! telling...! that's what I thought. So for us beginners without formal classes, caution is indeed in order. Sheesh, it's hard enough to get decent-looking welds...

 

[jts560]

The old timer who taught me how to weld told me when I asked him about making my welds look "pretty" not to worry about that as I was learning. He told me to just make a strong solid weld, and not care about how it looked. He called them "gorilla" welds.

My first thing I welded on was an old rusty, crusty utility trailer, so it didn't really matter if the welds were ugly. I gorilla welded the hell out of that thing.

 

[Pin_Head]

Taking a class at your local community college would sure be the quick way to figure out the difference between good and bad welds.

If you can't take one, don't do any welding on load bearing stuff until you have mastered the particular type of joint you need to make. Mock it up with the same material in the same welding position, then weld it and let it cool. Then test it by bending it over 180 degrees in a vise with a sledge hammer. If it doesn't crack, you have it figured out. If it cracks, go back to the drawing board and read the appropriate chapter in your welding text book and try it again until you get it mastered.

 

[denis]

But then, how do you practice on getting good penetration? Is it by appearance? Trial and error with breaking and sawing open stuff afterward? Wet pools? What?

Good cleaning and a perfect ground are mandatory.
Set your amperage a tad below the point where you blow through ang go to town.
On the fillet and butt joints use a weave pattern to keep the joint flat.
Corner and lap bump up the amperage and travel straight and fast.

practice practice practice

 

[fj40charles]

Cheap quality welders generally do not produce the best quality welds. If you want to eliminate one variable, I'd suggest you get a a decent 230v wire feed welder to start with.

Taking a welding class at a community college is a great idea. Listen to experienced people when they provide advice.