Welding Question

[HerrDeacon]

I'm all set to build the bracket to support my fairing I'm building for my CB350 and I'm currently practicing welding with some similar sized material that I'll be using. I'm very new to welding and have to say that it is much harder than it looks. I'm using a Lincoln Mig Pak 140 and don't have any gas so I'm using flux core. I don't have any money for gas or a different welder so it is what it is.

One question I have is how do you know that you have a good structural weld? I've welded some stuff before but didn't really care how solid it was since it was under no load, but with this bracket holding the fairing, even though its really light, and being subjected to vibration I want to ensure the welds are good. I'm sure experience helps here but for a newbie whats a good way to tell? I whacked on this practice piece with a hammer and it held great, but don't really want to do that with the final part. ;D

Also, in my practice I burned through the metal a couple of times but couldn't really understand exactly why? Could I have stayed in one spot too long? Wire speed not fast enough? The material is 18ga so its fairly thin (at least for my green welding hands). I don't mind making mistakes as long as I understand why and can learn from it.

Here are a couple of pictures showing some of my practice welds. It was a square tube and I welded each side at a time and inspected it before moving to the next side (hence the gaps in each weld). Each side got better as I went with the last one looking pretty good to my untrained eyes. First picture shows the hole I burned through and the second showing the third attempt (left side) and final (right side).

Have to say its been very fun practicing though, opens up a lot of possibilities if I can learn this correctly.

 

[xb33bsa]

flux core wire is really horrible choice for welding thin tubing,you would be much better off stick welding with 6013 or 7018 ac or even 6011
even better of course is oxy ace welding for tubing, oh well, all you can do is practice you gotta keep a puddle going so all of that flux doesn't include in the weld
welding in hot shorter bursts always uphill slightly will help
preheating the weld zone will help a great deal as well

 

[Nebr_Rex]

In the second pic, the right side looks pretty good for a beginner.
A little more weld build up and more centered in the joint would
be better. Flux core burns hot. 6010 and 6011 rod will act similar.
Ideally thicker metal should be used with flux core. To make your
situation work I suggest doing what I've done many times before.
Weld by tacking in series instead of a continuous weld. Just a
bunch of tacks welds in line on top of each other.


.

 

[HerrDeacon]

Thanks Rex. I think I'll get out today and see if I can find some thicker stuff.

 

[rbradyn]

I agree with Rex. Make a good spotweld..let off the trigger and move to the edge of the puddle. Allow it to cool till you can barely see it glowing through your shield, then hit it again..ect. I've welded some pretty thin stuff that way.

 

[TheCoffeeGuy]

Top welds, and weld on left in bottom picture, all look like too hot a setting and too fast a feed speed. Go to the instructions which came with the unit and see what they say to use on your thinnest piece in the weld. Start there then adjust slightly both feel and heat until you get a good weld.

For good penetration you need to be feathering or beveling back the edges of the metals where they meet. So you are in essence welding in a V groove all the time. For example, even that square rod, once you cut it to the length you need, before you weld, sightly bevel the contact edges on all sides.

The key to welding is the "pool" of melted metal from both your wire and the material you are working, to keep it moving. Both a continuous weld, and the "joined spot weld" systems can be used on thinner material. See the pool. and move the pool.

 

[HerrDeacon]

Thanks guys, I just came back from picking up some thicker stuff. I'll see what I can do with it.

 

[HerrDeacon]

Think I'm getting the hang of it now. Picked up some thicker tube and its going pretty good. Far from professional but I'm pleased with the progress so far. Thanks for the help!

 

[SONICJK]

You can weld 18 gauge with a Lincoln 140 and flux I do it all the time.
Try setting B and about 4 on wife speed.
Go slow and make little C's with your weld, overlapping each one a little bit.

 

[HerrDeacon]

You can weld 18 gauge with a Lincoln 140 and flux I do it all the time.
Try setting B and about 4 on wife speed.
Go slow and make little C's with your weld, overlapping each one a little bit.

My wife doesn't come out in the garage, let alone weld ;D ;D

Thanks, I'll give it a try.

I just finished welding up the main support for the fairing, not the prettiest welds but very happy with it. Great feeling to be able to make something like that on your own.