HomemadeTurbo - DIY Turbo Forum - Grade my new welds please HUGE PICS 56K NO WAY

Quote:

Originally Posted by BmCRace.com

The nice things to 3/32" is that the tip on the tungsten lasts alot longer because it is thicker it can absorb the heat alot better so you have less grind time and tungstens last longer.

Exactly right. The shop I work for buys both sizes. It seems that the guys that use 1/16" tungsten run out and come to bet more twice as often.
You only use the sharp tip of the tungsten anyway, so the diameter of what's up in the cup isn't going to make any difference in the weld. I've welded .006" stainless with 3/32" tungsten. It worked fine.

There's no reason to be changing your arc length during a weld like this. It's just wasted effort that accomplishes nothing. Circles= wasted movement. A weave can often be useful to get a wider bead with the same heat though.

As for moving forward and back...ummm this isn't stick welding. Don't do it. You won't find one of the most talented welders doing this...because it's not helpful.

The welds look pretty good to me overall, but one thing is of concern:
Look at the stops and starts in the pic below. http://jg-fab.com/weld-pictures/DSC03362.JPG
Notice the craters where you stopped. They are darker than the rest and have what is often called an "open crater" or "fisheye." This means that there's a small hole in the middle of them. Even if you can't see it with your naked eye, it's most likely there in a few of these places. This is caused by tapering off your heat too quickly. Here's what happens... Imagine you fire up and make a puddle in middle of a piece of steel. The heat starts to soak into the plate in all directions. When you stop, it continues to soak outwards, away from the puddle. We all know that metal shrinks when it cools. The outer edges of the puddle cool faster, since they are closest to the rest of the plate that's soaking heat from the puddle. As the outer areas of the puddle cool, they pull the center open, like a doughnut. Tapering off your heat slower at the end will prevent this.

Also, this crater area should be hidden in the final weld. how? Well, this crater has a rear edge, just like all the ripples in the weld. When you fire up again, fire up and remelt that edge, move forward, then add wire if that's what you're doing. In other words, don't leave the crater unmelted when you restart. Remelt it and go from there.

You'll find this will eliminate the poor look of the stops and starts. You may still see them, but it's easy to make them look better.