Further Down the Rabbit Hole, or Plasma Cutters, MIGs, and Chop Saws oh my!

cathead said:
My thought on chop saws: You cant trust them... There is all that centrifugal force built up and if something binds
the blade can disintegrate and do a lot of damage to the operator. Maybe it would be OK for small rods or something
but I can do just fine without one. Also, a chop saw spews abrasive and hot particles which is somewhat hazardous.
I find myself using a hack saw for the small jobs, much safer.
Click to expand...
Decided not to try to trust a chop saw. Band saw and Starrett 14/18 and 10/14 blades on order.
 
Here's a brief update. I did some MIG practice over the weekend, and the beads look pretty ugly. They did, however, significantly improve. Other than the obvious speed/feed issues, I'm also getting a lot of porosity on the top surface. I remember seeing something about what causes that, but I can't remember. I did learn that just because everything goes dark doesn't mean I've blown a fuse--I have an auto-darkening helmet.:confused 3:
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The HF band saw arrived tonight, as did the 44" tool chest. I haven't unpacked the band saw, but the tool chest is pretty impressive. It will make a nice home for my Gerstner chests and Reed vise.
 
I haven't seen a spending spree like this in a long time, ACHiPo! I'll say this; when you get into a hobby, you don't fool around!!
 
The porosity usually comes from a lack of shielding gas coverage. Assuming your using hard wire and 75/25 gas, make sure your regulator is set for around 12 to 15 CFH. 12 should be plenty.
 
Porosity can also be due to holding the gun too far away from the weld, holding the gun at the wrong angle (>5-15 degrees from perpendicular), welding in a draft so the gas dissipates, contaminants in the weld, a bad regulator or hose, plugged up gun from spatter, etc. Lots of things can do this. Probably the most common are the gun being too far from the work and/or held at the wrong angle. It takes awhile to learn how to coordinate your hands.

Hang in there; it will come.
 
bss1 said:
The porosity usually comes from a lack of shielding gas coverage. Assuming your using hard wire and 75/25 gas, make sure your regulator is set for around 12 to 15 CFH. 12 should be plenty.
Click to expand...
I'm using 75/25. The regulator just measures pressure--I don't have a flow gauge. I've got the pressure set a little above 30 psig. Next time I fire it up I'll have to make sure I'm getting flow out the nozzle. I can add a rotometer, but doubt I need one.
 
mikey said:
Porosity can also be due to holding the gun too far away from the weld, holding the gun at the wrong angle (>5-15 degrees from perpendicular), welding in a draft so the gas dissipates, contaminants in the weld, a bad regulator or hose, plugged up gun from spatter, etc. Lots of things can do this. Probably the most common are the gun being too far from the work and/or held at the wrong angle. It takes awhile to learn how to coordinate your hands.

Hang in there; it will come.
Click to expand...
I'm sure the angle is not as consistent as it needs to be--I noticed when I paid more attention to it my beads got better. I'm welding on a concrete garage floor, so not much issue with air currents, but ergonomics leave a lot to be desired. I'm using the MIG pliers to set my wire length so it should be correct. I need to confirm the flow--I can only measure pressure.
 
Be careful welding on concrete. It can get hot enough to pop chunks back at you. (My guess is that trapped moisture expands).
 
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