First mig welds with MM175

[deere_x475guy]

Well, last night Will and I got together at my house and tried out the new MM175. One of the things I really wanted to do was try some welds and then see if they could be broken. I had some 1/4" flat bar around so we did butt joints. The joints were prepared by makeing 45 degree bevels leaving about 1/16 inch land. The setting we finally arrived at was 10/70. Pretty much spot on with the guide on the inside of the cabinet. At first it seemed way to hot. But the joints we did early with smaller setting could be broken. A u shaped weave was used for this one with very slight pauses on the tip of the U. As you can see the metal bent but the weld held fine.

[deere_x475guy]

Here are some of the welds we did. Wil and I both learned something this evening. We had some welds that appeared to be very solid and good penetration. But when put to the hammer and vise test they broke very easily. I am glad we tried this little exercise. Now we know that what may appear to be good solid welds may not be the case. We also did welds on the 1/8' stuff and found that the specs called for were to hot. I burned through the first welds rather quickly. I ended up setting both voltage and wire speed slightly lower and got some good solid welds that did not break.

Have fun all

Bob

[Dan]

Bob

I still think that the 10 and 70 setting is to high. One problem I think I see right now is that you are trying to weld out the joint from one side in a single pass. 1/4" is to thick of a material to short arc a groove joint out in a single pass. If your going to weld the joint out from one side you should run a root pass, then a cover pass. Now before you apply the cover pass over the root make sure you remove any silicon islands from the face of the root pass. Now of course I like the 1/16 land that your leaving on your joint design. Are you butting the joint up tight or holding a slight root opening? If your butting this joint up tight, remember that when you use this joint design for a real situation that you need to back gouge the joint and weld it from the back side too. Remember though that I general prep this joint design out by beveling the joint from both sides. There are a couple advantages that this gives. For one it requires less weld metal to weld the joint out. The second advantage is that by running a weld bead of the same size from opposite sides of the joint, weld distortion is very little. The welds pretty much cancel one another out. Now by welding the joint out from one side weld metal shrinkage is going to cause the outer edges of your material to pull upward from your welding table. Now you can off set this distortion by trying, through trial and error, to off set your peices in the opposite direction, so that when you weld out the joint the weld shinkage pulls the parts up to were they set flat on the table. Some thing new to practice.

[deere_x475guy]

Thanks Dan, I will try that tomorrow when Will and Aaron are here and do the setting your suggested.

Bob

[morpheus]

I like those welding gloves you've got on in the pics Bob. I got a set like that for Christmas, VERY nice padding on the inside

- jack

[deere_x475guy]

I was a little late reading your post Morp...I got those for Christmas also..my daughters got them for me. They are nicely padded yet very flexible..