Bobcat Arm

Date 01-06-2006 05:50

Over the years, I have welded several of these. I tried simply grinding and butt welding the arm back together the first time, but it developed cracks and broke off again 2 inches from the weld. The next time, I made a backing plate to fit the inside of the arm. This time, it held and is still holding. I would suggest using a 150 degree preheat, and wrappiing the arm with some sort of insulation to slow the cooling process. Also, keep the innerpass temp to about 200 degrees. Take your time and dont let the weld zone get too hot. I use 3/32" E7018 and make sure not to weld with more than 3/4ths of the rod to avoid any more heat input than neccesary. One other factor to bear in mind is sometimes, these arms have lots of hydralic fluid on them from broken hoses, blown seals, etc. Make sure you remove all traces of oil if you find any.

Good luck.

Mike

By shadowelds (*)

Date 01-11-2006 01:25

I ended up using two 1/2 plates on the inside of the arm about 18 inches long 9 inches on each side of the break. Then i drilled holes through the arm in five places on each side of the break, then plug welded the holes. Making sure that i V -ed out the broken leading edges and then welded that to the 1/2 plate as well. I used a wire (.035 wire) welder on the highest setting of millermatic 200. We will see how long this holds.

By Stick rod Date 01-08-2006 07:54

Don`t think I could give you much better advice than that.

By RonG

Date 01-08-2006 14:34

Something to keep in mind on a repair such as this.

Use a Diamond shaped plate when feasible so as to avoid (if possible) welding directly across the direction of the working load on the arm.