Hard facing a bucket

[excelagator]

Patrick brings up a good point!!

I have been welding roughly a year now at home and at work. I have welded up some things I wanted to be dead on. I like to weld things up like torquing head bolts, tack welds every 3 inches squaring things up, alternate sides and allow to cool some. I have noticed that if I get the dreaded "Ping" while cooling, something cooled rapidly. Get the tape measure out and check it. Using this method I have been managed to get things square within a couple of millimeters.

Granted I am not a professional welder, but a little thought and patience goes a long way.

Dan

 

[RonMar]

This is the sort of thing that separates weldors from guys with welding equipment.

Owning a gun doesn't make you a marksman.

Very true!

Taking it easy and letting the heat spread and dissipate is good. (Make haste slowly!) Alternately welding one side and then the other is useful some of the time. There is really no way to just tell someone how to not get heat distortiion while welding except some useless comment like just do it right and it won't warp.
Pat

You pretty much summed it up in that though. "It is all about balance grasshopper" When you heat things, they expand. When you cool them they contract. When you lay down a weld bead, you are laying down molten metal over a certain ammount of area. This metal then solidifies and as it cools it shrinks. Take a new plastic garbage bag and lay it on a smooth surface such as a table top. Place your hands flat on the plastic sheet about an inch apart. This represents your weld bead. Now while pressing down, slide your hands together and see what happens to the sheet. This is your weld metal contracting. This effect is greatest at the surface. If you are welding on one surface of a sheet of steel, such as the bottom of a FEL bucket, you will shrink this surface. The opposite surface, without the weld remains the same. So one surface becomes shorter than the other. I just described a piece of pipe. The inner surface is shorter than the outer surface... With no force to resist it, the straight sheet will pull into an arc.

The easiest way to avoid this is to weld equally on both surfaces. Lay a bead on one side, flip it over and lay a bead in the same spot on the other side. This will aply the same shrinkage force to both surfaces and the sheet will remain relatively straight. For doing an edge, first weld one edge(one side of the sheet) then the other edge to apply balanced forces.

I finish weld much like I assemble. During assembly, I tack all over the place, measuring and aligning the assembly for true as I go along. When I weld, I weld all over the place, usually on opposite sides to apply counter shrinkage forces to keep the assembly square. Much like the described torque pattern used to keep an assembly square while tightning down it's fasteners.

 

[montejw]

Welding will cause the metal parts to pull towards the weld, so it will act as if the metal has shrunk. It expands initially, then shrinks as it cools. Was your friends bucket bowed up into the bucket (frowning bucket) or down (smiling bucket)?

The thing to do is go in small bits spread out. 4" here, 4" way there, 4" way over there, etc. He probably went in full beads, or as far as a stick would go, then did another bead next to that.

 

[Hookblock]

Thanks for all the input, I want to get set up better to pre heat the bucket. and I am waiting for some info from yomax4 (thank you). I hope to have something done by this weekend, or next week after christmas. AND will work on posting pictures

 

[john_bud]

I mostly see hardface done in a cross hatch pattern. X

The little squares are about 1" to 2". I heard that there is some science behind it as you want to have the soils you work in to fill the spaces while you work. That acts like a buffer and keeps that area from wearing. The bucket then rides on the smaller area of hard face metal and only wears (slowly) there.

I would imagine that smaller squares for gravel and larger for soil, but that's not an expert opinion!

jb

 

[Hookblock]

Yomax4, I did receive the information you mailed. The cd was very informative. Based on the cd application recommendation, Stoody 19 or Stoody 31 would work. The 31 is more corrosion resistant, but I went with the 19. The material calculation figured that I needed 12 lbs of rods, which I thought that I could start with 10 lbs. Checked floor and back, it had consistent thinning.

The plan of attack is to preheat the bucket edge to about 200 degrees, using 5/32 rod at about 140 amps, reverse polarity, starting with cross hatch pattern in the main area of the cutting edge (alternating small welds from side to center to other side of bucket) and finishing with a straight bead on the main cutting edge. The bucket also has stiffener plates that run perpendicular to the cutting edge which I was also planning to cross hatch into the rotation. There's a small area along the outside of the bucket where I was going to run short parallel beads.

"it would be a good way to spend a day. David from jax"
I agree!

Two links that I found informative:

[URL="http://www.weldingweb.com/"]

 

[Highbeam]

It may be odd but sometimes just adding material is as important as adding hardfacing. I have actually used plain 1/8" 7018 rod to add a bead of material to the digging edge of each grouser on my bulldozer. The single bead was thin enough to offer a noticable traction advantage as well as preventing further wear on the grousers. That 7018 bead laster longer than I kept the dozer. It visibly smoothed/polished out with abrasion but was protecting the base metal for hunreds of hours. Easy as pie too. Almost my most pleasant welding experience ever.

 

[Hookblock]

Well today was the day I got something finished that I started awhile ago. I hit everything with a wire wheel.

 

[Hookblock]

The cutting edge I marked out at 3'' and the two straps that run with the bucket at 2''

 

[Hookblock]

Then the preheat. I got it to about 300 degrees, no picture then.