Dec3 Contest ~ Project 1 ~ From I Love Plasma Wear Pad Over-Haul

[I_Love_Plasma]

Well, some wear out the cutting edge wear bar and some wear out their wear pads, in hopes of lengthening the life of their wear bar.


My dad is a wear pad guy.


Here is the over haul on one of the snow blower wear pads that I did. It took about 35 minutes to complete. 23, E7018, 1/8", baked rods (1.4LBS). (Baked rods are very nice, especially when they are still hot right out of the oven.) Running spot tacks a 78 amps on my Power Arc 200, then for the actual welding I used a nice 122 amps so I could just lay in steel fast, and it's a pretty fluidity puddle, gives room for minor bumps or jiggles from operator error. haha.

This pad had completely worn off, leaving a post and a doughnut shaped disc. The hole in the disc was roughly a quarter inch larger than the rod and the edge was tapered down to nothing. So I took a scrap piece that would span the hole in the disc, and welded it to the post (like a "T" shape). Then I put the disc on the shaft tacked it from the top side. Next I turned it over and fully welded and built up the bottom side of the pad. After doing this I did two passes on the inside of the pad.

Here are some pictures, sorry I did not take then with my good camera. Cell phones nice....not LOL. Sorry forgot to take a picture of how it looked before welding.
,,,,.

Nice big chunks of slag, and no slag inclusions with my new PowerArc200 and a better technique.
,

Post your comments, tips or ideas!

Thanks for looking,
ILP

[DaveO]

Is this the equivalent of a skid shoe? I'm curious to know how much you saved with a refit vs. buying a replacement.

[I_Love_Plasma]

Yep you are correct. I have only heard them called wear pads, but after Googling skid shoe ... Any way, I used 23 rods and piece of scrap that had paid for itself at least once before. The rods cost about $4.14. I just searched Ebay and found a decent cheap set that would be a direct fit. They were $19.95 + S&H (Each, not pairs, and no combined shipping; from a quick search). Savings look to be about 75-80% of new.

Great question, glad you brought it up,
ILP

[DaveO]

LOL, I googled "wear pads" and got nuthin. Let's see, saved 75%, did it yourself, didn't have to wait for shipping, experience to do it again in another application next time... sounds good all around.

[I_Love_Plasma]

ha ha yep Experience is the biggest part for me. But then again even Jody does practice pieces. Yeah skid shoe's are something that you can just keep over hauling if you watch to see how worn they are getting. Just add some more weld or if it's got heavy wear throw a piece of scrap steel on the bottom and weld it in.

Thanks,
ILP

[I_Love_Plasma]

Correctly to temper a detail it is necessary to know mark of a steel .
Some marks of a steel are quenching in water some in oil and is obligatory with the subsequent stress relieving

So what would you do for cold rolled steel? We grade it as A-36, I do not know how they would grade it over there

He explained that he always used old used motor oil for this purpose because the carbon in the oil from the byproducts of combustion helped in the hardening process. He also said his "secret" ingredient that he added to the oil was saltpeter (potassium nitrate). He claimed that this gave the steel a superior quality.

HAHAHAHAHA WOW! Heck of goodness, potassium nitrate is a powerful oxidizer. If he had tried ammonium nitrate in his oil, he would have been long dead before you met him. That mix would have exploded similar to the Oklahoma City freakola bomb; I still hate that guy.

But thanks for the reply, if carbon helps with the hardening, maybe use, used diesel engine oil (with potassium nitrate added)? Do you know how much potassium nitrate he stuck in his oil per gallon?

Thanks Gabe for your reply.

ILP

[donor76]

[QUOTE=I_Love_Plasma;21626]So what would you do for cold rolled steel? We grade it as A-36, I do not know how they would grade it over there

At our countries different classifications of a steel, therefore to me it is difficult that or to advise. I can tell one: if А-36 that concerns low carbonaceous steels I am afraid of it will not temper, but give durabilities can ,,cementation,,

[67cudafb]

I thought A-36 was hot rolled steel?

[Joe from NY]

If he had tried ammonium nitrate in his oil, he would have been long dead before you met him. That mix would have exploded similar to the Oklahoma City freakola bomb; I still hate that guy.

But thanks for the reply, if carbon helps with the hardening, maybe use, used diesel engine oil (with potassium nitrate added)? Do you know how much potassium nitrate he stuck in his oil per gallon?

ILP

No, sorry. i found alot of references to the process on google, but none i saw gave percentages. there was a discussion on this on the practical machinist website a bit back.

[Powertig]

I'm with you guys, for some reason new isn't as good as it used to be. Any time I get an opportunity to practice on something you know is just going to get worn out again sounds like fun, you can play with settings different bead patterns and just plain experiment with less concern that it look good. All the while saving headaches and money and down time. Good for you!

[I_Love_Plasma]

Thanks man, yeah exactly. I used lower amps for tacking because the shoe had worn so thin. Then just blasted her with 122amps, it's always "fun" welding without a care to how good it's going to look. My main goals were to build the pad up with scrap and rod, without slag inclusions in the beads. Oh, one other thing I did is quench the piece while it was still blazin' hot. No some may disagree with this procedure, but my intentions were to harden the piece. Thus, possibly increasing the wear life...hopefully.

ILP

[DaveO]

I need to learn more about quenching and why and how it's done, or maybe someone could comment. I've heard that doing it improperly can make the piece brittle, rather than harden it.

[I_Love_Plasma]

Yeah that is something to check into. Not that quenching a huge chunk would cause the whole piece to be brittle. and it shouldn't matter to much on skid shoes. But just the same, I do hope someone comments with experience in quenching.

Great post,
ILP

[donor76]

I need to learn more about quenching and why and how it's done, or maybe someone could comment. I've heard that doing it improperly can make the piece brittle, rather than harden it.

Correctly to temper a detail it is necessary to know mark of a steel .
Some marks of a steel are quenching in water some in oil and is obligatory with the subsequent stress relieving

[Joe from NY]

About 25 years ago, near my job in the South Bronx, there was an old one-man machine shop. At that time I was changing around my '67 FL, and I needed a few things here and there fabricated. It was an old-time shop that still used overhead leather belts on pulleys to run the lathes and other stuff. i was fascinated with all the old machinery and processes he used to get jobs done. he would let me hang around as long as i wanted, and he would show me how he did his work. Once, he was hardening a part by quenching it in oil. He explained that he always used old used motor oil for this purpose because the carbon in the oil from the byproducts of combustion helped in the hardening process. He also said his "secret" ingredient that he added to the oil was saltpeter (potassium nitrate). He claimed that this gave the steel a superior quality.
That old guy was in his 70's then, and was winding down his business. He said he used to have a whole staff of men during WWII, and he showed me old blueprints for parts he was contracted to make that were used on submarines. I wasnt too into tools then, but he told me that when he eventually liquidated his shop, i would be welcome to take whatever he had that i could cart away. Foolishly, I never bothered to follow up on that, and he did have some beautiful old american iron there, Buffalo drill prersses, Bridgeports, grinders, loads of round stock etc... The place was like a museum and i didnt appreciate the access i had to it at the time. I was younger and more into running around and getting laid.

[I_Love_Plasma]

So what would you do for cold rolled steel? We grade it as A-36, I do not know how they would grade it over there

At our countries different classifications of a steel, therefore to me it is difficult that or to advise. I can tell one: if А-36 that concerns low carbonaceous steels I am afraid of it will not temper, but give durabilities can ,,cementation,,

Yes it is mild steel, low carbon.

I thought A-36 was hot rolled steel?

A-36 is the grade steel, almost always, it comes as "hot rolled" finish, but you can get it in "cold rolled" finish. It depends what shape you are buying.

No, sorry. i found alot of references to the process on google, but none i saw gave percentages. there was a discussion on this on the practical machinist website a bit back.

Yeah, that's okay thanks for the link. I think it would PROBABLY be safe to stick up to 1/8th the weight in oil of potassium nitrate, anything higher would make me nervous. I will guaranty instability if you mix higher than a 1-Nitrate to 3-Oil (by weight, NOT volume). But a few ounces per gallon will be fine.

[redbeard]

Instead of quenching it, how about slathering it with some hardfacing rod?

[Joe from NY]

... how about slathering it with some hardfacing rod?

thats what she said.

[bobwills]

I am one who dont quench unless its its something that really dont require holding things together. When you quinch it hardens the metal. But like you said it makes it more brittle. The metal will be less likely to be bent but instead of bending like normal it tends to crack where the weld meets the base metal on a side. In the case on this skid plate quenching may be a little beneficial. The best hardening process is quenching it in oil for the best result, Its real good for knife hardening when making knives. But a slow cool is the best for most welding. I usually even leave the slag on for a while just so it slows that much slower.

[I_Love_Plasma]

Instead of quenching it, how about slathering it with some hardfacing rod?

Good idea, other than I don't have those rods in stock. I'm still working on getting my rod inventory built up.

thats what she said.

Huh??? I'm a dude.