How do I weld a bucket tooth
This thing is harder than Chinese arithmetic. It has three chunks out where the pin passes through to hold it to the bucket. I told my customer that it may not be possible to weld it without heat treating, possibly before and after welding. He needs it tomorrow, so that's out, as is going out for special material or filler. I can cut replacement segments from cold rolled and TIG them in with 4130 or ER70. Anyone have a better idea?
A new tooth is a hundred bucks, so I can't spend much time on it. It's tempting to tell him it can't be done economically.
If the tooth is available off the shelf immediately, tell him to buy it. Teeth take a real beating and if he could break a good one, a scab is just waiting to break. The following is only if he has to dig tomorrow and nobody has a tooth. If you dig without a tooth the shank wears and then the teeth don't fit properly and either come off or break more easily.
$100. is a pretty big tooth. Is it retained by special pins so that the finished width must remain the same? I'd scab in cold rolled, but I'd weld with 309 or 312 stainless if I didn't have specific dissimilar material rod on hand. I'd preheat to 500F as well. If I had to use ER70, I'd probably preheat to 700F but I'd clip test it first.
I have no 309 but a good supply of 308. Would that do?
308 or even 316 will work just not as nicely (309 is txt book weld anything to anything filler, 308 & 316 ain't far off composition wise) More importantly they all create a very ductile soft (ish) weld that resists cracking due to shrinking on cooling. Bucket teeth really are dirt cheep and a std consumable item in a lot of soil types. There normmaly fairly hard and incredibly tuff, never ever try - take on drilling them. Buy the right tooth + its matching sockets if you ever have to mess with them.
Preheat is a good idea, i would not worry to much about affecting temper, more about getting a good weld. Don't quench it, let it cool down in still air as much as possible after welding or wrapp it in something insulating if you have the option.
There's a bin of kitty litter oil dry for just that purpose. I'll see how the 308 works.
It's done. It took 45 minutes to cut two pieces and weld them in. He can dig tomorrow, and if it holds I've saved him some money. If it doesn't . . .well, I tried to tell him, but he would not listen.
It was 500 when I started, over 600 by the time I finished with the hot glue. The break was through the hole, and the fill piece put a flat on the side. Tomorrow I'll round it out with a die grinder, but that won't take long.
Thanks for the advice. And my customer thanks you.
"...308 or even 316 will work just not as nicely .... More importantly they all create a very ductile soft (ish) weld that resists cracking..."
This is not true.
309 series works well to create a ductile weld that should not crack.
308 or 316 will allow the formation of iron carbides when allowed to cool to quickly (requires post-heat).
Carbides being very brittle, they can crack easily.
It seems like every weldor in the world thinks all SS fillers are universal weld-all fillers.
Not sure why that is. Probably human nature to draw conclusions in the presence of limited information.
Only 309 series (one of the small few) will allow joining carbon steels without the danger of cracking from a super hard HAZ.
It will break at the repair if he uses it in rock again. I hope he doesn't blame it all on you.