I have a b8200 front pto that is cracked into two pieces. It still functions. Has any one successfully welded cast? Any chance of anyone knowing if Kubota used gray cast iron? Thanks
Welding cast pto frame
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There are some of YouTube tutorials on this subject. Given the importance of your situation and my extremely poor welding skills I would have a dedicated welding shop fix it. The cost would be reasonable relative to the cost of a catastrophic failure methinks. Good luck.
Welding cast iron is an art, experience is required. If I had to do it, I would select brazing if no load is on the piece. Just my thought.
weldingpros.net
Brazing cast iron - How-To Guide, Tips & Techniques
Brazing cast iron has proven successful in cast iron repair, maintenance, and casting reclamation applications.
weldingpros.net
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GreensvilleJay
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I used to braze cast iron a lot 40 years ago,far less 'shock' that 'welding' . The pieces have to be 100% CLEAN and preheated.
I have successfully welded cast iron on two occasions. I am not a professional welder. I barely qualify as an amateur. I read up on it in a “how to” book and followed the advice and it worked out just fine.
First clean and carefully fit the parts. Grind a slight “V” or notch if a stressed area. Heat the parts but only to the point below any “glow”, I.E. about 800-1000 degrees. IR thermometer may assist in this …but I only made a WAG on it. I used a small tip acetylene torch, blue-flame (non carburizing)…then used a MIG welder to weld it…then used the torch again to allow it to slowly cool.
Both items did well and are still in-use. (9N Ford casting and large cast-iron plumbers vise-jaws.)
First clean and carefully fit the parts. Grind a slight “V” or notch if a stressed area. Heat the parts but only to the point below any “glow”, I.E. about 800-1000 degrees. IR thermometer may assist in this …but I only made a WAG on it. I used a small tip acetylene torch, blue-flame (non carburizing)…then used a MIG welder to weld it…then used the torch again to allow it to slowly cool.
Both items did well and are still in-use. (9N Ford casting and large cast-iron plumbers vise-jaws.)
I suppose there are many ways to approach a problem, some less intense. I guess it depends on the item being welded and, the stress that item must endure. In my 45 years operating a automotive machine shop I've stepped in a lot of problems to solve....ahhh, think it out and, you will overcome.
There is a way to tell by the sparks thrown when a grinding wheel is used to tell if it is cast iron or steel which I don't recall for sure. Also if you tried to drill a unimportant spot I think you would see the difference as cast iron makes kind of a powder and steel a curl. I agree with Jay as I have brazed cast in the past with success but it has been a while.
Bill
Bill
I recently made my own 3pt tilt cylinder by cutting off the obvious cast steel ears on the base end and welding on steel to make the angle required. I could see that it was welded to the cylinder steel so i assumed I could make it work and it does. The only thing different than a bought one was the base is down on the link not on top.
I am not trying to steal the thread just point out if it is a cast steel part vs cast iron it could be a simpler fix for the OP.
Bill
I am not trying to steal the thread just point out if it is a cast steel part vs cast iron it could be a simpler fix for the OP.
Bill
TheOldHokie
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They are indeed and cast steel is easily welded. Most people assume all ferrous castings are iron. Tractors are often steel.
Dan
Spark Test: One of the easier methods to check cast iron vs cast steel is by spark test. The specimen can be grinded using an abrasive wheel and looking at the spark pattern and spark color, an experienced person can inform if the material is Cast iron or cast steel. Steel will most often give off bright yellow sparks, whereas iron produces more of red or orange sparks.
In cast iron, the spark color tends to be the brightest at the end of the spark whereas for cast steel the spark originates at the grinding wheel and extends outward
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Thanks for all the advice. Had a friend tig weld it. It appeared to be high carbon steel. Got it together. Thanks again.
Please do report back on how it is holding up after you use it for a while...
Update: installed fine, factory shoulder bolts are a must for alignment. Got to looking at my drive shaft and noticed the previous owner? Welded it in to one piece. I made all new components, ordered new bushings. I reused the splined end. I've used it once a week to more than a month. Working great!! I got the bushings at messiks 30$ each, ouch! Glad they had them. The shaft is what caused the PTO case to crack, I think?
I have welded cast iron many times. Complex fractures are very difficult to keep aligned during the process, and it can be difficult to manage the heat on complex pieces that have varying thickness.
Managing heat is key. Once the crack is prepared (ground with a "V" along the crack for adequate weld penetration), I heat the pieces in a forge or even a BBQ grill until they are uniformly cherry red. Have your clamping set-up ready to go ahead of time, and then quickly clamp and weld before the pieces cool. I'll have a wire brush handy to brush the ash off the cracked surface before clamping. Then, as soon as you're done welding, toss it back on the fire, and let the fire burn out, ideally over several hours. You want the piece to cool off as slowly as possible after welding. You have maybe 5 or 10 minutes at most to do the work before returning the piece to the heat.
I use a mig welder with regular solid steel wire (0.030" or 0.035"). My mig welder is a Hobart 185.
Again, you'll have the best success if it's a simple crack and the pieces have uniform thickness. I've had complex pieces simply crack in another place while welding due to poor heat management. Thinking of that Farmall F-12 belt pulley I tried (unsuccessfully) to fix. I also think that older pieces are more of a challenge due to the primitive metallurgy.
One thing to be aware of. The weld is SUPER hard. So, if there are threaded bolt holes along the crack, you will never be able to drill them out or re-thread them if there is weld bead in there. The only other 'machining' I've tried on cast iron welds is grinding. That's usually not too challenging. Die-grinding the weld, even with carbide bits, is not very productive. You can scratch at it, but not really cut it.
Another thing to be aware of. Cast iron that is heated up to glowing gets quite soft. Crumbly would be a better word. So, don't go beating on it with a hammer before it cools back down, or you'll break it again.
Maybe try it on a junk piece of cast iron before you tackle your project.
If you successfully manage the heat, after welding, the repaired piece is every bit as durable as it was before.
It's actually quite satisfying to 'save' a piece this way!
Good Luck,
-Paul
Managing heat is key. Once the crack is prepared (ground with a "V" along the crack for adequate weld penetration), I heat the pieces in a forge or even a BBQ grill until they are uniformly cherry red. Have your clamping set-up ready to go ahead of time, and then quickly clamp and weld before the pieces cool. I'll have a wire brush handy to brush the ash off the cracked surface before clamping. Then, as soon as you're done welding, toss it back on the fire, and let the fire burn out, ideally over several hours. You want the piece to cool off as slowly as possible after welding. You have maybe 5 or 10 minutes at most to do the work before returning the piece to the heat.
I use a mig welder with regular solid steel wire (0.030" or 0.035"). My mig welder is a Hobart 185.
Again, you'll have the best success if it's a simple crack and the pieces have uniform thickness. I've had complex pieces simply crack in another place while welding due to poor heat management. Thinking of that Farmall F-12 belt pulley I tried (unsuccessfully) to fix. I also think that older pieces are more of a challenge due to the primitive metallurgy.
One thing to be aware of. The weld is SUPER hard. So, if there are threaded bolt holes along the crack, you will never be able to drill them out or re-thread them if there is weld bead in there. The only other 'machining' I've tried on cast iron welds is grinding. That's usually not too challenging. Die-grinding the weld, even with carbide bits, is not very productive. You can scratch at it, but not really cut it.
Another thing to be aware of. Cast iron that is heated up to glowing gets quite soft. Crumbly would be a better word. So, don't go beating on it with a hammer before it cools back down, or you'll break it again.
Maybe try it on a junk piece of cast iron before you tackle your project.
If you successfully manage the heat, after welding, the repaired piece is every bit as durable as it was before.
It's actually quite satisfying to 'save' a piece this way!
Good Luck,
-Paul