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Looking for some direction from 12V, Popeye or others with experience in big iron. After 50 hrs in the rock piles, I'm seeing some cracks in the loader frame of my CAT 920. There's rust in the cracks so they are old, but I looked this over pretty close before I bought it and I'm pretty sure I've opened the cracks up worse . My plan is to grind them down into a V, do a first pass with NiCad, fill the V with 1/8 7018 and do a final coat with 5/32 7014. Should I be preheating or trying to slow down cooling? Thoughts, advice? I really don't want these to get away on my because of the loads in these areas.
250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Been there and done those. It's good cast steel that welds well with 7018 and 400-450 degrees of preheat but my preference was Hobart Fabco 802 dual shield wire. That is going to take some serious gouging to get to the bottom of the cracks. The boom pivots at the top worry me the most, they are under a lot of stress. You will probably have to remove the boom to get all the way around the mounts.
Reply:Yes, you didn't mention taking it apart.It's a giant pita, but without that I don't think you could properly clean, inspect, grind or weld.Grease will just keep melting weeping and seeping.You can preheat and burnout parts on a propane bbqWhy the switch to three rods ?I don't see an advantages to going from 7018 to 7014
Reply:
Originally Posted by 12345678910
Yes, you didn't mention taking it apart.It's a giant pita, but without that I don't think you could properly clean, inspect, grind or weld.Grease will just keep melting weeping and seeping.You can preheat and burnout parts on a propane bbqWhy the switch to three rods ?I don't see an advantages to going from 7018 to 7014
Reply:Do you have an air arc? Hot 6010 will get rid of some of the carbon left over after gouging. Forget the 7014 use 7018 for all of it. If you stay with it after gouging you shouldn't need too much preheat.
Reply:I would not even think about welding the cracks,,I would find some big steel and weld it on like a fish plate,,Look at the D10 blade Popeye is working on right now, he is adding AR plate as the fix,, you need to do something like that,,Something large, like 2" thick, cut and ground to fit, then weld it on.CAT had the capability to make those as castings,, you have the capability of re-making it with steel.I think you have a 10X better chance of the unit working long term with steel bars welded on, as compared to trying to weld the existing part.AND, those cracks occurred for some reason,, whatever the reason, each crack is a poster sign that is telling you that more strength is needed for the job you are trying to do.Fixing it back to "original" is giving you no greater strength,, fix it back to original, means do less work, or expect it to crack again.Bigger steel always trumps a repair. Add bigger steel.
Reply:
Originally Posted by SweetMK
I would not even think about welding the cracks,,I would find some big steel and weld it on like a fish plate,,Look at the D10 blade Popeye is working on right now, he is adding AR plate as the fix,, you need to do something like that,,Something large, like 2" thick, cut and ground to fit, then weld it on.CAT had the capability to make those as castings,, you have the capability of re-making it with steel.I think you have a 10X better chance of the unit working long term with steel bars welded on, as compared to trying to weld the existing part.AND, those cracks occurred for some reason,, whatever the reason, each crack is a poster sign that is telling you that more strength is needed for the job you are trying to do.Fixing it back to "original" is giving you no greater strength,, fix it back to original, means do less work, or expect it to crack again.Bigger steel always trumps a repair. Add bigger steel.
Reply:
Originally Posted by SweetMK
I AND, those cracks occurred for some reason,, whatever the reason, each crack is a poster sign that is telling you that more strength is needed for the job you are trying to do.Fixing it back to "original" is giving you no greater strength,, fix it back to original, means do less work, or expect it to crack again..
Reply:If you are looking to do a long lasting repair do as the following. Step 1: Tear the repair area apart and degrease. Step 2: Decide how you will brace the part to keep it from twisting the bores from each other. Step 3: ArcAir, torch, 9" grind or die grind the crack out complete. Step 4: Clean the area with a good solvent and make sure the solvent is gone. Step 5: Preheat to atleast 350 deg if you can get it there. Otherwise do your best. 20lb propane weed burners work great. Step 6: Weld it out. My choice is either 8018 C-1 or a Ni 80 wire. Esab or select arc are my choices. Otherwise if you want 7018 or equiv wire will work. Again, not my choice. A needle scaler between passes does wonders to relieve stress. After the hot work is done, wrap with insulation to slow the cooling. Step 7: Optional, grind the repair completly smooth to get rid of any chance of a toe crack. You could gusset or fish it, but that can also make to repair worse as it could just transfer the fracture to another point. But don't just slap a plate over it or a heavy piece of Steel and call that a repair. That's just asking for a failure and a big embarrassment.
Reply:
Originally Posted by whtbaron
Looking for some direction from 12V, Popeye or others with experience in big iron. After 50 hrs in the rock piles, I'm seeing some cracks in the loader frame of my CAT 920. There's rust in the cracks so they are old, but I looked this over pretty close before I bought it and I'm pretty sure I've opened the cracks up worse . My plan is to grind them down into a V, do a first pass with NiCad, fill the V with 1/8 7018 and do a final coat with 5/32 7014. Should I be preheating or trying to slow down cooling? Thoughts, advice? I really don't want these to get away on my because of the loads in these areas.
Reply:
Originally Posted by 12V71
Yeah, seen those repairs before... Crack continued right through the repair part. Start at the bottom and do it right. Done a bunch of these that had no room to add plates and they are still holding.
Reply:[QUOTE=SweetMK;8814266]I would not even think about welding the cracks,,I would find some big steel and weld it on like a fish plate,,Look at the D10 blade Popeye is working on right now, he is adding AR plate as the fix,, you need to do something like that,,Something large, like 2" thick, cut and ground to fit, then weld it on.CAT had the capability to make those as castings,, you have the capability of re-making it with steel.I think you have a 10X better chance of the unit working long term with steel bars welded on, as compared to trying to weld the existing part.AND, those cracks occurred for some reason,, whatever the reason, each crack is a poster sign that is telling you that more strength is needed for the job you are trying to do.Fixing it back to "original" is giving you no greater strength,, fix it back to original, means do less work, or expect it to crack again.Bigger steel always trumps a repair. Add bigger steel.[/QUOTIf you are talkin about the bottom of the blade on the corners that AR plate is not the "fix". The fix was welding the cracks up and repairing the corner that was wore through. After all that was done the 3/4 and 1inch AR plate was added for wear. Just wanted to clarify that.Yes these cracks in this loader need to be gouged out and welded...slappin some 2 inch bars on them will do absolutely nothing and will not even be needed when its repaired properly
Reply:that has to be disasembled and gouged out some how, grinder, air arc, scarfing tip, something to fix it right. otherwise your just wasting your time. but it has to be gouged out to be fixed if not may as well spread bondo on it. I picked up an old john deere grader dirt cheap because of a cast steel break but it had to be disassembled and gouged out to be fixed. if you dont want to fix it one choice is send it thru an auction and get one in better shape I have bought equipment like that knowing I have to fix it but dont just run beads on that without proper prep. all you will do is draw attention to the problems without fixing anythingDo not argue with an idiot. He will drag you down to his level and beat you with experience.
Reply:
Originally Posted by 123weld
all them cracks are "operator error". in other words a dummy is tearing it up. the higher ones are from running start and impact (trying to cut into something/hard dirt).the others are lifting/bouncing to much weight w/ one side of bucket. just plain abuse. i grew up on a 920, like most kids grow up on a bycicle. i n the 70/80s, they were a great loader for grain and loading trucks. ours scraped on cement all day loading trucks, so important that arms werent tweaked for a even flush scrape. the case w-14 was its competiton in the day. anyway, i remeber as a little boy, a truck driver delivered a load of cotton seed, he used our 920 to push it under the commodity shed, then, he couldnt figure how to turn it off. my 14-15 yr old babysitter (who lived on a dairy down the street), who was babysitting us, she went out there and showed the truck driver, to just lift the pedal. we never turned the key off behind the seat
Reply:No air arc so I'll be using the grinders and weed burner. I think if I block it up safely I can get at it as well as I will by taking the loader off... either way it's going to be a pain. Thinking about dragging a junked combine out of the bush to set the loader on so there's no way it will come down. Might have to order in a needle scaler, I was thinking about getting one anyway.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:
Originally Posted by whtbaron
No air arc so I'll be using the grinders and weed burner. I think if I block it up safely I can get at it as well as I will by taking the loader off... either way it's going to be a pain. Thinking about dragging a junked combine out of the bush to set the loader on so there's no way it will come down. Might have to order in a needle scaler, I was thinking about getting one anyway.
Reply:
Originally Posted by whtbaron
No air arc so I'll be using the grinders and weed burner. I think if I block it up safely I can get at it as well as I will by taking the loader off... either way it's going to be a pain. Thinking about dragging a junked combine out of the bush to set the loader on so there's no way it will come down. Might have to order in a needle scaler, I was thinking about getting one anyway.
Reply:I don't think there really is a "gouge mode" on a $250 Chinese plasma, but I've got some new tips that seem pretty impressive relative to what it had so I'll give it a go. It won't cut plate 1/2" thick, seems to max out around 13/32" but it's a start. How wide would you expect that V to be on top?250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:
Originally Posted by whtbaron
I don't think there really is a "gouge mode" on a $250 Chinese plasma, but I've got some new tips that seem pretty impressive relative to what it had so I'll give it a go. It won't cut plate 1/2" thick, seems to max out around 13/32" but it's a start. How wide would you expect that V to be on top?
Reply:
Originally Posted by whtbaron
I don't think there really is a "gouge mode" on a $250 Chinese plasma, but I've got some new tips that seem pretty impressive relative to what it had so I'll give it a go. It won't cut plate 1/2" thick, seems to max out around 13/32" but it's a start. How wide would you expect that V to be on top?
Reply:
Originally Posted by 12V71
My "V" would be as wide as it is deep.
Reply:
Originally Posted by Popeye an old miner
yup but you can make a narrow v in deep castings too, I dont know how thick this is unless its solid and parts of it probably are. With a narrower V you dont need as much filler and save some time, it takes a bit more skill to weld it though manipulating your rod in there. I try not to make my V too wide, it puts a whole bunch more heat into the casting than what needs to beSometimes what works well is to make it like a U, strait walls instead of slanted walls, Its harder to use the heavier rods though, I did that on a haul truck wishbone a long time ago the casting where it broke was 3 inches thick and the corners were about 4 1/2 inch thick....lotsa rods on that one and had some tight places to work in as well. 2 14 hr days doin that one.
Reply:That thick material you wouldn’t need a gouge mode. Gouge mode spreads the stream so it doesn’t burn as deep. Torch angle and the way you maneuver will do a lot. You can get it close with the plasma and then clean it up with the grinderMillermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:
Originally Posted by 12V71
One thing I remember about 930's is that if you have problems like that up front, you may have cracks in the top of the rear frame just behind the rear cab mounts and possibly in the bottom of the rear frame at the middle of the transmission area. The ones I worked on had oversized buckets and extra counterweights for handling silage. The oversize bucket made it hard to get over taller trucks, so the operators would shake the bucket hard to empty it.
Reply:Hated silage, it would always want to bridge in the hopper. Corn loads were the best.
Originally Posted by farmersammm
Hated silage, it would always want to bridge in the hopper. Corn loads were the best.
Reply:Finally got back to this one yesterday. I was able to get at the entire crack without removing the loader, and as it turns out, that part of the casting is hollow, so grease wasn't an issue and I really wasn't dealing with as deep of a crack as I thought I was. I put the loader up on a solid block to gain some clearance. I consulted with some experts at a local welding shop that does a lot of big jobs. When I asked for the best rod, of course I opened myself up for the most expensive, but I want this job to last. He didn't like the idea of using the plasma and said I'd have to grind the remains back anyway, so I went at it with a cutting disc and a couple Snap On rotary burrs in the die grinder. I washed everything back before I started with brake clean and I think I was into the grinding for about an hour and a half. I was going to start with the easy crack over the lift, but it washed off with brake clean so that was an easy fix. Unfortunately that didn't give me an "easy" spot to try out my new blue rods but they weren't bad to work with. I was pushing the high end of the heat scale because I wanted penetration. That was alright for the flat part of the upright, but tended to droop a lot when working out of position on the side. I got good penetration and solid metal in the crack, but I had to work in short bursts to keep the rod from overheating (I was running around 135 AC) so it didn't leave the prettiest weld. My new needle scaler got a workout and I used Rose to help me with the warmup act. I really wasn't happy with it and thought I was going to have to grind it all out again until I started grinding and found it was all solid metal except for a couple gopher holes away from the crack. There was a blemish in the cast that seemed to be letting water into the crack so I ground that up and sealed it as well. I'm not sure if that contributed to the problem or not. I do want to thank everyone that helped with the advice..
No cracks here... I got off lucky...
These are the rods I ended up using... high tensile strength and they are supposed to leave a more flexible weld. For $500 Cdn. they come in a pretty blue color that makes me thirsty...
Attached Images
250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:More pics...
250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Still not 100% happy with the front of the weld. I've got a DC machine coming in hopefully before the end of the month and I would like to grind it down a bit and try a few beads with that. I also found an old repair and a small crack on the inside of the casting that will require some overhead so I'd like to have the DC for that as well. The other locations aren't as critical for strength so I'll give it some small jobs (like lifting a sick 35 ft. cultivator) to test out my work.
Last edited by whtbaron; 07-16-2021 at 12:37 AM.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Are they castings or forgings?
Reply:I believe it is cast steel, not cast iron. You can see where they have been welded into the original framing during construction. Seems to weld well...250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:That seems like a good strong repair. Those must be expensive rods. but I suppose for a one off a kind repairif the weld is successful they are well worth it. I thought you got an Lincoln Ideal arc Last year. Did the dealnot work out? Any way you are doing a good job with the repair on your own.
Reply:
Originally Posted by whtbaron
I believe it is cast steel, not cast iron. You can see where they have been welded into the original framing during construction. Seems to weld well...
Reply:
Originally Posted by Josey
That seems like a good strong repair. Those must be expensive rods. but I suppose for a one off a kind repairif the weld is successful they are well worth it. I thought you got an Lincoln Ideal arc Last year. Did the dealnot work out? Any way you are doing a good job with the repair on your own.
Reply:
Originally Posted by whtbaron
Yes, I'd give it a small F for presentation, but it seems to be a solid, well penetrated weld that is slightly thicker than the original metal so I'm hoping it's good. Looking at that 2nd crack out in the sunlight yesterday and I'm thinking it might not be a crack at all.... have to get in there with a light grind or wire brush and see what's going on for sure. I lifted the center section out of the sick cultivator and replaced it yesterday with no problems so I think it's good to go. In hindsight, the shop did offer to split the $500 package up for me, but I thought I'd be replacing a lot more metal than it ended up being. I'll keep them for sensitive places like frame repairs so I'll still get my money's worth out of them. The big Lincoln is still a purchase in the works... nothing wrong with the deal it's just been complicated with the distances and Covid restrictions involved. Might be time to just bite the bullet and pay the frieght bill. I bought a Miller Dialarc off Dave last fall and the border restrictions are finally being relaxed enough that I can go pick it up so that's the one I hope to have here before the end of the month. With all this hot dry weather it's looking like we could be in for an early harvest so it's not giving me much time this year to get through all the equipment and get it ready for next year.
Reply:WHAT??? Don't tell me I'm in the sh*thouse now !! I figured my Lincoln Idealarc was off the table when you picked up Dave's Miller which was closer. I just sold it along with other welders within the last month. Three Millers, two Forneys, two Lincolns and my Lorch.
This loaded this one......
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Reply:Thats a nice lookin little welder there, ol boy up the road from me has one just like it it aint as pretty as that one though and he really could use some decent weld leads for it. His leads got more electric tape on them what he got rubber. I offered to GIVE him 100 foot of my old 2.0 leads after I bought the 4.0 stuff Im usin now but he wont take em, so I gave them to Joe for them to use in the shop
Reply:
Originally Posted by old miner called Pop
That looks good from here, how did you like welding the cast steel? Ive always felt welding cast steel was easier than welding plate or structural shapes especially if Im stick welding...but most folks tell me Im crazy and nuts. For some reason most guys I work with hate weldin cast steel for some reason. You can find out with your torch if that one you think might not be a crack is a crack or not. Just heat it up a bit if it is a crack it will open up....or....did you notice any of your grindings hanging in a line where you think this crack is? For some reason and I dont know why, but grindings will hang out in a crack, whether its overhead flat vertical or any other crazy angle it is. I discovered many cracks just keepin my eyes open for that.I like your needle scaler...best doggone thing since the zipper
Reply:
Originally Posted by 12V71
That's "poor mans magnaflux" when the grindings collect on a crack.
Reply:
Originally Posted by old miner called Pop
yup it works dont ask me how or why but I found a lot of cracks that way while workin on other stuff...its all good...makes for a bigger paycheck at the end of the month
Reply:You can always get dye penetrant to check for cracks. Those Eutectic rods are good for removing broken bolts too.
Reply:
Originally Posted by Lis2323
WHAT??? Don't tell me I'm in the sh*thouse now !! I figured my Lincoln Idealarc was off the table when you picked up Dave's Miller which was closer. I just sold it along with other welders within the last month. Three Millers, two Forneys, two Lincolns and my Lorch.
This loaded this one......
Sent from my iPhone using Tapatalk
Reply:
Originally Posted by old miner called Pop
That looks good from here, how did you like welding the cast steel? Ive always felt welding cast steel was easier than welding plate or structural shapes especially if Im stick welding...but most folks tell me Im crazy and nuts. For some reason most guys I work with hate weldin cast steel for some reason. You can find out with your torch if that one you think might not be a crack is a crack or not. Just heat it up a bit if it is a crack it will open up....or....did you notice any of your grindings hanging in a line where you think this crack is? For some reason and I dont know why, but grindings will hang out in a crack, whether its overhead flat vertical or any other crazy angle it is. I discovered many cracks just keepin my eyes open for that.I like your needle scaler...best doggone thing since the zipper
Reply:
Originally Posted by whtbaron
I thought I could feel something there with my fingernail, but the more I look at, the more I think it's something like tar that got winged at it. I'd rather not put more heat into that casting if I can avoid it... pretty sure I can get a hummer disc in there to check it out without dismantling anything. I didn't find the casting to be especially challenging... that was more an issue with getting room to work in awkward positions. That being said, I was also working with rods I had never tried before so a better test would have been seeing how it welded with something like 7014 that I'm more used too. I didn't notice any grindings going that direction, but I didnt' spot it until after I had painted so I was really watching for it. The needle scaler is a beast... I think I'm going to like it for slag removal. I ran that , a cross peen, the chipping hammer and wire cup in a drill over the weld between each bead.
Reply:I never thought of using a blunt air chisel for peening.... have to make note of that for next time. I was really pushing the hot end of what the rod wanted for penetration so I didn't have a problem getting it into the cast. I'm really not used to working with a gap that wide and I couldn't seem to come up with a pattern or weave that could work the entire width of the weld as I got closer to the top. I normally just work in a small swirl pattern, so this meant I either started going side to side or end to end with a single bead as it got wider. As long as I kept the slag clean, I didn't seem to have a problem with gopher holes in the weld itself, but right at the top outsides it didn't blend well the cast.... it just seemed to go cold at the outside edges, hence the grinding to get back to solid metal. I don't think it was an issue for strength, but like I say, it got a little ugly.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:I guess if we're going to talk about the ugly, I may as well post it. The holes aren't as serious as they look... I was already above the original surface of the casting. As I ground things flat, they disappeared.
You can see on the old repair that the guy had a nice downhill weave going on.... I just couldn't seem to get that kind of control with the heat I was putting into it.
250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:Don't worry about trying to run from one edge to the other on a wide opening. Stick to stringer beads, best bet for strength. Vert, flat, horz or overhead stringers are my go to for cracks, AC or DC current. Although vert down I don't use much. I have used it with a E9045 rod when I needed to have the weld pull a certain direction.
Reply:I sure wish we had internet and this forum 30-40 years ago when I could have really benefited from the knowledge you guys contribute.
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Reply:A winter in welding class back in my 20's would have made a huge difference too... kinda wish I had done it now.250 amp Miller DialArc AC/DC StickF-225 amp Forney AC Stick230 amp Sears AC StickLincoln 180C MIGVictor Medalist 350 O/ACut 50 PlasmaLes
Reply:
Originally Posted by whtbaron
I never thought of using a blunt air chisel for peening.... have to make note of that for next time. I was really pushing the hot end of what the rod wanted for penetration so I didn't have a problem getting it into the cast. I'm really not used to working with a gap that wide and I couldn't seem to come up with a pattern or weave that could work the entire width of the weld as I got closer to the top. I normally just work in a small swirl pattern, so this meant I either started going side to side or end to end with a single bead as it got wider. As long as I kept the slag clean, I didn't seem to have a problem with gopher holes in the weld itself, but right at the top outsides it didn't blend well the cast.... it just seemed to go cold at the outside edges, hence the grinding to get back to solid metal. I don't think it was an issue for strength, but like I say, it got a little ugly. |
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发表于 2021-9-1 23:14:12