Fixing Cracks in a Backhoe - Big ! with pics

[john_bud]

Eddie,

Thanks for the accolades! Coming from a guy that rebuilt his dozer, dump truck and dug a monster pond, it means a lot!

The crack repairs that I am doing now are actually pretty minor. Well, the cracks themselves are numerous and in places that you would rather not have cracks, but fixing them isn't all that hard. Like anything else, when broken down into smaller chunks and each one of those is done one by one and then the job is finished. In this case, it's just inspect a part, find a crack, clean a crack, grind a crack, weld a crack -- repeat. Some times, there is a cycle of grind out the weld you just put down, clean it better, grind it better, weld it better then find a new crack. (I havn't shown those pictures!)

So, that isn't all that overwhelming. The real question is would I buy the backhoe at all, knowing the amount of repair it REALLY needed. Uh - no, I would pass on it and look for one that is in better shape. This is advice for anyone that is looking for a piece of heavy equipment and thinks that they are handy enough to buy a broken one and get a "bargain" that way. I'm fairly handy with tools and such and have been able to fix all of the things that have been broken, but the cost in terms of time, labor, materials and money have taken it out of the relm of bargain !! (fer sure) When in doubt, spend more up front and buy a better unit in good tight shape. With no prior repairs.

Now with that said, I now have a tractor loader hoe that can lift 3100# with the FEL, dig to 14' with the hoe and pick up 2550# to a load height that is just crazy. It has a newly rebuilt diesel engine that is now balanced to a gram, rebuilt Sherman combo trans (underdrive-direct-overdrive), rebuilt 4 speed, rebuilt differential, rebuilt brakes, new radiator, all new front end bushings, hand formed PS lines, rebuilt PS column, rebuilt PS pump, reset injector pop off and pattern, new loader bucket edge (with bolt on cutting edge), all 4 loader cylinders rebuilt, retooled 36" hoe bucket, lots of cracks fixed on the hoe , 6 of 7 hoe cylinder rebuilt, 40 some bushing in the hoe/loader, dozens of new hydraulic hoses, new switches, wiring, lights, gages, all striped to bare metal, primed and painted. (Whew! glad that wasn't overwhelming....)

jb

 

[john_bud]

Did some more welding today. Actually, I had to do some re-grinding as the cracks were aparently open for a long time and the space between metal sheets was full of oil and grease. I used a lot of brake cleaner to degrease, but it bubbled and boiled when I started welding. Knew that wasn't gonna fly! So.... broke out the O/A torch with a rosebud tip and heated the metal up to burn out the organics. It's sort of neat in a perverse way. Started heating the edge where the weld was going to be, then moved the heat farther down and around. Lots of smoke and some fire erupts from the crack. Kept on heating until it quite the flame, then went to the othe side and did the same thing - with the same result. Then came back and repeated until there was no flame and no smoke. It would have been easier if the acetylene didn't give out. Rats! The cylinder would lose pressure and then the flame would back fire into the tip (loud!!), which gets your attention.

Here are some pictures of burning out the grease and the finished weld. Just for the record, I did wire brush the areas after the cooking and before the welding. It's not the best job of welding in the world, but not too bad (I hope!)

Just a few more on this end of the boom!













jb

 

[gbick]

John, You certianly seem able and confidant enough to take on a project that most would consider overwealming or impossible. Our hats are off to you! Concerning the acetylene loosing pressure loosing when using a rosebud, this may be a safety issue. I am no expert, but for 22 years, I was a millwright at a now- closed papermill. Occasionally, the company would bring in experts for safety training. One such person was from a welding supply company. He said that when the flame goes into the rosebud, it's because the rosebud is using gas faster than the acetylene can vaporize in the tank. The solution was to draw from more than one tank at a time. We used a 2 tank manifold with a rosebud. The flame inside the torch, instead of outside as it should be, will damage the torch and could hurt you. Another change that occured after that training was flashback arresters put on all oxy-accetylene torches. I was convinced enough to purchase arresters for my garage torch. Be careful. This country needs more like you. A happy and productive NewYear to you.

 

[john_bud]

gbick,

I'm not sure about "able and confidant", too stupid to know when to quit and too stubborn to give up -- may be more accurate. But thanks anyway for the compliments. The draw from the Acetylene tank is actually pretty small as those things go, I'm using one of the smallest rosebud tips. The issue is the tank is about empty and I can't get any more gas until Tuesday. May not want to go for a while - I unloaded wood from my truck and trailer yesterday and the ground was so wet and gooey, I left the truck in front of the shop. Well, it didn't freeze up overnight, in fact it warmed up to 42F and rained a couple inches! Now it's 10x muddier and gooier than it was. Yuck.

Did a bit more welding this morning. I took one picture of the boom supported by the engine hoist at about a 45 degree angle. That's a tip! If you want to REALLY pour on the heat, move the work so the weld is in the down direction. I realized that I hadn't been showing that I really move the boom around to make my welding easier and hopefully, the welds better. Without an engine hoist or similar, it would be tough to do. I had just finished the weld on the inside support bracket. There is a crack under the bracket, but there is no way to get to it. The background smoke is from the grease under the bracket that I couldn't get to. It was not coming out from the weld area, but the heated metal surrounding it. Fixing 43 year old equipment can get nasty! Thankfully, it's not too cold and having the door open is feasible.

The other pictures show one side and the finished welds. I did some more grinding on the bottom welds as I suspected that there was slag in there. Sadly, I was correct! Instead of 2 lines of pigeon poop, there is one decent weld.

 

[thingy]

Down hill is the only way to weld mig,,,turn it up,,point your nozzel slightly up hill,and weave,,just slightly,,and move,,,,clean and put another pass over,,more weave,,if you got a choice uphill or down,,go down with the mig. thingy

 

[Dargo]

Down hill is the only way to weld mig,,,

No kidding? I just defied the laws of physics this month then. I burned about 25 pounds of wire on vertical and overhead welds with my MIG; all vertical welds were done moving upwards. They look no different than welds done on a flat horizontal plane.

Generally I prefer to push the puddle with a MIG and drag with stick, no choice with TIG. I prefer to weld vertical seams uphill with both stick as well as MIG. I can go either way, but with a good MIG, each "tack" that is stacked on the previous tack is done while the previous tack is still glowing. The end result is one continous vertical bead. Worse yet, I always turn up the heat when doing so as well. Amazing, I was not aware that such a thing is not possible.

I've seen instructors teach both ways, and I passed AWS certification either way.

 

[john_bud]

No kidding? I just defied the laws of physics this month then. I burned about 25 pounds of wire on vertical and overhead welds with my MIG; all vertical welds were done moving upwards. They look no different than welds done on a flat horizontal plane.

Generally I prefer to push the puddle with a MIG and drag with stick, no choice with TIG. I prefer to weld vertical seams uphill with both stick as well as MIG. I can go either way, but with a good MIG, each "tack" that is stacked on the previous tack is done while the previous tack is still glowing. The end result is one continous vertical bead. Worse yet, I always turn up the heat when doing so as well. Amazing, I was not aware that such a thing is not possible.

I've seen instructors teach both ways, and I passed AWS certification either way.

Dargo,

Oddly enough many of the verticle welds I fixed looked the same as the horizontal ones -- equally bad that is! Too bad YOU didn't do them, then they would be equally GOOD.

Me, not being certified as a welder (although I have been called certifiable - just not in relation to welding.....), I need to do every thing possible to make decent welds.

I also like to have the torch pushing to new areas to weld, it seems to be easier. Hotter on the hand holding the torch going over the top of the fresh weld, but easier. Is there a technical reason why uphill or downhill is better? Pushing vs pulling the puddle? While I can make metals stick, knowing why one method is better than another is important too!

Happy New Year!

jb

 

[Dargo]

Is there a technical reason why uphill or downhill is better? Pushing vs pulling the puddle? While I can make metals stick, knowing why one method is better than another is important too!

Happy New Year!

jb

Actually I was teasing him because he said that was the only way to go. I've heard several long time welders swear either way is the best on both issues. Since my dad, after being a professional welder for decades, taught me to weld, he forced me to go both directions and use either hand when learning. I don't get on the dedicated welding boards much except to try to find answers to specific questions about stuff I don't normally deal with and to see if there are new products for specific applications. I've got to laughing at how brutal the discussions have gotten about exactly what you've asked.

I have to go out today to finish a project I've been working on for about a week, and all the welding left is overhead. Since my dad does not know this forum exists, I'll tell ya, that sux! I still hate all overhead welding!! Yes, I can do it, and yes, I know how to do it. Still, there's nothing like having your "mistake" drop down inside your boot, down the back of your collar etc. It seems that anytime I break my pattern and rhythm, I'll get a nice hot glob for my effort.

You're doing a great job. I only weld as a hobby and because I'm too cheap (and picky) to pay someone else; except on aluminum. I don't do nearly enough stuff with aluminum to buy the equipment or keep in practice. Believe me, I've seen certified welders who most definitely could not lay a bead as well as you have been doing. And, some of these guys do it 8 hours a day 5 days a week. I suppose there is a certain art to it past the basics. However, I am so bad at art that I consider it "art" for me to sign my name. I can make relatively detailed sketches in my head, but my hand definitely won't put them on paper.

 

[thingy]

Dargo,I've passed many qualification tests too,and gave more tests than I took my self,,,just cause you pass a certification test really don't mean much,it just means you passed that individual test,,so I wouldn't get all carried away with that.
I've passed up and downhill tests,,and will say that if you got a choice,down hill with the mig is the only way to go,you can weld up,and you can weld down.
Some will say you get more penatration and fusion up than down,,there might be some truth to that,,but if you know what your doing,you can get all you need down,,the object of welding any two pieces together is to make them one piece,,you can achieve this up as well as down.
About all gas line,[pipeline] is welded down hill,,its just something you learn over time,,that being down hill is the way to go with a mig,,,but gotta say here,fixing a machine like we are talking about here,mig,[up or down] wouldn't have been my first or even second choice,,stick or fluxcore woulda been my picks,,but if mig's all you got,well,,,,thingy

 

[Dargo]

Dargo,I've passed many qualification tests too,and gave more tests than I took my self,,,just cause you pass a certification test really don't mean much,it just means you passed that individual test,,

Correct, whoop dee doo,,,,,,what's your point?

Some will say you get more penatration and fusion up than down,,there might be some truth to that,,but if you know what your doing,you can get all you need down,,the object of welding any two pieces together is to make them one piece,,you can achieve this up as well as down.

This makes it obvious that you don't "get it". I was teasing before (and stated so if you care to read) because it's well debated which is best. Again,,,,,,whoop dee doo,,,,,what's your point???

About all gas line,[pipeline] is welded down hill,,have you ever tried it down? thingy

Hmm, "about" all are welded down? Not all, bar none? Again, if you read earlier, I clearly stated for all to read that I am a hobby welder; I don't do it for a profession. Is there something about that which eludes you? Have a happy new year and you just may want to relax a bit. When someone states that they are just having fun, and the fun is very light hearted, it's not exactly normal to take offense. Many times I've stated that I'm a competent welder, not the world's best. Apparently you seem to feel that you are the world's best. Good for you. I'm happy for you. It's just that I'm positive that a few of the guys I know who have welded longer than I've been alive, and travel to 15 to 20 welding related shows per year to demonstrate welding techniques to welding instructors, are considerably better than you think you are. Again, just in case you didn't seem to be able to comprehend it, I am not the world's greatest welder. Clear enough? However, I'm competent enough to catch a slip by you.