Hello HEF, I have been trying to paint my 931b and have found 3 cracks so far, one is near the top of the bucket close to the hinge. There are 2 at the bottom on each side where the front is attached to the frame. What is the best way to weld?? or should i weld on a steel plate over to reinforce the metal??
You will need to vee out the cracks to insure plenty of weld penetrates into the steel. 7018 rod would be what I would use & always good to preheat when possible.
Hi JBGASH, Should i use a grinder, or cuttin torch, to get the weld surface V groove, or something else ??sam.
I'm sure someone will argue with me but the bottom 2 pics I would just weld it's not that thick to require preheat and vee etc. I guess it depends on how big of a welder you have lol. Not sure what the top pic is I can't quite make it out.
Definitely grinder, torch or grinder to V out groove. Not just for weld penetration but to make sure there are no underlying cracks that will start and spread again. Wouldn't hurt to preheat metal to prevent any new weak spots from forming from being welded cold and because the metal looks like it may be tired it wouldn't hurt to add a bit of metal over top if you wanted to beef it up. I don't understand what you mean by "where the front is attached to the frame" but usually anywhere the frame is involved definitely preheat or you will be repairing it again and possibly worse. Good luck
I would use a grinder. It does not take very long to prepare for the weld and it is very important.
I have welded cracks as these as a mechanic, take a 4 1/2" grinder with a hard wheel, slot the crack out to a 45 degree angle(roughly) on both sides, 90 degree overall, leave about 1/8" solid material at the bottom of the vee, use 7018 rod inside a heated shop where the steel has come to at least 60 degrees F or acclimated. I use a small 3/32" rod at around 100A for a root pass, deslag and wire brush, overlay with 1/8" at 130A two to three passes side by side, extend at least a inch past the end of the crack to decrease tension on the steel, take a torch and heat the area after welded to almost smoking then allow to air cool slowly. Grind out the back side, overlay with either 3/32 or 1/8 single pass and heat up with torch again, destresses the weld area. As a precaution, look over the entire bucket, look for stressed areas where the steel is expanded or distorted, flexing regions, this could be the cause for the stress cracking here.
Hi DMiller, Thanks for the advice, This loader was used in demo, and i will have to do some work to the bucket, cracked in corners, I will try to get my good friend to help weld when i get the crack ready to fix. sam.
Sounds like this isnt dmiller's first rodeo ............
Been wrenching since 1976, have had to deal with machines like this quite a few times over the years, currently fighting an old loader trying to recover some use in what may have been a just a pile of scrap iron and I am too stubborn to let it die.
It amazes me, we can't find new mechanic's but the old ones never seem to die. My dad and step dad are te same way been wrenching since long before I was born in 76 and still going! Wosama can you zoom out a bit to see the area we are working on here?
New mechanics are coming into the fold, just find the work too harsh or too hard and the tools too costly so many leave before they ever get very good at it. I twisted bolts on most every type/style/name brand of machine in the US from cars and heavy trucks even working strip mine machines at one time. Dirty, crippling if you do not pay attention, full of potentials to cost you money if done wrong or impatiently. Too easy today to become a armchair quarterback sitting at a desk pushing keyboard buttons making the world safe for web surfers like us. Us old farts will die off, then the sh-t will be on the door knob when there is few to train the newbies that do come to work.
Hi DMiller, I am just a young guy, 64, starting out i have plenty new tools, from cheap to expensive, i know what you mean, some time i ask myself why i'am doing this, i could be fishing. But i keep on working trying to bring this old loader back to doing what it was made for, i do think it will do the job ahead, and should last untill i get to old and decrepid, then i will get after the fish. sam.
Metal fatigue
Hi mage76, the old cat took a hit, ten tons brick an concrete, across the bucket an engine, wiped out the lines, they dug it out.
That would explain a lot, I would look at the bends and rolls on the bucket, try to work out those stressing the edges.
Hi DMiller, Well a friend said to drill a small hole at the end of the crack, then i plan to grind out a v shape to weld up. sam.
Hello HEF, i found a good welder to fix that crack at the top 4 in 1 bucket, He had an Ark Air outfit to clean out the crack, grind out and weld back together.
That looks like a good job. The only thing I would do beyond what's in those photos is grind the repair welds smooth. Apart from removing possible stress risers it also has the effect of making the repair invisible, which is always the sign of a good repair.
Hi Nige, I thought that's what i should do, thanks for the advice, the guy that did the work had to make a few passes to get it filled. Also i have to get the new pins in the bottom fixed, and a few more cracks. sam.
Great looking welds, nice and deep, good fill-in so should hold a long long time. With the gouging out of the cracks most of the stresses should also be relieved.
Hi. HEF, Got few minutes to day to grind, sam.
I would also drill a hole at the end of the crack too prior to welding
If you gouge out the entire length of the crack (plus a bit extra to be on the safe side) and then grind out and prep all the residue after gouging - then weld up the crack as per standard procedure - then you should not need to drill the end of the crack. If you have an existing crack that you can't get round to fixing immediately, drilling a hole just past the end of the point to which the crack has progressed to right now can be a good way of preventing the crack propogating further until it can be properly repaired.
Hi Greg an Nige, I did drill a hole, my welder man said that the hole should about the same thickness, diameter as the metal is thick. I hope to have him return soon to finish up. I will post a photo or 2 of the work, and a line bore guy has me on his rador to work on the bottom pins. So stay tuned to see, thanks for the advice and trying to keep me on the straight and narrow. Sam.
A couple more photo to view, HEF, sam.