I posted this on another thread, titled Safety Relay. I am hoping here my question will get answered. My excavator went off the side of the trailer. I lifted it (flipped it?) with my Mahindra's loader bucket. I gouged the side of the boom in front of the light mount. It is about a 10th of an inch deep. Should I blend out the gouge and weld a bead over it, or just blend it out, or just ignore it? You can read how the ex went over the side of the trailer here............ HeavyEquipmentForums post #42 hugs, Brandi
I don't like welding on booms. Will it crack with a bead welded over the gouge? There is no crack in the gouge right now. hugs, Brandi
I'd buff off the sharp / high spots. I'll bet it's just a scratch beneath. I've seen far worse used by far more abusive and they just keep on digging. Knowing it's yours, maybe prime and paint but I wouldn't run a bead on it. Personally. Good luck
Ive seen a lot worse. Ide leave it alone myself but watch it for awhile for cracks.
I guess I should have said why I wouldn't address that scratch it doesn't protrude up into the top strap or the bottom strap of your boom section since there's no damage to the corners or edges there's no real reason to go after it as I stated before knowing that it's yours you'll probably want to primer and paint it just to make it look less noticeable You should see some of the gouges that I have seen where guys will put a pin on bucket on a quick attach bracket so when they go into full curl the teeth are digging into the bottom of the Boom yours is no big deal it'll be fine
I'd give it a good buff to smooth all the sharp edges off it then blow a coat of yellow over it. No welding.
Thanks guys! I had a feeling I shouldn't put a bead over it. So it's the tops and bottoms (or in a corner radius?) were all the stresses can make a gouge crack out? I will blend out sharp edges and "blow" some paint at it. hugs, Brandi
It's on a reinforcing plate already so it's not a big deal. buff it down and see how it looks. You could always do like the auction yards and use a little body filler before painting it.
I looked at the upper photo and realized you are so right, that area of the boom is plated over already. Thanks! I won't fill it with bondo. Easier to see if it cracks with blending it, then paint. Once I straighten out, the thumb lines will cover over it. hugs, Brandi
I finally got time to blend the gouge out. It wasn't that deep and is smooth and painted now. The threads for the boom light are no good, so I'm gonna welded a new attach plate on. My question is should I just weld the sides? Or can I weld the top and bottom also, since it is not welded directly to the boom? hugs, Brandi
If it were me, I'd burn along the top and bottom. No vertical. Let it cool, chip the slag, seal the verticals with a bead of silicone, paint and move on. If it were me.
Okay. I got confused, as I slept since I welded one on. After I read your post, I went back to the thread where I asked where I could weld plates on. I thought it was the sides, but Y'all told me the top and bottom. Thanks! hugs, Brandi
I agree with Nige and others, just take off the sharp edges and leave it alone. Welding creates a stress concentration at the toe of the weld and "heat treats' the metal, so you can easily make it worse. It is not near any welds or joints so it should be fine. If it was a critical location they wouldn't have put a light bracket there. "So it's the tops and bottoms (or in a corner radius?) were all the stresses can make a gouge crack out?" I work on structures along with designers...and lets just say it can get complicated. All metals deform under load and can fatigue when subjected to pure tension, pure compression, or a combination of both. Any change in cross sectional area along a load path creates a stress riser. The question is that stress riser large enough under the loading to fatigue the material and start a crack? Depends on the loading per mm², base metal, severity of section change, angle relative to load path, aggravating factors such as weld beads and bolt holes, random overload events, etc. Then for good measure throw in multiple simultaneous loads. (That's why computer modeling has had such a dramatic effect on structures over the last 25yrs.) The idea of slowly changing the cross section is why you see radii in place of sharp corners, why doubling plates are often fish-mouth or diamond shaped. On the negative side blending costs money because they are harder to manufacture. So it comes down to a balance, what do I need to do to make this machine live X hours for most of our customers. (cant design for worst case customer, it would cost too much and machines wouldn't sell) On the mining equipment I work with we have some critical welds that must be hand ground and blended - a huge amount of labor but a very significant increase in life. Little sensors 5-10mm long can be attached to the parts to measure the actual deformation while in use to confirm the computer analysis. In this application the most critical part is almost certainly the top plate in tension, especially between the cylinder anchors on the corners. Hard to see from the pictures exactly how that joint is constructed but it appears to be a relatively large weld bead. My guess is they were trying to get the weld toe farther down away from the corner. This just scratches the surface. Hundreds of people have written very large books on this subject and many more make a career out of this. (Airplanes get real interesting - stressed skin, over 1 million rivets with corresponding holes, ~400 lives, big lawsuits potential) ISZ
Uh.............I think you are confusing the boom gouge with the welding of a new threaded light mount plate. The boom gouge was blended out already. You can see it already painted forward of the new bolt plate in the second photo of post #11. The question on welding of the plate has already been answered. I have been an aircraft mechanic for 43 years, specializing in sheetmetal structures. 26 of those years with a major airline. Your post above sounds like an engineer wrote it. Not that is bad. I came a hair's width of going to Texas A&M for Aerospace Engineering. hugs, Brandi
I just looked at your image that you posted. There's no reason you couldn't burn all the way around if you wanted. You would be welding to an existing plate, not the actual structure. It was late , I was tired. That's if you want to. I'd still do it the way I suggested originally. That way if a failure happens, easier cuts to replace.
How bad are the threads? They don’t look all that bad in the picture. Will they clean up enough with a bottoming tap to work? Presumably they are metric, maybe the next larger inch size tap would work. Not a lot of strength required for that application, I would sure try to make what is there work first, though I would not be afraid of welding to it if no alternative.
That is what I was thinking, that it's a plate welding to a plate. But I will keep to the rule and just weld the top and bottom. hugs, Brandi
The threads are M14-2. When I put a new bolt in, I grabbed the light shroud and pulled the bolt out. They were toast. I even thought about tapping a 1/2-13 hole below it, but decided to go with a 1/2 bolt tapped into the new plate. I'm welding it on today. Thanks. hugs, Brandi