Best abrasives for grinding down booger welds? (1 Viewer)

[artech]

And thanks again for your opinion Pinhead. I'm sure you are right. But since none of my stuff has ever broken I guess I'll just keep on keepin' on the way I do since it does seem to work.

 

[Pin_Head]

It won't cost much to have a pro do the critical welds and you will feel better, especially being an EMT and seeing what can happen when things go bad.

 

[artech]

You might be right there, I just got my roof rack extended(I can't do aluminum with any of my rigs) and the guy was very reasonable. Maybe If I tacked everything well where it needed to be and then dropped the whole thing off so he could work it in around other jobs, he might work with me on the price. Have to check into that. Thanks!

 

[Pin_Head]

Not every weld on a bumper is that critical, like welding the cover on the frame, but bumper hitches and spare tire mounts have a high dynamic load and can benefit by having full penetration welds with a low hydrogen electrode with zero inclusions or defects.

 

[LINUS]

So when I get around, to prepping my 4x4 labs, and I come visiting with after hours beverages( I don't drink adult beverages), you can help me weld my bumper, I can tack it together but want it purty

You bet! (I actually do hire out jobs for people)

The 350P welder even has a pulse setting I use (I'm working my way to building my own welded AL tub river sleds & small salt hulls) - that pulse makes my MIG look like "stacked dimes" as if it was TIG'ed. Same setup Wooldridge uses for their hulls.

During fins & fur season I am out constantly if not working, but by Halloween to March I encourage PNW crew to hit me up if you want custom work.

Seems like The SW & NE guys have fab-for-hire - nobody up here tho, and I have TIG, MIG, and plasma cutting & a good ol' oxy torch here @ home.

 

[LINUS]

If you don't know the difference between 7018, 6013 and 6011 rods, you have no business welding on trailer hitches and spare tire carriers in my opinion. You can tell a weld is bad by looking at it, but you can't tell if it is good enough for critical applications. You can only tell by testing them and that is one of the things that they teach you in welding class, besides things you should not be welding on if you are not certified.

The one thing here I wish instructors would emphasize is how poor penetration a mig weld can have, yet look pretty to an untrained eye & so "Joe new guy" thinks he's rockin' it out, just to crack a cold weld.

There's a really great guy on Youtube "welding tips & tricks" is his title/name - anybody who's new to either MIG or TIG I highly recommend his videos - it's great to get his POV since most us who weld get pigeonholed into a small segment / are hired & specialize in processes where it's nearly an event to hange the settings on your machine & loose some of the bigger picture.

I think his name is Jody, the guy speaks at a level both us seasoned guys track with yet breaks down some of the stuff beginners may need to hear a few sentences on.
He'd easily be in demand as a instructor if he wasn't self employed.

 

[LandCruisinMy93]

The question was about dressing welds, well, if you have it welded professionally you'll still have welds to dress. Having done a metric sh!t ton of work with an under powered MIG and utilizing the blue wrench and a digital thermometer to pre-heat...I recommend the Bosch brand or DeWalt brand flap disks. When you compare life expectancy of HF to even Forney brand disks, Forney is still a better buy, buy the Bosch and DeWalt seem to last longer and continue to cut well as the wear. They may be more expensive initially, but they're the better buy in the end. I use a 36 grit and an 80 grit, 36 to knock the weld down close to where it needs to be, 80 to get it 90% of the way and the I use a DA to finish it out to an even reveal and paintable surface...a skim coat of body glaze and block sand. Makes it look better than most manufacturers products. Years ago I used to work for the company that was the first high production manufacturer for Road Armor Bumpers, learned a lot about finishing Bumpers from that...but they mostly powder coated their stuff. Anyway, best of luck to you.

 

[gummycarbs]

MIG would be great but it is just not in the budget, I can barely afford the bumper!

Well, I was going to say that I bought a Drico 150D MIG/stick welder that I've been very happy with, but it looks like it's no longer sold. $259 for 150 amps, and all you need to add is a C25 bottle ($5/mo rental here) and a flow meter to do real MIG.

For what it's worth, you can find other great values on the Chinese MIG market. I'd take a Miller or Lincoln over them any day if money were no object, but they're way better than no MIG welder!

 

[Anvil]

As a guy who has been forging and fabricating for a living for over 30 years (www.irontonforge.com), I recommend a zirconia sanding discs for grinding the welds. Then use a round flap wheel (not flap disc) to blend the seams.

Here's a pic of my bumper, I built last year. There are no grinding/sanding marks anywhere. Just my two cents...

 

[BILT4ME]

Was planning on beveling all the joints, then tacking from the front, pulling it off the truck, and welding from both front and back sides in order to get deep enough to make it strong. Probably will lay 3 or 4 beads on the back of each joint to really hook it all together. Then grind the front smooth and fill whatever needs filling. Uses a lot of rod, but in my limited experience stuff really stays together after being done that way. And since time is pretty much the most abundant asset I have...

MIG would be great but it is just not in the budget, I can barely afford the bumper! Gonna hafta be done with plain old arc, that's all I got that'll work on steel this thick and it does do the job. Just looking for advice from folks on their favorite abrasives to clean up my mess afterwards.

For the final finish I plan on sandblasting it and priming it with an etching primer, then rattle-canning whatever color I decide on. Might try a cold galvanize base then paint over that, since rust is always an issue up heah. Going with spray paint to make repairs easy, as this truck gets dragged over stuff quite a bit. But the road salt means bare metal gets rusted fast, so quick finish fixes are desirable and it'd be nice if it all kinda matched. Plus it fits the budget, so there it is!

And as a side note, Paramedics make squat for money. Seriously. I made more driving a forklift than I make providing advanced life support in the ambulance, and while that sucks, it is what it is. I love what I do but it is damn hard to make a living at it. So I do budget builds. Don' be hatin'!

I would recommend an epoxy primer coat rather than a cold galvanizing. Regular paint over cold galv does not work well. there are other steps that must be taken and won;t give you the "easy fix" aspect I think you're looking for. Google it if you disagree. We don't paint over anything we cold galv for industrial work, as it has different properties than paint.

 

[artech]

I would recommend an epoxy primer coat rather than a cold galvanizing. Regular paint over cold galv does not work well. there are other steps that must be taken and won;t give you the "easy fix" aspect I think you're looking for. Google it if you disagree. We don't paint over anything we cold galv for industrial work, as it has different properties than paint.

Yep, gotta research that more first. Just need some kind of finish that can take dragging over rocks and easy touch-up so it doesn't rust. Rust is a real bitch up heah. And I haven't had much luck painting over galvanized surfaces, it never lasts.

The question was about dressing welds, well, if you have it welded professionally you'll still have welds to dress. Having done a metric sh!t ton of work with an under powered MIG and utilizing the blue wrench and a digital thermometer to pre-heat...I recommend the Bosch brand or DeWalt brand flap disks. When you compare life expectancy of HF to even Forney brand disks, Forney is still a better buy, buy the Bosch and DeWalt seem to last longer and continue to cut well as the wear. They may be more expensive initially, but they're the better buy in the end. I use a 36 grit and an 80 grit, 36 to knock the weld down close to where it needs to be, 80 to get it 90% of the way and the I use a DA to finish it out to an even reveal and paintable surface...a skim coat of body glaze and block sand. Makes it look better than most manufacturers products. Years ago I used to work for the company that was the first high production manufacturer for Road Armor Bumpers, learned a lot about finishing Bumpers from that...but they mostly powder coated their stuff. Anyway, best of luck to you.

Now THAT is the kind of info I was hoping for! Thank you so much!

 

[1973Guppie]

Was planning on beveling all the joints, then tacking from the front, pulling it off the truck, and welding from both front and back sides in order to get deep enough to make it strong. Probably will lay 3 or 4 beads on the back of each joint to really hook it all together. Then grind the front smooth and fill whatever needs filling. Uses a lot of rod, but in my limited experience stuff really stays together after being done that way. And since time is pretty much the most abundant asset I have...

MIG would be great but it is just not in the budget, I can barely afford the bumper! Gonna hafta be done with plain old arc, that's all I got that'll work on steel this thick and it does do the job. Just looking for advice from folks on their favorite abrasives to clean up my mess afterwards.

For the final finish I plan on sandblasting it and priming it with an etching primer, then rattle-canning whatever color I decide on. Might try a cold galvanize base then paint over that, since rust is always an issue up heah. Going with spray paint to make repairs easy, as this truck gets dragged over stuff quite a bit. But the road salt means bare metal gets rusted fast, so quick finish fixes are desirable and it'd be nice if it all kinda matched. Plus it fits the budget, so there it is!

And as a side note, Paramedics make squat for money. Seriously. I made more driving a forklift than I make providing advanced life support in the ambulance, and while that sucks, it is what it is. I love what I do but it is damn hard to make a living at it. So I do budget builds. Don' be hatin'!

4 passes?????

 

[artech]

4 passes?????

Sure. On the inside of a right angle joint- one in the bevel/gap, clean it, one on either side of that bead, clean those, and one on top and clean that. And hot, hot, hot- wanna see that blue come through to the back side. (I remember that from shop class, thank you Mr. Gagne!) Grind and fillet(or not) to taste and paint. Makes one hella strong joint. I'm sure there are better ways, but with my limited equipment this method has always worked for me and I've never had one fail. Of course, it takes 4 times as much rod to do it this way and probably way more than 4x the shop time, but it does work. I have to watch the warpage though, it gets pretty bad. But that joint will not come apart without a cutting tool.

I think for this one though I'm gonna take some of the advice on here and get the crossmember, recovery points, and hitch mount welded by a pro at the shop. The rest of the grunt work I'll do myself, as well as the cleaning prep and finish grinding. That should save enough money to keep it within my limited budget. Can't see using glazing putty and block sanding on it since it will most likely be getting bashed up fairly often and there's no need to try and keep it pretty, just trying to keep it from rusting.

You should see my BIOR skid plate, it has less than half the original paint left on it! Still holding up even though it's gouged and scraped up pretty good, and come to think of it the welded support leg I put on was done with 4 passes. Still as solid as ever. Have to spray more paint on it a few times a year, but that's it.

 

[1973Guppie]

Sure. On the inside of a right angle joint- one in the bevel/gap, clean it, one on either side of that bead, clean those, and one on top and clean that. And hot, hot, hot- wanna see that blue come through to the back side. (I remember that from shop class, thank you Mr. Gagne!) Grind and fillet(or not) to taste and paint. Makes one hella strong joint. I'm sure there are better ways, but with my limited equipment this method has always worked for me and I've never had one fail. Of course, it takes 4 times as much rod to do it this way and probably way more than 4x the shop time, but it does work. I have to watch the warpage though, it gets pretty bad. But that joint will not come apart without a cutting tool.

I think for this one though I'm gonna take some of the advice on here and get the crossmember, recovery points, and hitch mount welded by a pro at the shop. The rest of the grunt work I'll do myself, as well as the cleaning prep and finish grinding. That should save enough money to keep it within my limited budget. Can't see using glazing putty and block sanding on it since it will most likely be getting bashed up fairly often and there's no need to try and keep it pretty, just trying to keep it from rusting.

You should see my BIOR skid plate, it has less than half the original paint left on it! Still holding up even though it's gouged and scraped up pretty good, and come to think of it the welded support leg I put on was done with 4 passes. Still as solid as ever. Have to spray more paint on it a few times a year, but that's it.

yeah no offense meant, just seems like alot of work when you can get the same result from 1 good hot mig pass and not have to do any of or very minimal clean up. If I were in your position I would tack everything together and take it to someone to finish weld. It will end up looking better and should not cost much if all the guy has to do is to burn in strong welds.

 

[artech]

I agree totally, it IS a st-ton more work, but it is work that I can do with the stuff I already have. And hopefully I can work something out with the shop guy and get it done like you say, but my spendable cash is measured in $20's, not $100's. I need the stressed parts done right, the rest is just work. Hopefully a very flexible delivery time frame and me doing the clean-up will make the cost of doing the whole thing low enough so I can pay it, otherwise I'm gonna have to do the rest myself.

That's the big reason why I don't have a MIG- can't afford a good one, and I figure that a crap one would just be more trouble than making 4 passes with my(already paid for) buzz box, which actually does what it can do pretty darn well even though it is very low tech. I have laid down a few beads that were pretty decent looking, but mostly I'm just welding the hell out of stuff to make sure its strong enough. And like I said, the plow rig I built takes a beating every winter and keeps coming back for more.

Either way, it's gonna need lots of flap wheels before it's done!

 

[pandathrust]

I would look into the diablo sanding attachment for an angle grinder. They are by the grinding wheels and cutoff disks at Home Depot. Those are all I use now for sanding since they are cheaper and you get more sanding for your money if you don't hog out material too quick. I'd get some hard grinding disks too just to get the welds baselined then work it with a 36 grit diablo sanding wheel and 50 grit when you're done. Don't skimp out on the grinder or cut off disks like those at harbor freight, they are not worth the threat of an exploding disk in your face.

Good luck with making it. There really isn't anything hard about it and I'm sure you can do everything but maybe the recovery points with your welding set up (depending on how you are feeling about your welds). Don't want one of those flying off in a recovery

 

[artech]

Don't want one of those flying off in a recovery

You are absolutely right about that! I have profound respect for things under tension, we deal with that a lot in bad weather. So no skimping on those!

And thanks for the advice on the Diablo setup, I'll check into that. (Never heard of it before.) And I have seen your pics, your rig is awesome! You have some great fab skills! I really like the tailgate thing you are doing now, I bet that comes out great too. Thanks again for the idea on bracing the wings on the bumper, that should really help when my rig comes down hard on something.

You do great work!

 

[inkpot]

Not familiar with Diablo sanding/grinding stuff, but I do use their reciprocal saw blades. They make a great Greenwood blade that

 

[inkpot]

Not familiar with Diablo sanding/grinding stuff, but I do use their reciprocal saw blades. They make a great Greenwood blade that

Works great for trimming trees and brushing trails.

 

[Burbot]

Here we call it bird turd. My welding is fair but my grinding is great! Cause I get lots of practice at it. Norton flappers in 80 in a 6 pack. Any brand on sale. I use a hard abrasive disk to remove the worst then a flapper. I refuse to weld rusted metal. Clean metal leaves less mess. Grind it first tack with w feed then stik it solid. On suspension trailer ing gear etc I leave it to a certified welder.