Technical 3M Cubitron Abrasives

I posted this on Garage Journal and hope it's OK here.

I was a little hesitant to buy the more expensive 3M Cubitron abrasives but took the dive. After the past couple of weeks of grinding MIG welds, I have to say that these are hands down the best abrasives I have ever used. These things cut like nothing else and they last a lot longer than regular abrasives. So far, I have been using the 2 and 3 inch roloc discs in 36 grit to cut welds and have now ordered some 60 grit and some 80 grit hookit discs for my D/A. I also bought some for my mini belt sander.

On the 2 & 3 inch discs, I have cut down a couple of roloc holders so that I can continue using the discs, as they are still good even when the edge wears out. So, I have a 2 inch roloc and a 1 3/4" and a 1" that I can use to get all the use out of them. I also did similar with the 3 inch roloc holders. If you haven't tried these, you are in for a treat. Bite the bullet and get them. Previously, I used 3M Green Corps discs and these are heads and shoulders better.

 

totally agree, been using them for a few years now and would never go back to anything else.

 

Damn it Jim, I'm a grinder, not a welder! Those 3M rotolocs make me look like I know what I am doing

 

When you're welding 90 year old Henry steel, you have got to be a grinder, unless you can and want to fabricate new panels.

 

I have been using the 3M roloc 3"grinding discs for years in grits from 24 up through 60. They used to be much thicker and in my opinion better suited for grinding down welds. I almost always tig weld and use S-2 rod, which is a bit easier to cut down than a mig weld. On a dead flat panel, I always cut the bead down close to the parent metal with a 3M or similar 1/16" thick cut off wheel on it's edge. Then I will use the sanding discs to finish it off before hitting it with a 3" 3M 80 grit sanding screen. That leaves a nice finish. As for the newer purple Cubitron products, it seems to me like the grit is a little more aggressive initially, and you have to be careful not to cut in to the panel out from the weld.

 

I was given a sample years ago from a 3M rep at a tool show. I looked for a long time before I ever found any for sale. The guys a paint supply store looked at me like I was crazy. Must of been new top secret.

 

I'm using them to cut the weld down from the start, unless the weld is in a crevice. They are much faster.

 

Well, the 2" rolocs I've been buying are about .50 each. These are $2+ each... are they four times better/lasting?

 

3M is usually ahead of everyone else quality-wise, but I always jokingly say 3M=3 x the money. The price of most abrasives has gotten out of hand.

 

Yes

 

It is what it is. For me, it's worth it. Try it, you'll like it.

 

Yes they are. These are leaps and bonds better.

 

I use the cubitron only because I can’t find the old green style 3M anymore. I don’t think they make them now. I have tried some Benchmark abrasives three inch discs and while they aren’t quite the 3M quality, they are about 1/3 the price, and lasting over half as long as the old 3M’s, I think they are a better value.

 

I have been using Cubitron II cutoff wheels, flap disks and grinding wheels personally and professionally for 10 years. I worked as a welder on tugs and fuel barges maintaining our own fleet doing everything from sideshell repairs to pipeline work. We used Cubitron exclusively because it works!
Now I am lead welder for a road construction company maintaining vehicles and equipment and welding underground infrastructure. When I started they used cheap consumables and it took forever. I converted them over to Cubitron and the added cost of the disks is worth the time savings alone!
I also own a small (me) welding/repair company doing in-house and mobile repairs. Again, the added cost of the Cubitron products out weights the cheap quality of anything else.

Recently I started using Cubitron III products and they are even better than the Cubitron II ever were!

 

There’s a world of difference between heavy work as you describe and 18-20 gauge sheet metal work.

 

yes i too see a difference from the green to purple discs the purple is better but now you only get a box of 15 instead of 25 and at a higher cost.................

 

I am doing 20 and 18 gauge sheet metal work. MIG welds are hard to grind and time and effort are less with Cubitron. That is important to me. YMMV.

 

But they last longer and cut faster.

 

I also use them for sheetmetal work on my cars and customer motorcycle tanks/fenders. I also used to work in a street rod shop.

 

I used some red 3M discs that were better for welds but loaded right up if you got into paint or bondo. Were they an early version of these?

Gary

 

I used the green ones for years. I started using the purple ones after debating the price issue. They are well worth it and they do work better and last longer. I also cut them down to get a new edge and use different size roloc holders the small ones work good for starting on a weld bead because they don't cut as wide and you can see better. You get the most for your money that way.

 

They are the best I have ever used, I usually buy them on EBay.

 

I have discovered one problem with Cubitron. The 3/8 x 13" belts in 36 grit do not work well on my mini belt grinder. The bend radius of the tip wheel is too tight for the 36 grit and it comes off the belt fairly quickly. 60 grit, however, works just fine and is recommended for this tool.

 

I'm thinking another advantage of a better cutting disc is it will put less heat in the material being ground.

 

That is also true.

 

I have been doing this a while and while I really like the purple 36 grit, for 80 I will hold on to the greencorps as long as I can. What I don’t like about the new stuff is how inflexible they are. I don’t use anything in between.

for cutoff wheels, the Cubitrons are pretty amazing. But for myself, way too expensive. I have been using the 3m Silver 87461 wheels at home and they are pretty comparable and much more affordable.

 

Another convert here. It was Karl on the "Make It Kustom" YT channel that turned me on to them a couple years back and I followed his idea to buy rolocs in the 3 inch size only and cut them down for reuse on smaller holders. A quality holder also makes a difference vs the swap meet cheapies that I used to buy. I now use 3m brand holders in 3, 2, 1.5 and 1 inch sizes and can get 5 or 6 fresh edges out of each 3" disc.

 

Yeah Karl’s YT channel excellent!

 

Since we're on the subject, what is everyone's method for cutting them down?