Cutting power of grinding Vs flap discs?

[julianf]

I've never really had much power out of grinding discs, and I fear I'm missing somthing?

When would you use a grinding disc over a flap disc?

Thank you.

 

[Gareth0123]

For pre weld clean up and prep work including veeing on stuff up to 12mm thick I get on really well with 115mm X P36 Zirconium (Blue) sanding discs.
I get 8-10 minutes actual work life out of each disc which is a comparable to grinding disc work-lifespan.
However, on a cost per unit/lifespan basis I have found them to be considerably more economical than similar grade flap discs.

 

[Munkul]

I've never really had much power out of grinding discs, and I fear I'm missing somthing?

When would you use a grinding disc over a flap disc?

Thank you.

When you want to work the edge of the disc and not the flat, grinding discs are better. They also don't clog up as easily with rust and crap. They don't deflect, so you can dig into stuff harder.
They have their place... not as enjoyable to use as flap discs due to the NVH, but sometimes a far better choice than flap discs.

 

[Blobber]

I find with body work grinding discs are good to get the top off the weld and then finish off with a flap disc, the hard discs dont put as much heat into the panels

 

[fizzy]

I seem to always use flap disks these days. Much safer and just as fast.
In fact I use my Black and Decker power file even more. Love it. I use the blue 40 grit belts - last much better and never break.

 

[eddie49]

I use the blue 40 grit belts - last much better and never break.

Do you have a link to a supplier? ( Sorry for thread hijack.)

 

[Richiew]

I use grinding discs very rarely now. Maybe my welding is improving?

Perhaps I am just less fussy these days...

 

[MetalMonkey]

How about fibre discs?
I find them better than either flap discs or stones for removing stock or welds in a hurry.

 

[Memmeddu]

I do prefer flap discs over grinding discs
Because they're more pleasant to use cause less vibrations.
However grinding discs are cheaper and last longer for heavy metal removal .
But ceramic based flap discs eat much more than grinding ones with all the advantages and disadvantages of flap discs

 

[Memmeddu]

How about fibre discs?
I find them better than either flap discs or stones for removing stock or welds in a hurry.

What do you mean?
For fibre discs I mean "scotch brite" ones
Which sure have their place but don't last long

 

[mtt.tr]

I use grinding discs for grinding and flap discs for cleaning or finishing.

Horses for courses

 

[PhillipM]

Flap discs are generally much faster anything than grinding discs tbfh. But, when you want to work the edge of the disc into a corner, a grinding disc is what you want.

 

[anto44]

Grinding discs are better than flap discs for grinding out fillet welds right into the root, flap discs always leave a big radius in the corner

 

[tigdlo]

Really depends what you are doing, out of all the abrasives I have, zirconia flap discs get used the least. Currently I use 6mm grinding disc for control and working on the edge of the disc into a corner for example, ceramic/zirconia flat sanding discs/fibre discs for general cleaning and a 36g Cubitron for rapid material removal. For final finishing norton blaze strip/clean discs are very good, blends the flat spots from sanding very well.

 

[hermetic]

There are grinding discs, and then there are grinding discs! I like flap wheels too, but they don't last very long, although they do last better if you are working on paint and rust free metal, great for paint removal, but dont last long! As for grinding discs I have found that the Lidl ones last really well, but seem to cut really badly unless you sit on them, wheras the softer ones remove more metal, faster, but have a short life!

 

[brightspark]

grinding disks are what it says for grinding . fast metal remover / flap disks are just rotary emerycloth for light metal removal and sanding

 

[grim_d]

I don't use many grinding discs these days unless I need to remove a lot of material...and simply because they are cheap.

40grit flap for stock removal, 80grit flap for roughing in, 100grit fibre disc for smoothing out...then the real game changer is a unified blending disc like Norton rapid blend for final blending.

Not a great photo but trust me those discs are the mutts!

 

[Shedendman]

Depends on the weld you've done,if neat and ok,maybe a tidy up with a flap,but if you've made a total hash of your joint,to which it looks like your granny would have done better blind drunk,etc(and dont say we've not)
then smash the 6mm in and go over it again
I read somewhere just because you're good at grinding,it dont make you a good welder

 

[Turbo]

I find grinding discs are still the best for rapid metal removal. I recently bought some Lidl next generation discs & they are scarily good at grinding down welds with less dust & sparks.
The ceramic flap discs do come close to grinding discs & leave a nicer finish but they are relatively expensive & they are easy to overheat by working them too hard.

Something I use a grinding disc disc for is when I've forgot to bevel stuff before tacking it up. I run the grinding disc along the joint cutting a 6mm groove which serves as a bevel to get good penetration on thick steel.

 

[MetalMonkey]

What do you mean?
For fibre discs I mean "scotch brite" ones
Which sure have their place but don't last long

These:

https://www.3m.co.uk/3M/en_GB/p/d/b40064717/

Didn't think much of them until I tried them - now I'm a convert.
There are other brands, but those ceramic cubitrons work very well IME - last dozens of times longer than a flap disc and eat metal quicker than a grinding stone.
Leave a nice flat finish. They are also a fraction of the cost of a flap disc.

Obviously they have their limitations, only work well on flat surfaces - but that means you can save the expensive flap discs for getting into the tight corners which is really what they are good at.
I still use grinding stones for digging in, creating a groove, etc.