this is what happens when science curiosity and stupidity all come together i'm actually testing
grinding discs today and i'll explain this part of the experiment in a little bit i would like
to find the best grinding disc to remove mill scale so you've heard me use the word mill scale
but what exactly is it well it's an iron oxide that is formed on the surface of the steel during
the hot rolling process it's also recommended that you remove it before doing any welding so
that's what this video is all about so when choosing the best abrasive for removing material
the fastest these are the ones that i found that worked the best the norton blaze ceramic flap disc
the third ceramic combi click the brand new walter flex cut last but not least
we have the typical hard disk and then there's lots of other options to use for stripping mill
scale i mean i have vinegar but that's really slow you could use a typical normal wire wheel you got
paint strippers and then of course my go-to when i want surface finish the diamond wire wheel
but today we're just looking at the four fastest methods for production all of these discs work
extremely well when they're brand new but as a welder my experience is once they get a little
bit of wear on them their performance really starts to decline for this first experiment i
want to put some wear on all the discs so i want to grind off one inch of this quarter
inch thick flat bar that's going to give us a better representation of how they're going
to do on the job no use testing a brand new one that's for salesmen in three two one go
now that all the disks are worn out i like to run the experiment and i'm gonna try to remove as much
mill scale as possible in 30 seconds this is going to give us a good baseline of how effective that
these discs are even when they're wore out and i want to see how loud each one of these grinding
discs are so i've set up a decimal meter behind me at approximately eight feet and we'll see how loud
they are how loud is too loud well at 85 decibels it's recommended that you wear hearing protection
and any noises above 100 for a long durations you can suffer some permanent hearing loss
test number one hard disk
look at that we got some results cut the mill scale down that's for sure
it also gouged the base material pretty good and take a look at that
99 decibels for the hard disk pretty loud it's deferred ceramic in three two one go
interesting i can definitely tell that a lot of the bite isn't there but it left some low spots
a little smoother surface than the hard disk saw the decibel meter hit 98 a little bit better than
the hard disk overall worked pretty good let's test the ceramic norton blaze flap disc next
felt like i had to push down pretty hard to get it to bite also it was just skating you can hear the
grinder going this is the problem with these discs you get them two wore out you got to push harder
and harder and harder but it did a pretty good job the norton blaze came in at 98. i'm actually quite
surprised i thought it'd be quieter than that next up is the walter flex cut ready for the test
this thing really grips like it grabs it feels like the hard disk the way it it able to get
underneath the surface so you get these little streaks in there and zero to no chatter when
running that 99 db man this disc is also loud so this is the ferd diamond wire wheel and it's
designed for mill scale removal one thing you have to be careful of is spinning this thing too fast
so i recommend putting it on a variable speed grinder and turning it down to its lowest
speed these little barbs will get thrown out so make sure you wear your eye protection it
probably has more usage than any of these grinding discs so this is a fair test
wow that's pretty good 82 db that's the quietest yet so let's take a look to see how they all did
first one is the diamond wire wheel and it looks like i got about 15 inches of mill scale removed
and what i do notice is the surface finish it left the natural metal which means i didn't go beneath
the mill scale which it could be an advantage like i said before you just have to be careful
not to catch the edges the next one is the walter flex cut this thing really did move some material
looks like i missed a couple spots here and there looks like around 18 17 18 inches and this thing
just felt like it bites no matter what i when i push it it just removes material even just with
my hand it's like sandpaper still this thing still has a lot of life in it i think this thing could
go to nothing and still cut just as good i wish i could be mr smarty pants and tell you guys what's
inside this grinding disc but i think walter's keeping it a secret even looking at it under the
microscope it's hard to tell what's inside what also lends to the performance is the dish shape
of the disc this allows that contact patch to be nice and wide and allows you to get the grinder
at the correct angle i could use this disc all day the next one is one of my favorites i have a love
hate relationship with flap discs this thing did a really good job not a lot of patchy grindy work
and i noticed i have to push really hard to try to get it to bite so what's happening is the ceramic
is a really good grinding media but it's only held on by glue so what i think is happening is
the disc gets really hot heats up the glue so that it's no longer able to hold onto the ceramic and
it gets flown off leaving behind only the fabric with perfectly good ceramic hidden underneath it i
have a whole box full of flap discs that are half used because there's still life on them you just
have to find the right circumstances where they work well seems like the first 50 is really good
the second 50 is horrible but overall as good feeling in my hand not a lot of chatter this
did feel awfully noisy still but it works pretty good so the blaze did 10 and a half inches or so
let's go to the hard disk these things are cheap they've been around forever they work well they
pretty much cut all the way to the end oh yeah really feel it biting so that's going to cut
all the way to where this thing is nothing anymore what i also notice is that you get a lot of these
lines in your work because the contact point is so shallow and it definitely cuts the metal
underneath the mill scale which is good and bad depending on what the applications for and it did
looks like the worst for speed at seven inches i think that's just due to having to go back and
forth over the material so much there was some chatter in here which i could feel through the
handle and the vibration that is going to really fatigue you during the day if you have to do a lot
of grinding and this is the third ceramic combi click with the rubber backing pad and this does
a fantastic job of absorbing all those vibrations you know it still cuts pretty good it looks pretty
good too i think there's quite a bit of life left in it it probably did the best job on the
surface finish so if you're wanting to grind mill scale with a grinder and not leave big old gouges
because of the way this flexes with the rubber it really has a wide swath and leaves you a really
nice finish it moves the material we got 10 and a half so about the same as the ceramic blaze and
these things are doing very similar but this disc doesn't have the same problem this one does with
its own little flap getting in its way if i were to choose between these two i mean i like this
one if you're just removing mill scale i've always wanted to know what would happen if two grinding
discs tried to grind each other so i'm building myself a little grinding arena to test it i'm
also going to pull out the high speed camera and the fleer thermal imaging camera to see if we can
capture something intriguing like i said this is just for fun and it's not a practical experiment
but i do want to see what happens everything's locked in place so what's going to happen this
one's stationary it's not going to move it's only going to spin this one i'm going to rock into the
fixed disc then i'm going to try to keep constant pressure on the discs with this rod and because
they are opposite of each other they're spinning different directions so they should be swiping
and one of them's going to disappear and one of them is going to stay let's get this party started
for the first match up we're going to go with the norton flap disc versus the hard disk and then for
the second match up the third combi click versus the walter flex cut and the winner moves on fight
safety glasses are on this is gonna get dangerous let's see which one lasts the longest here we go
gary okay here we go three two one go
oh look at all that smoke oh chips flying everywhere
okay
feel it whoa okay that was ridiculous oh look at this smoke that is so cool looking look at the way
that disc looks okay let's take a look at the hard disk here you can see where that contact patch was
oh we're getting down into the fibers there all the ceramic there's all our disk on the table
all the way down to the glue this thing didn't even stand a chance i thought for sure the ceramic
would be tougher than this hard disk but it just goes to show this is only as good as the glue and
i can see that when i'm actually grinding the glue is the weak spot and this is why they don't last
as long hard disk winter moves on we're learning absolutely nothing here but we're having fun
now let's go with the ceramic ferd this is basically a piece of sandpaper versus the
walter disc with who knows what's inside i don't know mystery material for the ceramic disc we need
to put this rubber backing pad on first and then this cool disc just clips on all right
here comes the walter locked and loaded ready to go let's turn these things on oh man i'm scared
it's so scary here we go
wow as soon as i saw blue smoke i knew we were done for
ceramic not a chance oh it's blistering it's i could see it growing the walter did good you
know what i'd put this back on the grinder and go back to work man okay let's check
out the flear so this little cursor is going to target the hottest spot in this rectangular box
so the ceramic is running cooler but the hard disks are running hotter but they're lasting
longer so that's kind of confusing i guess that's why we're doing this science experiment
the next battle is the walter versus the norton hard disk there's something you've
always wanted to do but you're smart enough not to oh let's plug these things in oh i hate this part
okay i killed it in the line of safety the glue started to come out look at that what was this if
that was the glue the walter definitely took more damage besides for some chipping on the outside
walter didn't do too bad look at that material though that's pretty tough stuff hard disk i'm
actually surprised the disc didn't explode they kind of came to a stalemate probably took away
a good half of the material oh and that's what our little uh string string he came from was that
plastic the two center hubs started to touch each other so if i had to choose the winner
of this whole battle from early experiment to now i'm going to choose the walter flex
cut because of its versatility its speed and its longevity to go up against the tried and
true hard disks and all the flap discs all of these are still going to remain here in my shop
these are all my personal grinding discs and i also sell all of them on the fireball tool
website a lot of you guys probably didn't know that but the walter disc is now my new found
favorite the one problem i found with the walter disc is that you can only buy them
in a pack of 25 which can be quite an expensive purchase all at once so what i've done on the
fireball tool website for you guys is break them up into five which is a lot smaller investment
and you get to try them out for yourself i know when it comes time to remove material mill scale
and stock the fastest i'm going for this disc it also comes into a five inch size which i like
the hard disk is great because it's cheap the ceramic is great if you're not looking for
scratches but for speed it's hard to beat this walter thank you guys for watching i've learned
a lot today about these grinding materials hope you guys did too and i'll see you on the next one