(buzzing)
- Welcome to weld.com I'm Bob Moffatt.
I have Mr. John Thompson here with PFERD.
We're welding guys.
PFERD's been helping us out with the abrasive side
of the industry here.
Appreciate the education, got a problem.
Need some help.
- Okay.
- I'm pretty good on the outside of something.
How do you go about blending,
and what tools do you have for reshaping welds and stuff
and working with stuff on the insides of parts?
- Well you know, that's just it.
A lot of people can handle outside corners.
They can handle a lot of being able to get into
railing work and things like that because it's accessible.
The challenge you run into on an inside blind corner is
you've got to be able to control
and be able to take the material and maneuver it.
We have talked about variable speeds before
and controlling speeds in a couple of the other videos
when it was just knocking welds down.
No different when you're in an inside corner Bob.
You still have to be able to control it.
- But I'm thinking,
what tools?
What are we doing here?
What are we using to shape things with?
- Well we know we can't do it with a right-angle grinder,
right, because the disc is way too big to do the job.
You can't get in there, all right.
And so there's other things that are available.
Now a lot of guys,
and I'm sure you've used these in the past,
can use a cartridge roll.
They go pretty simply on a mandrel assembly,
and they just slide into place.
They don't last very long.
You buy boxes of 'em.
You go through them like crazy.
In the end they don't cost much per item,
but you've got to use a lot of them to get something done.
Now, what we did was we took a look at it and said,
what do I want to do inside this weld?
And what I've got to do is,
I've got to from the X axis, Y axis and Z axis
from the center.
So I need to have a little excess material there.
You did that for me and it was great.
- Okay, so we're blending this.
We're making this weld radius,
blending everything
back in? - Absolutely.
What we're going to do is take where you put the weld
in that corner and made it convex,
we actually have to make it concave so that water
or anything else would flow against that corner.
- Okay.
- Okay, you're going to see this a lot in sanitary work.
You're going to see it a lot where people
have to want to blend things.
Even in railings,
you've got railings with the rails that come down
and you can blend in those areas so that
they don't rust as quickly,
instead of trying to put on
extra paint. - You see that in railings
where you rub your fingers - Absolutely.
- Along there, you don't want any sharp edges
or anything else.
- Exactly, see and all those are tight little corners
and it's where all the clock keeps running,
you spend a lot of extra time,
you've got all the rest of it finished
and you're forever sitting there in all the tight corners,
right? - Okay.
- So, what are we going to go?
We can use cartridge rolls,
that's not an issue.
But actually what we've done is in this case
we've designed a specific family of carbide burs,
tungsten carbide burs,
that are actually made for different materials.
We make one primarily for carbon steel.
We make another family primarily for stainless steel.
We make another family for aluminum.
We make for cast iron,
they're working in foundries,
being able to take all the parting lines and get around
in the cast irons.
We even make a version for titanium,
and being able to go in on stuff on parts
and be able to grind out excess weld.
Tool and die stampers,
other things that are available.
So in this case what we have is a really good weld
that you have given us
on all three corners and tight corners,
and we're going to now show initially
how to concave and shape that weld
and then we're going to come in with another step
and we're going to blend it all the rest of the way too.
- I'm going to get a face shield on for this.
- You can put one on.
I think it's a good idea.
The technique is to pull.
You never push a bur.
When you push a bur that's when they bounce.
You just lightly keep stroking it and pulling,
and what's going to happen is
it's going to take the material and shape it.
So for instance I come in this corner.
(buzzing)
We're going to start heading this way.
The first thing you have to understand is
we've got to control speed and we're back to our old friend
the variable speed tool.
And the reason we are is because what we're trying to do is
I may have different diameters here.
This particular one happens to be a 3/8 diameter
that goes down to a 1/4 inch.
I'm going to run this actually right around 19,000 RPM.
But for instance I may have a 1/2 inch one the next time
I want to use a bur.
I'm actually going to take that down a
little lower. - Down a little lower.
- [John] Because what I have to do is I have to maintain
the same surface speed per-minute speed
and as I pick up the diameter I have to slow the RPM.
- [Bob] Okay.
- [John] Okay, once again a lot of people went
out and bought really great straight-shaft grinders
and stuff that are single speed.
They thought, this is great, this is all I ever need.
Problem is they may work for as grinders for cut-off wheels
and three-inch cut-off wheels
and they work with a couple of things
then all of a sudden you get a material
you're running too fast.
- [Bob] Okay.
- [John] Chatter.
Chatter and bounce all over - Digging in the inside
you can lose control of your cut.
- [John] And a lot of heat.
You're either burning up the burs or burning up
the cartridge rolls like crazy or you're taking the material
and making it all kinds of colors
as you're trying to work here.
- [Bob] You can't do that.
- [John] This is why you're really in a long one
unless you're going to have a dedicated tool
only one size in a dedicated tool.
And that gets pretty pricey to have a bunch of them
sitting around with different flap wheels and everything.
You get a variable speed tool.
(grinding)
And at this point the biggest thing I want you to see,
and this is why a lot of people don't like to use
carbide burs, is when it jumps away from 'em,
it marks up all around the surrounding surface.
But by pulling it,
even coming to that corner,
and digging in slightly in that corner and pulling back.
I'm even leaving the color,
you can even see that the color on the material
from your heat-affected zone.
I'm not even jumping against that.
- I could hear it.
You kind of bounced around a little bit until you got
that bit to settle down and cut
and then you started pulling.
I could hear it. - I'm just lightly stroking
it, remember I'm going from a convex surface.
I'm going from the bulk of the weld,
and I'm trying to turn it and dig it out the other way.
So in the beginning what I'm doing is just getting
a little pocket built up.
- Right.
- And working that pocket.
And then when I'm coming down here and out toward the legs
I'm actually lowering it down,
so that I'm coming from the middle of the bur
to the tip of the bur.
- Um-hmm.
- Where people get in trouble is they're coming back
and they go oh I just got to, and they jump forward,
one of the flutes of the bur catches
that little high spot they've got and it skips up
on the surface and puts a bunch of hits.
Now that's why I don't like burs because.
Hey, the bur was only doing what it was controlled to do.
If you lose control it's going to go
any place it wants to go.
So that's really where we're at.
So, I just wanted to have you see here that we're taking out
and concaving the area
but we literally have no skipping
because I'm pulling the bur
and we're not even getting to the point
we're starting to take out color.
And that's actually a big indicator
because I'm going to take the excess weld off,
but by leaving the color line--
- Uh-hmm.
- I don't undercut to the parent material.
When I start taking that color line out
now I'm going to wind up with actually a dip
in the parent material. - Oh I see.
- And we don't have much parent material to begin with.
We're sheet metal. - Exactly!
This is 18-gauge material,
we don't have a lot to play with,
so you sure can't put a line right next to it
where you undercut it because it's going to crack.
- Right.
- You can't do it.
So all of this is control.
You'll see I'm not sitting there just buzzing back and forth
and ripping it off.
This is not a scenario where you're going
to be able to do this in a minute or two.
- This is an art.
- This is control. - Okay.
- The same as when you were welding.
You're coming in there and you're working that bead
and you're controlling it.
Now you're coming in and you're scooping out the excess
material and you're controlling that bead.
So we have 1/3 one to do here and stuff.
You can see the pocket's starting to get shaped.
We're going to clean up this a little bit more
and we're going to take that third one away okay?
What you're also going to see is you'll notice
I'm not going real fast,
I'm kind of actually letting the bur do the job.
A lot of times with abrasives people get excited
and they start going back and forth and back and forth
and back and forth and they spend so much time
floating around that they really never get
the material removed.
- [Bob] I want that job done quick.
- [John] Well, quick then I guess would be a good idea
of letting the bur cut and if I'm moving back and forth
like this, - Right.
it's never in any stock to do any good.
So my rate of travel is slower.
You see it a lot in welding, right?
When you really want to control it and you've got
the right wire feed and the right ampage,
you're at a steady pace.
And then you see somebody else come by
and they're a little nervous,
and what do they do?
- Crank things up - Correct.
- [Bob] And break away.
- And it starts going and they've got lumps
and everything else.
It's the same thing
It's building the muscle memory and the control saying,
look I'm not bouncing around,
I'm not chewing up the side walls in any one
of the directions and what I'm doing is letting
the bur do it.
I'm literally coming in there and wiping it like a rag.
Now I've made my pocket,
and I've gone in all three directions,
and I've started to concave that area.
I still you can see the color,
I'm watching that because if I get to the point
where I start to take color out what happens is
now I'm starting to touch the parent material.
And then I've got to be really careful,
because all I want to do with my next step
is blend in that last little transition
from where the weld itself
came to the parent material itself.
- Now what is required to do that?
Do you need to change to another shape of bur?
Or do we need to change to another finish?
- Well once again just like we changed grit size
in one of the other episodes,
we were talking about variable speed,
and we went from an 80-grit scratch,
which was the way you used to do things.
But now I found out you're doing
a whole lot of 150-grit scratches,
because it's actually two steps,
but you're winding up with a much better control.
- All right.
- It's the same thing we have to do here.
This is the heavy lifter.
This is the one that's going to scoop out
the majority of the material. - Okay.
- And then we're going to go with a finer grain
and in a little bit different type of a setup, okay?
As far as how it's made. - Okay.
We'll show you that in a couple of minutes.
- [Bob] All right.
- So we did step number one and we've actually shaped
the welds and stuff without undercutting them.
You can see that the tungsten carbide bur really
doesn't care 'cause it was running at the right speed,
didn't build up any real heat,
the shank itself is still silver-colored,
because we didn't stress the stone
or stress the bur. - The point on this thing
is still razor-sharp.
- [John] Right.
- So what's the next step,
how are we going to blend the rest of this in here?
- Well now what I want to do is I want to take
the last that was here,
this is mainly the areas that are right next
to the parent material.
Okay, I made my concave groove and now I've got to make
that transition to put it into here.
You can use this 120-grit cartridge roll,
you can use a number of different things,
and some people will pick finer grooves than that.
One of the things that we make and we show
is this is made out of leather.
- [Bob] Stop it.
Leather?
- Leather.
We've taken leather,
regular animal hide leather,
and we have ground it to about the consistency
of a real fine talcum powder.
It's real, real fine.
And then we take that and we mix it with abrasive grain,
so we embed the grain into the powder,
and then we mix in a little bit of the same resin,
basically the same resin as what we used in grinding wheels.
And then we take that and we put this into a hydroform.
This is a collapsible form that uses water around the jacket
that just really mash this into the form that we want.
And it also puts in the back hole.
After we do that we take the shank itself
and we glue the shank into the existing hole that we've made
with hydraulic adhesive,
an adhesive that actually expands to lock
that shank into place.
- Okay.
So you're using a medium and suspending
an abrasive inside that? - Absolutely.
- Okay, so right now I'm guessing
that's got to be low speed.
- Excellent guess.
- I mean, am I right or?
I don't know
I mean common sense it's going to tell me,
you spin this thing this is capable of 25,000 RPM.
- Yes.
- You spin that leather and that's just going to melt it.
It's too much for it.
- Well I'll tell you what, I'll tell you what.
This ought to be fun.
Let's take this the same speed as that.
So let's take this particular machine all the way up
to about 19 to 20,000 RPM, which is what we ran
that stone at. - Okay.
- Now the first thing we're going to do is
we're going to shape it a little bit.
- Okay.
- And what we use to shape it is a shaping stone
and it's the same kind of shaping stone
that is actually used to shape vitrified mounted points
and to shape some of the bonded points that we may use
and stuff that are actually abrasive grain that are mixed.
In case of vitrified, they're actually mixed with glass.
- This is aggressive, what is this?
- That's actually made out of volcanic rock.
It's actually formed and stuff
and cut directly from volcanic rock.
And it's very open porous, all right.
- I see that.
- What it's going to do is you see with the point
is it's like sharpening a pencil.
What you're literally going to do is build what you want
right on the edge of that point.
- [Bob] Interesting, so that finish or that point
is kind of what you want that shape to be down there?
- Absolutely, see and you can buy pre-made points,
points that are pre-manufactured to size.
These are called W shapes,
these non-pre-made points
and the reason they're there is
because you don't know exactly what you're going to be
working on. - Right.
- You don't know if it's going to be a 3/8 radius,
if it's going to be something that's a little tighter,
in this case we're a little bit tighter.
By buying a W shape and literally like you'd sharpen
a pencil you're just going to turn around
and get this into the shape that you want
and then when you use it it'll maintain that shape
as it continues to keep coming in here.
- Okay, so,
we pretty much chewed that off pretty quick.
I understand that's aggressive and open porous
but what's the weld metal going to do to the--
- Let's find out.
- Okay, what do--
(buzzing)
- What you're going to get is you're going
to get a little dust.
- [Bob] Sounds like I'm at the dentist.
(John laughs)
- Well maybe if you was a horse doctor you might be okay
but you never know.
Okay.
We're going to take this,
we're going to tap this off and you're going to see
what that leather did.
That leather took the scratch from the mounted point
and now we took the collar out
and we actually transitioned it
into the parent material without over-grinding it.
- [Bob] Interesting.
- Now we've got a little weld spatter in there
and stuff like that.
We chase that a little bit different way we probably
chisel it off or we would use maybe a little more adjustment
on the machine to cut down on the spatter.
But the whole idea behind using this
is that what you've done now is you've gone from
the last little bit of the weld parent.
You've gone into the actual parent material
and blended it through. - Blended it.
And that's where we get into flute grade codes
and finish codes and--
- Absolutely.
Here's your leather.
Take that home with you.
There's a little bit of horse there,
a little bit more for you there.
That's about the consistency we start out with.
- Was that the right RPM?
Or was that too much?
- Actually it was running a little fast
but what wanted to show you is even in reality remember,
given the diameter here, this is a 3/8 diameter.
This is a 3/8 diameter.
Okay, I would have run it to have it last a little longer
I'd have it running probably around three or 4,000 lower
but if people didn't,
you notice it didn't hop all over the place.
It gave me a real high end - Oh it was smooth.
finish right away.
- Yeah it was smooth.
- So it tends to be a little bit less speed-sensitive.
The only thing you're going to consume is you may
wind up consuming more of them if you don't run
at the proper speed.
- But these things are going to last way longer.
- Not only that but more importantly
my next finish that I could do on here
is to go to that 1,500 grit compound on a felt Bob,
and I can put a mirror finish in this from your raw weld
using the carbide bur,
going with the leather
and then going into 1,500 grit compound.
- Uh-huh.
On a crappy weld too. - And I can't...
But I can't control that just at a 120 grit
from a cartridge roll.
- I know and this is only one shape.
- Yeah, that's it.
- Yeah I mean I've got nothing Yeah it's a tapered shape.
by the way, once you wear this out,
you're into your steel pin.
Now you're putting your steel pin into your stainless.
That's not cool. - And that's real bad news
when you're going along and you got it all
just about finished and you hear that
dink, dink, dink, dink, dink
and pretty soon you're going,
Okay, okay this is not good.
And yet you can't shut that short.
If you cut it short you have no strength,
a lot of guys'll take these longer shanks like this
and they'll say, well to heck with that.
I'm going to cut it all the way back here.
The problem is that there's no strength here.
- Uh-uh.
- And you'll just blow them out at point
or the cartridge roll way.
So you have to use the shank that's intended
for cartridge rolls.
- [Bob] So does this get a rinse?
We can go in and give this a rinse?
- [John] That's the other aspect about it,
the only thing about the leather is
you're not dealing with anything that's going
to pick up any moisture, do anything else,
and so when you come down and of course you've gotten
rid of the spatter and some of the other things,
made sure everything was nice and even,
you flush it out with a little bit of a sanitizer cleaner,
send it back into plant.
- Wow.
I'm learning a lot here.
This PFERD training is very beneficial and we really
appreciate your time, really appreciate your time.
We've got some other products and some other solutions
that we're going to shoot so make sure you stay with us.
Thanks for watching weld.com.
Check us out on Facebook and Instagram as well.
This is ha ha.
This is hrgh.
(laughs)
- [John] Yeah you know what this is really made out of?
Slow running reindeer, man.
I'm telling you right now, yeah.
Yeah Santa ain't got nothing on us boy.
(laughs)