Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Emmo
 
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Default 7" grinder faster?

I mig weld square and rectangular tubing to make furniture. I use a 4 1/2"
grinder to grind down the welds. I think I am spending more time grinding
than welding. I am wondering if getting a 7" grinder would make this go any
faster? Thanx!

__
"All it took was all I had..."


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Default 7" grinder faster?

I have no real idea what kind of furniture you are making, how
decorative it is, what kind of material, how the weld appears, or why
you have to do so much grinding. But, I hate to say this but IMO, you
need to work on your welding skills so you don't have as much grinding.
Unless what you are trying to achieve is the appearance that there is
no weld. In which case I would learn to use plastic filler (aka bondo).
A 7' grinder will make your grinding go faster, but just lugging that
thing around will wear you out. The whole point in my book is to have
the weld as pretty as posible so that not only is the piece admired for
it's beauty, but the weld is too. I hope this was of some help, I'm not
trying to pick on you. More details would be good, so that we know more
about what the trouble actually is.

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Andrew VK3BFA
 
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Default 7" grinder faster?


wrote:
I have no real idea what kind of furniture you are making, how
decorative it is, what kind of material, how the weld appears, or why

The whole point in my book is to have
the weld as pretty as posible so that not only is the piece admired for
it's beauty, but the weld is too.



I would LOVE to be able to weld that good - can you do it with arc, or
does it have to be MIG - I have to grind a lot of my welds as I am a
crap welder. (Getting better, but still crap). (and its taking far too
bloody long......) And if I want to put something on top of the welds,
ie bench tops etc, then I HAVE to grind them down so the wood sits
flush.

Found the 4 inch angle grinder to be the best - easier to use as its
lighter, more control too - my 9 inch one wants to go berserk and chop
out too much too easily. Its great for demolition when I really stuff a
weld and have to start again....The 4 inch was $20 at the local
hardware supermarket - and strangely enuff, I get best results from $1
Chinese grinding disks from Trash and Treasure stalls. The expensive
ones wear out fast and wont take the meat off. Go figure.

And, if I am feeling artistic, I can sorta grind them into nice
symetrical shapes..... but usually dont, as its going to be covered in
grey zinc primer anyway.

I feel that when you are competent enough, then you can be artistic. I
am glad most of my welds cant be seen....


Andrew VK3BFA.

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Emmo
 
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Default 7" grinder faster?


Unless what you are trying to achieve is the appearance that there is
no weld.


Thanx for your response. This is what I am looking for - the appearance of
no weld. I want to make the surface smooth and flat, so even with bondo, I
need to grind out the bead.

I do need to become a better welder, for sure, no offense taken.


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wayne mak
 
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Default 7" grinder faster?

I spend more time grinding before welding, the actual welding goes quick,
its all the prep work and post work. If you grind good "V" s before welding
you will limit any post weld grinding and have a strong weld. But I think
its normal to spend more time preping than welding.
"Emmo" wrote in message
...

Unless what you are trying to achieve is the appearance that there is
no weld.


Thanx for your response. This is what I am looking for - the appearance
of no weld. I want to make the surface smooth and flat, so even with
bondo, I need to grind out the bead.

I do need to become a better welder, for sure, no offense taken.





  #6   Report Post  
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RoyJ
 
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Default 7" grinder faster?

I have a good 7" grinder, two 4-1/2" grinders (the el cleapo from Harbor
Freight), and a nice 4" Mikita. The 7" grinder with a disk will take off
way more metal than the 4". If you want even more serious metal removal,
use a grinding stone (be careful to get an appropriate guard, when a
stone blows up it gets messy!)

Assuming that you have a high interest in cosmetics and require flat
weld areas, I suggest:
-Weld prep with a fairly deep 'V' grove, gives you good pentration,
keeps your weld bead down flat. This can be done with a grinder (lay a
whole pile of parts with the edges raised on a 2x4 and do them in
quantity) but a 2" vertical belt sander is the best way.
-Practice your weld technique to get good looking welds on the underside
that don't need any touchup, minimal bead on the outside that need to be
ground.
-Use a 7" grinder with a disk to knock down weld bead.
-Use a 4" or 4-1/2" with as sanding disk to clean and polish the
surface. These grinders are cheap, have one loaded with 40 grit paper,
another with 60 or even 80 grit. Use a cube tap and have all of them
live at one time.

Emmo wrote:
I mig weld square and rectangular tubing to make furniture. I use a 4 1/2"
grinder to grind down the welds. I think I am spending more time grinding
than welding. I am wondering if getting a 7" grinder would make this go any
faster? Thanx!

__
"All it took was all I had..."


  #7   Report Post  
Posted to rec.crafts.metalworking
 
Posts: n/a
Default 7" grinder faster?


Andrew VK3BFA wrote:
wrote:
I have no real idea what kind of furniture you are making, how
decorative it is, what kind of material, how the weld appears, or why

The whole point in my book is to have
the weld as pretty as posible so that not only is the piece admired for
it's beauty, but the weld is too.


I would LOVE to be able to weld that good - can you do it with arc, or
does it have to be MIG - I have to grind a lot of my welds as I am a
crap welder. (Getting better, but still crap). (and its taking far too
bloody long......) And if I want to put something on top of the welds,
ie bench tops etc, then I HAVE to grind them down so the wood sits
flush.
I feel that when you are competent enough, then you can be artistic. I
am glad most of my welds cant be seen....

Andrew VK3BFA.


Yes, you can do it with arc. The whole idea is suface prep, knowing
your machine, having the right rod, and lots and lots of practice. I've
been welding off and on for over 20 years, and I'm still not perfect.
I'm also one of those characters that learned to weld on a farm, the
first time I took a real welding class and they handed me some clean
steel, I was overjoyed. Needless to say after welding rusty, dirty,
nasty metal, the class with clean steel was a breeze.

Another thing is playing with the machine, set your temp higher and
lower, change your feed rate (moving faster or slower), different arc
lengths, all kinds of different things just to see what happens. An old
welder told me "You wanna learn to weld? Then practice welding
overhead, when you can get a good weld overhead, and not burn yourself
to a crisp, then you will be a welder."

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Steve B
 
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Default 7" grinder faster?


"Emmo" wrote in message
...
I mig weld square and rectangular tubing to make furniture. I use a 4 1/2"
grinder to grind down the welds. I think I am spending more time grinding
than welding. I am wondering if getting a 7" grinder would make this go
any faster? Thanx!


Sometimes, when I want a MIG weld to look impressive, I will turn up the
heat a bit, and do a series of spot welds. It looks like TIG welding. I
set my autodark so that as the puddle cools to the right temp, the
visibility comes back on, and I zap it again. Then, I just buff with a cup
brush.

If you want flush flat welds, go with a smaller wire and don't deposit so
much metal. Anything you grind off will not have anything to do with
strength, as it will be gone. All that is left in the root and between the
pieces will determine the strength.

Your furniture may require a flat flush finish. If so, just don't put any
more on there than you need to get strength so you don't have to grind it
off.

Steve


  #9   Report Post  
Posted to rec.crafts.metalworking
Emmo
 
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Default 7" grinder faster?

Thanx to all. I do currently use three 4.5" grinders, (2 from HF, 1 DeWalt)
with a grinding wheel, a coarse grit flapwheel sanding disk, and a finer
grit flapwheel, all plugged in all the time. But I have not been doing much
of any v-grooving or other prep work. This is mostly 14 gauge tubing, so
penetration is actually less of an issue than burning through, at least for
me.

Thanx to these responses, I plan to go ahead and use this month's HF
discount coupon and pick up one of these 7" grinders, and I also plan to do
a lot more experimenting with prep and with my settings on my Hobart 175.

"RoyJ" wrote in message
ink.net...
I have a good 7" grinder, two 4-1/2" grinders (the el cleapo from Harbor
Freight), and a nice 4" Mikita. The 7" grinder with a disk will take off
way more metal than the 4". If you want even more serious metal removal,
use a grinding stone (be careful to get an appropriate guard, when a stone
blows up it gets messy!)

Assuming that you have a high interest in cosmetics and require flat weld
areas, I suggest:
-Weld prep with a fairly deep 'V' grove, gives you good pentration, keeps
your weld bead down flat. This can be done with a grinder (lay a whole
pile of parts with the edges raised on a 2x4 and do them in quantity) but
a 2" vertical belt sander is the best way.
-Practice your weld technique to get good looking welds on the underside
that don't need any touchup, minimal bead on the outside that need to be
ground.
-Use a 7" grinder with a disk to knock down weld bead.
-Use a 4" or 4-1/2" with as sanding disk to clean and polish the surface.
These grinders are cheap, have one loaded with 40 grit paper, another with
60 or even 80 grit. Use a cube tap and have all of them live at one time.

Emmo wrote:
I mig weld square and rectangular tubing to make furniture. I use a 4
1/2" grinder to grind down the welds. I think I am spending more time
grinding than welding. I am wondering if getting a 7" grinder would make
this go any faster? Thanx!

__
"All it took was all I had..."


  #10   Report Post  
Posted to rec.crafts.metalworking
RoyJ
 
Posts: n/a
Default 7" grinder faster?

If you are welding a lot of 14 ga, I'd suggest going to some .023" wire.
Buy a 10 pound spool for a trial. Have somone play with the wire feed
speed while you are welding, there is a magic spot where it all starts
working. You can easily hear it, the sound gets crisper, less variation.

Emmo wrote:
Thanx to all. I do currently use three 4.5" grinders, (2 from HF, 1 DeWalt)
with a grinding wheel, a coarse grit flapwheel sanding disk, and a finer
grit flapwheel, all plugged in all the time. But I have not been doing much
of any v-grooving or other prep work. This is mostly 14 gauge tubing, so
penetration is actually less of an issue than burning through, at least for
me.

Thanx to these responses, I plan to go ahead and use this month's HF
discount coupon and pick up one of these 7" grinders, and I also plan to do
a lot more experimenting with prep and with my settings on my Hobart 175.

"RoyJ" wrote in message
ink.net...

I have a good 7" grinder, two 4-1/2" grinders (the el cleapo from Harbor
Freight), and a nice 4" Mikita. The 7" grinder with a disk will take off
way more metal than the 4". If you want even more serious metal removal,
use a grinding stone (be careful to get an appropriate guard, when a stone
blows up it gets messy!)

Assuming that you have a high interest in cosmetics and require flat weld
areas, I suggest:
-Weld prep with a fairly deep 'V' grove, gives you good pentration, keeps
your weld bead down flat. This can be done with a grinder (lay a whole
pile of parts with the edges raised on a 2x4 and do them in quantity) but
a 2" vertical belt sander is the best way.
-Practice your weld technique to get good looking welds on the underside
that don't need any touchup, minimal bead on the outside that need to be
ground.
-Use a 7" grinder with a disk to knock down weld bead.
-Use a 4" or 4-1/2" with as sanding disk to clean and polish the surface.
These grinders are cheap, have one loaded with 40 grit paper, another with
60 or even 80 grit. Use a cube tap and have all of them live at one time.

Emmo wrote:

I mig weld square and rectangular tubing to make furniture. I use a 4
1/2" grinder to grind down the welds. I think I am spending more time
grinding than welding. I am wondering if getting a 7" grinder would make
this go any faster? Thanx!

__
"All it took was all I had..."





  #11   Report Post  
Posted to rec.crafts.metalworking
R. Zimmerman
 
Posts: n/a
Default 7" grinder faster?

There is a wide variety in grinding discs. Generally if you want a long
lasting disc it is hard and takes metal off very slowly. If you opt for a
disc that can remove metal faster you will find that it has a shorter life
because it wears away faster exposing the sharp abrasive particles.
I worked in one shop where the foreman thought he was saving tons of
money. He selected the hardest discs. What happened is that people would
discard the discs after only an inch had been worn off the rim. Also his
grinders were always burning out because people were grinding longer and
pushing like crazy.
Try a softer fast removal disc before going up to a seven inch.
Randy



"Emmo" wrote in message
...
I mig weld square and rectangular tubing to make furniture. I use a 4 1/2"
grinder to grind down the welds. I think I am spending more time grinding
than welding. I am wondering if getting a 7" grinder would make this go any
faster? Thanx!

__
"All it took was all I had..."




  #12   Report Post  
Posted to rec.crafts.metalworking
Emmo
 
Posts: n/a
Default 7" grinder faster?

Is this hardness something you just have to try to determine, or is it
labeled and I just haven't been paying attention? I think you might have
just hit the nail on the head, as the wheel I am using now I got at Home
Depot, vs. HF for the ones I had been using, which, now that I think of it,
seem to be softer...

"R. Zimmerman" wrote in message
newsJNMf.76575$sa3.75077@pd7tw1no...
There is a wide variety in grinding discs. Generally if you want a long
lasting disc it is hard and takes metal off very slowly. If you opt for a
disc that can remove metal faster you will find that it has a shorter life
because it wears away faster exposing the sharp abrasive particles.
I worked in one shop where the foreman thought he was saving tons of
money. He selected the hardest discs. What happened is that people would
discard the discs after only an inch had been worn off the rim. Also his
grinders were always burning out because people were grinding longer and
pushing like crazy.
Try a softer fast removal disc before going up to a seven inch.
Randy



"Emmo" wrote in message
...
I mig weld square and rectangular tubing to make furniture. I use a 4
1/2"
grinder to grind down the welds. I think I am spending more time grinding
than welding. I am wondering if getting a 7" grinder would make this go
any
faster? Thanx!

__
"All it took was all I had..."






  #13   Report Post  
Posted to rec.crafts.metalworking
Emmo
 
Posts: n/a
Default 7" grinder faster?

OK, Roy, thanx for this suggestion. I would never have thought of doing
this, but it makes good sense. I'm definitely going to try this.

"RoyJ" wrote in message
.net...
If you are welding a lot of 14 ga, I'd suggest going to some .023" wire.
Buy a 10 pound spool for a trial. Have somone play with the wire feed
speed while you are welding, there is a magic spot where it all starts
working. You can easily hear it, the sound gets crisper, less variation.

Emmo wrote:
Thanx to all. I do currently use three 4.5" grinders, (2 from HF, 1
DeWalt) with a grinding wheel, a coarse grit flapwheel sanding disk, and
a finer grit flapwheel, all plugged in all the time. But I have not been
doing much of any v-grooving or other prep work. This is mostly 14 gauge
tubing, so penetration is actually less of an issue than burning through,
at least for me.

Thanx to these responses, I plan to go ahead and use this month's HF
discount coupon and pick up one of these 7" grinders, and I also plan to
do a lot more experimenting with prep and with my settings on my Hobart
175.

"RoyJ" wrote in message
ink.net...

I have a good 7" grinder, two 4-1/2" grinders (the el cleapo from Harbor
Freight), and a nice 4" Mikita. The 7" grinder with a disk will take off
way more metal than the 4". If you want even more serious metal removal,
use a grinding stone (be careful to get an appropriate guard, when a
stone blows up it gets messy!)

Assuming that you have a high interest in cosmetics and require flat weld
areas, I suggest:
-Weld prep with a fairly deep 'V' grove, gives you good pentration, keeps
your weld bead down flat. This can be done with a grinder (lay a whole
pile of parts with the edges raised on a 2x4 and do them in quantity) but
a 2" vertical belt sander is the best way.
-Practice your weld technique to get good looking welds on the underside
that don't need any touchup, minimal bead on the outside that need to be
ground.
-Use a 7" grinder with a disk to knock down weld bead.
-Use a 4" or 4-1/2" with as sanding disk to clean and polish the surface.
These grinders are cheap, have one loaded with 40 grit paper, another
with 60 or even 80 grit. Use a cube tap and have all of them live at one
time.

Emmo wrote:

I mig weld square and rectangular tubing to make furniture. I use a 4
1/2" grinder to grind down the welds. I think I am spending more time
grinding than welding. I am wondering if getting a 7" grinder would
make this go any faster? Thanx!

__
"All it took was all I had..."



  #14   Report Post  
Posted to rec.crafts.metalworking
Steve B
 
Posts: n/a
Default 7" grinder faster?


"Emmo" wrote in message
...
OK, Roy, thanx for this suggestion. I would never have thought of doing
this, but it makes good sense. I'm definitely going to try this.

"RoyJ" wrote in message
.net...
If you are welding a lot of 14 ga, I'd suggest going to some .023" wire.


Guess you missed it at 4:13 PM PST today when I posted:

If you want flush flat welds, go with a smaller wire and don't deposit so
much metal.


But, then, going to a 7" grinder to finish off MIG welds on 14ga. iron IS an
option, too.

Steve



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Emmo
 
Posts: n/a
Default 7" grinder faster?

Yes Steve, I heard ya, and I appreciate it. Certainly makes sense to put
less down, and I can wait on the big grinder until I see the results from
that.


If you want flush flat welds, go with a smaller wire and don't deposit so
much metal.


But, then, going to a 7" grinder to finish off MIG welds on 14ga. iron IS
an option, too.

Steve







  #16   Report Post  
Posted to rec.crafts.metalworking
Steve B
 
Posts: n/a
Default 7" grinder faster?


"Emmo" wrote in message
...
Yes Steve, I heard ya, and I appreciate it. Certainly makes sense to put
less down, and I can wait on the big grinder until I see the results from
that.


I do lots and lots of tubing. I have three hand grinders. Each a 4"
Makita. One has a thin grinding wheel, one a sanding disc, and one a cup
knot brush. It really saves time from switching them all around.

That being said, I have found that a light touch and a small wheel is better
for taking off material than a bigger one. The bigger one leaves bigger
marks which, in turn take more time to take off unless they are too deep,
then you have to fill them up with weld metal and grind that mostly off.
AGAIN.

Try to get the best results you can using the smallest wire you can and
removing the least amount of material you can from the final weld. Or just
get a good looking weld and buff it with a wire wheel and paint it. Flat
"invisible" welds are nice, but a lot of work unless justified by the final
price of the item, and then, they should each take the minimum amount of
time to achieve.

Just some observances from my shop.

Steve


  #17   Report Post  
Posted to rec.crafts.metalworking
Wayne Cook
 
Posts: n/a
Default 7" grinder faster?

On Tue, 28 Feb 2006 00:38:33 GMT, "Emmo" wrote:

Thanx to all. I do currently use three 4.5" grinders, (2 from HF, 1 DeWalt)
with a grinding wheel, a coarse grit flapwheel sanding disk, and a finer
grit flapwheel, all plugged in all the time. But I have not been doing much
of any v-grooving or other prep work. This is mostly 14 gauge tubing, so
penetration is actually less of an issue than burning through, at least for
me.

Thanx to these responses, I plan to go ahead and use this month's HF
discount coupon and pick up one of these 7" grinders, and I also plan to do
a lot more experimenting with prep and with my settings on my Hobart 175.

I think your money would be better spent buying higher quality
grinding wheels. Sait make very good ones.
  #18   Report Post  
Posted to rec.crafts.metalworking
R. Zimmerman
 
Posts: n/a
Default 7" grinder faster?

If you try an industrial supplier he will have a catalogue. Most quality
manufacturers supply several hardnesses and well as discs intended to
aluminum and stainless steel.
All I know is the foreman I work for now buys softer discs. He doesn't
like seeing people taking forever to bevel prep an edge. We buy 7 inchers
and use them up until they can be used on our smaller five inch grinders.
Randy

"Emmo" wrote in message
...
Is this hardness something you just have to try to determine, or is it
labeled and I just haven't been paying attention? I think you might have
just hit the nail on the head, as the wheel I am using now I got at Home
Depot, vs. HF for the ones I had been using, which, now that I think of it,
seem to be softer...




  #19   Report Post  
Posted to rec.crafts.metalworking
Gunner
 
Posts: n/a
Default 7" grinder faster?

I went out to the tool storage shed for my newish variable speed
Sawzall and the 7" Milwaukee grinder today..and they appear to have
grown legs and walked off.

****.

Picked em up at an auction for $20 for the pair.

Gunner




"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3
  #20   Report Post  
Posted to rec.crafts.metalworking
Steve B
 
Posts: n/a
Default 7" grinder faster?


"Gunner" wrote in message
...
I went out to the tool storage shed for my newish variable speed
Sawzall and the 7" Milwaukee grinder today..and they appear to have
grown legs and walked off.

****.

Picked em up at an auction for $20 for the pair.

Gunner


Yeah, I had $2500 worth of stuff do the same thing. Put in higher fencing,
more gates, more locks, motion lights, fake cameras, and now lock everything
all the time. A real PITA, though. Wish I could just shoot the *******s.

Steve


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