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Discussion Starter #1
So, I was watching YouTube (YEA, I know,,, dangerous!! :laugh: )

The guy was refinishing paint on a car, and using a 7 inch variable speed polisher

He had the item # for the polisher listed,, DEWALT DWP849 7-Inch/9-Inch Variable Speed Polisher - Power Polishing Tools - Amazon.com

Then, just for grins,, I looked up the 7 inch grinder,, both are about the same amps,, the grinder seems to turn a higher speed.

So, is a polisher simply a grinder with variable speed?

Would the grinder have more rugged bearings? DEWALT D28499X 7-Inch/9-Inch 5.3-Horsepower Large Angle Grinder - Power Angle Grinders - Amazon.com

I have never owned either,, it would be nice if one tool could do both,,

Maybe the top speed of the polisher (3,500 RPM's ) is too slow to grind? :dunno:

I tried comparing watts of each,, that does not make any sense,, I think the grinder watts are off by 2X,,, :flag_of_truce:
Oh well,, any help/guidance would be greatly appreciated!! :good2:
 

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I do a bit of grinding now and then. Well, every now and then I do a LOT of grinding would be a better way to put it.
I actually own the Snap-On version of that Dewalt polisher.
Most in that speed range are labeled as polisher/sander.
They are a bit slow for grinding work, but they will do it just fine, if a bit slower.
Bearing/internal part wise, the only difference I found when searching for parts for mine was the gearset itself is different depending on if its a grinder or polisher/sander. Otherwise they were the same. I got it for a steal, but it needed a new gearset. Someone was using it as a heavy grinder, and apparently had dropped it or something, as the grinding disc also showed damage.
That was better than 10 years ago though, so it could be different now, though I doubt it. It wouldnt be cost effective to have two different bearings for the same head with just different gears.

All that said, I bought it to be a polisher. I have no use for a grinder of that size, and have never even seen much use for one that size either. I used to work for a conveyor manufacturer, and the shop guys used the smaller 4.5" and 5" grinders. The install guys did too. I guess I cant see much advantage to the larger grinding disc, but that doesnt mean there isnt a need in some cases, otherwise nobody would buy them.
If you decide you need one, make sure you get one with the with the speed control that maintains speed regardless of load.
They are much nicer to work with than the standard type.

Im also not big on grinding discs anymore either. I went to heavy grit flap discs a few years back and even though my thumb doesnt like them much, I prefer them over grinding discs. For me, they work just as fast, and you can finesse them a bit more so you arent cutting in so fast while still doing work.

Another general note on polishers.
If you arent familiar with them, meaning if you havent worked with them extensively, Id recommend an orbital polisher.
You can damage a finish REAL fast with a rotary polisher.
I guess kinda like a tractor, it depends an awful lot on what you plan to use it for.

But then again, Im a self proclaimed oddball, so take that into account too!
 

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Im with @IndianaJim when it comes to having a grinder that size. We do a lot of fabrication work where I work and a typical 4 1/2" grinder is all anyone uses. Sure there are a couple of old 7" ones in the shop but they are just too unweildly to be using on a continual basis.
Also, most of the 4 1/2" grinders these days take a variety of blades for concrete / material cutting that just wouldnt be practical for any sort of 'precision' work. Using a 7" grinder in most cases these days is like using a bazooza as a fly swatter.....sure it will work but in most personal uses its just way too much overkill.
 

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Discussion Starter #4
Using a 7" grinder in most cases these days is like using a bazooza as a fly swatter.....sure it will work but in most personal uses its just way too much overkill.
I guess my metal fab falls in that category,, 100% of my needs have been met by 4 1/2" grinders for 40 years,,

I have even worn out several Milwaukee grinders, but, the Makita is still running,,, and it was the first one ever purchased,,

I want a polisher,, so I guess the right thing to do is buy a polisher, and forget 7" grinding,,, :good2:
 

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Sometimes because of what and how much needed grinding, I would break out the big 'ol B&D 7" and have at it. But 99.9% of the time our 4-1/2 and 6" Metabo's took care of business!:good2:
 

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Their are times for the 7" but man the damage it can do to you using it! I really have to hang on to one tight. A 7" Cup Brush on some steel lips or rough edges can jerk the crap out of the handles! I have lost a couple times using one and prefer the 4-5" ones and flappers are nice for a lot of grinding. Sometimes you got to go get the big one but very few times for me anymore.
 

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If you use one of these for polishing be ready to repair all the swirl marks. Running one of these large disc polishers is an art form. On an edge you can burn the paint to the metal before you can say "don't do it".
Yep. Thats why I mentioned the orbitals. Rotary polishers (which these big monsters are) are for professionals.
Ive run them on black a few times (living dangerously), but I used to work in a body shop too, and used to use them a lot.
These days though, I prefer the orbitals.
Much like shooting, running a rotary buffer is a perishable skill!
 

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Discussion Starter #9
Yep. Thats why I mentioned the orbitals.
Much like shooting, running a rotary buffer is a perishable skill!
I have a Porter Cable orbital,, it is nice,, but there are times I just would like to try doing a bigger area,,
The orbital worked good on the hood of the JD 650,, but, even that took some time.

I may have been using the wrong compound, and wheels, I will get some of that at Walmart, and some from Amazon,,

My 180K mile Silverado has LOTS of scratches!!

On a similar note,, I ordered a PDR kit ,,, the Silverado has a couple dents,,, :flag_of_truce:
 

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Discussion Starter #10

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I love Chinese stuff...especially the description!...

"1)When you want to use it, you can just press the button*
2)you have to clean your car with TOWER
3) (The best for last!)..."it can minimize hand fatigue during usage, which can give you a good using experience"

Look at the #3 picture...it has a European style round prong plug
And that "giving you a good using experience "...sounds like a buffer with a happy ending
When it arrives in June, may be the best experience ever!

Sent from my SM-S320VL using Tapatalk
 

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I actually own one of the cheap ones. It came from US stock for $14. Bought it years ago. It is a gutless wonder but it does rotate. Has a dial for setting speed and if you wait long enough after pushing the button it gets to speed. I think I used it once right before I spent 3 days with the orbital trying to get the swirl marks out.

Last time I used a large one before that was at Fisher Body School in the 60s. :laugh:
 
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