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-   -   Want to polish edges of grante for outdoor countertops. Advice needed!! (http://www.diychatroom.com/f15/want-polish-edges-grante-outdoor-countertops-advice-needed-62651/)

Rhizzlebop 01-24-2010 12:42 PM

Want to polish edges of grante for outdoor countertops. Advice needed!!
 
I'm using some scraps of granite that are as large as 7ftx18" in size. Some are shorter. I will use an angle grinder witha diamond blade to trim them to a fairly square 18" width with flat faces. (aka no real profile).

My issue is how to restore the smooth granite edge. It doesn't have to get to kitchen countertop smoothness, but I'd like them to look fairly good. These are going around the edge of my deck outside.

I found a granite polishing pad set for 35 bucks on ebay that has from 50 -3000 grit and says for dry polishing. I can get the base to attach to a grinder for about 10 bucks.

My problem is, that I'm now reading that A, I HAVE to use a variable speed grinder and slow it way down, and B, that dry polishing doesn't work well, and i'll eat up the polishing pads quickly.

I am looking to do one counter at about 7ft long, another is about 4.5 ft long and another about 3 ft long. All 18" wide. So, a good distance of edge to polish, and I don't think the project is worth paying someone 10bucks a ft or more to polish them.

Any advice or help would be appreciated.

The pads I found on ebay say Korean made for whatever thats worth.

jlhaslip 01-24-2010 06:10 PM

those pads work better if you 'spritz' some water on it while you are grinding.

user1007 01-24-2010 06:57 PM

Toss them in a truck and take them to your local stone guys. Slip em a few bucks. Job done. Cheaper than buying all the stuff and DIY.

Rhizzlebop 01-24-2010 10:44 PM

I also have thought about using a corded drill that I can run at the slower rpms with these polishing pads.

I checked home depot and they don't even carry a varable spped grinder though I did find some online. I figure if i can get a drill at around 1500 rpms that should do the trick.

Mop in Hand 01-24-2010 11:49 PM

I hope that you mean from 50-3000. 300 grit on granite doesn't polish, it will be more dull than you think. Wet pads work best. An angle grinder is the way to go. SDSESTER has the right idea. You will end up spending $500.00 or so just for the right equipment

Bob Mariani 01-25-2010 08:27 AM

The pads alone will cost more than the project being done by a pro. I polish the edges to 8500 grit with wet diamond stone grinders on a wet feed 4" angle grinder. Then polishing pads are used with 4 more levels of polishing. You need each grit, no skipping a size or you leave too many scratches. And it takes skill and practice to maintain even pressure.

Rhizzlebop 01-25-2010 11:42 AM

I did mean 3000 in that first post.

remember, these are for outside on my deck. I don't need a mirror kitchen grade finish on the edges.

I found a set of pads from 50 to 3000 grit, on ebay, for 40 bucks. If I can get an adapter and use a slower speed drill, then another 10 for the adapter maybe.

I also found a site called bargain tool that sells a whole kit included the pads from 50-3000 plus buff. AND a variable speed electric grinder with water feed for 140 dollars plus shipping.

If I took these to a stone shop, they will probably charge 10 bucks a ft, and we are talking about 40 linear ft of edge.

Plus I will get the personal enjoyment knowing I did it myself.

My alternative to not trying this at all is to build some kind of wood frame with a vertical upright "decking board" edge to cover the edges of the granite and all you'd see is the flat top surface but I really don't wanna go that route.
(it would look kind of like an edge when someone uses granite tile on a counter, and the edge is framed in wood, except it wouldn't be a tight wood edge, and I'm afraid grit and crap might get between the wood and the stone.

nap 01-25-2010 03:18 PM

well, you usually get what you pay for. The last time I bought some cheapo cutting wheels for my 4 1/2" side grinder, I realized that they lasted as long as 3 of the cheapos I had purchased before yet they were not 3 times the price, only about 50% more.

but, what do you have to lose but the $140 and some time if it doesn't work well enough for what you want.

Snav 01-25-2010 03:38 PM

Stone cutters and crafters often use rouges and buffing compounds to achieve the desired finish.

It's not *just* in the pad or grit.

I use to craft jewelry and always used a dia-glo buffing compound for stones that were tough. I never did any huge projects - always small projects like faceted non-precious stones (like chunks of granite and onyx) - and using a hand block.

If i had your project to do I'd do it that same way, a hand-block with the traditional graduated grits of paper and then adding the compound in the end. I would avoid electric buffers because they can quickly screw up all your hard work.

nap 01-25-2010 05:35 PM

Quote:

Originally Posted by Snav (Post 388896)

I use to craft jewelry and always used a dia-glo buffing compound for stones that were tough. I never did any huge projects - always small projects like faceted non-precious stones (like chunks of granite and onyx) - and using a hand block.

If i had your project to do I'd do it that same way, a hand-block with the traditional graduated grits of paper and then adding the compound in the end. I would avoid electric buffers because they can quickly screw up all your hard work.

can you expand on this?

hand block? what to use for actual abrasive?

Is there such thing as rasp of file for stone? maybe something large like 10+ inches?

Snav 01-25-2010 06:41 PM

Quote:

Originally Posted by nap (Post 388973)
can you expand on this?

hand block? what to use for actual abrasive?

Is there such thing as rasp of file for stone? maybe something large like 10+ inches?


By hand-block I was referring to a basic hand-clamp for sandpaper, can be found at any hardware store and some craft stores. . . they don't always have to be for sandpaper - you can use buff pads and other things in there as long as they aren't too thick.

To apply a buff, rouge or polishing medium (like dia-glo http://www.contractorsdirect.com/Con...ffing-Compound) you cannot use a sandpaper - it usually must be a soft cloth (like the plush pad on a mini-buffer used for autos). When I used dia-glo I had a buff-pad in my hand-block, I'd spritz it 'til it was wet, sprinkle a little bit of the medium into the cloth and either rub it on by hand or with the mini buffer on low speed.

(Why a mini buffer (an orbital buffer is what they're also called) - they're cheap, the replacement pads are super cheap and available at almost any auto supply store and they have low RPM's and a cushion underneath - they're for high-speed polishing cars, and that's an easier surface to scratch than granite so it's a safe match) A mini buffer is about 4 or 5 inches - regular buffers are 9 or 10 inches and up.

If you can buy a small chunk of granite tile - break it into a few pieces - you can practice on that.

Now, if your granite is rough then use a variety of stone working tools to define the edge. I'd bet that a tile-rasp would work nicely.
Use the dia-glo or similar medium when you're ready for the final step.

Rhizzlebop 01-25-2010 08:04 PM

Well, I figure if the korean pads arecheap, then that could mean they last long enough to handle my project whereas the 200 dollar pads last for months. I figure, worst case I may have to buy a second set of 50, 100, and maybe 200 pads cause those would get the worst beating, and that might cost me an extra 20 bucks, IF they were needed.

Mop in Hand 01-25-2010 10:01 PM

Go for it, Rhizzelbop. Spend a little more time on the 200 & 400 grit. Doing this project by hand would take forever.

nap 01-25-2010 10:12 PM

I was looking around for some more info on this and found a site with this near the end of their explanation:


Quote:

If you go through all the grits and have not been drying the stone and checking for blemishes after each grit, when the stone dries you may be shocked to find some remaining scratches. And you have to start all over again from the beginning.


Polishing is just plain labor

unlvrebel 07-26-2010 01:16 PM

Bringing back from the dead. Curious how Rhizzlebop's project turned out? Looking to take on some granite polishing myself. Currently practicing on scrap right now. Almost there, but can't quite get to that glossy finish. Got it mirror smooth but parts of the black (black galaxy) look like they have a bit of a film on them.


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