I am buillding a table and a credenza and plan to use marble for their tops. I have some marble slabs 7/8″ thick of various widths and lengths that I obtained from some 1910 vintage butchershop counters. These slabs need to be cut to size and resurfaced. Some are pitted up to about 1/16 inces deep. I would also like to shape their edges, if feasible, with power tools owned by most woodworkers. I have searched Google to try to find information on working marble, but have not found very much useful stuff. There are some messages here on Knots on cutting marble, but nothing on resurfacing or refinishing, other than taking them to a monument shop. I have purchased a diamond saw blade and some silicon carbide sanding belts and plan to learn by trial and error. If anyone can add to my knowledge on working marble or refer me to publicatons or web sites, I would appreciate it very much.
Thanks,
Irv Miller
Replies
Why not find a local stone shop and see what they use & do? There should be a couple in town where people get granite/marble countertops, etc.
Hi Irv,
I studied stone sculpture in college. For marble sculpting we use tool steel points, chisels, rasps and files, so steel will cut it. I know that marble slab is resawn from blocks using a wire saw, a copper wire running an enormous bandsaw through an abrasive slurry then through the marble, so abrasive will cut marble.
So you are on the right track with the diamond wheel.
If it were me (and one day it will be as I have some marble that my wife wants me to employ) I'd get it cut the size you want it. If you want to add a decorative molding to the edges I'd look at the profile and determine if there is an angle that can be drawn that will intersect the high points of the profile, then dress the edges to that angle, which will reduce the amount of marble to be removed profiling.
For a simple angle, bullnose or just rounded corners, a four-in-hand rasp/file and a cardboard profile gauge is all you need, and some elbow-grease. Finish with silicon-carbide paper (wet) progressing through grits 'til you get to polishing. Then buff out with white (tripoli?) compound.
If you want a more complex profile like an ogee, then I'd get out a router, with a good quality carbide bit, set a fence up and take extremely light cuts, no more than a 1/32-inch and even less as the cutter begins to engage fully as you cut the full profile in the last passes.
The reason for the very light cuts is cooling, since you can't water cool, you have to limit the feed rate and let the tool cool down between passes.
Obviously this is a job requiring utmost safety, so use a face sheild, gloves and a heavy apron. And try it on scrap to perfect your technique before attacking the showpiece.
But I'd avoid real fancy molded edges if you can. Sharp edges don't always work well in stone because minor fractures in the stone that may not be apparent, can flake out at corners as you're cutting and aren't satisfactorally repairable.
Good luck and post the results.
DavidC
Thank you David. Your post is very encouraging. I tried my just-arrived 7" MK diamond blade in my portable circular saw and it does a good job on my 7/8" slab. I just go slow, firm, and steady in a forward dry cut with the blade set full depth. The saw goes through fairly smoothly with no sizeable chipping and no evidence of overheating. I tried an 8" long cut on a broken end of the slab, so I did not have to worry about saving the waste. When I eventually cut my 8-foot slab in half, I will have to come up with a set-up that fully and rigidly supports both halves so that I don't end up breaking off a chunck as I complete the cut. Would I be better off to first score the slab with a shallow cut, or cut half-way through first, and then complete the cut at full depth? Perhaps then, if I stress the setup before completion, the slab would more likely break on the partial cut rather than in another place.
I just received a shipment of silicon carbide sanding belts from 40 grit up to 400 grit. I will try to resufrace a sample piece of marbel soon, and will report back to this forum on the results.
I had not considred steel tools until I read your post. I will try rasps and files on the edges if I cannot adequately control my belt sander for chamfers or round-overs. I am also tempted to try an ogee carbide router bit as you suggested. On the other hand, for edging, I could make cherry molding to complement my cherry credenza. The current issue of Fine WoodWorking, October 2005, pp 66-67, shows a marble kitchen counter top with oak edge that look quite neat. However, I do like to learn new techniques, so I plan to try edging the marble even if I decide to go with wood edging.
Thanks again, David, for sharing your knowledge.
Irv
http://www.easternmarble.com/cmsitems/attachments/107/product%20catalogue.pdf
Not the best idea to use woodworking tools for marble but it can be done on a limited basis. The dust is extrememely abrasive and will shorten your tool life. Covering the dust ports with a breathable rag will help a bit. Marble is best worked wet with diamonds. There are special wet grinders available that makes the process a lot cleaner and safer. This pdf has a lot of regular tools being used with diamond tooling.
Rick, Thanks for the pdf reference. I started to download it, but at 12 MB and with my 21.6K dial-up connection, I cancelled so that I could get back to this forum. I expect to get high speed internet in a week or two, so I will download it then.
Irv
I did some marble way back...
I used Automotive wet/dry papers.. Marble sort of works like a really Hard/Soft.. Yes I said hard/soft.. Depends on what you do..
I for one thinkin' about it... And the cost of all that 'paper'..
I would look for a Marble/Slate cutter (as in kitchens) and see what they charge for what you want..
NEVER hurts to ASK!
Irv -
Rather than try to hone an entire 1/6" off the slab to get rid of the pits, you'd be better off (in my humble opinion) to get some epoxy fill material formulated for marble work, fill the pits then dress the surface smooth. Marble is softer than granite, plus there are several types, read hardness, of marble itself. I wouldn't even attempt to work marble with woodworking power tools. Diamond tools are what's needed in high speed tools like routers. There are "dry" diamond bits available but as has been mentioned, the dust created is horrendous. That's one of, but not the only reason stone is worked with water. Dust control as well as lubrication and cooling of the tool bits.
You might be able to rent a stone profiling machine but I doubt it - it's a rather unique tool that few beyond stone fab shops would have use for so I don't see it being in your local tool rental yard. Forget about buying one unless you intend on doing lots of stone work; they're pretty pricey.
Check around for dry diamond bits and if you decide to go that route, address the dust problem!
As for using power sanders and silicone paper, this might work depending on how hard the marble is. Harder marbles will tend to "burn" when worked with high speed sanders. Again, dust is a major, major concern. But I think you're asking for a lot of hearache thying to take a whole slab, even a small table top slab, down the depth of the pits you mention. I'd fill 'em first.
Dennis, Thanks for the reply. Do you know of any internet sources for the epoxy you mentioned that is formulated for marble? One of my problems is not being able to find out much about marble working techniques, tools, and supplies. I have found some stuff on marble tile cutting and floor finishing, but it is mostly about diamond abrasives and pads to work the abrasives. I don't have the guts to walk into a stone fabrication shop or monument works and ask them to divulge the tricks of their trade.
Irv
Here is a follow-up for those who are still interested:
Sawing Marble<!----><!----><!---->
I have been successful cutting a rough end off of a 7/8” thick marble slab with a 7 inch MK dry masonry diamond blade (MK Diamond 154417 MK-725D 7" x .080" x DM-5/8" Diamond Blade) in my Porter-Cable portable circular saw. This blade is a general purpose masonry blade. All it takes is a slow, steady, deliberate cut at full depth; much like sawing lulmber, only slower. I used a clamped straightedge guide.
<!----> <!---->
Resurfacing Marble<!----><!---->
I have been able to remove saw marks and deep (1/32”) pits and put a chamfer on an edge by sanding with my 3”x21” belt sander using silicon carbide paper. I started with 40 grit and worked my way up using 60, 80, 100, 150, 220, 320, and 400 grit belts. I then switched to 400 grit sheet silicon carbide paper, first dry, then with water and finally 600 grit with water.
<!----> <!---->
Final Finish<!----><!---->
I have experimented with Watco Satin Wax for a dull finish and with a paste wax, Tree Wax, for a shinny finish. Either treatment is easy to apply and seems to work well.
I plan to experiment with a router bit for edge treatment. If anyone is still interested, I will post the results.
Irv
Edited 10/26/2005 12:12 am ET by Irv
Edited 10/26/2005 12:13 am ET by Irv
Edited 10/26/2005 12:18 am ET by Irv
I'd love to hear how a router bit does....
Diamond coated router bits are used for this. Carbide will fracture.
Please do post your router bit information. -robert
I plan to try a carbide bit, one that I feel I can sacrifice. I will use a face mask, safety glasses, and take microscopic cuts to start with to see what happens. My marble saws with a diamond blade and sands with silicon carbide paper not too much differently than wood does with a carbide blade and aluminum oxide paper. I will post the results, but it may take a while. I'm busy with a lot of outdoor fall work while the good weather holds up. Please be patient. Sign up for email notification if you have not done so already.
Irv
I'd wear a leather apron and heavy gloves and a face shield and pray like heck. If the bit fails or you knock off a chip, something is going to be comming at you very fast.
Frank
Irv:I think it's foolhardy to even try carbide bits on stone. Just my opinion but here's a quote from the Master Wholesale web site:"Granite is a composite stone made of mica, feldspar and quartz. To polish marble, you need to use diamond abrasives. The Master Wholesale Rockmaster Diamond Wet Polishing Pads are designed to put a perfect shine on granite slab or tiles. Use these pads with a variable speed grinder/polisher with a water hose.Softer stone such as feldspar, limestone, marble and soapstone can be polished with Rockmaster Wet or Rockmaster Dry polishing pads, or with our 5" or 7" sandpaper pads. We carry a wide array of velcro polishing pad holders to fit the surface and type of work you are doing."I don't work for, own stock in or otherwise stand to profit from promoting their products. Nor do I suggest they're the only source for this type of stuff, just the only one I've ever dealt with in my extremely limited experience of working various types of stone.I would seriously suggest you visit their site to explore the options they have available before you hurt yourself:http://www.masterwholesale.com/index/Stone-Polishing-and-Edging.html
Dennis,
"To polish marble, you need to use diamond abrasives. The Master Wholesale Rockmaster Diamond Wet Polishing Pads are designed to put a perfect shine on granite slab or tiles. Use these pads with a variable speed grinder/polisher with a water hose."
I think Michelangelo might take issue with that statement, his Pieta and David seem polished well enough, and I do not believe Rockmaster's fine diamond products were available in Italy during the 16th Century.
For light shaping of one or two edges, carbide is fine as long as a light cut is taken and you observe safety precautions in-case the bit shatters. Personally for one table top I would use high speed steel bits and plan on sharpening along the way.
For polishing, silicon carbide automotive papers starting at 220 and heading up until you get the right amount of shine or you get bored, then switching to wax and buffing will do for small jobs.
For regular or production work, you are correct, diamond tools are only sensible.
Best Regards,
David C
DC -I think Michelangelo probably had more time available than you and I and the next guy (grin). To be sure, you can cut and polish stone my hand. But remember, he was working in marble, not granite.I had the distinct pleasure of watching both master stone masons and apprentices at the York Cathedral stone shop doing the restoration of that fantastic edifice. Watching a young fella just working on a single plane of a single stone to get it perfectly flat was enough to discourage me from ever considering a career in the field! Painstaking would be an understatement. All with nothing more than ordinary steel chisels and wood mallets - the traditional way it was done when the cathedral was originally built.I stand by my opinion, as uninformed as it may be, that trying to work *granite* with carbide tools in an ordinary woodworking router is foolhardy. Marble, that's something else. It's a lot softer. But as I recall, the original post was on the subject of granite. I've seen pieces of soapstone that were turned on a lathe using ordinary HSS tools, too. But that's yet again another issue.A diamond blade for a portable saw isn't all that expensive nor are diamond coated router bits. Why take the risk?
I hate to hijak the thread, but this is cool.
My Grandfather worked in a marble quarry in Sicily before WWI to make some money on the side. He told me how they would drill holes into the cliff faces with sledges and iron bars. Once they had a decent hole they'd pack it full of black powder and then hammer a wooden plug into the hole. The plug had a hole for a fuse.
They'd put an iron net over the blast area to try to contain the fragments. As the youngest and fastest person, his job was to light the fuse and run. The old guys would get behind cover. The blast would seperate part of the cliff face that would then slide down the mountain and then get carried off to the mill by mules.
And you want to work the stuff with a carbide bit?
Frank
See his picture at http://www.worldwar1.com/itafront/faces1.htm
(Francesco Biscardi)
Edited 10/31/2005 7:31 pm ET by Biscardi
They don't do it much differently today, Francesco, but it's a little more controlled. The quarries manage to set the charges in horizontal holes along the bottom of huge blocks after the sides have been sawn loose from the mountain. When the charges go off they end up with this gigantic block that's then sent to the mill, or whatever it's called for sawing into slabs.Many of these 'saws' used in the quarry remind me of chainsaws, actually. They run in a slurry of abrasives and water. They really wear the stone away rather than cut it. Thus my apprehension with 'cutting' stone with a tool that's meant for .... cutting rather than grinding.
Dennis,
I see your point, and I wouldn't run a router in granite either, but the original poster wanted to cut, polish and perhaps cut a decorative molding on a single marble slab. Not production work and not granite. But the quote in your post implied that marble had to be worked with diamond tools. It doesn't.
For that matter, granite can be worked with steel tools, it first has to be bushed, meaning the surface fractured slightly with a bush hammer, then it can be carved. I've done both.
There's bunches of different ways to get things done. For regular or production work in stone I agree that diamond tools are best.
If I had to make one or two chisel handles, I wouldn't go out and buy a lathe, I'd use a draw-knife and scraper. To me, making a single item does not justify specialized equipment when there is another, albeit slower, method available.
Best Regards,
David C
You're correct, David, I went back and looked at the original question and yes it was indeed marble rather than granite. My apologies.And yes, marble is softer than granite and quite possibly could be worked with carbide. In fact, some of my old tile setting tools, nippers in particular have carbide cutting edges. What concerns me is that the carbide in woodworking tools, eg router bits seems to be a different formula or something than what these tile tools contain. The woodworking tools seem to chip or break easier than that on the tile tools. I used to use a carbide tipped hole saw not unlike a drill press fly cutter that also was tipped with carbide. It would dull but not break. It ran dry. I guess my experience with the friability of the carbide in router bits makes me really leary of applying them to even marble.
The title of the post is Working Marble Slabs. That is why everyone is talking marble - I think the Granite talk is a side line discussion.
1 - measure the board twice, 2 - cut it once, 3 - measure the space where it is supposed to go 4 - get a new board and go back to step 1
Edited 11/1/2005 2:28 pm ET by Ricks503
First, thanks to RickL on the link to the Eastern Marble PDF and to DennisS on the link to Master Wholesale. These sites gave me some good ideas on what tooling is available, perhaps some clues on how to use such tooling, and also the cost. Diamond router bits start at about $200 and go up to about $600. Some of the associated router guides are in the $2000 plus range. This was enough to motivate me to continue my experimentation with carbide on marble.
Here are my results so far:
Using a 1/8" radius carbide round-over bit in a Bosch 1617 EVS router set at its mid-range speed of 3 (settings are 1 to-6), and using 1/64th inch increasing depth increments, I proceeded to route. I moved the router forward at quite a slow, but not snails-pace, rate. The sound and feel of the router was not too much different than when routing hard wood. There were no unusual vibrations, no clinks like chipping marble or carbide. I made a smooth sweep, stopped the router, set the cutter depth another 1/64th of an inch deeper, and repeated with another pass. I did this for 5 passes until the round-over was compete. But I didn't stop there. I then continued with 4 more depth increments and passes until half of my previous round-over edge was now a bead. When I was finished, I checked the speed setting. It was now 5.5. With all of my depth setting changes, I had, at some point increased the speed to almost full speed. I don't know at what point I did this, but I don't think it made much difference.
After I unplugged my router, I checked the carbide on the bit visually and with my fingernail for nicks. The blade looked and felt as good as it did prior to its exposure to the marble.
I feel very comfortable with the process - not threatened at all. I will try a 1/4" round-over or even larger if my design calls for it. Right now I'm thinking 1/8" round-over or 3/16" chamfer. The round-over is very smooth and can be easily brought to a final finish by hand with silicon carbide paper when the top surface is given its final finish. The right angle part of the bead shows mild chipping, but could be rounded over with sandpaper and still look like a fairly respectable bead if it is possible to complete all edges with no major chip-out. A bull nose could be accomplished with a round-over bit rather than taking the "double" cut with a bull nose bit. Maybe I am extrapolating too far for this one experimental cut, but I see a lot of possibilities with carbide on marble if I go slow and take the proper safety precautions.
I have attached some photos. The first three are of the saw cut. I used a saw guide not only to locate the line of cut, but also to protect the marble. I found that even an aluminum saw base-plate can scratch the marble surface One photo shows the router, the routed edge, and some of the safety gear. One shows both the round-over and the bead. The last shows some of the minor chipping on the bead's right angle.
Irv
Edited 11/1/2005 10:55 pm ET by Irv
Congrats, Irv. Thank your for posting the followup and yes, I'm happy to have been proven wrong. Really. I personally would never have tried this and probably won't if challenged to profile the edge of a piece of marble. But your careful attention to feed and depth of cut does indeed prove it can be done.Again, congrats and thanks for the update.
Rick -Mia Culpa.Somehow granite crept into the discussion which ignited my afterburner. Too many chocolate eclairs and home brew. I'm waiting to hear a followup report from the guy when he toasts his router bits on the MARBLE. (grin)
To polish marble, you need to use diamond abrasives. You forgot AND ALOT OF WATER to cool the cutter!
I have no idea what cutter they used but I was frankly amazed to see an installer use a router to put a bullnose edge on a granite countertop he was installing in my home. He worked for a fairly large local stone supplier, with a very good reputation. The results were/are gorgeous.
I'd really like to know if this is common practice, and where the cutters come from.
-robert
I am definitely interested in your experiments with the stone. I noticed a while back that Home Depot had some concrete grinding tools in their rental department, and I wondered at the time how well that might work for roughing out stone.
All of those who want to tell you all the things you can't do might be right, but I would be more willing to bet that you can stretch the envelope here just a bit for all of us.
<I have purchased a diamond saw blade and some silicon carbide sanding belts and plan to learn by trial and error. If anyone can add to my knowledge on working marble or refer me to publicatons or web sites, I would appreciate it very much.>
Bosch makes a tool for stone finishers and installers that has different grit discs for polishing surfaces and edges. I wouldnt bother with the belt sander but a 4 1/2 grinder has tremendous capacity for edges and cutting. Its all in the attachments. I must add USE A RESPIRATOR! Stone dust is bad for lungs. aloha, mike
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