Cut & Polish Marble ??? Seal it?? How?

[Granny]

Have a piece of marble that I'd like to polish and cut for a shower shelf? I don't have access to any marble shop here... has to be sent away to be done, of all things.

Is this do-able? I have cut it to the shape I need, and can rough sand it, have all grits, up to 1500, wet sandpaper..

Any hints, helps.. I have looked at carving sites etc, ...

Thanks

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[Mike2]

Hi Granny.

You should find that piece of marble very easy to cut on your tile saw. Rounding the edges followed by a final polish should also be quite doable with sand paper, either wet or dry. Start out with maybe 120 grit and work your way up to the level of polish desired.

Do you have a scrap piece you could practice on? If so, give it a whirl and come with any difficulties you might encounter.


:)

[Granny]

been playing around with this marble, and the shelf is coming along nicely, but decided that I didn't want it to be really shiny... do I just stop when the look is right, then apply a polish to protect from staining? or

[Davestone]

Granny, the (honing) that's stopping short of a full polish, can be achieved with sandpaper,maybe 220 up to 800, and an impregnating sealer, the same as you would use to seal the grout joints.

[Granny]

this marble is kinda tetchy (sp), thanks for the assist, off to try another

[Davestone]

Granny, if i'm usin Crema, or other soft or veiny marbles i double up my shelves for strength,cut two pieces turn the finish edges to the outside, then Akemi, or epoxy the two pieces together.

[Mike_Snyder]

Sorry to hijack this thread, but I have a similar issue. I do have access to stone fabricators, but if I can do this myself, I'd prefer to save a few dollars, that is if the supplies are cheap. I have some crema marfil that I will be installing on the top of a small knee wall, the marble is ~5/8" thick, and I wanted to polish and maybe round slightly the outside edges. The total length of the finished edge will be roughly 8 feet. From what I have read here, it sounds like I can simply use sandpaper. Can if be sanded by hand? Assuming I start with 200 grit, and go up from there, would I go up in 200 grit increments until 800? How long would this process take to get to a polished edge?

[Mike2]

Hard to say Mike. The time required for your 16 lineal feet is dependant upon how much rounding over is desired plus the existence of saw marks along the cut edge. Starting out at 200 grit will even add more time to all that. Increments of 200 grit or so sounds about right.

:)

[Granny]

I have re-cut the piece that broke, then upended my belt sander, with 120 aluminum oxide grit paper, and rounded off the edges, and sanded the saw marks off the back side of the triangle

Found that using my little mouse sander, with progressively finer grit works best for the finer sanding

(also cheated a bit and used some pumice powder and water on the surfaces)

I think I'm happy

now, back to work

Thanks again, thank goodness for this site!

[Mike_Snyder]

Thanks Mike & Granny. I'll play around with it and see how it looks, if I can't get it right, I can always take the pieces to the stone fabricator. I do have sanders, a blet sander and a reg vibrating type, I also have a small(think 4") angle gringer too. ANy special type of sandpaper I will need? Sorry fro the dumb questions...just haven't a clue what I need. Thanks! This site is awesome, I apreciate all the guidance everyone has been able to provide. I don't think I would have tackled this MBR project without it, and JB's books too!

[Mike2]

Mike, this is just a rule of thumb but don't leave 120 grit until all the saw marks are gone. Life will be so much easier for you later on. Else wise when you get up to 600 - 800 or so they will stick out like a sore thumb and you'll have to go right back to the beginning again. :bang:

Don't axe me how I know that to be so. ;)

[doitright]

Hi Mike :)

Regular aluminum oxide paper will work, but carborundum (sp?) paper is the best. This is the black sandpaper similiar to wet/dry sandpaper.

The different grits will yield different results depending on the equipment you're using. For example a 400 grit on your right angle grinder will possibly yield a high polish while it won't on the detail sander.

Practice with what you got, and don't be afraid to try something different. The best advice is what Mike suggested, don't move on to the next grit until you have an even scratch pattern, and can't see any scratches from the previous grit. A halogen light on a stand will help with being able to see them.

[Granny]

the paper I used, after the initial belt sanding, is black, marked Gator Grit, of all things, waterproof paper, the 600 grit is a different brand, also black waterproof, looks like Trask, or Itask....

couldn't find an 800 grit anywhere - we are somewhat deprived here in the North...

1500 is marked 1500b waterproof

;o)

[Mike_Snyder]

Thanks again for all the helpful repiles! Sounds like my angle gringer will be the tool of choice since I might be able to get the polish I am looking for without haveing to go up too high in grit. It doesn't have to be perfect, just look good! This vertical edge isn't going to catch/reflect the light like a horizontal surface would. One thing I as told and now see is that this polished cerma marfil tile really does show all the fine surface scratches in the light. I was warned here, so it wasn't a huge suprise. I still like the finished product.

I will post final bath remodel pics once I manage to Kerdi the shower and get the shower finished, my old bathroom remodel target was (starting on Memorial Day) to finish by Laor Day..well, aside from the shower, I did meet that goal! :-) Since I had a ton of prep work in terms of tearing up and old mortar bed and relocating all plumbing lines, so I am still staisfied with the progress. ew target date is Thanksgiving...if I miss that, Christmas! ha ha

[MasterGranite]

For honed marble we use wet paper up to 320 grit, that will yield a good smooth honed finish without swirls (if ya do it right). Practice makes perfect!

[Mike_Snyder]

Success! I just want to tell you fine folks again that this place rocks! I went to the local Advanced Auto store and bought an array of sandpaper in different grits. I first used my belt sander with 120 grit (that did make long scratches in the surface) and the dust was prety bad. The I switched to my finish sander and moved up to 220, then 320, then 400, then finally 800 (all wet.) Didn't take too long and the results are really purdy. Not quite the sheen as the surface, but close enough for government work and my bathroom. I guess I could use some kind of polishing pad/buffer and get a higher sheen, but the 800 did a nice job. I had 1000 grit paper, but decided not to bother with it.

Thanks again to y'all and this board! :tup1: