Grinding / Polishing / Small chips - Tile Advice

[Julian 'Farmer' Bonsall]

Hello
When cutting ceramics with my table saw (Wet Saw, 180mm disc, MARCRIST DIAMOND TILE BLADE from screwfix) I get some small chipping to the glaze. On a recent kitchen I moved to cutting almost all tiles with a grinder as it was much quicker (using either a ck850 or Protilers blade) but there are still small marks on the glaze. I used the side of the cutting edge to remove the very small amount of tile to remove this unwanted edge.
I noticed on the forum various grinding pads and wondered if a set would be useful for my toolbox. I was looking at something like this :
Sigma Diamond Grinding Pads (multiple grits available) | Buy Sigma Tile Cutters Online from Pro Tiler Tools - https://www.*******************/product/sigma-diamond-grinding-pads--multiple-grits-available-

 

[Concrete guy]

What you linked to are dry diamond polishing pads. Designed predominantly for polishing granite and other hard stones. The key word here is "polishing".

You'd be better of buying some electroplated diamond hand pads, many of the tilers on this forum use them, either ours or bought from eBay or from Protiler tools. They all do the same thing.

(I can't post links it breaches the advertising rules of the forum - but they are easy enough to find).

Even if you did feel like setting yourself up with some polishing pads for a mechanical polisher. For what you guys do (tilers that is ) you'd be hard pushed to better Silicon Carbide discs. Mainly because they work on pretty much everything you're going to come across and it's only small volumes of edges you're ever going to be polishing.

The advantage of diamonds really kicks in with volume. If you're polishing hundreds of linear meters of product on a daily basis then it makes a lot of sense. That said you'd have pads for marble, pads for granite, pads for quartz and pads for porcelain.

So the average tiler (and I know there are a lot of tilers here that are above average!) will do everything they need to do with some hand pads and silicon carbide discs (if they have the need to invest in a polisher).

 

[Concrete guy]

Note for the more "experienced" members of the forum that Silicon Carbide is also known as Carborundum.

So you may have come across solid black rubbing blocks of this stuff for all sorts of uses. Mainly they were used for cleaning tools but they work equally well tidying the edges of tiles up.

It's pretty much the hardest thing available bar Diamond.

 

[Julian 'Farmer' Bonsall]

ATS - thanks for your reply thats very helpful. I've posted a photo of what I think you mean. What I have tried to use is some 400 Grade Wet and Dry (also Si Carbide) from my playing with car paint work. It was just a little slow and being a paper not suited to tile edges.
Is there any type of grinder option available (I have never used the blocks) or, even if there is, any point to one? (i.e. is the hand block quick?). At the moment I run two grinders and pop the cut tile onto the second one with a cheaper disc in it just to take the cut edge off, but its really far to aggressive.

So really a solution for the cut edges of a glazed tile. (Electroplated Diamond Polishing Grinding discs - ATS Diamond Tools - https://www.atsdiamondtools.co.uk/product/electroplated-diamond-polishing-grinding-discs/) (115mm Electroplated Diamond Grinding Disc - ATS Diamond Tools - https://www.atsdiamondtools.co.uk/product/115mm-electroplated-diamond-grinding-disc/).

I can see a tool that is rigid is needed for my needs but not at all sure quite how aggressive the tool needs to be.

 

[One Day]

You want a soft velcro face backing pad for 4.5" grinder, then some 60 and 120 grit silicone carbide discs. I use these day in day out for tidying up porcelain edges.
Diamond is for polishing.
Rubber Velcro Backing Pad M14 - ATS Diamond Tools - https://www.atsdiamondtools.co.uk/product/rubber-velcro-backing-pad-m14/

 

[Concrete guy]

I have to tread carefully here Julian as I'm not a forum sponsor.

The hand pads pictured above are ideal for tilers, they are quite rigid and ideal for tidying up edges of envelope cuts, that kind of thing.

The #50 is quite coarse. Most tilers are going to be using #100, #200 or #400 grit pads or a combination.

Velcro backed discs are a stonemason/concrete product, basically a version of the hand pad that can be attached to a polisher. You'd be using that on thick edges (20mm/30mm) or surfaces and as such are a bit aggressive for ceramic and porcelain tiles.

The electroplated grinding discs we brought in due to demand from tilers. They are #120 grit and a general purpose tidying/finishing tool.

It's also worth noting that the grit numbers for silicon carbide and diamond are not algined.

Diamond pads run generally from 50-3000 grits, above that they are variations of buffing pads, 5000 grit and such.

Silicon Carbide run from #36 (extremely coarse) to #1200 (used by glaziers for polishing glass).

So a #400 Silicon Carbide isn't grinding, it's polishing. As impish mentioned above, you'll need #60, #80 or #120 for shaping and light grinding. #120 probably being the most versatile and used SiC grit disc.

 

[Julian 'Farmer' Bonsall]

Impish - smashing and thanks. I just know using the side of my cutting disc is wrong.
A quick look at ATS as examples (dont know what Velour disc is)

Its very appreciated.

SAIT Velour Silicon Carbide Discs 125mm - ATS Diamond Tools - https://www.atsdiamondtools.co.uk/product/sait-velour-silicon-carbide-discs-125mm/

Rubber Velcro Backing Pad M14 - ATS Diamond Tools - https://www.atsdiamondtools.co.uk/product/rubber-velcro-backing-pad-m14/

 

[Old Mod]

Very informative Alan, @ATSDiamondTools,
thank you for respecting forum sponsors.

 

[Concrete guy]

Velour backed means it fits on a velcro type backer.

Plain back is just that, it's plain paper and you use a contact adhesive to glue the discs to a plain backer.

In anything other than a stone production factory environment, velour and a velcro backer make more sense.

 

[Julian 'Farmer' Bonsall]

ATS thats really helpful and useful information.

I wonder if the grades are similar to wet and dry paint finishing paper.

They sound like just what I could use in my battery grinder - really appreciated.

 

[Julian 'Farmer' Bonsall]

So I purchased an electroplate 115mm grinding disc. I had an already cut floor tile (with glaze chips) to try the new tool out on. I also compared a segmented blade (for stone cutting), a Marcrist CK650SF (110mm x 1.7mm), and a Marcrist CK650 (115 x 1.1mm).

Images : Grind disc, 3 x cut discs, precut floor tile, cuts with 3 blades, after grind top, after grind cur face.

I did attempt the wet sponge (you may see damp tile) but I don't think I had it wet enough.

I have found an issue with the grind disc. If the direction of grind is from the glazed surface towards the biscuit its very good (I am not quite so keen on the actual shape of the disc - flat would be my choice) but if one grinds from biscuit to face then I had some surface chipping. I am not sure if this would happen with a pad/paper solution. Where you have an 'L' in a tile it could be tricky to always grind from the glaze.

 

[Concrete guy]

I have found an issue with the grind disc. If the direction of grind is from the glazed surface towards the biscuit its very good (I am not quite so keen on the actual shape of the disc - flat would be my choice) but if one grinds from biscuit to face then I had some surface chipping.

That's quite normal, think of it the same way you would cut a piece of timber, you always cut into the finished surface so it's doesn't splinter. As opposed to cutting up through the finished surface

A flat blade would be unforgiving, they are called electroplated vanity blades and designed more for marble and other soft materials.

 

[Flintstone]

The slots you have cut there have some bad chipping, I never get chipping like that with grinder and wet sponge, I use ats blades, mainly the turbo blade, cut slow, two passes, persevere with the sponge it makes all the difference.

 

[Julian 'Farmer' Bonsall]

@Localtiler understood and thank you. I will give the sponge some more practices. I would much prefer a bigger 150mm disc and maybe have more space for the sponge.

The thin slot you see was done with a wet sponge and slowly (they were all done as I normally cut) I also wet the tile with a small puddle around the blade as I was struggling with the sponge, I should have videoed it really (even for comedy value) - I chose that tile as it chips like no other (and being a dark tile I thought better for images) I have cut and it was to demonstrate the new electroplate grinding disc. One of the cuts is completed with a blade normally used for motor and brick work.
I chose the CK650 over a Premtool Turbo Fastline as I took it as preference on the kitchen I did recently. I can repeat with the Premtool blade if necessary.

 

[Julian 'Farmer' Bonsall]

A flat blade would be unforgiving, they are called electroplated vanity blades and designed more for marble and other soft materials.

Thanks for the quick delivery and the help and advice. It does just what you suggested - as hopefully can be seen it cleaned up the badly chipped tile a treat.
I don't understand what you mean by a flat disc would be unforgiving? I have always used the side of a disc in the past to clean up the edge which is flat? I have in the past held the tile perpendicular to the disc and removed the biscuit until I get a clean face on the glaze. Maybe that is not correct? With the curved face this technique would seem to not be the best.