There exists great debate in cutting porcelain but recent conclusions seem to be going in one direction only. To cut into porcelain the most important choice is the material to do it.
Diamond is of course one of the hardest materials on the planet and so it makes a great deal of sense to use diamond. But with diamond comes cost. Some claim carbide is a better choice. But with carbide comes heat. And if carbide gets hot it goes blue. And when goes blue it goes blunt. Preventing this requires water. Lots of it. A carbide drill used with plenty of water will cut porcelain. But therein lies the problem. Plenty of water is not the thing to have in a newly installed area. And so it just comes down to diamonds.Once you get your head around the idea that only diamond can do the work then carbide and the water part is eliminated. Eliminating water is a good thing. But don't confuse it with the total elimination of water. Diamonds set into metal crowns need to be kept cool otherwise the metal heats up, expands and release the diamonds. Some water is required to act as a coolant for the metal, and also as an aid to wash away the ground out material.
Now we know only diamond is capable of doing the work the next challenge is applying the diamond to the drilling surface. One method is to clamp the diamond crown into a fixed pillar drill.
The tile is placed underneath and a hole formed by pulling down on the drill lever. The fixed pillar drill prevents drill slippage by gripping the crown firmly in place. There are three major disadvantages to fixed drill cutting. The first is most obvious in that if the tile has already been fitted to the wall then it cannot be moved to be drilled. The second is that the throat depth on the drill governs how far you can push the tile back. Some cheaper drills have a shallow throat depth which can be problematic on cuts deep into the tile. The final problem is portability. Most installers would prefer not to be carrying heavy pillar drills about on work sites.
To improve portability and achieve the drilling of vertical preinstalled tiles a method had to be developed to place a diamond crown onto the tile without it slipping. The first method was to fit the crown with a pilot drill.
The pilot sits in the middle of the crown with the purpose of drilling a small guide hole first. Once drilled the pilot then guides the crown onto the tile to hold it while the diamonds cut out the actual hole. But this procedure is also not without its faults.
Most pilot drills are not diamond but in fact carbide. As we know carbide if allowed to heat melts easily so has to be kept cool. To prevent heat building up the kit is further supplied with an arbor. The purpose of the arbor is to introduce a continuous stream of water to cool the pilot. At the point of drilling the kit must be pumped with water which makes for a messy operation and the use of extra equipment which adds to the complexity of the job and adds cost to the user. The other cost is of course the pilot drills themselves.
Most carbide pilots are not cheap and yet they have a relatively short lifespan. And finally when using pilot drills it is possible to pierce or puncture hidden obstacles such as pipes that may lie undetected behind the tile.And so an alternative method has been developed.
By removing the pilot you remove the need for an arbor and a lot of water. Solving the problem of drill slip proved to be by reversing the way the crown was guided. Rather than secure the crown from the inside it is possible to secure it from the outside. Recently anti-slip drill guides have been produce in plastic which hold the crown steady from the outside at the point of drilling. The drill plate is able to stick to a slippery tile surface by the use of pad feet.
Use of plastic is advantageous for a number of reasons to include flexibility on tile surfaces, non abrasive to the diamond crown, quickly able to wear to slight diameter tolerances of crowns. It is also cheap to produce thus significantly reducing the cost to the user. The provision of cheap diamond drilling solutions throws up quite a few extra benefits. The first is that precision drilling is available en mass. Diamond crowns provide a perfect finish in any material including cheap ceramic. Now you might think there would be no demand to drill ceramic with diamond but you would be wrong. At today's affordable prices the quality of workmanship achievable is highly improved.
That has got to be good for the tiling industry because tilers at any level can now drill neat accurate holes into any tile at any angle. And lets face it that finish is what the customer is going to see for many years - and appreciates. An example might be where a renovator uses inexpensive tiles to achieve a minimal "look" relying on the quality of the fixtures and fittings to add the value to the room to sell the house. By upping the installation game and producing accurate neat holes the installer can mimic the look of very very expensive rooms quite easily. Diamond drilling allows that possibility. Drilling with diamond also speeds up a job in that fast accurate holes can be bored into the tile with zero waste. Because the diamonds grind rather than drill they will not break tiles reducing costs. They are also fast to use and on softer material have a huge lifespan. In fact it would be nearly impossible to wear out a diamond crown on a ceramic tile no matter how many were cut.