So, I have this metal washing basin/tub from the 1920's, which I would really like to drill holes in, and then protect from rust with a metal protector (which I've already bought). I would then protect furthermore with a plastic sheet with holes in it, then I would hopefully love to plant some stuff in it. I was just wondering how I drill holes in metal, because I tried with a normal drill and it just blunted the drill bit. Also, I would love to cut up some fine china cups for an art project so that they are perfect circles which don't break. Does anyone know how I could cut through china cups without them breaking? Thanks a heap, guys.
Tile saw would be the SAFEST way the expencive way is to get them proffessionally cut around $30
I tile and drill, every day of my life, as well as sculpt in clay, your quest is a noble one, but the cups issue will certainly be a major challenge, and hopefully you expect to use a gross of cups, with possibly a 10% success rate. Beyond that &Perfect& is relative, though a valid quest as well. No offense meant to those who said Wet Saw, or such, but you might find your perfect circle, shooting across the room. backing up to the sink, (no pun intended) you're dealing with and enamled, cast iron sink, it sounds like, The process for drilling is tedious in the enamel, which is essentially GLASS after being kiln fired over the cast iron at 3600 degrees (approx) The same &BIT& used to drill the cast iron, my very well NOT be effective without damage, on the enamel. In any case a small pilot hole to start, then a conical grinder drill bit might be as successful as any other method. In all I think you should assume that the enamel will be damaged at the point of the hole. Then there is the thought of how you define &NORMAL& drill bit?? Your thoughts of the process, after the fact are valid, but at some point you might still expect some rust from moisture intrusion. OOPS backing up again,,, sorry. Wash basin/tub,,, I thought sink. ah well... What is the METAL of the tub? I want to assume that even in the 20's it could be galvanized? THIN STOCK? Cobalt bits would do the job. Just my two &sense& Time for a beer and get outta here, LOL.
Cutting china cups: I have never tried this, but I should think that, since tile is ceramic also, a good tile saw like the kind that you can rent that is water cooled, should be able to do what you want. I have spent many hours cutting ceramic tile in my life; the more intricate the task the more times and more care you need to exert. Go slow and don't force it and be very very careful and it should work. Drilling holes in metal: Again, go SLOW with the drill bit. Make sure it is rated for drilling in metal. The biggest mistake people make with drilling in metal is going too fast. Exert a bit more pressure on the drill than you would with wood. Again, go REAL slow. 40 -50 RPM to start and increase or decrease depending on how well you feel it bite. WEAR EYE PROTECTION. ALSO: Get an oil can and keep the drill site well oiled as you go. Keep the site COOL by using a liberal amount of oil (motor oil will do as will even lighter grades). As your hole gets deeper, back out and clear the shavings and clear the tip.
A regular, &twist bit&, designed for drilling holes in metal, should be able to bore right through a metal wash basin, like, say, if it were galvanized or painted. But, if the piece has a baked on porcelain finish (like the &spatter ware& from the depression era, or even any white finish on a basin or pot), I would suggest getting a masonry bit. These kind of bits have a tungsten carbine cutting bit at the business end and are designed to cut through most hard materials (tile, brick, concrete) and should be adequate to penetrate through a porcelain glaze. Then, finish the job with a regular twist drill. Masonry bits are not very expensive. You can buy them singly, at most any hardware store. I've fabricated some tanks for holding water from sheet steel and I coated their insides with a liquid, two-part epoxy, which can be brushed on like paint. Use a throw-away brush. The brand of epoxy I used was System-Three, which was formulated for marine use. It's a little pricey if you're not going to need a lot of it, but it does stand up extremely well to constant immersion and it did protect the base metal very well. You might get some two-part epoxy that comes in a tube, cut it with a little alcohol or acetone so that it's brushable and apply that to the inside of your basin. As to your china tea cups though, that would be a challenge. I'm picturing myself doing it with a small rotary tool, like a Dremel, in a router base, or mounted in a table, with a diamond encrusted wheel in the chuck and then going slowly around the perimeter of the cup, cutting the slices off. I would cut a 1/3 portion of the circumference and leave the three, very small bits for last. Are we talking thin, bone china tea cups? or sturdy stoneware ones? I think that you would be in for a lot of trial and error with some failed attempts until you got the feel for working with the materials.
