Drilling through a masonry wall for a screw fixing. is in that a skill ? I use the right(?) masonry drill but but the area crumbles and...
I use the right(?) masonry drill but but the area crumbles and the drill seems to follow lines away from where on earth I started. Then I reach a section strong to drill through but still it moves and crumbles. Is this avoidable ? I'm presuming its a reasonably thick deposit of plaster. Of course the plug then doesn't fit snugly and all I'm moved out with is a wall with holes within it.
Your drill should have a switch, regular and "hammer." Use the "hammer" setting. You should also be using a masonry bit(different from a regular bit.) If you are doing this and the stuff still crumbles then you need to use a regular bit and the usual settings on the drill. Using a masonary bit with a rotary drill is problematical at best . You need to use a hammerdrill and start your hole next to a masonary punch. Run at high speed. Without the hammer effect the drill bit will stroll. Good luck,you can do it.
to keep the drill bit from drifting, create a small indentation surrounded by the masonry by gently tapping a staple set, or even a nail that will allow the tip of the bit to bite. Run the drill slowly until the bit starts to cut, then speed it up. I'm a short time confused by the rest of your question,"reasonbly thick vein of plaster". If it is plaster, the masonry bit would tear it up pretty good. If you are freshly trying to insert a screw into masonry without using a masonry anchor, a Tapcon masonry screw should screw directly into the masonry without pre-drilling.
Hope this help. Drilling masonry can be a bit of an art. If the masonry is really hard,i.e. concrete, then use a sharp masonry drill and use the tack hammer setting. If the masonry is soft and crumbly use a really sharp or new masonry drill bit and switch the hammer setting sour as this will tend to crumble the masonry even more.Keep the spiral flutes on the drill bit clear of dust by withdrawing the drill bit from the hole, this will stop the drill bit jamming up.
Answers: when drilling thru concrete you should have a hammer drill but you can do minus.first take a punch and give yourself a starter point. you will find that you do not move as much from your starting point. subsequent, when you come to the point where you think you are hitting glutinous plaster, you are realialy hitting a stone in the cement. that will make your hole sloppy. the road to aviod this is to get i punch or a mason nail, put it surrounded by your hole and give it a couple of shots with a sledge hammer that will help break the stone and drilling will be easier.