I have a question for anyone. I am attempting to drill 200 1/8" holes in a 100 year old piece of a local dam that was removed recently. It is a slab 5'x4' and laying flat. The client wants a large amount of lettering on this with stud mounted aluminum letters. The piece is filled with round river rock from small pebble to 2" rock aggragate that is millions of years old. I only have to go 1" deep. I tried a standard masonary bit...it would take for ever. My other option would be a diamond bit(don't know how long each bit would last)or a core bit. I can't find any core bits at 1/8". I also will use a piece of material to transfer my hole pattern on so I can keep it somewhat straight while drilling as it will walk all over. I will use a rotary hammer drill.
Anyone with some expertise with this? Any tricks to help this along?
I appreciate it muchly....
Jackson Jacksonsignartstudio.com Port Angeles.
Posted by Dale Feicke (Member # 767) on :
You've got yourself a project there, Jackson!
First off, there are hammer drill bits, and there are hammer drill bits. You definitely don't want the variety that the hardware store carries. Look for industrial drill suppliers, like maybe Grainger, Global Industrial, or a supplier that just specializes in drilling equipment.
There you'll find much better quality bits, that will last longer and drill quicker.....and make this nightmare a little more manageable.
Posted by Jackson Smart (Member # 187) on :
Hi Dale
Thanks for the response. I am still doing some research on this. You are right about the hardware store bits. I have to use SDS bits and a rotary hammer drill.
Hope all is well with you and have a great year.
Jackson
Posted by Raymond Chapman (Member # 361) on :
I'm tired just thinking about it.
Posted by Jackson Smart (Member # 187) on :
Haha....Ray.
I have to do it and I am alredy tired.
Woe is me...woe is me...will I ever learn? This too shall pass.
Jackson
Posted by Sam Staffan (Member # 4552) on :
Hello Jackson, Using the proper Drill and bits for this job would not take very long at all. Hopefully there is a rental near you that you could get the equipment from. I use a Hilti rotary hammer with Hilti bits and going only 1" should not take much longer than going into hardwood. here is a clip to show the differences in Hammer Drills verses Rotary drills for cutting and speed. I am assuming you already have a rotary since that is the bit you are looking for.
[ March 26, 2014, 04:18 PM: Message edited by: Sam Staffan ]
Posted by Dave Grundy (Member # 103) on :
I would dread having a project like Jackson's but after watching the video....THAT type of drill makes it look like a piece of cake!!!
Thanks for the video Sam.
Posted by Si Allen (Member # 420) on :
200 holes???????????
Posted by Brad Ferguson (Member # 33) on :
Two hundred holes in a 4'x5' space is indeed a lot of holes. You are obviously installing a large quantity (60? 70?) of smaller letters. Your hands should be a little numb when your done.
The main problem I foresee, and maybe it won't be a problem at all, is the possibility that chunks of concrete will break loose between the holes, leaving unsightly divots with exposed aggregate. There seems to be more of a tendency for this to happen when using hammer drills that have a larger, coarser hammer action. A smaller hammer action may be an advantage here, though they are slower. Also, a smaller hammer action may make it easier to keep the tip of the bit on the mark when starting the hole. Large aggregate can tend to deflect the bit, but you're only going one-inch deep, so maybe that's not a problem.
Hammer drills that can be set to 'hammer only' action may allow you to start holes more accurately. You can use the hammer only to make a small dent before you switch to rotary/hammer for the remainder of the hole. I would think that accuracy and care in starting the holes is critical on a job like this.
For those who have never used hammer drills, applying lots of pressure on the tool is usually not recommended. Let the drill do the work.
200 holes with my old Hilti beast used to wear me out. This job is on a piece lying flat, a big advantage.
I would be interested in knowing how this job turns out, Jackson — what tools you end up using and the time it takes.
Brad in Kansas City
Posted by Don Hulsey (Member # 128) on :
Thanks Sam! I have been trying to explain that to people for years, but didn't know that video was available.
Many years ago(about 25)I was installing a sign on an old sidewalk. It required 8 holes 1/2" dia. x 2" deep. I pulled out my trusty DeWalt commercial hammer drill with a diamond tip bit. After 20 minutes I had the first hole almost 1" deep, and the bit was dull enough it needed to be replaced. 35 minutes and $139.00 later I was the proud owner of a new SDS rotary hammer. It took 17 minutes and 1 bit to complete that hole and the other 7.
Jackson, It sounds like this is a loose slab. If so, DO NOT use the hammer only function. This can set up a vibration that can actually split the slab. That one cost me big time.
For 1/8" holes I would have an extra bit handy. One standard SDS carbide tip bit should drill 200 holes with no problem, but an 1/8" bit is easy to break if you lean on it wrong.
The side handle is for control, NOT for extra pressure. You will want to apply a slight pressure, but it is true that you need to let the tool do the work.
The most important thing is, this sounds like something that cannot be replaced. I would be sure to have it in writing that you are not responsible for any chipping or cracking, even though I don't think that will be a problem.
Posted by Raymond Chapman (Member # 361) on :
Recently I installed a large number of Gemini letters on multiple limestone walls and drilled over 1,000 holes. Some were off ladders, some standing and some sitting down. All with a Milwaukee hammer drill and a 5/16 bit...actually, a bunch of bits.
I wish I had known about the Hilti products.
Posted by Jackson Smart (Member # 187) on :
Thanks for the extra information. Great video Sam. I have come to this conclusion already thru research, but the video convinced me. Thanks
Don...I am going to use the rotary hammer drill. I can rent it locally and order the bits. It is recommended that I use SDS bits.
I am also going to make a template of 1/2" plywood to use as a guide(with pattern) so the holes will start straight and hold the bit while drilling. I said 1" deep, but may go deeper if it drills easily. The aluminum posts are 1/8" dia. so I will go a size bigger so I can mount the letters better. I have to drill all the holes and then when the slab is installed I will set the letters. Of course, the client wants to put the phone book ad on the sign...haha Normally I would turn this job down, but they are great customers and I feel the need to handle them and not send them away.
Brad...I will keep you all posted with some pics (if I can post them here) so you can follow my progress. Thanks again...you all are great.
L8tr... Jackson
Posted by Ian Stewart-Koster (Member # 3500) on :
Thanks for the good info. Here's another rotary hammer (drill) comparison that's an eye-opener (7 minutes-watch to the end): https://www.youtube.com/watch?v=vPGyUyLaVrE Posted by Sonny Franks (Member # 588) on :
Thanks guys - y'all just saved me a lot of time and energy on an upcoming installation.....
Posted by Steve Purcell (Member # 1140) on :
For that many holes I'd have at least 20 bits on hand and a source of water.
Posted by DianeBalch (Member # 1301) on :
![[I Don t Know]](graemlins/dunno.gif)
This too shall pass. 