How to drill holes for post shoes in rock?

[ajaxajax2000]

We are building a fence around the property and have now reached an area where we have about 20 - 30 cm of soil/sand and underneath is rock or blasting stone. So our post anchors do not go deep enough. I've now acquired a hammer drill and guess I will have to dig away the soil/sand and then drill holes for the metal rod in the fence shoe. A few questions regarding this:

1. If the rod in the fence shoe is 17 mm thick, is a 20 mm drill sufficient if I want to use some kind of anchoring compound? If not - is a 25 mm drill hole too large?

2. The rod is 20 cm long. Do I need to cool the drill bit with something to drill that deep? If so, with what? Water?

3. Should I run at a low speed during drilling? Or go full speed?

4. Should the SDS-max coupling on the drill bit be greased before inserting it into the machine? If so, with what grease?

Many thanks for your answers!

 

[Kapsyl]

Point 2. Cool the drill. I usually pour water into the hole..

 

[Cruzze]

We are building a fence around the property and have now reached an area where we have about 20-30 cm of soil/sand and underneath is bedrock or blasted stone. So our post anchors don't go down far enough. Have now obtained a rotary hammer and guess I need to dig away the soil/sand and then drill holes for the iron pole in the post shoe. A few questions regarding this:

1. If the pin in the post shoe is 17 mm thick, will a 20 mm drill be enough if I want to use some kind of anchoring compound? If not - is a 25 mm drill hole too big?
20 mm is fine. It's very important to blow out the drill hole with compressed air or a hose and mouth power afterward to remove the dust (stone dust).

2. The pin is 20 cm long. Do I need to cool the drill with something to drill that deep? If so, with what? Water?
Let the rotary hammer rest on its own weight and don't press it down, just hold it so that it stands straight. Check the drill at regular intervals and let it rest. It shouldn't need cooling.

3. Should I run at a low speed during drilling? Or go full throttle?
Go at a moderate pace. It's important that the drill doesn't become extremely hot, as mentioned.

4. Should the SDS-max coupling for the drill be lubricated before inserting it into the machine? If so, which lubricant?
I usually use MoS2 or similar.

Thank you very much for your answers!

 

[ajaxajax2000]

Point 2. Cool the drill. I usually pour water into the hole..

Thanks!

And on point 4, I now see that there is a tube of grease in the bag, so it goes in first.

 

[ajaxajax2000]

We are building a fence around the property and have now come to an area where we have about 20 - 30 cm of soil/sand and beneath it is rock or blasting stone. So our post anchors do not go down far enough. Have now acquired a hammer drill and guess I have to dig away the soil/sand and then drill a hole for the metal pin in the post bracket. A few questions regarding this:

1. If the pin in the post bracket is 17 mm thick, is a 20 mm drill sufficient if I want to use anchoring adhesive of some kind? If not - is a 25 mm drill hole too large?
20 mm will be fine. It's very important to blow out the drill hole with compressed air or a tube and mouth to get rid of the dust (stone dust).

2. The pin is 20 cm long. Do I need to cool the drill with something to drill that deep? If so, with what? Water?
Let the hammer drill rest on its own weight and don't press it down, just hold it so it's straight. Check the drill at regular intervals and let it rest. It shouldn't need cooling.

3. Should I use a low speed during drilling? Or full speed?
Go at a moderate pace. It's important that the drill doesn't get very hot as mentioned.

4. Should the SDS-max coupling of the drill be greased before inserting it into the machine? Which grease, if so?
I usually use MoS2 or similar.

Thank you very much for your answers!

Great! Thank you very much!!!