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Coring 3" holes

TonyS Member Posts: 849
I have a job coming up for 5 minisplits in an old farm house with brown field stone walls. Anyone have some good methods of drilling 3" holes in stone walls?


  • eluv8
    eluv8 Member Posts: 174
    Coring stone wall

    If you call around you should be able to find a concrete coring company. They should be able to quote you a price to come out and core the stone for you.

     If you live in a small town you may have to look into doing it yourself. I have cored concrete with a rotohammer and a coring bit that looked a lot like a really long holesaw that hooks up to a garden hose. You might be able to rent one from the local equipment rental center.
  • Rough job TonyS,,,

    Be sure to keep the bits relatively cool,,, meaning always clean the core out & keep a vacuum handy to withdraw the "tailings" in between.. :-) 
  • TonyS
    TonyS Member Posts: 849
    Dave, have you ever used

    these Im thinking about giving them a try
  • Nope,,,

    When I came across that I "rented" the equipment, and never had a preference,,,, I just wanted the holes drilled,,,, lucky-me.. I may have to drill 5 a year  :-).
  • Big Ed_4
    Big Ed_4 Member Posts: 1,775
    True Stone walls

    If so the house could be balloon construction ??? Drop the lines into the cellar ... Heat sink the inside head line set and braze the connections , leave a slack loop in the cellar ...
    I have enough experience to know , that I dont know it all
  • True Stone walls

    "If so the house could be balloon construction ??? Drop the lines into

    the cellar ... Heat sink the inside head line set and braze the

    connections , leave a slack loop in the cellar ..."

    I`m lost Ed,,, what are you talking about????
  • Big Ed_4
    Big Ed_4 Member Posts: 1,775
    edited March 2010
    Balloon Construction

    Most stone houses used balloon construction inside wall with no insulation ... It's a clear path into the cellar ... Then look for a way out side to the condenser ... Chisel a hole and patch it behind the condenser ... Just another possibility for him ... If so its a very clean job

    Thinking out of the box , rather then diagonal core drilling ....
    I have enough experience to know , that I dont know it all
  • SteveMac
    SteveMac Member Posts: 8

    Dynatech bits and tool rock. I own a drill and about six different size bits. I've drilled stone, reinforced concrete with 1/2" rebar, and asphalt. I use it exclusively as a hand drill which requires a fair amount of effort. If you plan to do alot of drilling, buy the drill press att.achment. When you hand drill, you can drill at any angle, 45's or whatever you want. You can also drill just a partial diameter hole. For example you can drill just half of a 3" hole to a half moon shape if you want. Worth every penny you pay
  • TonyS
    TonyS Member Posts: 849
    I called Dynatech today

    The man I talked to was Glenn, very helpful. He explained that wet drilling offers speeds up to 3 times as fast as dry coring if that is an option. What I'm going to do is lay out the units inside and then punch a 3/8 pilot hole to the outside, then take some plumbers oakum and plug the hole from the inside after all five units have a pilot hole I am going to wet core the holes with a handheld machine and a lift. They have some good videos on their website that show different procedures. I will let you guys know how it goes. Going inside the wall was not an option but it was worth taking a look.
  • TonyS
    TonyS Member Posts: 849

    have you ever used the drill press option on a stone wall. This wall is pretty uneven and I was wondering how well the levelers work.
  • Royboy
    Royboy Member Posts: 221
    edited March 2010
    anyone tried

    this kind of bit

    with a rotary hammer? I have a 1" Bosch rotary hammer & was thinking to try this but would prefer not to waste the money if the bits won't do the job. stone can be pretty tough, I know, - I was just thinking of using this for block or concrete ...
  • Chris S
    Chris S Member Posts: 177

    I use those type of bits with my Bosch SDS max for drilling 2" oil lines.  block is a piece of cake,  concrete can take a while,  stone will be difficult.   I'd be hesitant to buy that on ebay, asI'm used to paying over 200 for good bits.  Kinda like some of the mail order tools, thay look good in the flier...
  • Royboy
    Royboy Member Posts: 221
    yeah, I know

    sometimes eBay can be a deal, sometimes a waste of money

    where do you get yours?
  • TonyS
    TonyS Member Posts: 849
    Thin wall cores

    for a hammer drill. I have them for a sds hammer drill. I use it for 2 and 3 inch holes in block and brick for vent terminals. They work ok for the softer stuff but they always break out the back of the hole. The nice thing is they fit in a lightweight hammer drill that is easier to hold on a ladder. I tried them in a hard stone facing and it took forever.
  • EricAune
    EricAune Member Posts: 432
    They are nice

    I too, like Chris use this set up with my Bosch.  I have even gone as far as wearing them out, then having the carbide teeth replaced.  Nice option.  They are available at most reputable tool centers.  Don't let the cost deter you too much if you already have the drill, they last a long time and are a cheap alternative to standard core drill.  
    "If you don't like change, your going to like irrelevance even less"
This discussion has been closed.