What's the best way to punch a 2" hole for a drain pipe through a cinder block wall?

Page 2 of 2  

<stuff snipped>

So far, it's a once in 25 years job so I think HF might do the trick. I will have to cut some smaller holes to mount an HDTV antenna and rotor in the next few weeks, but after that, the block wall should be safe for another 25 years. Thanks!
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Having used a 3/8" and 1/2" hammer drill and concrete bits before several times and also gone the 'rent a real rotary hammer route, it will be the rotary hammer from now on. A few minutes with one of those beats long sessions with a hammer drill.
Harry K
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

the 70 buck harbor freight SDS one works fine for occasional use.....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Decisions, decisions. So far, the use interval has been 20 odd years and I don't really need another tool to store but if it's dramatically faster, I might just rent one on a day I need some other rental tools as well.
Thanks for the input
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
news:0ead0499-8924-4079-b4cc-
<stuff snipped>

<<Having used a 3/8" and 1/2" hammer drill and concrete bits before several times and also gone the 'rent a real rotary hammer route, it will be the rotary hammer from now on. A few minutes with one of those beats long sessions with a hammer drill.>>
Here's what I googled about rotary hammers:
http://www.lowes.com/lowes/lkn?action=howTo&p=BuyGuide/buyingguidedrill.html
is only vaguely helpful, and http://en.wikipedia.org/wiki/Rotary_hammer_drill wasn't much help either. How MUCH faster would you say it takes to bore a 2" hole with a rotary hammer than with a hammer drill?
Thanks,
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
news:1583afa4-82f9-4b4b-ad0b-
<stuff snipped>
<<Excellent points. The worry about 'crackign the block' is no biggee. The likely hood of making a tight fitting 2" hole without using a core drill is zero so it will have to be patched in any case. I have done the BFH route and patched the remains later, used a 3/8" hammer drill and small concrete bit and probably a few other methods. If I ever have to do it again it will be 'rent a real electric hammer and decent bit, drill a ring of holes and knock out with hammer' Of course being careful to miss the web.>>
It's beginning to look like renting the right gear is the way to go. Thanks!
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

cinder
blocks
You are probably correct. It has the very rough and granular texture I associate with cinder blocks, but I'm not quite sure how to tell the difference without a hardness tester.

you
some
Newer
the
House was built in the midst of war shortages in 1942, if that helps. There's also a section where the block has heaved so I can get a better idea what I am dealing with by inspecting that section of the wall. I believe it's open enough to make the two/three determination.
Thanks for the input.
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1940s --- I would venture that you have 3 core blocks, they started cutting back on the concrete used in the 60s.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=41983
costs a bit more but well worth the money, makes a multi hour star drill job a 5 minute no work event.........
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<stuff snipped>
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?ItemnumberA983

I had already put the much cheaper ($29):
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberE338
in my cart but now I am not so sure. I need it to make one hole. I have some masonry bits but I assume they may not be for hammer drills. The unit you recommended has a bit pack with it, and a brush and the rubber cup design looks more protective of the drill. I am not sure that matters, though, since I will be drilling and my helper will be using the shopvac to catch what probably will be substantial debris. Both are made by Chicago. One's a 1" and the other's only 1/2" and one weighs 5 pounds and the other 10. The thirty dollar price difference buys me this carbide hole saw:
http://www.westerntool.com/product.htm?pidB9588
Decisions, decisions.
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

and hit the center core.

drill in the

they
cutting
I'm not so sure what I've got. As I recall from the rupture, these blocks were much darker, almost blue in color. The way they broke open under the basement window sill does not speak to a strong cohesion, either. They are definitely darker and more granular than the grey blocks you find at the BORG. IIRC, they are smaller than your average concrete block, but I've not had a lot of experience with them. Looks like stone flakes pressed together. When I get home, I'll take some pictures of the ruptured area and post them.
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

See why learning history is so important, kids? Thanks for this mini lesson!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

As a certified old fart, I have a wealth of useless information clogging up my brain. Trivia that I rarely get to use except for the rare occasion.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

You'll enjoy this article if you haven't read it already (it made my 75-yo father feel really good): http://www.nytimes.com/2008/05/20/health/research/20brai.html?scp &sq=brain&st=nyt
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

They make 2" masonry bits for hammer drills. Drill each side instead of drilling all from one side. This is what causes blowouts.
Just a reminder, if it is a 2 inch pipe, the bit needs to be at least 2.5.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

to
or
They make 2" masonry bits for hammer drills. Drill each side instead of drilling all from one side. This is what causes blowouts.
Just like drilling through wood like that causes splintering. Excellent advice, thanks. I have a masonry bit with a small diameter (3/8" IIRC) and an 18" long shaft that I thought I would drill through first to give me a center hole for the hole saw guide bit on each side.

Already factored in. It's 1.5" pipe.
Thanks!
-- Bobby G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 3 Jun 2008 23:37:02 -0400, "Robert Green"

I've only done this once. Used a star drill and small sledge. Worked fine if a bit slow, IIRC. Block did not crack. FWIW YMMV
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.