I want to find the "easiest" way to drill holes straight through metal
posts that are filled with concrete.
I have 14 metal fence posts that have been filled with concrete. I've
found that this setup is sometimes called a Lally or Lolly column.
I want to wrap these posts with cedar, to make them look like regular
wooden fence posts. My plan is to drill a hole directly through the
lally post at 1/4 and at 3/4 of its height. (2 holes per pole.)
Then, I plan to sandwich the post with 2x4 cedar and run a bolt
straight through the holes. I think that will be strongest way to
build the wooden post using the existing poles.
Everyone I've talked to has said this is a good plan, but that
drilling though the lally post will be very time consuming.
I have not tried to do one yet, but would like to find out if there is
a "best" way to approach drilling the holes.
Doing research online I have found 3 different suggestions.
1) Use 2 drills. Drill through the metal with a standard bit, then
use a hammer drill with a carbide bit to get through the concrete,
then switch back to the metal drill once I reach the far end of the
post.
This sounds tricky to do without dulling the metal bit. I'm sure I
will always hit the concrete as I'm drilling through the first side of
the pole. I'm concerned the metal bit will be dulled every time I hit
the concrete. I wonder if this approach is the best solution, and I
just have a dozen extra metal bits handy.
2)Use a hammer drill with a carbide bit for the entire hole.
I've seen suggestions that this would work -- but also lots of posts
saying this will not work, as the carbide bit will not get through the
metal.
3)Use a regular drill with a metal bit for the entire hole. This will
be slow, but should work it seems.
Again, I'm not sure about the dulling the bit issues, as well would
not want to spend 30 mins per hole, since I have at least 28 holes to
do.
I have also seen various suggestions around starting with a small bit
first, then working up to a larger bit. I'm not sure if this approach
is recommended, or if it's just a time-waster.
I am willing to rent tools and buy bits (within reason) if it will
make a large difference in the amount of time or effort it will take.
Please ask if you need more information! |
Clarification of Question by
cgorgon-ga
on
08 Mar 2006 16:20 PST
This is the first time I'm using Google Answers. I don't know how to
change the expiry date. I'm looking for a quick reply if possible. A
quick incomplete answer will be better than a long one that comes in a
week later.
I don't need a comprehensive answer, just one that gives me a good solution.
Thanks.
|
Request for Question Clarification by
denco-ga
on
08 Mar 2006 19:39 PST
Howdy cgorgon-ga,
You are looking at too much work.
Route a flat shallow groove, one at the top and bottom, around the exposed
sides of the wood used to wrap the posts. Use some metal strapping or wrap
baling wire around the posts, placed in the grooves so they stay in place.
You can get fancy and cover the clamp/wire with a piece of rope, etc.
Looking Forward, denco-ga - Google Answers Researcher
|
Clarification of Question by
cgorgon-ga
on
09 Mar 2006 12:23 PST
Hi Denco,
I like the idea of your suggestion. It does seem to be considerably less work.
My concern would be strength of the the post. I maybe didn't make it
clear that the end goal is not just to have wrapped posts so these
metal poles are no longer eyesores, but to then use this wrapped posts
to build a normal wood panel fence.
Do you think using your proposed technique, it will be strong and
secure enough to build my fence? It seems to me there would be too
much torque to make that approach strong enough?
|
Request for Question Clarification by
denco-ga
on
09 Mar 2006 15:48 PST
Howdy cgorgon-ga,
Shouldn't be any real problem. Most certainly use metal strapping with
multiple fasteners into the 2x4 "sandwich" wood. Make sure to place the
metal strapping under stress as you fasten it in place, and overlap the
strapping with a fastener through the overlap. You would want to place
the strapping at the 1/4, 1/2 and 3/4 locations. You would then attach
your fence runs as one usually would.
You might have to offset the fence 1/2" either to the front or the back
in order to make sure you are getting enough "bite" for the fasteners.
Looking Forward, denco-ga - Google Answers Researcher
|
Clarification of Question by
cgorgon-ga
on
10 Mar 2006 14:14 PST
Thanks Denco!
The more I read, the more I like your idea. All the other comments as
well have made me realize that drilling and bolting is not a good
idea.
I'm not clear on some of your comments -- but I'll get my tool rental
place to give me a rundown of techniques as well.
My current rough idea (in case anyone following the saga is interested) is:
- dado a shallow grove onto the face of the 2x4s
- sandwich the metal fence post with Two 2x4s
- metal strap these 2 pieces together
- nail in 1x6's across the "open" face of the post (covering the open
side of strapping as well)
That hopefully gives me a strong fence post (that roughly looks like a
6x6 post) that now I attach my fence panels to (attached to the
strapped 2x4s)
IN THEORY! ;-)
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Request for Question Clarification by
denco-ga
on
10 Mar 2006 15:05 PST
Howdy cgorgon-ga,
Yep, you got it visualized perfectly. I would use galvanized screws instead
of nails to fasten the 1x6s in place. Optionally, you could lag the 2x4s in
the sandwich instead of strapping them, but you've the idea.
Report back here your results, and I can then "formalize" your answer for you,
if the results are positive. Thanks!
Looking Forward, denco-ga - Google Answers Researcher
|
Clarification of Question by
cgorgon-ga
on
13 Mar 2006 15:00 PST
UPDATE:
The saga continues, but with a happy ending.
I went to rent the strapping and tools, and was told to abort the
strapping option. The metal strapping is only painted, and will rust
over time. It also apperently isn't made with long term applications
in mind.
They suggested that if I searched, I should be able to special order
galvanized strapping from somewhere, but still he suggested that even
if I could find the strapping, it would be a sub-optimal solution.
With 3 of us standing around, scratching our heads, the "obvious"
solution revealed itself. We didn't have to drill through the metal
pole and bolt to it, we could drill through the wood, on each side of
the metal pole, and bolt the wood to each other.
We sandwiched a pole with two 2x4s, tested "clamping" it with 4
carriage bolts (2 near the bottom, and 2 near the top) - and it was
extremely tight and secure.
As an extra bonus, we discovered that "rough" cedar 2x4s are actually
a bit larger than regular 2x4s -- so the total "open side" span was
just under 5.5" (not the 5" it would have been if it wasn't "rough").
This meant our 1x6 cover board didn't need to be ripped down. More
time saved!
So. There you have it.
Thanks to pugwashjw65 for providing what seems to be the best answer
to my original question.
More thanks to everyone else for realizing that I was asking the wrong question!!!
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Request for Question Clarification by
denco-ga
on
13 Mar 2006 19:20 PST
Howdy cgorgon-ga,
For whatever it is worth, please note that my last posting stated:
"Optionally, you could lag the 2x4s in the sandwich instead of strapping ..."
Looking Forward, denco-ga - Google Answers Researcher
|
Clarification of Question by
cgorgon-ga
on
14 Mar 2006 12:18 PST
denco - i am definitely willing to accept your answer. :-)
It was the process of discussing it through here that definitely helped!
|
HI Cgorgon,
If you haven't used a hammer drill, I can understand your plan to do
so, but to avoid total frustration I would suggest that you drop the
idea. And, as mentioned, it would be very difficult to line
everything up straight, two 2x4s on 14 fence posts. Its bad enough
just trying to bore two holes in the right place for a horizontal
shelf (for me, not for Retbuilder, I'm sure).
Since you mention 1x6s, I would understand the the posts are 2 inches.
If so, then you only need 2x2s instead of 2x4s. Draw a sketch for
yourself to be sure.
If the posts are 4 inch, you need 1x8s to cover the open sides. You
don't want any free play (though this could be eliminated by inserting
blocks of wood to fill the space), and you don't want any shortage.
Planed 2x4s will probably have slightly smaller dimensions, causing
gaps when add the 1x6s (sticking with your dimensions).
Now that I understand that fence panels will be hung on them, you need
to use screws to fasten 1x6s. When you are sure of your measurements,
you can put together 3 sides of each post at your work bench, rather
than doing all the work at the posts. Infact, you may be able to
complete them and slip the over the posts, leaving the screws on one
side only have set and tightening them on site.
The problem with this method is that the wood will be resting on the
ground (less of a problem if it rests on the concrete footing of the
posts. Maybe this can be avoided by letting the four sided wooden
post hang from a cap that rests on the top of the steel post. Of
course then, it must be fastened with good screws and not just nailed
in place. You will need a cap in any case.
Well, that is the way I would do it, if I am envisioning the situation correctly.
Good luck, Myoarin |
