recycled propane tank oversized derby hat

http://www.frontiernet.net/~wwixon/propanetankderbyhat.jpg
i don't think i've showed this to you guys before, did i? i started this months ago, and haven't worked on it for months. i was
holding out till i had it finished and installed before posting a picture of it here, but god knows maybe i'll NEVER finish it. the idea was to bolt/chain it to a (four foot tall) boulder that i erected near the road in my front yard, kind of a goofy take off on "mr. potato head". i still have to complete all the welding, right now it's just dozens of tack welds, and i wanted to put on a hatband, i cut out the hatband but have to attach it...
(long version...)
....and then weld on some sort of anchor to attach a chain. (i'm sure it's going to be, at least attempted to be stolen, more probably it *will* be stolen). i'm thinking maybe something like a 3/8" thick wedge of steel welded to the inside top of the hat, then a 2' long section of (tempered?) chain, maybe with a 1/8" stainless cable threaded through and swaged on the ends. the thing i'm having difficulty imagining is how i'm going to (vandal proof) attach the chain/cable to the boulder. thinking using a hammer drill and drilling 2 or 3 1/2" holes and putting in lead anchors and use 3/8" lag bolts and maybe buttering it up with some epoxy before bolting it to the boulder? round off the lag bolt heads with a grinder. i'm worried it's going to be SLOW going with my hammer drill, maybe NO going(?), maybe going through several carbide bits to drill solid stone? any suggestions on how to get a secure vandal proof attachment? i don't want to bolt it directly to the boulder, i'm thinking that'll be a temptation for someone to try to pry it loose with a crowbar and bend it all to hell in the process. central part of the brim is thinner (made from a recycled water pressure tank) than the propane tank part and so it'll be easily damaged if someone tries to pry it loose. i just don't think it would be as nice visually (bolted directly) than if it were kinda "loose" (on a chain hidden under the hat) from the boulder. i am a little worried about the "attractive hazard" (or whatever it's called, legally) aspect of having this thing bolted to a boulder in my front yard. oh, and i'm afraid some jerk is going to try to put a chain on it and try to yank it loose with his truck or something, maybe tip over the entire boulder.
well, i just wanted to show you guys. it didn't occur to me to ask you all for suggestions till i started typing this message. any suggestions?
b.w.
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William Wixon wrote:

Nifty!
How about a few lengths of aircraft cable welded to the inside of the brim and epoxied into the boulder?
Your rotary hammer would make the holes post-haste.
--Winston
--

On YouTube, all the tools have volume controls.

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On Mon, 23 Nov 2009 23:29:38 -0600, "William Wixon"
vERY VERY COOL!
hummm...have you ever heard of something called a Claymore Mine?
They are quite easy to make impromtu...and really prevent folks from sucessfully stealing anything and getting away with it.
Do you have a backhoe as well? You might need one...
Gunner
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On Mon, 23 Nov 2009 23:29:38 -0600, "William Wixon"

<Snip>
First, I must disabuse you of a silly notion - There is No Such Thing as Vandal-Proof. Period. Don't even use the term, because you aren't even fooling yourself.
You aim for "Highly Vandal Resistant" and go from there - the Vandals see something marked Vandal-Proof as a personal challenge, and will do insane things just to prove you wrong. They will come back later with sledgehammers and torches just out of spite.
You don't tug on Murphy's cape, or spit into the wind.
With the proper carbide impact bit in a proper impact drill, most stone will part like the red sea. You can rent one for a half day for cheap, and you can always trade up to the next size if it won't dent the rock.
If it's a good solid stone like Granite, three or four anchors and attachment points should do it. If you can figure out where to conceal the lead wire up the back side of the boulder, rig it up with a set of burglar alarm contacts like an armored Garage Door magnet and switch. And get a contact with the End Of Line resistor built in. If they lift up the brim of the hat to cut the padlocks and/or chains to steal it, they trip the alarm switch.
And put a tamper switch on the cover of the junction box coming from the house with the alarm circuit, where it transitions to the flexible armored lead going up the backside of the boulder under the hat
If the fool kids try to short the exposed (armored) wires to bypass the alarm "Just like in the movies", they alter the loop resistance and trip the Loop Tamper instead. Use a 24-hour monitored circuit, and let the alarm company know exactly what it's connected to.
--<< Bruce >>--
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On Tue, 24 Nov 2009 01:31:59 -0800, the infamous Bruce L. Bergman

tanks, take their gallon and go, letting the rest melt your asphalt. I almost couldn't believe reading that in the paper. :(
-- It is not because things are difficult that we do not dare; it is because we do not dare that they are difficult. -- Seneca
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wrote:

A friend of mine said in his younger days in the navy, they would find a car broke down along the road and take a chisel and punch a hole in the tank and drain in to a wash tub for fueling their cars. One time they pull up behind a car and when punching the hole, a guy ane gal pop up from the back seat. They left the hammer, punch and tub in the haste to escape.
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Bill McKee wrote:

Keep an eye on him. Bob
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of
in
have
i
it's
the
(vandal
drill
the
going
central
than
pry
directly)
my
on
the
all
Belt and suspenders solution.
Inside, weld a couple of cross bars. On top use a hole saw to cut a hole and drill a couple of holes around the rim.
Set the derby on the bolder, transfer the drill points to the rock.
Drill holes in the rock with a hammer drill at a bit of an angle. Epoxy into the rock some rebar or other steel rod. Also drill a couple of holes for rebar inside and put a 90 degree bend in them so they can hook over the rods welded inside.
Bend the rods around the edge to a vertical position after the epoxy sets and trim them so they are even with, or almost even with the rim.
Set the derby in place and caulk anywhere there is a gap around the edge.
Weld the rim holes to the rods and grind flush.
Use the hole in top to pour concrete almost to the top.
Weld back in the slug you cut pit with the hole saw and grind to a nice finish.
Paint, and then place on the top of the dome where only a potential vandal would see it "Smile asshole you are on camera." Even if you don't have a camera, any potential thief will think twice before assaulting the sculpture.
--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
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