Securing a sign

[Matty F]

I'm renovating a sign that's about a metre wide and made of 3mm copper. When it's all polished up I reckon someone will try to steal it.

It has been bolted with six 5/16" steel bolts (with hex heads) into a very large piece of steel that nobody can possible move (weighs about a ton and is welded to a vertical rail concreted into the ground).

It's been suggested that Allen bolts be used instead - the thief would need an Allen key. But I want to think of something better. e.g. locking one or more of the bolts with a padlock. But how?

The existing four bolt heads on the ends can be unscrewed with a spanner but are somewhat covered by the letters on the sign, which are

20mm thick aluminium that is bolted to the copper with 30mm spacers. Those bolt heads are not accessable until the copper is removed.

I'd like to modify the two bolts holding the middle of the copper. At the moment the aluminium letter in the middle of the sign has to be removed to see those bolts, so it's a bit of a puzzle to undo the sign, but a feat which I achieved in a few minutes.

Sure the thieves may damage the sign trying to get it off with a jemmy, but I don't want to give them the satisfaction of stealing the copper, or the aluminium.

A thought that has just occured to me is to use round head bolts in the middle. When they have rusted in and need to be removed in 40 years, an angle grinder can chop off the heads.

[Jethro]

35 years ago, when I put up grilles to protect my Dads business, he said the insurance company insisted the screws be welded to the frame, as thieves were adept at simply dismantling the grilles .....

[Nightjar]

Which they would probably have. There are various security bolts around, but, again, most thieves would be able to lay their hands on the right tools to undo them.

You could use shear bolts:

option might be to use locking wheel bolts for a car.

Colin Bignell

[Matty F]

I think a possible solution is to use six Allen bolts with round heads, and fill the hex hole with epoxy and paint it all with zinc paint. If I need to remove the bolts I can drill out the epoxy. In the dark the scrotes won't figure that out. Before seeing the main mounting bolts they'll have to figure out that one of the aluminium letters has to be removed - the one also with Allen bolts with heads filled with epoxy.

[Thomas Prufer]

I bought a grill fixing set: rounded head bolts, like a coach bolt head, with a Torx hole innit. Came with little soft aluminum plugs that loosely fit into the Torx holes, and a few smacks with a hammer molded them into the holes well. They will probalby drill out easily, and just to pick the bits of plug out of the edges to open.

Other ideas would be left-hand threads, and the fiercer kinds of Loctite. Or a bolt that turns, barely, but doesn't unscrew...

Thomas Prufer

[dennis]

ditto.

Ordinary shutters with motion detecting cctv should be enough if someone looks when motion is detected.

If vandals aren't a problem, internal shutters and an alarm with break glass and motion detectors should do a good job, and can be automatic.

[Dave Liquorice]

But make noise, tea leaves don't like noise.

Depends on the design and material. If the outer case of the locking nut is free to rotate and domed/tapered it makes angle grinding tricky and the dome/taper holding it with something hard. If the material is also resistant to being ground that slows 'em down as well.

Nothing will stop a determined thief. If they can't cut or remove the bolts/fixings they'll angle grind around them and leave you with little bits still attached to the steel back plate.

[Brian Gaff]

Could one ask exactly why its made as it is, and not simply copied in plastic and then the copper sold for your own funds?

Brian

[The Natural Philosopher]

Or my favourite, a left hand thread not screwed fully home on a live round.

[Nightjar]

There is no such thing as absolute security. You are only trying to make life sufficiently difficult for the thieves to go elsewhere.

Manufacturers spend a lot of money developing car products and, if locking wheel bolts were that easy to bypass, there would be a lot more missing alloy wheels.

I assumed that a 1 metre wide copper and aluminium sign was going to be outside somewhere.

Colin Bignell

[Matty F]

It's a museum with lots of heritage items in it, so everything has to be genuine and original if possible. I don't suppose there's much plastic anywhere.

[Matty F]

Yes it's outside at chest level, right by a 100 kilowatt transformer. Hmmm, That gives me an idea!

[dennis]

Well yes, but he did say he was repairing it and not fitting it. I did think it was a lot of worry if it was inside, or just worth a lot? I also wasn't paying much attention to the rest of the thread only a specific post.

[dennis]

Its actually quite easy to remove most alloy wheel locking nuts, but I won't go into that in an open group or there will be a lot of missing alloy wheels. They deter casual theirs which is all you can hope for.

[dennis]

We had a bit of looting and riots near one of my work places a couple of weeks ago. there is a substation behind and they were working on it. Jokingly I asked if I could connect the 4kv to the shutters. they left a reel of cable and said don't use the yellow phase as there is a fault they are working on.

I didn't do it but I was tempted. 8-)

[Owain]

Is it possible to

(a) cover the sign with motion-detecting CCTV (and have it email/SMS alert someone if there sin't continuous monitoring)

(b) run an alarm cable/sensor through the sign and the sign-posts and connect it to the security system. You can get brittle wire which is run through the middle of window bars and fractures if the bar is bent or cut.

Owain

[Peter Parry]

Or drill out the hex pert of the head so there is nothing to attach to.

Don't you have a girt big riveter in the museum workshop though? Slack handful of boiler rivets should do the job.

[Part Timer]

Google for "locking wheel nut removal"? (Dennis thinks he _IS_ Google).

[dennis]

No need for the insults, I have nothing to do with google and seldom google anything other than prices if I am shopping. Google is full of cr@p which you should know if you use it.

[dennis]

Not if they are just metal thieves, the copper will tear easily if they put a bar under it next to the bolts.

If its on display then covering it with a cage made from weld mesh would be pretty secure. You can bend the mesh and put the bars through holes in the wall and weld a washer on the back to stop it being removed.