Mounting an aluminium sign

[Jason Judge]

Hopefully an easy one: I am going to screw an aluminium sign to the keystone next to the front door of our office. It is right on a public footpath, so will be seen right up close, and will probably be touched by kids as they walk by (from a local school - they are always knocking on the door and running away, oh the wags).

Anyway, two things that occur to me:

1. What would look good, won't leave sharp points, and could not be easily removed or fiddled with?

1. Being an aluminium plate, I assume I can't use any other kind of metal that would touch it due to an electric reaction. Is there any metal that *is* safe? Chrome? Brass? Aluminium screws?

-- Jason

[Malcolm]

Mount it on a wooden base - hardwood/pressure treated softwood/WBP ply or Marine ply and fix the wood to the wall

Malcolm

[Jason]

What would be the reason for this? There are two keystones - one either side of the door about handle height - that are a couple of inches bigger than the sign, so it does not need to span any gaps or concrete.

Even if I did use the wooden panel, I still have the issue of what type of screws to use. The sign already has four screw holes, on in each corner.

What the hell, here's the front door:

keystones (or whatever they are really called) are the grey squares.

-- Jason

[dave]

That still leaves the original question open, what screws to use to prevent corrosion.

What I would do is to find some plastic (not sure what to call them, you find them made out of brass, or brass plate that you use to screw countersink screws in and leave a slightly raised, but smooth fastening.)

Make sure the holes are big enough, so as not to contact the aluminium and everything should be fine.

Dave

[Spamlet]

Whatever you do, the kids (or 'scrap' metal tea leaves) will soon have it, if they can reach it. Get a mason to inscribe your keystone. Much nicer anyway.

S

[The Medway Handyman]

Pan/round head Pozi screws - put them in with a driver.

I don't reckon thats a problem in practice. I wouldn't worry about it. You see loads of ally signs & steel screws around.

[Jason]

Nice idea - never thought of that.

[Dave Plowman (News)]

Fit small PVC grommets to the sign to insulate the screws from it. Maplin sell assorted packs.

[Nightjar]

Cadmium, not that you can get cadmium plated screws anymore. However, stainless steel will do for all practical purposes, unless you plan to take your office to sea.

Colin Bignell

[Andy Dingley]

Aluminium isn't too bad for this, unless you use cheap stainless screws (a bad combination). Best approach though is to use plastic washers. Easiest washers are those for numberplates - plastic washer beneath, snap cap over the top.

Auminium sheet isn't worth so much that thieves will stop to unscrew a small sign in an obvious place, but you might still like to use clutch- head screws.

If it's really big, use studs instead of screws. These are also easy to mount with resin fixings into drilled stone, especially when the hole is a hundred years old and already on its tenth sign. Then you lift the sign into place over the studs, which is rather easier than holding it up whilst you mark and drill screws. A bit of heatshrink over the stud threads stops corrosion adequately. For nuts, use the conical shear-off security ones. They can't be removed (angle grinder) and they a bit nicer than hex too. Screwfix etc. sell all the bits.

If you use brass or stainless acorn nuts for the very best looks, these need to be crossdrilled and pinned afterwards, or maybe just Loctited. Kids might not steal the sign, but they _will_ have a go at the shiny nuts. I'd keep a few spares around too.

[Jason Judge]

We are at the coast, so we are *nearly* at sea. When the storms arrive, it does bring a lot of salt half a mile or so inland - you can see it on car wind-screens.

-- Jason

[Jason Judge]

Thanks! Plenty for me to go through there.

The acorn nuts I think are just too big and bulky (this is a small sign, about the size of a laptop screen). The stone *is* 100 years old, but has never had a sign on it before, but I suspect it has had its share of bell wires in its time.

Clutch-head screws, some heat-shrink where the screw goes inside the hole in the sign, and number-plate washers are beginning to sound like the way to do. I'm also looking for a stone mason to inscribe it first, but it is probably not worth the expense.

I'll post a picture when it's all done - you have ALL be MOST helpful :-)

-- Jason

[Dave Osborne]

Stainless security screws.

e.g. eBay 320421832522 or 220477941260

[Nightjar]

In that case, I would be more worried about the effect of the salt on the sign than that of electrolytic action. However, if it has been well anodized, neither ought to be a problem. If you are really worried about the screws, insert them through a thick piece of polytheme and trim it off around the screw head.

Colin Bignell

[Spamlet]

you're welcome,

S