Fixing stone to stone

[ven]

How could I fix a stone or reconstituted stone block approx ten inches by 4 inches by one inch thick, with a carved dedication on one side, to an Ancaster stone church wall?
It would need to be vandal-proof.
Mirror plates are ugly and will show and rust if steel, if the screws are stainless steel they will show bright for evermore. Small brass mirror plates could easily be hand-made but that still leaves the screw problem.
Could the supporting stone wall be chiselled reasonably flat and a modern adhesive used between plaque and wall?
The supporting wall is of a crumbly sedimentary stone so perhaps an intermediate thin perforated (for the adhesive to anchor to) brass plate, Rawlplugged to the wall then a modern adhesive between the plate and the back of the plaque?
If that was successful it would be for life!
Advice, please, and thanks.

[John Rudd]

You could drill part way thru the stone with a masonry bit, into the wall, use stainless bolts secured with a resin based adhesive type bond.....check out the range of materials that Screwfix do....like this...


http://www.screwfix.com/c/screws-nails-fixings/resin-fixings/cat840022

[ven]

I should have said that the plaque hasn't been drilled, it is perfectly plain.  I didn't have any input into the design - I would have thought that a couple of fixing holes are essential.
Nowt so queer as folks.

[Pete.]

One inch thick is hard to work with, very easy to break when drilling or blow the front out if you drill the back. I would use a bush hammer to prep the wall as flat as possible then glue the plaque to it with a resin such as Hilti HIT 200 which is light grey coloured so won't look out of place like the coloured epoxies. If you edge the back of the stone plaque with some kind of removable trim like a foam strip say 10mm wide you could remove that afterwards to leave a tidy edge and make the plaque look like it's 'hanging' but with a good solid backing so it can't easily be busted off.

[BaronJ]

I would make sure that the area of the wall is as flat as possible by letting a secured metal plate into it then securing the plaque with a suitable adhesive.  If the metal plate is slightly below the stone surface then it could be made to look like the plaque is part of the stone.

HTH.

[Stilldrillin]

Some thirty years ago. I fixed several brick sized, silly face tiles, to my concrete garage wall. 

Using ordinary silicone sealer. Held in place for a couple of hours, using a clothes prop.

They're still fixed solid........... 

David D

[ven]

Thanks very much for your advice
Ven

[lordedmond]

Ven

Just get some mashed potato that will fix till the end of time , sorry just joking

What I would do is to drill the wall for rawlbolts fasted two washers a small one then a fender washer to make a key, do four times , then get a builders adhesive the two pack is best you may have to make up a frame round the plaque to contain and temp fix till set.

As you stated its crumbly so you need to get into a sound part

Stuart

[Will_D]

It would need to be vandal-proof.

Therein lies the challenge.

If a plaque has a visible gap or a line of soft silicon or why. then the b'tards will try to lever it off!