Restoring a broken gravestone advice.

[mart]

I am planning to attempt the restoration of a headstone that has broken in to many pieces. The average size of these pieces may be only 5" diameter.

It dates from the 1800s and the material is actually stone, as opposed to granite or marble.

The first job would be to take plenty of photographs. As the gravestone is laying flat on the ground face up, the individual pieces are still in the correct position, with small gaps where the cracks are.

I would use a piece of 18mm ply with a few pieces of timber spaced across the underside of the ply to brace & prevent flexing.

Then lay the individual pieces of stone face down in posotion on the ply. Screw some pre drilled 4x2 all the way around the stone thus clamping them in a "frame"/shuttering.

Mix some quick drying concrete adding black cement colouring to this first part of the mix, in case any of the mix should permeate through the cracks towards the front side. Then, while still wet top up with enough concrete and smooth off.

Any tips advice or suggestions appreciated.

 

[slim_boy_fat]

Wonder about drilling & pinning for reinforcement, but maybe the parts are too small?

 

[Ton-up]

I have repaired a few stone garden ornaments using stainless rod resin-fixed in. I also used resin-fix as a 'glue'. Worked great, but you might see a grey line.

 

[Robotstar5]

Write a number on each piece in chalk and take a picture "just in case"?

 

[MattH]

I'd of thought epoxy would be better suited as mortar/concrete is not really a glue.

 

[arther dailey]

cement on its own will not really be good enough, drill and pin as suggested, stainless studding gives a good grip to the resin mix, I have used gorrilla glue but be warned it foams and expands pushing the joints apart,this can leave an ugly line at the joint,if not clamped properly, so its better to hollow out the centre slightly to allow resin to infill and grip.and not blow out of the joint.the gorrilla glue is certainly strong,but the stone needs to be solid to start not crumbly.
Obviously there are many types of specialist epoxy, be aware some can only be used on dry stone,where as others need it to be damp.

 

[mart]

I think most of the parts would probably be big enough. I fear that with the age of the material-(say 1840, that is over 170 years old) it may not stand up to even small diameter holes being drilled with the vibration etc?.

You don't get a 2nd chance really with this sort of thing.

 

[mart]

cement on its own will not really be good enough, drill and pin as suggested, stainless studding gives a good grip to the resin mix, I have used gorrilla glue but be warned it foams and expands pushing the joints apart,this can leave an ugly line at the joint,if not clamped properly, so its better to hollow out the centre slightly to allow resin to infill and grip.and not blow out of the joint.the gorrilla glue is certainly strong,but the stone needs to be solid to start not crumbly.
Obviously there are many types of specialist epoxy, be aware some can only be used on dry stone,where as others need it to be damp.

But won't the cement / concrete stick to the back of the stone pieces like 'the proverbial' to a blanket?

 

[mart]

I'd of thought epoxy would be better suited as mortar/concrete is not really a glue.

Maybe I could use a coating of epoxy on the mating surfaces of each piece of stone? Then when hardened & dry fill the frame up with concrete?

As Arther D mentions, there are many types of epoxy resin.

I think I am going to need to do my homework on this one, and look at bit deeper in to it.

Professionals tend not to like to share their secrets accrued over many year's experience.

 

[mart]

@arther dailey: when you say stainless studing, do you mean something as basic as 6mm stainless threaded rod for example? Or, is studing a bit more elaborate than that?

 

[GW8IZR]

I did 'er indoors great grandfathers stone a good few years ago, whilst hilti will not give you any specification for 'sticking' stuff with their resin mortar it does work and hasn't suffered any subsequent frost damage. This includes slate parts which isn't easy to bond to. If you drill and pin for strength the pins do not need to be big or strong, a small stainless wire in the resin makes a big difference. Critically they must not corrode bursting the joint.

 

[CompoSimmonite]

Check with cemetery what you are allowed to do first. Some church's might require permission before work starts.
My mother died in 1969 and no headstone ever placed on the grave by my father. Despite all the other graves around being polished marble church have said CURRENT rules would apply if I ever had a headstone installed - which I think is matt granite.

 

[dobbslc]

You can drill it with a diamond bit without any hammer action, it should drill quite easily. Epoxy resin and stainless stud should hold it for a good while.

 

[arther dailey]

@arther dailey: when you say stainless studing, do you mean something as basic as 6mm stainless threaded rod for example? Or, is studing a bit more elaborate than that?

yes,the thread gives grip to the epoxy,re diam depends on size of stone really,common sence should dictate that.

 

[arther dailey]

you also have a option of making a stainless frame, like a picture frame, if its a flat headstone,although depends on whats allowed of course, like you say you can only do this one time, re studding dont be tempted to go to big as can cause problems with heat expansion in heat wave weather.and of course use only stainless.
If you decide to make a concrete slab on the back to reinforce there a re specialist addatives that would help , but I suspect it wouldnt be the best long term. If you can find what type of stone it is there maybe a quarry that could sell you some stone dust, this should produce a better finish than mortar when dressing the cracks.
see if you can speak to Sika rep re addatives,adhesives that are suitable, or a firm called Bretts if they are still trading.

 

[brightspark]

@arther dailey: when you say stainless studing, do you mean something as basic as 6mm stainless threaded rod for example? Or, is studing a bit more elaborate than that?

its threaded so gets a better grip so just another name

 

[Kent]

There is a product for this. Its actually stone colour resin
Wracking my brain but the namesn Gone comes in a tub pre mixed

 

[bigegg]

Are you planning to make the cracks a "feature" or to disguise them?
If a feature, I would use a pourable epoxy resin.
There are a LOT of videos on YouTube about using clear, or coloured, epoxy with embedded stones/other stuff to make tables/worktops etc.
It will easily be strong enough with say an inch thickness on the back.
You could add fibreglass matting to reinforce.
Natural stone - I'm assuming sandstone? - is quite porous, so epoxy will "grab" really well.

 

[angellonewolf]

is this to be mounted back in to a chuch yard ? you might need to cheack the rules and regs to whats alowed

a bloke used to come in to our work used to do install those and refurb them as well and there is a lot of reg to what is alowed now stasrted about 8 ish years ago

 

[mart]

@GW81ZR: I have not heard of resin mortar, only epoxy resin. I will do a search of this by Hilti. It sounds like a good substance to use for the type of material I will be repairing.
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@bigegg: I don't want any cracks to show at all ideally, but realistically they will show on the front surface where the written inscription is.

My hope is that the end result will be a vast improvement on the current state of the headstone regardless of cracks showing.

At the moment there are spaces between the broken pieces, not just cracks.
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Drilling: I think selecting the smallest drill bit, using the variable speed trigger no hammer, and going very steady is the way to go. I feel that the stone will be very easy to drill in to. I just hope it does not disintegrate.
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Very valid points made there about church & local authority rules per se.

This small graveyard where the gravestone is, has been purchased by a registered charity, so fortunately no longer comes under the jurisdiction of the aforementioned.

The intention of this charity/group is to preserve, restore, maintain and generally improve this "abandened" graveyard for the benefit of the local community. There is a lot of local history connected to it.

Eventually incorporating a wildlife habitat and having open days for the general public.