Cracked the windowsill made of marble, glue it together?

savio · 20 Dec 2009 at 9:42 PM

I accidentally cracked one of the marble window sills when I dropped it on the floor, which feels really unfortunate q(;^

p

Since the edges are reasonably intact, I think it will still look okay if I manage to glue them together. The question is just how to go about it?

I have a tube of PL400 lying around, which I know many say works for most things.

savio · 21 Dec 2009 at 11:36 AM

No tips?

I was thinking of trying to clamp the edges with a screw clamp after applying a generous amount of PL400.

Then maybe gluing a steel rail on the underside over the actual joint to strengthen it further.

Am I completely off track or could it work?

Avemo · 21 Dec 2009 at 11:49 AM

I would rather try some form of epoxy. PL400 will probably show as a colored crooked dull stripe in the joint. I have no experience in gluing marble, but epoxy tends to be strong. The type of epoxy you buy in boat accessory stores is better than fast-curing universal products.

There's not much to lose. Glue is cheaper than a new marble countertop. Sometimes marble countertops are sold on Blocket.

Erik

Mikael_L · 21 Dec 2009 at 12:34 PM

You might want to do some more research on which glue is suitable.
Personally, I think Cyanoacrylate glue, but I'm not at all sure about this.
Otherwise, something 2-component curing like epoxy of some variant.

Can't you call a stonemason, gravstensmakare, or someone similar?

Please let us know here what you find out and how everything goes.

savio · 21 Dec 2009 at 12:40 PM

Mikael_L said:
You might want to research a bit more about which glue is suitable. I myself think of cyanoacrylate glue, but I'm not at all sure about this. Otherwise, something 2-component curing like some variant of epoxy.

Can't you call a stonemason, gravestones maker, or something like that?

Please let us know what you come up with and how everything goes.

Hmm sounds advanced

The problem is that I have so much else to do and don't have time to make this a big project. The thing is also that I'm going to paint the surface anyway, so I can probably paint an ugly transition nicely. Don't you think PL400 would work?

Mikael_L · 21 Dec 2009 at 12:46 PM

I think PL400 is too soft an adhesive.

edit:
It depends on how it is broken. Is it a small corner that has chipped off, or is the board broken in the middle and the glue joint will be subjected to significant stress?

If you smear PL400 there, you might have gone too far for some other adhesives.

pinebar · 21 Dec 2009 at 1:00 PM

I did the same thing with an old Kolmårdsmarble windowsill. I took it to a stonemason. They milled grooves on the back, glued in reinforcements, and glued the slab together. They also polished it. It wasn't noticeable at all afterward. So my recommendation is to check with a stonemason to see what they would charge to put your slab back together.

savio · 21 Dec 2009 at 2:14 PM

Mikael_L said:
I think PL400 is too soft a glue.

edit:
It depends on how it's broken, is it a small corner that's chipped off or is the board broken in the middle and the glue joint will be subjected to significant stress?

If you smear PL400 on it, you may have limited the options for other glues.

The board is completely broken, the breakpoint is at one edge so one piece might be 30cm while the other piece might be 150cm.

Certainly, the glue joint will be subjected to stress, but I also think it's quite close to one of the total 3 windowsill brackets.

savio · 21 Dec 2009 at 2:15 PM

pinebar said:
I did the same thing with an old Kolmårdsmarble windowsill.
I took it to a stonemason. They milled grooves on the back, glued in reinforcements, and glued the slab together. Additionally, they polished it. It wasn't noticeable at all afterward. So my recommendation is to check with a stonemason to see what they would charge to put your slab back together.

I'm convinced they would solve it well, but at the same time, I think it might be expensive. I'll call and see if I can reach someone.

savio · 21 Dec 2009 at 2:22 PM

Called a stonework company but they thought it sounded too advanced to mill in reinforcements and such.
They thought it was better if I glued it together myself.

Use some common epoxy glue they said.
Where can I get that, I asked, to which he replied: at a gas station.
I guess they mean something like this:
http://www.kjell.com/?page=/kjellfakta/lim/

Hmm, should I dare to try it?

Avemo · 21 Dec 2009 at 3:37 PM

I think the result often turns out better if you use a variant that cures slowly. Clas Ohlson has a version of super epoxy that cures in 4 hours.

http://www.clasohlson.se/Product/Product.aspx?id=59032852

Are you able to put it under tension in some way? I would apply epoxy to both surfaces and ensure there are no bare spots. Then assemble and leave it under tension overnight without moving or loading it at all. Do not wipe off the excess, but let it cure and then remove it with a chisel. If you get fast-curing that claims to cure in 15 minutes, let it still sit under tension overnight. Full strength never comes in 15 minutes for epoxy.

pinebar · 21 Dec 2009 at 3:41 PM

savio said:
I am convinced that they would solve it in a good way, but at the same time, I think it could be expensive. I will call and see if I can reach someone.

It depends a bit on what type of stone it is. Naturally, it might be cheaper to buy a new one instead. I had all window sills in the old model of Kolmårdsmarmor, which is difficult to get new, so I thought it was worth repairing. But a new one from one of the types available at Bauhaus will probably be cheaper.

savio · 21 Dec 2009 at 4:45 PM

Thank you for your answers!

I have now purchased the glue I linked to earlier.
http://www.kjell.com/?page=/kjellfakta/lim/

I will test it and see how it goes.

But I'm considering reinforcing the gluing with something on the underside that won't be visible anyway?

What would be suitable there?
Do you think fiberglass fabric would be of any use at all?

Pysslarn · 21 Dec 2009 at 9:30 PM

savio said:
The thing is also that I will paint the surface later anyway, so I can probably paint an ugly transition nicely.

Sorry but I don't understand anything... Are you going to glue together a window sill made of stone and then paint it? I probably misunderstood you but feel free to clarify your intentions.

Best regards
Ronnie

savio · 21 Dec 2009 at 10:12 PM

Pysslarn said:
Sorry but I don't understand anything... Are you going to glue together a windowsill made of stone and then paint it? I probably misunderstood you, but feel free to clarify your intentions.

Best regards,
Ronnie

That's correct!
The windowsill is made of marble and is brown and incredibly ugly, so it's going to be painted white.