Stone Repair

That's a tough piece to deal with. No matter how nice and sound the repair or substrate you'll always be giving it those Gary Coleman eyes.

I've had great luck with lesser flagstone in worse situations and less attention.

Sound ground is the most important prep.

You have a fine plan. Some edge bonding will mitigate potential flexibility.

Pressing high strength repair grout into the crevice will do the same.

"When a man says he's going to do something, he'll do it. The wife doesn't need to keep nagging him every 6 months."

Fifteen years? Man, I thought I knew how to procrastinate.

Can you just flip the stone upside down, and put the side with the thin crack down? If so, you could force the cracked section to break off, and then once it's installed you'll have nothing to worry about.

(Here's where the OP adds more info to the problem...)

It's a long story about how I came to possess these stones, one at a time. (legally)

It's another story about how it took 15 years to have the time to attack a project (has to do with adoptions) that I expect to take much more than a day.

These stone posses unique visual features on one side only, indicative of when the sediment was deposited millions of years ago.

Turning them over is not an option for me.

" ( legally ) "

Notice how legally is in parentheses ?

Like we would of thought otherwise, ya, uh huh, sure !

Maybe the 15 years was a statute of limitations or something,,,

I was going to suggest getting another piece,

But that might take another 15 years.

Is that dinosaur entrails, poo, or what?

I think you would be better off setting up a frame, with top and bottom of steel, then pumping full of grout. Once grout has set, remove frame, and voila, there's your stone, now a rectangle. Use toothbrush, dental pick, etc. to remove grout down to the interesting layer, then finish with thick layer of acrylic. Use for windows 10 treatments.

For paver stones I would go to Sutherland's, or Lowe's.

Heck Lyn, for that matter, what if you very carefully wedged this thing open, what if there is an even more interesting fossil inside?

Is there a treatment for windows 10 disease?

That last one is a really interesting possibility!

Yes, after downloading the Windoze 10, and the laptop or other gizmo goes {poof}, she no worky, you taka de framed fossil, and placa de lapatop on her, and smash er.

Not personally familiar with repair of stone, but have heard of methods that use vacuum to encourage adhesives/fillers to get into small crevices. A bit like windscreen repair that by removing all gas, then the filler/adhesive must occupy all available voids.

Primary suggestion is that thermal expansion rate must very closely match that of the original stone, or else failure will happen in freeze/thaw cycles.

Perhaps you could make the stone crack so that it breaks in large pieces, then use a decorative method of rejoining the stone along the break lines.

The Japanese call this Kintsugi.

What about hydraulic cement? You should be able to get enough in there to at least prevent water from getting in. It's also paintable about an hour after using it so you could match the color of the stone.

I live in the desert, so it never really freezes here. Frost pry is not an issue.

Because of the brittle nature of the sandstone, I'm hesitant to break it, but if it cracks for some other reason, that could work.

Hydraulic cement will seal the edges but leave a space between the fragile top layer and the parent rock which I feel sure would break when a load was applied. I may have the same problem with the thinned epoxy but I think I have a better chance of completely filling the crack if I take my time.

How about completely setting the piece in cement with a 1" to 2" edge around it. You can precolor the cement as you are mixing it or paint it after to match the stone.

I have seen stamped concrete that you have to look twice at to realize it's not stone.

My plan is to tamp the soil level, soak it, then check for level and lay a sand base, then concrete all the joints. I've also considered setting it in mortar and finishing the edges with colored mortar. I figure to do small sections at a time and that would be better than a sand base.

It won't see any heavy traffic so I may do a small test first. We have pavers all throughout downtown and they are all laid on a sand base with a concrete border.

They are also done by experts and I'm just a hack.

I still have to lay out and fit the stones before the first one goes down. I'll do that on the other side of the driveway then lay them one at a time in small groups.

I haven't thought about sealing it, my inclination is not to.

I've had a 3x6' section laid for 10 years and it is none the worse for wear, except where it has settled due to poor workmanship on the installer's part.

I for one would be interested on how it comes out, which ever way you do it. Keep us posted and post pics when it is all done. _{^{Providing it doesn't take another 15 years....}}

The down town pavers are probably laid on sand (or a dry sand/cement mix) that has been compacted with a vibratory tamper. They will also all be the same thickness so laying an even top surface that the public can walk over without "tripping and suing" is relatively easy. Your stone will all be of differing thicknesses and maybe not parallel top to bottom so a simple sand bed beneath the stone is not practical. You cannot tamp the whole area level as the finished surface would have trip points and tamping under individual flags will not be consistent, the flags will settle, move and most likely crack over time. Lay on a 1"-1½" thick bed of soft mortar 6 parts sand to 1 part cement that is troweled into ridges so that as the stone is placed and pushed down the mortar from the top of the ridges is displaced into the troughs and has somewhere to go. Tap the stone down into the mortar with a rubber mallet until the top is at the correct level relative to the adjacent flags. Once the mortar is set this method provides support over the whole base of the flag so it will not rock or crack. I don't know how old you are but I suspect that you don't want to relay this path twenty years from now. A word of caution. Sandstone will erode quite quickly with continued foot traffic. If possible place the patterned features that you want to keep in positions away from immediate footfall.

" I don't know how old you are "

While Lyn has never officially mentioned how old he is,

he has mentioned in many a previous posting that he is an old man,

so that should give you some round about idea of his age,,

I'm almost older than dirt!

No, I never want to re-do this walk.

Lyn, do you have a still in your backyard? Those glasses and that hat make you look like you should be on "Moonshiners".

an uncanny resemblance to Richard Petty...

Petty's hat is fancier.

I'd burn that pimp hat before it'd go on my head.

As to my back yard, I had horses years ago, in Arkansas, and I knew moonshiners then too.

@tonyhemet I can rent a wet tile saw for 4 hours for $35.00., but I an NOT going to saw the stone.

I'd burn that pimp hat before it'd go on my head.

it looks like a Charley 1 Horse. Styles similar anyways.

Nice hat, models.

There were hats in that link?

I was complimenting the models' nice looking hats. But yeah, you got me on that one, those girls would make a cowboy want to settle down on the lonesome prairie.

I was thinking more Willie:

really?, how 'bout this guy?

Lotta ugly under that black sombrero!

Lotta sweet toons tho'

I've decided that one of the musics at my funeral will be "Roll Me Up and Smoke Me When I Die". Feel free to google it.

There is probably enough THC in Ol'Willy to make somebody high if they did smoke him!

I have heard that tune, I prefer Blue Eyes Crying in the Rain.

did someone just lite a reefer?

This will depend on the geometry of the crack:

Tape the edges with a strong tape, leaving a gap for inserting the adhesive on one side and a gap for a shop vac on the other side.

The vacuum from the shop vac will help suck the adhesive deep into the crack. You'll likely need one person to hold the shop vac nozzle while you apply the glue to the crack on the other side.

Maybe tape some cheesecloth over the shop vac nozzle as an indicator the glue is coming through.

One last idea, being sandstone, and sandstone is porous, I would want to seal it to protect it. Maybe just pouring sealant in the crack and putting a couple coats over the crack and allowing to dry in between is all you need.

I've made my first application of about 2 cc of thinned epoxy. It may all be absorbed into to stone. I won't know until it has cured or the solvent has flashed off and I make another application.

Eventually some will run out of the side and I'll have an idea.

I may reduce the solvent content and move the rock into the sun to warm it and thin the epoxy that way.

I know nothing about thinning epoxy, but my gut feeling is that the end result will be weaker than unthinned epoxy.

I do know there exists a very low viscosity epoxy. I have a friend who uses it to repair the wooden spokes and rims of old wheels. I understand that it soaks all the way through the wood, leaving an authentic original wooden spoke as strong as the original. I don't know if it is a one- or two-part epoxy. If you are interested, I can ask for details.

I expect your friend may be using a commercial version of my home blend. By adding a volatile thinner, MEK or acetone, with the mixed epoxy, the thinner all evaporates leaving virtually 100% of the base epoxy resin behind. Typical coatings such as this are 10-30% solids and the rest evaporates away and allows curing to take place.

Same with paints. Rattle can spray paint is mostly solvent.

I'd be curious to hear about it none the less.

I finally remembered to stop by my friend's place. The stuff he was using is:

I should have taken a picture of one of the cans (it is a two-part product), because it had more chemical information.

INTRODUCTION TO KWIK POLY^®

KWIK POLY^® is an entirely new product and material to most people. Kwik Poly^® is a trade name, and the product is a Polyol using two agents, a base and a catalyst. Because of its wide versatility, it will repair and preserve things that were previously considered unrepairable and routinely thrown away. It is combination filler, coating, and bonding agent. Restorers, hobbyists and people in all industries have longed for some material that is easy to use, sets up in minutes, and can be mixed and applied in any consistency depending on the job requirements. It will also vary in strength and physical properties depending upon different materials (fillers) that can be added into the two base liquids. This fast curing material is also impervious to gasoline, oils, thinners and most acids, yet will accept any type paint finish beautifully. It can be readily sanded, driller, sawed, nailed, cut and worked very much like hard wood. It can also be machined, tapped, turned, shaped, ground, and polished like aluminum.

Kwik Poly^® is initially a very thin fluid combination much like water, and its penetration quality in porous material is unmatched. Another of its key advantages is its ability to combine with tremendous amounts of filler, which can then be utilized in filling voids, dents, pits, and gaps in almost any situation, on just about any material.

Kwik Poly^® cures (dries) by the heat of chemical reaction between the two base materials, light and dark, which in that respect is similar to epoxies including fiberglass. However, this chemical reaction takes place much faster, which is another of its outstanding qualities.

Fillers can be just about anything imaginable and may be added in any quantities suitable for a particular job. Each Kwik Poly^® kit contains an excellent silicon filler, but one can add or substitute any type of dry material such as sawdust, spackling powder, plaster of Paris, concrete, sand, flour, gravel, and just hundreds of other dry goods.

When mixing products such as milled fiberglass, metal shavings, glass beads, and concrete, a much stronger, harder and more durable material is achieved. The end result will directly reflect what type and amount of filler used if any.

"

Thanks for the information. Polyol is a rather generic term, but I'm going to order some anyway for another small project..

I'll look for an MSDS to get more information.

I would cut the stone in half, then split the cracked piece, and then stick it back together....with mortar or grout...

If only it breaks that way, that would be great...

Not feasible for me. That would require a 40" long cut. The stone is 1 1/2" thick.

I've cut up 6" slabs of concrete, it's fast and easy with the proper saw....

I've rented gas powered concrete saws before. I'd have no use for it after I made the one cut. I'll pass on that idea.

I would use a wet tile saw.

Although the length of cut indicated is 12", a longer table can be fashioned to allow a longer cut.

Also the depth of cut is 2" ( 2 inches one side / flip the piece over / 2 inches on the other )

The Price is really affordable for a pro-quality saw

When done using it, sell it on Craigslist.

So far I'm liking the tamping. Wet settling and plopped onto a heap of mortar method.

I've set quite a few stones this way. It's the way to go in a tricky situation. It's Important to put down enough mortar that pushing down will settle it to the desired level as lifting up is an exercise in futility.

The bonus is that you can leave controlled gaps that can be filled with mosses, gravel, dirt, water etc.

..or grout

Me too. I can use a redwood frame and the driveway on one side for the slope and a 2x4 for leveling each stone. I have 1x2' redwood framed pavers between the pool gate and the kool deck.

I'm leaning toward mortar to fill the gaps, no further maintenance and easier to hose off.

PES, I did that long ago on a smaller walkway and didn't like it. You can't mow the grass and weed eating stains the stones sometimes. And here in the desert the grass may die. Thanks for the idea.

Grout can be applied using a grout or a " mortar bag " this looks like the same type of bag a baker uses to decorate a cake.

Go to your local concrete/ batch plant, or place that sells concrete block.

Take a sample of your flagstone with you, if they don't have a ready made color for your grout, then the on-site chemist ( mortar-man ) can custom make a colored grout for your purpose.

They also sell all types of mortar bag, trowels, spoons and chisels.

The shape of the flagstone is lovely and natural. You could do what the Japanese gardeners do, which is to let nature come through, breaks, cracks, and all. (I took a class on the Japanese Gardens.) We have several square-cut flagstones of Salem limestone in the backyard with separation cracks along natural planes of weakness, and no one has tripped yet. Even Michelangelo would approve -- let the stone speak to you.

In the fossil collecting world there is a product called PaleoBond.

It is apparently available in various viscosities.

I have seen it used successfully in a number of repairs.

Epoxy for fossil repair is considered a strong non-reversible bond.

Thanks. I'll contact them tomorrow.

Epoxy for fossil repair is considered .... epoxy.

Come on. It's epoxy. Selected perhaps, buy overpriced without doubt.

It's branding Lyn. I forbid you to contact them.

No, it is crazy glue type stuff.

I would stand the stone up on it's solid side and fill the crack with sodium-bentonite clay. I would tap the stone to get the dry powder as far down into the crack as possible and fill it with the clay and pack it in with the edge of a piece of tyvek or something. Then I would add water and let the clay split the stone.

Once Split, I would mix up some bondo or some other plastic, and glue the cleaned surfaces back together, and then lay them as planned.

This will force the inevitable to happen when it still can be dealt with without breaking the history, and allow for a repair before putting into service!

Another method to force the natural split is to submerge it in water and allow it to freeze. Then clean it and glue it and use it.

I repaired a 2" thick York stone slab that was broken in half using exterior grade PVA glue, I stood the slab on end brushed the dust off applied the glue and left it over night

this was a 30"x24"x2" slab, not light but I was able to lift it from the top without it coming apart, I used pva because it soaks in and leaves no gaps any excess can be washed off before it dries, I was lucky the break was clean & there were no chips along the edges, when it was laid and grouted you wouldn't now it had been broken.

bazzer

Using epoxy cement I would; 1) entirely fill the crack & let it dry, and 2) then epoxy another slab underneath the cracked slab, using multiple pieces to span the 40" if necessary. Basically forming a 2 ply stone wherein the underslab acts as reinforcement for the cracked slab. You can remove the extra sand underneath where the underslab(s) lie to enable the assembly to lie flat.

OK,

Here's the final plan.

Dam the outer edge of the crack with water soluble wood glue. Then fill the crack progressively higher and higher. As the top of the lower dam overflows, seal the next higher portion and inject more till the entire crack is filled with solid epoxy. If successful, I don't think any further reinforcement will be necessary.

The entire walkway is more decorative than functional, as the foot traffic will be very light.

Get out the camera ---

We obviously need to re-visit this thread in 1 or 2 years time to see how the repair stands up.

Two or three years? It may not even be finished in that short period of time!

I do not foresee any problems with durability. The stones, not mine.

Ah, come on now - we have to have the longest running thread in history.

"Ah, come on now - we have to have the longest running thread in history."

"I still have a two foot tree trunk to fell "

AND a rock to take to the geology department at the local college....

Help With ID of Meteorite

Celestine crystals are found in some geodes. The world's largest known geode, a celestine geode 35 feet (11 m) in diameter at its widest point, is located near the village of Put-in-Bay, Ohio, on South Bass Island in Lake Erie. The geode has been converted into a viewing cave, Crystal Cave, with the crystals which once composed the floor of the geode removed. The geode has celestine crystals as wide as 18 inches (46 cm) across, estimated to weigh up to 300 pounds (140 kg) each. - Wikipedia

Everyone gave up on learning the identity of Lyn's Mysterious Rock That Went to College - it should have matriculated by now, if not metamorphosed into another freaking kind of rock.

This is not the first time a poster on CR4 has left the stage with the audience on the edge of their seats.

Cheers to Lyn! I had forgotten all about your bout with skin cancer. That is what happens to a lot of us blondish boys when we grow up.

Now you're starting to sound like my wife!

"And another thing: you've been wasting your time on that silly CR4 site for ages now, why don't you pack it in for a while?"

Look who's talking! There is no need nor reason for unkind statements...

I did that. But the number of requests I received to come back were yuge! Largest ever, million, million and a half!

So, the opinion is sedimentary, and that the dark layers are limestone and the reddish layers are chert.

So there!

I suppose the reason for the water soluble Elmer's glue is to not get epoxy all over the outside of the stone?

It will capture the thin epoxy so it stays in place, then will simply disappear in time.

Piece of cake: USE EPOXY resin. 3M has excellent ones.

I do not have to read the history of this discussion.

Super glue is pretty runny until it is exposed to air for a little while. Use multiple light applications and allow a couple of hours of drying time between applications. It will flow into the cracks very nicely without leaving a mess. But it should be easy to apply.

For a stone that big, it could become expensive. But it should also be waterproof.

Hey Lyn, did you ever tell what that other mysterious rock was? The one with the blue or green inclusions? It seems that I never saw the end of that thread.

I think we should call you Rocky from now on. Hard head was already taken.

Once hardened, Super Glue (acrylic) is very brittle. I think an epoxy is a much better solution. Now the question is which epoxy. I have a pretty strong preference for two-part epoxies, especially in cases like this where it would be essentially impossible to get UV light into the depths of the crack..

I have epoxy on hand, for now, but will exhaust the supply before I'm done with this crack filling exercise. I have drilled a number of shallow holes along the crack to facilitate filling. I carefully clamped the stone to avoid cracking with the masonry drill before I drilled each hole.

I still have not begun the selection and marking process, that will take considerable time by itself. I have abandoned my original plan to closely match the stones as unworkable and silly and will now fit each stone with a 3/4- 1 1/2" gap and fill the spaces with mortar. I'll consult my resident fashion coordinator as to the color of the mortar, but my inclination is to just leave it natural.

Call me Stoney. That fits in better with my misspent youth, and early adulthood.

I'm stopping by the Arizona Museum of Natural History later today to see if they have an idea about my moon rock.

The community college didn't seem to want to be bothered with my rock.

Has it ever occurred to you that this crack in the stone might be just filled with silt, and the whole thing is ready to split apart? Take it apart, clean it, bond it back together using your epoxy trick.

Hey if you open it, and find a million dollar fossil, you gotta split it with me.

Too late to consider that.

yep - oh well. There are other fossils to be had. Good luck with your project, I bet it will look great when completed.

If you used a urethane type like Gorilla glue, it can be activated with water and it will expand like that spray foam insulation and then harden. You could wet the rock first and then apply the urethane glue to make sure it is more properly activated, but I think I would try it on some other rock of the same type first. All of this sounds very messy unless you have some way to inject it.

I have a good friend that can identify your "moon" rock. He was the state geologist for Kentucky until he retired. He collected rocks from all over the world, including China. Send me a sample and I'll have him identify it for free. No appointment required.

Two problems with Gorilla Glue. Too viscous to fill the crack and if id did fill it, I'd be afraid the expansion might crack the slab.

Without drilling holes in the face of the slab, I see no way forward but by using a very thin "glue" and letting the solvent evaporate.

Thanks for the offer but I confident enough in the two opinions I have gotten so far on the rock.

I've finished filling the crack. It consumed a good quantity of material, and time.

Next step is to lay out and arrange the stones.

Thanks for the update. Where's the photo?

Sorry, I didn't think it worthy of a picture. I'll take one tomorrow.

At my pace laying out the stones (next task) will take at least a week, or more.

In the past I have thinned polyester resin, but never epoxy.

Do you have any information on doing that?

It's commonly done. When I was in aerospace we used a lot of MIL-SPEC epoxy spray coatings for environmental/vibration protection. (I still remember the # of the spec. MIL-I-56058 rev x) A little trivia; the letter between the dashes is the first letter of the first word in the title, in this case, insulation.

The most common, readily available thinners are acetone and methyl ethyl ketone. Thinning accomplishes two things. It retards the chemical cross-linking and lowers the viscosity.

The amount of thinner added is dependent on the viscosity needed. Just mix the epoxy resin and hardener thoroughly before adding any thinner.

You must use a slow curing epoxy so that ALL of the solvent evaporates before curing begins. Also don't use this mixture on solvent sensitive plastics. Styrofoam will disappear!

As with any new material, mix a test batch and carefully evaluate the results BEFORE using this on any solvent sensitive plastics. Commercial spray coatings will (should) list the % solids of the fresh coating. 15-30% is typical, the rest is thinner, but much less that that will make it, "runny".

That's a tough order, especially if the wood is already coated.

Any increase in temperature will cause bubbles with porous surfaces like wood, unless it is completely sealed.

Using a solvent thinned coating might also cause crazing/wrinkling of the previous coatings if the solvent starts to dissolve them.

Not sure I have any "words of wisdom" here.

The only tidbit I learned during polyurethane finishing of an oak rocking chair I re-finished: Do not agitate the fluid while depositing it on the wood. Warm up the room before you start, and allow slight cooling while the application is going on. Keep a very light touch with the brush, never use foam brush, but use a real pig bristle or other animal hair brush. Use small or even tiny brush in detail areas (spines of the back, etc.). Never, ever make double or forward/backward strokes - guarantees bubbling of the finish. Never be rushed, take your time as though you are the Shogun and you hold all the time of the world in your hand. Keep your pride in your work throughout. Hold the work in the highest esteem, worthy of your full attention, and do not allow wifely distractions, or dogly interruptions.

You are the master of the domain of the paint brush.

Enjoy.

To fill the oak gran with polyurethane (the old solvent based stuff - brings a nice warm glow to oak) I have been using about a dozen coats - first half dozen coats I apply then use a blade and squeegee to essentially just leave the pores filled with the coating - the pores slowly fill in - eventually with a light sand they become filled.

With stair treads if the pores are not filled the coating breaks down and collects dirt quickly.

The same thing applies to a kitchen table - the pores must be sealed. Otherwise food collects inn them and water spills enter the wood turning it black.

Good quality brushes are a big help - I hate ones that shed bristles.

I just refinished my oak kitchen table with a stain / polyurethane combo. I had to sand the old finish off, using progressively lighter grit sandpaper, ended with 320 grit.

Put the first coat on thick, and it looked as you described, wasn't smooth, didn't fill in all the grain. I let it dry for 2 days and lightly sanded it again with 320 on a random orbital sander (built in vacuum), making sure I didn't go all the through the urethane . Tack clothed it off and applied 2nd coat. I was very pleased with the results.

Now the chairs are a different story......sanding them requires a lot of hand sanding.

This is the completed edge fill and some random shots of some interesting patterns and the complete (almost) selection. I've started digging out the grass and gravel for the walkway. I have a bit of a challenge around the base of the Orange Tree as some of the roots run through the path. I may use minimal concrete as a base there. For perspective, the stone in the lower right is 12x16 inches.

You could put paver borders, build up the middle walkway with sand, then pave with your stones, and maybe avoid the orange tree roots?

I have ample stones for the entire job. The photo represents those moved from the side yard, where there are that many more.

I want to keep the walk to 3 feet wide to preserve as much grass as I can. I haven't uncovered the roots yet to see what I have. Remember, I have no deadlines.

I am not that familiar with growing orange trees, but I would not want to damage any surface roots. Do the roots tend to work up to the top of the soil?

Maybe you can work your stones in around these, as they are irregular shapes.

I can't tell yet. I'll try to lay around them, if possible.