Aging Stone To Match Existing

RZB

Were about to build a set of stone steps for a client out of credit valley sandstone to match the old foundation. The existing foundation has a blackish patina or oxidization on it. Does anybody here know of a way to stain the new stone to match this. We've asked around and heard pickle juice, which just makes it look green and smell like pickles, not quite the effect we were looking for. Any suggestions would be greatly appreciated.

Tscarborough

It is a very complicated process:

Let them age.

If that is unacceptable to the customer, charge them to clean the old ones to match the new ones.

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It ain't Rocket Science unless you are building rockets.

Resta

Take an extra peace of stone and make a few samples. Wash stone from dust, make a color mix - "liquitex" matte medium and colors: charcoal grey, raw umber, hunter green. You can use a powder or acrylic paint. I like raw umber powder and other colors acrylic. On the glass of water use 1 spoon of matte medium, 1 spoons raw umber , 2 charcoal grey and 1/8 dark green. Mix it, put a large round brush into mix, take it out with right hand and keep in front of stone 1/2 inch, in the left hand have a spray bottle with water and spray on the brush toward stone and keep sraying on the stone to mach intensity of existent patina. Or you can use some textured sponges too.

Tscarborough

The problem with staining them to match is that once the aging process proceeds they will no longer match. You can rub dirt on them, but do not apply any permanent paints or stains.

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It ain't Rocket Science unless you are building rockets.

Resta

Yes it will match. They will age together. You must to make a stains match and penetrate in to sand stone, not a film/skim.

RZB

We told the HO we had a method but it would take a while, roughly 80 - 100 years, they didn't like that option so I just thought I'd see if anyone else had done a similar application. Has anyone seen the article where a company restored a cathedral in Chicago with a paste that peeled off like a facemask (or so my wife has told me anyway ) and the building went from a black caused by a century of pollution to white. Even the paintings inside, pretty cool stuff.

jvcstone

Since the aged patina is caused by the growth of organic critters (molds, fungi, lichens) , the aging process can be hurried by creating an environment that encourages such growth. Regular applications of growth medium such as liquid fertilizer, manure tea, buttermilk, can help establish the colonies of micro-organisms that result in the aged patina. (once buried a stone table and bench set in a compost pile for a few months--spectacular result)

Conversely, an application of bleach (or two) to the weathered stone will lighten it close to it's unweathered appearance. This will not remove the "case hardening" that also results from the weathering, but the results can be acceptable.

Your client needs to understand that it is an "aging process", and while the above can help speed the process, it won't happen over night. Stone exposed to the weather will darken faster than that protected by roofs and overhangs--(ever notice how much faster the chimney will darken above the roof line than the wall veneer does). To get immediate results, you could attempt to play momma nature with a paint mixture as suggested by Resta. Of course, practice on a few scrap pieces first. Might work out well enough to get you off of the job.

JVC

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John VanCamp
www.jvcstoneworks.com

Resta

Do you want to clean or put some aging on ?
Sandstone wary in color and cleaning with solvent with acid may cause discoloration. This paste what you say is call 'poultice' and it's made from kaolin, fuller's earth, whiting, chalk or talk. For whitening use amonia or peroxide. When poultice drays it pulls out the stain and pollution residue.

Resta

To get aging look patina in natural organic way. Take natural wood coal dust, put on the piece, put a hay on that and wet it with a goat urine, bury not deep and watering with urine for 2 weeks. Dig out. Works well.

Resta

Aging with colors looks like that. It may be to dark for you, but strength of color you make what you need.

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Resta

"Tea stain" color match on heart stone.

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Resta

You can do and match everything.

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RZB

Thanks guys, alot of great tips. I really appreciate the help.

RZB

Resta I was wondering how permanent are the stains you use? Do they fade or weather differently with exposure. Your work looks really good, we have never tried using any kind of dye or stain on anything before, just curious.

Resta

If you want keep it permanently you must use more medium matte and seal. If you use certain amount of medium matte it will fade very slowly and natural aging converts on the top. Like all artist coloration - it fades...sadly we see that on old paintings, frescos, murals...also on fabrics, drapery and etc.

denick

We've gotten results getting an initial start on aging where black was desired by using a black compost/humus. rubbing it in or making a mud / slurry and brushing or spraying on. Experiment in application and time before removal.
It has worked on several churches and homes to get an initial "old" look.

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Nick

"Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving" Albert Einstein

Michael Olding

Just a note about the staining... make sure you take your time! If you don't have an artistic bent with colors then hire someone who does.

Most stone are pretty forgiving but some are not and will stain deeply and quickly so go slowly.

By the way Resta I love that tea stain on that hearth. Very nice.

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Masonry repair expert - structural, restorations, tuck pointing, rebuilding, staining etc.