Is it poss. to stain exterior concrete?
Question: Can a newly-poured concrete driveway be stained to look “just so”? Which is the better product: a water-based or an oil based stain?
I wish to avoid a “painted” appearance. That’s why concrete paint is NOT an option. The main thing now is to get the three pours to look exactly alike. Those pours were done under different conditions and don’t have a uniform appearance. The pour has not yet been sealed.
I am interested in pro/con arguements for oil-based, semi-transparent stain (slate-charcoal gray). I believe oil-based stain is more likely to penetrate, while a latex-based stain is more likely to settle on the surface. A sealant will top off the finished product.
Thanks,
Mel
Replies
what is "just so"?
i prefer
what is "just so"?
i prefer acid stains vs water/oil based products to color concrete.
your main concern will be a dissapointment, they will not look the same. whatever product you go with will require a lot of maitenance to keep the look you are going for.
Acid stain is the way to go. I would let it cure for 6 months or more, the difference will tend to equalize.Then you just spray on the acid stain with an acid rated pump sprayer. Be sure you are wearing the right PPE. You can get an assortment of colors.
Once it is down, it is largely maintenance free.
Acid stain is the way to go
Greg, thanks for the pointers. I have never heard of acid stains. I must find out where I can get the product. I suppose I should test for color consistency first.
Thanks lots. Mel
It is cheaper if you can find a guy who will sell you the pigments and you get the acid locally. Shipping acid to a residence is expensive. I think shipping ended up being a significant part of the cost when I did it 10 years ago
what kind of acid?
Greg, what kind of acid are you talking about. I am sure I can get it locally. As for colorant, would a dash of the colorant used to mix paints (water and oil-based) do the trick? Or should I use powdered colorant sold at masonry stores?
Mel
Mel,
http://www.homedepot.com/catalog/pdfImages/82/8250f8d3-c666-4551-8919-67ab71031616.pdf
My local yard carries it and the box stores aalso.
KK
Thanks, KK
Thanks KK. I'll check out HD. The link was helpful.
Mel
I was gonna suggest that you just get Junkhound to park his truck there -- that will stain it up proper.
Only if you like polka dots !
I Have Just Done This Job
First, the final results depends very much on what you start with. What you will see depends on the original concrete color as well as how much of the stone is exposed, and whether the concrete was ever 'sealed.'
You prepare the concrete by first cleaning it, then by etching the surface. The etching material will give the stain something to grab on to and remove most sealers, stains, and contamination.
There are a variety of products sold specifically for preparing the concrete. All are pretty powerful chemicals. There is also the traditional "muriatic acid." If you buy the acid, you WILL want to dilute it substantially. To use any of these products, you simply mop or spray them on, work them in with a broom, and let them sit for awhile. As long as they's hissing and bubbling, they're eating away at the concrete. When done, you hose them off.
The 'stain' is sold in the paint department. It is as thin as water. How you apply it has a big effect on the final appearance. More stain = more color. Put a thin roller on a broomstick and experiment.
I did my front porch, and the final result was a solid color, not transparent at all. This was mainly because the concrete did not have any of the stone within exposed - just smooth gray cement showed.
Since this is a porch, I also sprinkled silica sand atop the wet stain, let it dry, and then applied some more stain. This made for a slip-resistant finish.
For a large area, or for the best possible appearance, you might want to chat with a firm that polishes concrete. These guys have special equipment that grinds the top off the concrete and exposes the aggregate (stone).
Another approach is to have a contractor put a thin layer of new material over the existing concrete. This will fill cracks and make for a very uniform appearance. The 'down side' is that these topping compounds have -at best- tiny stones; the result will be a plain, uniform surface without any 'character.'
I have done
Thanks for the detailed reply. The concrete pour (drive way with border of pavers) was poured in early Oct (no antifreeze agents added at the time). The rocks in the concrete are near the surface, since this was not a power-trowel job. The sealant is a simple latex additive used in a variety of masonry applications. It is a 50/50 solution of "milkL", hence it barely "seals" the concrete. I applied it more as a precaution against discoloration from falling leaves. I figured that since its a latex based product and concrete also is water based, no harm would be done.
I am tickled to apply my large grinder and grind down the top 1/16" surface, exposing the white rock. I've done this before in swift fashion. I think this looks lovely...might look great when stained, as I suppose the rocks won't absorb the colorant. I will need to experiment.
Don't worry, I have no problem working on hands and knees for a few hours...this, despite my age (senior citizen going on 40...if you know what I mean). I love hard work...and I get paid serious money to work "miracles" :) Again, thanks for your excellent and thoughtful reply.
Mel
Try Renting
At least ask the local rental houses about renting something like this:
http://www.csunitec.com/masonry-tools/walk-behind-concrete-grinder.php?PHPSESSID=4fb00d0008dcd37eebe5cce79ef0e5ff
Besides getting you off your knees, you'll have a more uniform finish from that much larger disc.
try renting
Good...will check it out....'cept I need to work close to the paver border, and that is where I hand-help grinder is the better option...but let me check out the beast. As a general rule, my son and I (contractor artists) prefer our "pioneer methods". We are not afraid to do things "the olde way", and our clients appreciate our hands-on style of work. We are not for everyone; only for those who appreciate attention to historic detail and fine art work :)
Mel
Staining concrete
The term 'stain', as applied to concrete, depends on what you are trying to accomplish and how the manufacturer labels it's products. Every stain' is different.
Acid stains are mineral salts in an acid solution, and as the acid reacts with the alkali components of the concrete the mineral salts cause color changes. This is a very permanent form of staining, but the results will vary depending upon the amount of alkaline material present, contaminants in or on the surface (oil, sealer, etc.), hardness of the concrete, and SLOPE (it tends to run). Proper cleaning before staining is important (NO ACID BASED CLEANERS for obvious reasons - you don't want to 'use up' the alkali components). After staining (takes several hours) a lot of messy residue needs to be washed away and neutralized (a weak household ammonia solution works well). Acid stains are usually available in local concrete supply houses, but if you need to order, shipping costs can be high because of the acid content. Color range is somewhat limited although some companies offer extended colors by adding pigments (see below). Sealer, while not absolutely necessary, will (usually - depending on the sealer) 'enhance' the stain color. Solvent based acrylic lacquers are most common, although there are many fine water based acrylics on the market. I have never NOT sealed a stain project - why go to all that trouble and then not protect it. On the other hand, any sealer will need to be maintained (re-applied periodically) and sealers are subject to deterioration from moisture coming up through the slab.
Pigment and dye stains are merely super finely ground particles which are carried into the surface by mixing them with any number of different liquids (such as acetone or water depending on the product) and spraying them down, usually with a garden sprayer (acetone and other aromatic solvents are very hard on common garden sprayers). Exterior work requires an exterior rated product. These absolutely require sealer since they are not generally well bonded to the surface.
Some pigmented stains (such as Smith's Color Floor, which I have used sucessfully many times) have an acrylic component built in which 'sticks' the color better. There are other semi-transparent stain manufacturers of this sort on the market. The manufacturer will usually vend a companion sealer since the solids content of the acrylics is very low.
Solid color stains (are these really what we think of as stains?) come in a variety of formulations, everything from acrylics and latexes to multi component concoctions. These will generally give the most uniform finished surface color except that porosity and surface texture differences may show off the colors differently. To me, the most natural 'colored concrete' effect is produced by a product called New Look, a four component kit. I've been using it for many years and am 100% satisfied.
Note that success in staining requires total adherance to the preparation, mixing, and application instructions.
Doing a rough grind to expose aggregate creates a unique effect, but be aware that you are removing the most consolidated, hardest part of the surface. A quality sealer is a must when doing this.
staining concrete
Thanks muchos, C-guru! A Heineken awaits thee! :)
Mel