On 12/3/2010 11:31 AM, blueman wrote:
Vic writes:
On Thu, 02 Dec 2010 12:40:53 -0500, wrote:
I need to patch some concrete outside and I want to be able to match the
color (basically 'dirty looking') and make it look old& weathered.
Can I just add a little 'dirt' (i.e. soil) to the mix to make it look
darker and dirtier or will this create problems such as encouraging
organic growth or weakening the concrete (I would only add a little
bit).
Any better ways to weather concrete?
Note: it's only a small patch so I was hoping for something simple and
cheap...
Don't use dirt.
You can try to match the aggregate stone, and the sand by using a
similar color. You can buy coloring also.
Last time I bought mortar color powder was 20 years ago, and it was
about 3 bucks a pound, smallest container being 5 lbs.
Never colored concrete.
If the job is small, you might look at aquarium sand and gravel to mix
in with cheap sand and gravel to your portland.
You'd have to test mixes, letting some set before you could see the
outcome.
There's other "issues" with patching concrete depending on what you're
patching.
The job is *real* small - basically we have an old millstone out front as a
stepping stone to our front porch (it looks really nice).
Whoever put in the millstone, filled the old central hole with concrete
that matches the stone itself pretty well.
HOWEVER, the fill is about 1/4 -1/8 inch short of the surface, so water still
pools there forming ice in the winter which is dangerous...
I would like to level it off with a thin veneer of new matching concrete
(erring if anything on the side of being slightly proud of the
surrounding surface).
I plan to use a latex binder instead of water in the mix so it will bind
better to the old stone and concrete.
I probably only need maybe 8-16 ounces total to make the patch so buying
pounds of colorant seems like a waste...
For such a small batch I didn't want to starty buying and mixing up my
own batch of concrete. So my plan was to use quickrete filtered of any
of the stones plus maybe a little mortar (all of which I have hanging
around) and add a small biit of something to make it look dirtier.
I just need to know what something to use...
Perhaps I would be best off adding some aquarium sand to the mortar mix
I currently have.
Any suggestions?
We used ready-mixed stucco patch on our condo's conc. block/stucco both
to patch broken stucco and as mortar to cover a hole with a concrete
paver
) It was to be painted and looked great afterward. For such a
small defect as you describe, it would probably work but would need to
be painted. Doubt it would last forever, but the precise center is
probably not stepped on very often. Paintable, and acryllic craft paint
is close enough to exterior paint. Or take some exterior paint,
leftover, and mix in a tad bit of acryllic artist color. I've used
artist colors...acryllic or oil...for scads of jobs that didn't need the
quart/gallon size of anything. Have mixed up my own "paint" from
varnish, stain from oil paints, lin. oil, min. spirits and a pinch of
varnish. The stucco patch comes sanded and unsanded, don't recall if it
is colored. If you rub some stones on the millstone, you could probably
end up with enough ground stone to color the stuff you patch with. I
don't use any reference texts...just mix up what I think will do the job
)