Painting a Concrete Porch –
Step 1: Muriatic Acid Safety
© Stephie McCarthy
Watch the marble painting process on YouTube
Watch the videos on HomeTalk!
This summer we began making a concrete porch look like
it's paved with green marble flag
stones and bricks.
You can see the painting of this porch here.
We are using concrete stains and watered down
primers and chalk paints marbelized together.
To make sure there was good penetration of
color into the concrete we decided to first wash the
porch with diluted muriatic acid.
Starting at the beginning, we gave the concrete a
good sweeping (power wash if you have it).
Muriatic acid is highly corrosive.
You must not let it come into contact with skin or be inhaled.
You also must plan ahead how you will dispose of your acid.
Muriatic acid can damage your lawn.
We have a large yard with poison ivy and you can guess
where we ended up washing our buckets. (Goodbye, ivy.)
We used special masks, face shields, chemical gloves, and boots.
Let a professional handle this type of work for you
if you find muriatic acid washing the least bit risky!
We are safety nerds.
Saftey is priority around here.
We turned up our glove cuffs to catch any
potential drips and had our clean rinse water and
neutralizer ready in advance
(plus the emergency baby wipes).
Turning up the cuffs of the gloves to catch potential drips.
The tricky part … we had no hose or water at this location,
so we trucked in 30 gallons of water and worked with
small batches of diluted acid, doing only half of the porch
at a time. That water was heavy!
Get your tools ready before mixing acid! We used an old scrubber mop and a
long-handled barbecue brush. Long handles are very important.
Time to prepare our solutions!
We used two buckets and a dishpan.
Here's how we prepared for small batch
acid washing with a diagram above to help.
1. we filled one bucket with plain rinse water,
2. we filled another with water and added baking soda
which will neutralized the acid,
3. we put water in the acid tub,
4. we put on safety gear,
5. we gently poured the acid into the tub.
Making the neutralizing rinse in advance.
Once we had everything ready and safety gear on,
we gently poured the acid into water.
It CAN splash no matter how gently you pour!
We scrubbed small sections of concrete at a time.
As soon as the acid touched the concrete it fizzed and
released fumes, not to mention a heck of a lot of dirt.
Because we worked in small batches we were able to
dispose of the soiled acid and start fresh for each section.
After the acid sat for about five minutes, we threw on the
bucket of baking soda water.
We swept the water off onto an area where it
couldn't harm plants.
We followed the neutralizing bucket with lots and lots of
plain water and a lot more sweeping.
Our industrial fan dried the porch quickly and
pushed the fumes away from the work space. Look how
white and clean the concrete looked as it dried. It's a lot more
porous now too, ready to accept stain, paint washes,
and sealer.
A few stains remain but these will give
realism to the faux stone and brick work.
Here's another view of the porch, BEFORE
and, here is the same corner AFTER cleaning with acid …
Next comes the fun part … layout out and
creating faux stones and bricks.
We tested the stain colors and diluted chalk paint a while ago —
And here's the first section of flag stones in progress …
Sidewalk chalk marks out the design … we can wipe this
off easily with baby wipes after our stains dry.
The fun begins!
Watch the acid wash video on HomeTalk!
Check out the rest of the project:
How to Paint Green Marble Tiles on Concrete
How to Paint Faux Bricks on Concrete
Transfering Art Patterns on Concrete
Our Newest Free Printables are here …
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