have just finished facing a fireplace w/ riverrock and type “S” mortar and am more than pleased w/ the results but know I could get more mortar off the faces of those rocks
shall I put on face shield, gloves etc ; cover cabinetry & protect slate hearth and scrub the proud of the mortar rock faces w/ a brush and 1 to 4 acid solution? it’s working when it sizzles / bubbles ? does the dripping, running between rocks on the mortar discolor mortar? sponge off solution top to bottom as I go so mortar doesn’t stick again?
all advice and ideas most appreciated
thanks John
Replies
I usually mix my acid a little weaker than that (asuming that you're mixing from full strength), and then I usually confine it to getting the haze off. If you've got areas where the mortar has any thickness at all, one application of acid probably won't get it all anyway.
And I usually apply the acid with a throwaway brush...helps keep it confined and not running down over your work. As soon as you've got a spot clean, rinse it off with water. A small spray bottle with a mist nozzle works well, especially indoors. (Outdoors, you can get a little more agressive). A brillo pad, an old piece of low nap carpet, or even a rag often works to clean things up along with the acid.
The acid may or may not stain your mortar; usually not, but it's always good to keep acid out of your joints.
But, before resorting to the acid, try scraping it off with a stiff putty knife, or an old chisel.
Another way, effective but messy (dusty), is to mount a cone brush in a 4 1/2" grinder or a drill motor that will spin up about 1500 RPM.
Get all the worst off and then go after the stains with the acid.
You probably know at this point, but, when laying any kind of rock, it pays to allow yourself time to tool your joints and clean up before the day is done(I always keep a bucket of clean water and a grouting sponge with me to keep things touched up)....ESPECIALLY if you decide to lay some artificial stone.
And the last thing you absolutely MUST do is post pictures!
hey thanks so much
the brillo pad spray bottle thing sounds good and hit any high spots w/ a putty knife - I'll do her
I did go at it w/ tooling the joints and many passes w/ the grout sponge but unlike w/ vitreous tile you can't go back the next day and polish upsnapped some pictures w/ my film camera and paying extra for putting them on a disc and finally I'm going to learn to post a picture!
With my son as a copilot hope to get to posting after the Hawks win a spot in the Super Bowl ( and w/ the primer Dinosaur sent me weeks ago )our heavens have realized the misguided notion it rains everyday in this great northwest eh? thanks John
4000 psi pressure washer works pretty good if you get to it wihin the first few days.
There are some non-acid masonry cleaners available from your local brick & block supplier.
Check it out.................Iron Helix
An aside note...Do Not store opened bottle of acid in a kitchen cabinet under the sink...ya see the fumes can still find thier way into another cabinet and DESTROY all the cookie sheets and cast iron skillets and some pots and pans.
don't ask how I know that tidbit.
Spheramid Enterprises Architectural Woodworks
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Not only that, you shouldn't store it low where a kid can get his hands on it.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
excellent point, being as I was childless back then, it was not a concern.
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Timing is key with acid washing- too soon and you end up spreading the mortar from the joints over the rock face, too late and it does nothing.
I've usually started with a 10 to 1 mix, and added acid from there until the mortar fizzed. put it on with a garden sprayer, use a stiff nylon or wire brush, and rinse, rinse rinse afterwards.
The wire cup wheel on the 4" grinder is good advice too. I would be careful with it on light colored rock, if that's what you have. And I would use a full face shield- those wires go everywhere.
zak
thanks guys camp muir zak et all
I'll be cutting the arch support tomorrow and seeing if I can get a bit of the mortar to release