Acid

[cx]

To:
Big-time expert tile guys.

From:
Lowly and unknowing builder (of really nice houses).

Over to the shallow end, John (BIG mudboss guy) suggested the following to a DIYer seeking help in cleaning grout residue from tile:

"... a tile cleaner (either sulfamic or phosphoric acid) from a tile supplier".

My question is, why don't youse guys use Muriatic acid (all same Hydrochloric acid) for heavy duty removal of such Portland-based materials. I, who do the rest of my Saltillo tiling incorrectly you might recall, have always used Muriatic. I also learned this in the concrete pumping business to clean cee-ment from vehicles and other equipment.

Your stuff is better?

[Bri]

Hi
I think it's a lot safer for the DIY'ers to use the Stuff from the tile shops...it's a lot less concentrated so there's less chance of having an accident. Muriatic works great..but if your're not careful, just the fumes in the air from the open bottle can rust the chrome on appliances, and even a stainless steel sink.

Brian

[cx]

Yeah, I'm sure familiar with that aspect of the stuff, Brian.

Made the mistake some years ago of leaving a closed (never been opened maybe) plastic gallon jug of the stuff stored in the back of my tool trailer on a job site. Fortunately it was closest to some not-so-valuable stuff, but all things metal within a couple feet were seriously rusted after only a couple weeks, as I recall.

Lesson learned. Gets stored out in an open shed now, and taken to the job when needed - and stored outside somewhere if necessary.

Understand your concern for the DIYers. Just a small whiff of the undiluted stuff can be a bit scary.

Just wondered if the other stuff was somehow more effective, since I've never used any of it. Never heard of any of it, truth be known.

[Bri]

To tell you the truth, I've never used it either...I never wash the tile anymore....I leave it clean when I'm finished grouting....if someone else makes a mess afterwards...eesnomaproblemo.

Brian

[John Bridge]

Bri pretty well hit on it. Muriatic is nothing to fool with. I do get around to recommending it, though, if the milder stuff doesn't do the job. With novices it's best to start on the low end of the scale and work up.

One of the ill-considered effects of the imporper use of muriatic is that it can actually soften the grout and erode the setting material under the tiles.

The beauty of sulfamic, on the other hand, is that it can't be over-concentrated. The water in the bucket will only dissolve a certain amount of crystals. The remainig crystals settle to the bottom of the bucket.

[Dave Gobis]

100,000's of thousands of feet installed in malls, fast-food, hotels, schools, shops, public buildings, and houses, no muratic in the last 15 years using a crew of 12 to 20. No, I don't like it or is it needed by a professional. Sulfamic, yes, on occasion. What changed my mind is watching a kitchen in a country club turn into rust before my very eyes. No, thankfully it wasn't mine. I was called to recommend a removal method for excess grout on the tile and one of my competitors decided to show them how to melt it off before I got there. I would have started at 20 to 1 but he went 5 to 1. All the stainless was trashed. Same thing happened to one of our trucks a few years prior with an open bottle in the back, every metal part of anything rusted including the racks in the van. Nope, not for me.

[cx]

Yeah, it's bitchy stuff, no question.

Is it your collective testimony that the Sulfamic in crystal form can be safely stored long term along with your tools and other metal things?

Does Sulfamic actually disolve Portland as does Muriatic?

What else do it do that we should know about?

[Bri]

I think any acid will desolve a cement based product..and usually Vinegar is plenty strong enough...unless it's really on thick. Im glad Dave mentioned that stainless steel story...it reminded me of a job at a food plant about 15 yrs ago, where a epoxy flooring company came in to acid etch the floors before they applied the epoxy. In this plant, even the duct work at the ceiling was stainless. They came in and poured the acid on the floors, maybe 50-50. The next day, everything was rusty red. I thought for sure everything was going to have to be replaced...but a cleaning company came in and washed it all...with MURIATIC!
And it worked! What's the deal with that?

BRian

[John Bridge]

Heavy concentrations of acid can be neutralized with baking soda.

Yes, the sulfamic crystals are safe in the tool box, as long as the lid stays on the plastic jar and as long as everything stays dry. I only buy the small jars, about a quart.

[cx]

Maybe I'll get me some of them crystals to have on hand. I'm sure the guys at HD will know all about'em.

Hey! I got me a free bucket there this very day! Gotta find that thread with the pichers and tell Harry. Didn't even try to sell it, girl just said "take the damn thing".

New company policy?

John, Bri, Kelly...

I emailed Christina's Uncle Art, and asked him about the muriatic acid Q. Here is his reply. (Uncle Art is a chemist). In past posts, I have referenced an Uncle who worked for the Portland Cement Association and help me learn a bit about the chemistry of grout, thinset, mortar, etc.



Rob,

Hello and congratulations to you and Christina. We
heard that Christina is expecting a new addition to
the family.

Turning to chemistry, the reason why sulfamic acid is
preferable over either muriatic acid (hydrochloric
acid) and sulfuric acid because it is safer to handle
(solid material). The other 2 acids come as
concentrated acid solutions. which fumes when exposed
to air. Muriatic acid, in particular, liberates HCl
which is a corrosive gas.

Acid attacks grout by simple acid-base reaction. The
cementitious materias are alkaline, therefore would
dissolve when expose to strong acids. During the
setting of the grout, it picks up CO2 from the air to
form carbonates. Carbonates are also easily attacked
by acids.

If at all possible use weak acid, like acetic acid.
It is safer to handle.

Uncle Art





Now I see why the muriatic is still bad news even when highly diluted-the gas that comes off of it is still present.

Rob

[John Bridge]

Hey Rob,

Tell Uncle Art thanks once again. And once again invite Uncle Art to join us. It's nice to occasionally have someone around who actually knows what he's talking about.

[cx]

Yeah, it's lonely out here.

I got to the edit button just in time so's I don't hafta do a

[Edited by cx on 09-18-2001 at 07:24 PM]

[John Bridge]

I think this is an occasion. Kelly actually made a "smile." Maybe we ought to start another thread about it. Or maybe we shouldn't.

[cx]

Pour it on!

I learned to ask no quarter even before I learned to give little.