Phosphoric acid etching?

[6togo]

So I rented a dual disc Edco grinder last weekend and did my garage floors it did a decent job overall and I have about 50lbs of dust from 700sqft of floor.
When I got done and cleaned the floor up there are misc. small spots though out the floor that really didn't see much if any grinding guess they are divets from the trowel and low spots. None are big maybe a few inches at most so I was thinking about going over the floor with a phosphoric acid etch I picked up from HD made by Klean strip.
Hopes are this will hit the small areas the big grinder didn't and it's not as nasty as HC acid is there any issues with doing this?
I plan to neutralize it with baking soda water and then degrease the floor once more with purple power.

 

[Shea]

Test those areas first with a water drop test. If they absorb the water well then don't etch. You don't want to flood the concrete with water at this point if you can help it. It only introduces possible moisture issues during application of your coating.

 

[LegacyIndustrial]

Correct-o-Mundo!!


Sent from my iPhone using The Garage Journal mobile app

 

[6togo]

Unfortunately I still want to degrease the floor when sanding the Edco was throwing small amounts of grease off hitting the floor. Guess they used cheap grease and it was getting hot so I don't want to chance having it present so the floor will be already getting wet.
I plan to coat the floor Saturday and clean it tomorrow night which gives it 2.5 days to dry will that be long enough?

 

[NitroShark]

Acid etching does not clean grease or grease stains up!

 

[Mr. D]

Does 50lbs of dust from 700sqft of floor sanding sound like a lot of material remove? Reason I ask is I have 600 sq ft to sand.

 

[6togo]

It seemed like allot to me also but I didn't get crazy and still see some stains to know I didn't remove much. I did hit it with the acid followed by the baking soda water hosed it out and then Zep purple degreased. I hosed it down 2-3 times when done then took my blower over the floor to remove heavy water followed by heat turned on.
It was basically dry in 2 hours but did leave a small amount of white residue what should I use on that damp mop?

 

[LegacyIndustrial]

Does 50lbs of dust from 700sqft of floor sanding sound like a lot of material remove? Reason I ask is I have 600 sq ft to sand.

The amount of dust varies based on:

Strength and Condition of Concrete
Weight and Speed of Grinder
Type and Grit of Diamond Tools

 

[6togo]

So I went over the floor tonight with a sponge mop twice and changed the water many times when it turned darker. The floor looks clean but when I run my fingers across it I still get a small amount of white residue it was about the same before I mopped.
Is this acceptable? On a side note the floor ***** water right up dry's almost instantly.

 

[pima67]

Because of the location, I used a garden sprayer and a wet vac to **** up the H2O until I couldn't find any residue

 

[Marctrees]

I find it really interesting that more people do not use Citric Acid.

Cheap, bulk bags from Chemical supply house.

NO bad fumes, did my 1200' floor in flip flops soaked w it.

WHY is it not better known ?

Fizzed great.

Marc

 

[6togo]

I ended up pressure washing the residue came right off and have the floor coated and flaked. Clear goes on in the morning.

 

[Marctrees]

Gee...

I have not done a floor w this finish...

BUT....

Shouldn't you have let it fully dry out a few days w venting at least ?? ??

???

???

??????????????

Marc

 

[Shea]

I find it really interesting that more people do not use Citric Acid.

Cheap, bulk bags from Chemical supply house.

NO bad fumes, did my 1200' floor in flip flops soaked w it.

WHY is it not better known ?

Fizzed great.

Marc

Because it does not etch as well as phosphoric or muriatic acid. It's almost useless for providing the proper profile on very hard and dense concrete.

 

[6togo]

I used fans and heat to bake it 24hrs prior to coating. The epoxy I used can be applied over damp concrete not that mine was.

 

[Armorpoxy]

We agree with Shea. Use either muriatic acid or our Armoretch buffered acid (kinder and gentler).

 

[Kevin54]

I used fans and heat to bake it 24hrs prior to coating. The epoxy I used can be applied over damp concrete not that mine was.

Oh believe me...It was damp. Just not at the surface.