Another Prep Thread: White after acid?

[maphill]

Hey all,

Great resource here! Here's what I've done so far:

1. New construction, couple months old, unused, in Colorado (dry)

2. Rented an orbital sander and went over it with 80 grit (use to sheets at a time to keep from ripping!)

3. Use H&C etcher a couple times. First half strength, second full strength.

4. Rinsed 3 or 4 times, once with a little baking soda in it to neutralize acid.

The problem is that after I added the acid, the floor had a "whiter" color... moreso in some spots than others. Also, only some spots had a sandpaper-like roughness, while others (especially where it is whiter) are smoother to the touch.

I worry that I didn't rinse the acid off soon enough (dried very quickly here in the low humidity) and the results of the etching are trapped still and it won't make a good bond.

Can anyone comment with knowledge or experience?

(This is not the white stuff from moisture in the concrete... it's not crystaline).

Thanks!

By the way, once the floor is prepped, I'm going to use AmourSeal 1000 HS and some chips (vinyl?).

Thanks,
Mark.

 

[red vette mike]

Hey all,

Great resource here! Here's what I've done so far:

1. New construction, couple months old, unused, in Colorado (dry)

2. Rented an orbital sander and went over it with 80 grit (use to sheets at a time to keep from ripping!)

3. Use H&C etcher a couple times. First half strength, second full strength.

4. Rinsed 3 or 4 times, once with a little baking soda in it to neutralize acid.

The problem is that after I added the acid, the floor had a "whiter" color... moreso in some spots than others. Also, only some spots had a sandpaper-like roughness, while others (especially where it is whiter) are smoother to the touch.

I worry that I didn't rinse the acid off soon enough (dried very quickly here in the low humidity) and the results of the etching are trapped still and it won't make a good bond.

Can anyone comment with knowledge or experience?

(This is not the white stuff from moisture in the concrete... it's not crystaline).

Thanks!

By the way, once the floor is prepped, I'm going to use AmourSeal 1000 HS and some chips (vinyl?).

Thanks,
Mark.

Mark: I just got through doing my floor and I had the same experience. Some areas were a different color than others, Yet I had put the muratic acid on every square inch and it smoked and fizzed over all of it. I think that is how it works. Others on this site said the same thing (do a search). Some used an etch that was not acid based and it did no smoking or bubbling-yet this was what the mfgr recommended. I think you have the 'etch' that you are looking for. Be aware that it took my floor from Sunday to Thursday to dry out completely. Tape a piece of plastic down to test for moisture. Good luck.
Mike

 

[maphill]

Thanks for the info, Mike!

BTW, I should have mentioned that the H&C Prep is Phosphoric Acid, I believe. I don't know if that will change anybody's insight, but it can't hurt to mention it.

Anybody else want to weigh in too? I mean, my floor is REALLY white in spots... (I should take a pic)

Thanks,
Mark.

 

[maphill]

Also, what prep do I need to do on the wood steps in the garage? I'd like to paint them too. The builder painted them with a blue/grey paint.

Thanks!

 

[Kingham]

Also, what prep do I need to do on the wood steps in the garage? I'd like to paint them too. The builder painted them with a blue/grey paint.

Thanks!

If you have a chaulky residue left... you need to rinse the floor a few more times and scrub it clean. you can use a concrete cleaner after the acid etch step to clean again. but just make sure to rinse very throughly.

for the wood.... If the paint is not pealing and shows no sign of this ..... surface the paint with 80 grit sand paper. make sure to sand it real good so the epoxy has something to stick too.

 

[SKINNER]

Be aware that it took my floor from Sunday to Thursday to dry out completely. Tape a piece of plastic down to test for moisture. Good luck.
Mike

Mike,

Did you pressure wash your floor or just hose and squegee? I cleaned and etched mine Wed using the hose and a foam squeege, and I'm hoping to lay the epoxy down tomorrow.