04-13-2010, 12:14 PM
I would put a caveat on the acid etching.
The thinset I use does not recommend acid etching... so I grind. I have seen sites that contradict each other on this, some strongly recommend against acid etching because of the chemical/structural changes in the base concrete for the thinset bonding, others recommend acid etching, if grinding is not an option.
Have not seen anything against grinding, so I do (and it is a supreme pain in the as..er....knees) plus I have had a lifetime of commercial acid exposure, and I really do not want to add more acid load (if you do decide use acid, take my advice and definitely wear all of the protective gear, including an acid respirator - not to do this will wear down your respiratory system & teeth.... not worth it for a floor...)
The thinset I use does not recommend acid etching... so I grind. I have seen sites that contradict each other on this, some strongly recommend against acid etching because of the chemical/structural changes in the base concrete for the thinset bonding, others recommend acid etching, if grinding is not an option.
Have not seen anything against grinding, so I do (and it is a supreme pain in the as..er....knees) plus I have had a lifetime of commercial acid exposure, and I really do not want to add more acid load (if you do decide use acid, take my advice and definitely wear all of the protective gear, including an acid respirator - not to do this will wear down your respiratory system & teeth.... not worth it for a floor...)