I've been looking at tearing out my fiberglass shower, installing Kerdi, and re-tiling the whole thing. During my research into this project, I've come across quite a few forums that have members typing in all caps about not mixing thinset with a cordless drill because the motor will burn out. Is this true? Even for small batches? My shower is only 3' W x 3' D x 6' H.
I've got an older DeWalt 14.4V drill that's on it's way to retirement (its batteries aren't holding a charge well), as well as a new Milwaukee M12 lithium ion 12V drill and an M12 Fuel 1/4" impact driver. Is one of those sufficient or should I go buy a cheap HF corded drill or check Craigslist to add to my growing collection of tools-that-rotate-things?
Best Answer
First of all, I have to say that with the volume of work you have you can just mix the thinset by hand. I once had to install about 2.7 square meters of tiling and mixed several small batches of thinset with a spattle - no problems at all, I wasted much more time on applying the thinset and installing the tiles evenly. Totally not worth risking the drill.
Next, you should not use any drill for mixing unless its manual says it's suitable for mixing or that it has overload protection that slows the drill down in case of overload. Drills explicitly suitable for mixing are typically professional drills with very low RPM (500-700 RPM) and so very high torque. The "HF corded drill" you reference is nothing near that. Drills with overload protection are typically professional cordless drills with smart electronics that monitors all the parts for overheating and reduces the output power in case of overload. The Milwaukee M12 you have likely has the right type of overload protection (that's the impression I have from reading the online specs of the drill) and so you likely could use it for this purpose.