Stop in for a cup of coffee

Was spaying the muriatic acid yesterday. Tell you what it works, even strips the paint out of the corner seams. Just have to be careful with it. Got a small sprayer just for that. Dollar store $5. Nice little sprayer actually.
View attachment 1715525355
Not familiar with the muriatic acid, where do you buy it?? When your done do you have to wipe the area, or spray it down??