The manufacturer of my new cement coping for my kidney shaped pool refuses to stand behind his product. 2 x4 marks have shown themselves as the coping was delivered and installed - that were not there three months ago. They are marks of where the coping had been stacked upon 2 x 4's and are now IN the cement.

Any suggestions of how to get them out?
a. I have had one coping piece ground down - and the marks come out - but the coping is now smooth and has to be acid etched all over again so as not to be slippery.
b. Someone suggest having each piece sandblasted.

Also white alkali has repeatedly come up on the surface of each cement piece. Sometimes it dries and upon the next rain disappears. Any ideas of how to remove the alkali or prevent it from appearing?