PC-Masonry is a thick paste. 1/4" wide crack is wide enough to fill. 1/64" is not a wide enough crack.
It is possible to tint PC-Masonry using powdered cement colors or universal tints used for paint. Alternatively, applying sand or grit to wet PC-Masonry's surface helps disguise it. PC-Masonry can be primed and painted.
PC-Masonry can stick to rigid PVC.
Yes, PC-Masonry can be used to secure a stone or concrete statue to a base.
Jim, I've used this product to fill the cracks between a concrete floor & a cast iron waste pipe. It did the job.
PC-Masonry is thick and is best for larger cracks. Perhaps, PC-Clear epoxy would work nicely. It is a liquid.
you can also try https://www.homedepot.com/p/Quikrete-10-lb-Hydraulic-Water-Stop-Cement-112611/100318494
If you temporally clamp the shelf in place, this should work.
I believe it is.
Yes, it will adhere in a garage that has an epoxy coat over the concrete.