PC Products 25543 PC-Fahrenheit Moldable Epoxy Putty, 1 oz Stick, Brown

Q: Can I use it to repair cracks inside fireplace? The front piece behind the screen has a couple of cracks in the block. Can this be used to repair it?

I did not use this product in that way, but, from my experience with the product, I would not hesitate to try it. Of course it would only work for small cracks and it might be tricky to be sure you get an airtight seal if that's what you need. For the record, I used it to repair a broken "bakelite" handle on a stovetop pot and it has held for a long time through many uses. Good luck.

Q: Can I use just a little bit and store the rest>? How long will it keep if stored after being opened?

This a two part epoxy, so when you take the roll out of the tube it comes in there will usually be aluminum caps at the ends. Leave one alone and peel the other one of the roll and save it. You will use it to seal off the open end. I like to cut my rolls with a very sharp razor. The act of cutting a piece off for use will squish the roll where you are cutting it, and, of course, this will activate the epoxy were it comes in contact with the hardener. Just slap the aluminum end back on and store it a cool dry place. I've held on to mine for over two years now and its is a little harder to mix now. But it still works.

Q: What color does it dry? Dark brown? Medium brown? Tan?

Mine dried a lighter brown than it looked in the package. The inner core is lighter, so when the putty is mixed it dries to a light/medium brown. It's pretty easy to work with and sticks well to metal.