I have some frozen meat that I would like to be able to cut while frozen so that some can be used now and the rest frozen for later use. It's to hard to cut through with a knife, so a saw would be better. I have a hacksaw but all the blades are painted. Is there a reasonably easy way to make them safe to use with food? I don't mind putting in some effort if I have a tool at the end of it that I can reuse many times. I have considered sandpaper but I think this would dull the teeth.
No, the hacksaw you pick up at your local hardware store is not food grade no matter how much you clean or scrape. If you are concerned about food safety, you don't know what materials are used in their construction or what the blade, paint, lubricants, frame, and other workings might have been treated with.
They make butcher saws with stainless steel blades specifically designed to address your concerns. They might be called meat saws or bone saws, but the name will be suggestive of their intended purpose.
I'd just go ahead and use any old industrial hack saw blade, and then if you are worried about contaminants, just cut off a thin slice adjacent to where the blade cut, once the meat is defrosted. Keep it simple.
Of course, what I generally do is cut the meat into usable size portions and then freeze it --- but that won't work if your meat is already frozen. I have occasionally put some in the microwave on a defrost cycle, and then when just a little bit defrosted, cut it, and refreeze the unneeded portion.