I was given two jars of powder coat paint . One jar is fine but the other is clumpy and does an unsatisfactorily  job .  Should  I just   throw it away or is there a way to unclump it  . I can squeeze the clumps into powder but dont know if its   worth the effort or if it would even work if I did get all the clumps out . The brand is Netcraft .

I had an issue similar to yours with some paint that got left out in the garage. I used a strainer to sift out the clumps and make the paint usable, but quality is still not great. It will work in a fluid bed, but you do not get smooth coverage. I do use it to tamp on secondary colors with a paint brush. I doubt the fish care but the quality will not be the same. I did get a kind of cool textured pattern with some of it.

If you have a scrap piece of metal you can determine if it is ok or not. I have a small mesh strainer and was able to break up clumped powder as Bdnoble84 described. I had it happen to some Protec brown and Harbor freight flat black, the Protec I was able to salvage most of it, the Harbor freight had to be thrown away. Now the reason I mentioned the scrap piece of metal is so you can use it to try the powder after the clumps are broken up. If you heat it and then apply the powder to it like you do a jig head, you'll know if the paint is any good by how it goes on, if it is smooth you are fine, if it ends up with a lumpy appearance then throw it out.

Yeah , I cant get satisfactory results with it .  I'm just going to toss  it .