Paste solder sparks and sputters

I retired about 1-1/2 years ago and started trying my hand at making
sterling silver jewelery.

I don’t have a problem with using sheet or round silver solder with
Handy Flux but every time I try to use the paste solder it sparks
and sputters all over the place and leaves a black residue at the

Is it the solder or is it something I am or am not doing?

Tom Kuzia

Try heating it more slowly.