I use Rio Grande’s paste solder nearly every day in my filigree work.
It is a great product and works very well.
Can’t say that I have seen it “spitting like a camel”
It is very different from sheet and wire solder, and I generally do
not generally use it on anything but filigree.
I think it would be suitable in many applications, but I have really
only tried it on my filigree pieces
Rio’s paste solder appears to be solvent based. The solvent seems to
quickly evaporate as the piece is heated, leaving behind a crusty
looking residue which then melts as the metal reaches the solder
Is it possible that your “spitting paste solder” is water based and
spits as the water boils off?