Had a small visit from the Tinsle Fairy today

I hadn't cast in a few years and today was teaching my SOL the basics. I had a baggie of sawdust that had been sitting under the bench and I added a small fistful to my bottom pour, heard a pop and got a few splatters on my welding shirt. Wasn't a whole lot to it, this time, but I guess the moral of the story is you never know when and where and how viciously she'll show up. Took the sawdust inside and dried it out in the oven, cured the problem. Was glad the SOL was standing there as he thought I was crazy when I told him to show up this morning in full combat gear. Reinforced my point.

That's surprising that sawdust would cause a blast.

I'm guessing you stirred it in before the "pop"?

I have never had that happen, and today was casting with range scrap ~ bullets and wood chips that had sat outside over the winter (still winter here and freezing today). I filled the pot with wood chips and range scrap, let it heat up and melt then skimmed off the char and jackets then set to casting. No problem. I even added more range scrap/chips to the melt a couple of times but let it sit on top first. I didn't stir in until it was all hot and smoking.

If there's water or condensation there it won't do anything until it is under the molten lead.

Longbow

Bug in the sawdust?

Bet it woke you right up.

SHiloh

Had a spider to cause a pretty good size tinsel fairy onetime,if I had not been wearing glasses at the time I may would have lost an eye.Got a few splatters on my face but already being old and ugly the tiny scars are hardly noticeable now.It taught me to pre heat everything going into the smelt and get it dry.

It was just a little pop, but kind of thinking that the sawdust being out there for so long might have been a little hydroscopic. Any way, dried it out in the oven and going to keep it in the house from now own. This is some stuff that one of our vendor sponsors sent me along with an order I placed with him. It's primo for the Pro Melt. (when it don't spit at you)

the old redwood dust.
that stuff was almost like talcum powder.