Polybutene is the key ingedient to make proper K-bond foundry sand as smokeless as possible.

5 Gallon Buckets: $89.99
(Plus Shipping in USA)$35.00

Note: Do not substitute Two-Stroke oil for Polybutene.
Some Two-Stroke oil does contain Polybutene, however it is typically in the range of only 5-30%.
The other ingredients in Two-Stroke oil defeat the purpose of K-bond sand.

I can supply larger or smaller quantities, send an email explaining how much you need and your location.

Schmidt Motor Works, Orange California.