Orion Motor Tech 1.5 Gal Vacuum Chamber with Pump Kit, 3.5 cfm Vacuum Pump and Chamber Kit with Tempered Glass Lid 5 ft Hose, Vacuum Degassing Chamber Kit for Stabilizing Wood Degassing Silicone Resin

Vacuum doesn't need to be really expensive. I understand one person's budget doesn't align with another, but... $100 chamber + pump. 3.5 CFM pump and a 1.5 gallon chamber. Considering buying them separately usually costs more, this is a reasonable price. This pump is adequate to reach a perfect vacuum up to 3 gallons reasonably in all altitudes. Vacuum alone isn't going to make clear pours. Vacuum is important to remove bubbles introduced early on. Combine with pour techniques and the appropriate resin and room temperature, you'll get a nearly bubble free cast. It works best with a pressure pot. Remove as many bubbles as you can, then condense any remaining under pressure. Pressure pots can get expensive.