So I found myself looking for ideas on a DIY sand/soda/media blaster and stumbled across your design. I like what you had going, but I'm curious how it worked for you? It's been about two months since your last post and I'm guessing that it didn't live up to your expectations. As soon as I saw the updated design with the tip, I knew what your result would be. I hope it didn't cause too big of a mess! So I was thinking to myself, what could be done differently to make this successful? Then it hits me, Daniel Bernoulli. He wrote a book back in the early 1700's on hydrology. Which is where Bernoulli's principle comes from. I don't want to go into elaborate detail, but I would recommend doing a quick search and reading about it briefly. It basically has to do with atmospheric pressure and it's relation to flow of inviscous fluids. However, it has application value in gases as well. In order to create the type of suction (atmospheric pressure loss in the tube causing AP to push the media up the hose) you would need to flip your setup around. By placing the tip or narrower end on the side of the incoming air and the widest part on the output, you'll be able to produce the effect that you're looking for. It's not the ideal setup however. Ideally, the "blowing apparatus" would work best if the transition from narrow to wide were a conical shape with the media hose connecting before the cone reaches it's widest opening. On either end of this cone you could have pipe or tubing of some kind of equal width to the opening on that end. If you search for "venturi" you'll be able to see exactly what i'm talking about. I'm going to see what I have around my shop and start making one myself. So if I come up with anything worth while I'll be sure to post my findings. But like I said, if you were to simply reverse your t-barb fitting with the tip installed to the intake, you should still get a desirable result. Let us know if that works better for you!