Problem: You want to sandblast a tube, but it does not fit in the dang sandblaster.
Solution: Make your own Sandblaster Doors™, to keep the media from flying everywhere.
The very sophisticated and technologically complex process is to
- use cardboard to make panels with a hole in them
- add gaskets and foam
- gaffer tape it to the sandblaster (with the doors open, obviously)
Step 1: Laser Cut Doors
Nothing fancy needed. Just need something that won't let garnet through. I measured the sandblaster door, put that into Fusion 360, and then laser cut the panel. This is completely unnecessary, as you can just stand in front of the sandblaster with a piece of cardboard and cut it out until it covers the opening.
For my 1.5" dia. tube, I cut a hole that was 1.6" because I will have a gasket that the tube will squeeze through.
Step 2: Add Sealing Features
We want the new doors to be as air-tight as possible. In the case of the sandblaster at Pier 9, there was a side of the hinge that would cause a gap. The quick and cheap solution was to add foam tape (thin layer of foam with an adhesive back) to the cardboard. The foam expands into the gaps you can't exactly design for.
Where the tube inserts, I added a square piece of gasket with a circle punched out. With a gasket making kit (available at Pier 9), punching a hole is easy.
Step 3: Hella Gaffer's Tape
And then to seal the edges, put Gaffer's tape everywhere.
Step 4: Fit the Tube Through and Sandblast!
But talk to your shop staff (required at Pier 9!) to make sure your set up is all checked out. And have somebody watch you when you first start blasting to make sure you don't have any leaks!
Kudos to Paolo for the initial idea.