CallMeAl In one of his videos he shows how he made a blast cabinet out of a clear storage container .
I made the 1 I left behind out of something similar to this.......

Did a cutout in the top and used plexiglass(not recommended though) for sight. Added foam around inside of lid and it was airtight. Worked great.
If I do build another one now, it will have a side door along with a top opening door. And be big enough to really blast anything of a good size in..... like bike frames and such. It's why I've put it off so far. Plus I need to rearrange the garage for it.