Got a couple of suggestions......Grit will build up along the inside edge of your door and fall to the floor every time you open it. Make a pan under the door to catch it or better yet, weld a piece of angle along the bottom inside edge of the door so any grit that lands there will slide back into the box. 2-Coat the backside of the inside with rubber your cabibnent with rubber. Grit will eat through the plywood, causing splinters and chips to mix with your grit and plug up you gun. 3-Get lot's of light inside the box. One of mine has a florencent fixture above glass accross the top. The other started life with a floodlight inside but it did not last long. Grit gets in the bulb socket and eats it away. It now uses a flourencent trouble light instead. 3-Gotta have a dust collection system. Shop vacs will have a life of about a month because the grit gets so fine that it passes through the filter and into the motor. Shopvacs use the filtered air flow to cool the motor, so it pulls all the grit right through the bearings. You need a "By-Pass" type of vacumm cleaner motor available from Grainger. Or a dust collection system from TIP. When you start using your blaster, get a doormat to throw inside to work on, one of the old matts made up of tires cut into strips and wired together. This will extend the life of the grill tenfold. Believe it or not, 90% of your blasting will be in one small area in the center of your view. Your grill will be eat up here first and need replacing within a year or two. What kind of grit are you planning to use? I use 60 grit aluminum oxid in one of my boxes and glass beads in the other. The alox is what you want for paint prep, glass beads for general clean up of aluminum and brass