I also purchased the Harbor Freight 110# sand blaster. I worked horribly out of the box. But, I was in the midst of a job - sandblasting a area that needed to be repaired on my backhoe so I couldn't stop - really needed the sandblaster to work.
Spent a couple hours figuring it all out, made some adjustments / modifications and now it works GREAT - I wouldn't trade it for the world - and I've used a lot of different sandblasters. The modifications:
1) The sand HAS to be dry - this is true for most sandblasters, but this one especially so - the 110# IMO is still a large size home unit so they are a little more sensitive than the big industrial ones. I purchase play sand from Lowes which is stored inside the store. If I purchase cheaper play sand from Walmart - you can see the moisture inside the bag because it is stored outside - and I suspect that moisture is one of the ways the vendor delivers the product to Walmart by weight. If the sand is wet I spread it out on plastic in the sun to dry before I sweep it up for step #2 below.
2) You MUST sift the sand - or spend lots of time taking the nozzle, manifold (the part at the bottom of the tank) apart - constantly. I just pulled a window screen off my trailer (a 1966 single-wide - the "Star Regal" model - not to put on heirs). At any rate, I pulled off a window sreen, frame attached and set it on top of a 5 gallon bucket - you'd be amazed at what sifts out of playsand - or any other type of sand, especially if you're recycling your blast media. All those little peebles are guaranteed to clog the sandblaster - you can either take the extra 4 minutes per refill to sift, or stop every 20 seconds of blasting and clear the jams from inside the unit.
3) MOST IMPORTANT - after the close nipples are installed firmly on the manifold - maybe even installed on the bottom of the tank - although I didn't do mine in this way - run successively larger drill bits down the manifold from the nipple where the heavy black blasting hose attaches at the bottom of the tank. The problem here is that the close nipple from the bottom of the tank to the center of the manifold sticks way into the manifold - it cuts off the passage by at least 50% which causes a ton of jams. Start with a bit that fits inside the end nipple (again the one where the black hose attaches). After you've cut off the protruding end of the center nipple (protruding on the inside of the unit) then move up 3 or 4 drill sizes (I use a standard drill index) to open up the ID if the end nipple. Go slow through all of this because the drill bit wants to catch the ragged end of the middle close nipple - I broke a bit in this process, but got it out easily. Again, this is the MOST IMPORTANT modification.
4) Moisture is a problem no matter where you are, I live in Florida where it is especially humid - bigger tanks help and I also use a variety of moisture traps.
Once this is all done - and it took me about the time it took to write all this down, you'll be amazed at how well this "Cheap" sandblaster works.
Let me know how this works out if anyone tries it.
Tremor, '85 Suburban 1/2 ton 2wd, high-mileage 350 (came with truck) or [more likely] swap for 6.2 H1 Diesel which I have on hand - never done conversion though and still have questions regarding plumbing etc.