Okay I have borrowed my buddies Central Pneumatic (harbor freight brand) sandblaster. It's one of those pot blasters. I've tried fine dry play sand and the black course media. No matter what I do, this thing clogs. Before I throw this thing over the hill, can somebody tell me what I might be doing wrong. The media is absolutely dry. I even took the ceramic orifice completely out of the hose and it still clogs.

 

Try not opening the sand valve at the bottom of the pot all the way, I found this helped on mine.

 

Hey doc you can't just pour these items in and blast. You need to get a fine screen and put it in the top of the pot and it will stop all the big stuff from passing and it should work better. Take a welding rod and clean out the tip also.

 

I'm with Jeff.. close the media valve, open the air valve, and slowly open the media valve til you get a reliable flow.. I had a heck of a time with pebbles in the play sand.. after I screened all that out it went much better.

the media valve was never open all the way.

Sam

 

This is also true !!!!!!!

 

Thanks guys. That makes perfect sense about the media valve at the bottom of the tank. What about the valve at the top of the tank after the split with the air line? Should it be wide open?

 

I always have it wide open..as much air in to the tank as possible

Sam

 

Also make sure your air supply is dry. Any moisture in the lines will make blasting miserable.

The valve you are referring to normally stays open...if you get a clog of wet sand, try closing it momentarily. This will force all of the air thru the tank....will usually blow the clog out.

 

I could never open the sand valve more than half when i blasted my trailer.
They are kinda finicky good luck!

 

Another tip is to use construction sand, not play sand or cheap stuff like that. You get it from a building materials store, where they sell masonry materials. Ask for #70 silica sand. It's a fine enough grit that won't pit bad, won't clog as easy, but is still course enough to clean up your metal good. As mentioned, your sand has to be absolutely clean and dry, as well as your air, too. You typically need a really big compressor with a dryer to make a sand blaster work well.

 

I use mine with the air valve open and I slowly open the "sand" valve until I have a good blasting stream. The one on the bottom is usually about 40 or 50% open, more than that will plug.

You MUST have a water knock out or it will plug all the time. I actually have two, one at the compressor and one on the blaster. It you don't take the water out you will plug often.

Using sand is dangerous because fine silica in the lungs can kill you. If you use sand instead of something like black beauty you better at least do it outside and have a very good positive pressure air supplying respirator. I would get black beauty and not risk your health.

 

Where can you buy black beauty and what do you ask for?
thanks
jim

 

Doc, You received good advice here. My original sandblaster was a Tip that I bought at Hershey about 30 years ago, the same basic design as your unit. I experienced the same issues but managed to get it to work better although it was always problematic. I installed a piping cross (a 4 way like a 3 way tee but with 4) at the bottom to help clean out if it did plug.
A few years later I ran across a used Lindsey pressure pot, also at Hershey, and having used one before, I bought it for the right money and sold the Tip. The secret is in the mixing valve at the bottom. I have never had it plug and I do mean never! Lindsey (a New Hampshire company) sold out about 10 years ago but one of the real big guys in commercial sandbasters (I can't remember the name) bought up the company with that design and last I knew they were still available but at a high price (Like $1000+). I paid about 1/10 of that almost 30 years ago. The Linsdsey's were always green in color but the color changed to red after the company was sold.

Edit: It was Marco that bought Lindsey. Northern has the Marco unit like my Lindsey for a big WOW! $1700

 

Black BeautyŽ Abrasive (Boiler slag, Coal slag) from READE

Coal Slag Blasting Abrasive — 25 Lbs. | Blasting Media | Northern Tool + Equipment

and I agree with the comments about the dryer and water trap.. the HF unit has a water trap

Sam

 

Heck yeah it's some good advice. And I appreciate it. I had my sand valve wide open. And take a guess who's gonna pick up a couple of those water traps today. I actually remember having one in my hand when I bought my compressor and somehow laid it down before I got to the checkout counter.