sandblasting

Bill,

Do you have a drier on the incoming air line? If not, then the blasting media will tend to stick together and not "flow". Or just drop a big vibrator in the media tank.

John

I do have a drier. You may be on to somthing about the vibrater. I have been hitting the bottom of my catch funnel with a hammer. An auger to push the beads into the airflow would work too. The top of the 50 lb tank has air to pressurize the tank. Then the air goes through the venturi, as it stops up the pressuer equalizes and the flow stops. The little ball valves that you adjust to mix the air and media have to be constantly Fcd with. I have to take out my gloved hands, turn off the air. There has to be a better way or nothing would get sandblasted EVER! I'm through messing with it today, but I may better look again at my moisture control. Here are some particulars, http://www.nortonsandblasting.com/nsbdryair.html

Just a wild guess, but perhaps heating the tank with a heat lamp would help the moisture escape.
I have a smaller set up (home made) but always have problems with high humidity here in Florida. I noticed that the moist sand tends to say at the bottom of the tank. For this reason mine seems to work better if I keep the pick up tube just below the surface (don't know if that is possible with yours)and I only fill the tank 1/4 full at a time. The biggest problem I have is keeping the hoses from collapsing in on themselves from the suction pressure.
I would also suspect different mediums handle moisture different. I tend to use medium grade silica sand, but my system is way under powered compaired to yours
Yep, just looked at your link, your system is in a whole different leage than the cheap system I use.

Well, if it is not due to moist air clogging things.......

I have run into a similar situation when sandblasting a 1967 Corvette chassis. The unit I was using was SUPER sensitive to the amount of sand going into the hose and nozzle.

You might just need to find the sweet spot.

Take the valve off the bottom of the tank and inspect it for dirt.All it takes is for onelittle pebble to get in there and this will happen.I think it runs for a couple of seconds because that's how much media is making it past the blockage.Try this and let us know

Oh and I almost forgot,after you remove the valve flip it upside down and tap it on something I havehad todo this a few times Hope this helps

I cant get to the page you posted but what I usually do with the cabinet we have is cover the tip of the nozzle and pull the trigger. The air backflows through the venturi and blows out any trash cought in the line. Then you just remove cover and blast away. Depending on which cabinet you have mileage may vary.

I have a cheap blast cabinet from Harbor Freight and had similar problems...I ended up drying my sand by pouring it into a box and putting it out in the sun or putting a two inch layer in the bottom of the box with a fan or a heater to blow on the sand and dry it. I also went to kiddy sand and it tends to clump less and is still pretty fine. I use to use the finer glass bead, but after switching to the Kiddy Sand I found it works better, plus its like $4-5 for a 20 or 30 pound bag as Home Depot. It works much better and cuts so much faster. That came from as a suggestion of another forum member and I will never switch back.

I purchased a higher quality blast gun...well at least I think its a better gun...but I made sure that it has a larger inlet where the sand is sucked in. below is the gun I have. Its not perfect but way better than what came with the cabinet.

Often my gun clogs...to unclog I also put my finger over the end of the gun and blast air, It helps.

I've seen what other forum members have for dryers....the good ones are $300-500...they have a heater type system that gets rid of all the moisture. Seems like the link you posted is a system you could blast a whole car with...way better than the garbage I have. Maybe put your blast media in the oven to dry out the moisture before putting it the tank? I agree there has to be a better way. [FLASH_VIDEO]

Good luck I know how frustrating it can be.

Hey Bill is this a new system? Pressure fed blasters can be finicky things. But once they are set right they work so much faster then the siphon feed units.

The moisture does not have to be visible, or the sand doesn't have to look wet to be a real problem. I fought with it for some time. I bought the HF line dryer and all my issues went away:

http://www.harborfreight.com/c...air-dryer-40211.html

They go on sale from time to time for $299....but something has changed in the HF ownership. I am not sure they will continue to do so.

We have also bought industrial line dryers from equipment liquidators for 1/2 that.

I have my compressor in a small closet but the heat and moisture build in the closet as well. I moved my air intake to another room; keep in mind the air intake is as noisy as the compressor:







I also dropped the dead-man. It is quite heavy after blasting all day on a car and the ceramic tips break every time you look at them. I started using the air hose quick couplers. I buy them by the handful. They have a slightly larger opening which means slightly less pressure but they cover a bit more area. I use one for an hour or two, when the side wears through I throw on another.







I sweep up the sand, filter it and use it again. I let about 25% go by the way side because it is not as sharp the second time through. I prefer play sand. It is the most consistent and is about the right grit for what I do. If it is damp I spread it out in the sun then sweep it up and use it:









Removing the rust after soda blasting and conditioning the metal to accept paint which soda blasting does not do:

Thanks you guys. It was nice to get up this morning with new ideas waiting for me. I see I'm not the only one that's been going through this. I'm dumping my sand, cleaning my valves and conditioning my air! Then maybe I can blast my GTS headers for my new 408! Bill 1362

I have the same set up as COMP2 and I have no issues .. I have used crushed glass, black beauty, sand and it dont clog ...but i use 125 psi conistantlty .. the problem is the damb media makes a damn mess ... i want to bring the car to the neighbors blast it and leave ..i hate sweeping the shit up all day long.

Ron

quote:

Originally posted by accobra:
..i hate sweeping the shit up all day long.

Ron

X2

I got that sucker runnin' now. Tips like Comp2 is using. I use the pressure tank and blow the media into the incubator. I do have to kick the tank all the time. I think I can put a rubber hammer on an old wiper motor.Recycle through the screen funnel. There are mouse droppings in my glass beads. I have a fan sucking out, and I'm wearing a resperator to. I should just dump what is contaminated? Is there a way to sterilize the shit?

Tank