Basic Blasting Cabinet Set Up?

[mcman56]

I bought a used blasting cabinet, the cheapest HF cabinet, and I have a 3hp compressor so it is about as basic as it can get.  It came with some kind of media so I thought I would give it a try.  It is not sand so I'm guessing glass beads or could it even be soda.  It got wet at some time so there was some caking which I tried to break up.  The blaster is not working.  I am getting air flow and some very light cutting action.  It looks like I'm even spraying some moisture.  There is no dust extraction system and there is very little dust blowing around inside the cabinet.  When I pull the gun apart, I do see a few little caked together chunks.  The feed hose does get full of media.  PSI set to 100 and it looks to have the smallest nozzle, 0.18".  At this point, I'm just interested in getting it working well enough to complete a small job.  Improvements will follow later.   I do have a wet vac to use for dust extraction.  I have a number of questions.
1. Are blasting guns tolerant of any caking/ clumping or does it need to be totally powder?  Do I need to clean out the whole system and start over?
2.  I'm in the process of rebuilding a 45 year old Honda motorcycle engine.  This is a revival not a restoration.  It has some baked on clay that purple cleaner, pressure washing and everything else I have tried will not touch so I got the cabinet.  Soda seems to be the big thing today but I'm guessing it is not going to get that baked on clay.  I also need to remove some paint.  Are there any recommendation on what media to use?  In this situation over cutting is better than under cutting and taking forever.
3. Will any small moisture filter remove the moisture? 
4. Any other recommendations for this situation? 
5. How much media is needed for a small cabinet like this?   

[ChipMaker4130]

Siphon feed cabinets are extremely finicky. The media has to be completely dry, with NO clumping. The air supply also needs to be dry. If you're seeing visible moisture while blasting, its never going to work well, if at all.

[NP317]

As stated, you must use dry air, and of sufficient CFM.
Then use a more coarse media than soda, which clumps easily with the tiniest amount of moisture.
These things are true with my HF sand blasting cabinet.
And a vacuum for dust extraction is a requirement, too.
RussN

[mcman56]

Do you use a water separator, an air dryer or both? A separator seems easier to maintain.
Dan

[TimTheGrim]

I have the HF table top cabinet with the single side door. The HF siphon gun was always less than satisfactory so I replaced it (the gun) with one from Eastwood which is a great Improvement at a reasonable cost.

[RSG]

As mentioned above moisture is a killer especially for siphon style cabinets. Certain things like a long length of air hose (50' or more) from the compressor to the cabinet will help for starters to cool the air to condense moisture. I made a 50' copper cooling coil for this application that can be bleed. Then a desiccant air dryer after that will solve moisture problems.

If you want to cut fast go with Garnet to start but any sort of final profile finish you'll want to consider some sort of glass bead after, assuming this is aluminium we are talking about. I prefer sizes in 3 to 10 for this.

If you do plan to upgrade down the road Tacoma Company makes a wonderful array of "kits" for the HF floor model cabinet.

[mcman56]

I cleaned out the whole system and bought some glass beads. It is working OK but I do see some occasional moisture. I did install one of these water separators but nothing accumulates in there. Is there a better separator or something else? The air compressor is working very very hard.
https://www.harborfreight.com/oilwater- ... 68246.html

[Bill Shields]

Not much of a separator for the volumes of air you are pushing.

One the size of a quart oil can would be the minimum I would recommend...your compressor is going to work very hard just to push air through this

[whateg0]

A small compressor will exacerbate any moisture issues you have because the air never gets a chance to cool before it leaves the tank.

[mcman56]

Can anyone recommend a specific separator? I'm not understanding how size matters when what I have is capturing no moisture.

[Harold_V]

The air compressor is working very very hard.

I suspect you won't like what I'll say, but please understand I'm not trying to annoy you. I'd just like to relate what I've been through, perhaps with the chance that you may glean something useful

I've owned and operated a blast cabinet for more than 52 years. I started out (briefly) with a 3/4 horse Craftsman compressor, which I had originally purchased for use with a spray guy. Needless to say, I did a lot more waiting than I did blasting, and came to realize that it simply was not up to the task. I then turned my attention towards a replacement, but I wanted to ensure that what I purchased would not be less than adequate. Didn't need to be overkill, just adequate. I was also somewhat limited by my three phase service, which was, then, an open delta. I would not be capable of operating a much larger motor than the five horse I chose.

After some research, I landed on the five horse compound Quincy that I own currently. It operates between 150 and 175 psi, and delivers right at 20 cubic feet/minute@ 175 psi. I tend to operate my blast cabinet @ 100 psi. The compressor can keep up with the blasting process, and even manages to stop occasionally. It has a low and high pressure cylinder, with the air being discharged from the compressor through a finned cast iron housing that dissipates some heat. When I operate the compressor for blasting for a prolonged period, the tank, which is 80 gallons, gets quite warm. Once that happens, moisture no longer condenses within the tank, and is forwarded to the airlines, where it cools and condenses. I can blast for short intervals without any moisture, however, so I get by reasonably well under normal circumstances.

It is not likely that you will be capable of prolonged blasting with your three horse compressor, although you certainly will be capable so long as you're willing to wait for air recovery. A larger tank, in and of itself, won't solve the problem, as that only prolongs the period of time before your compressor starts, and will also prolong the recovery time.

I highly recommend you pursue a cooling coil similar to that which was built by RSG. I have that in mind for my setup, although the current price of copper is certainly a deterrent.

A comment on "capturing" moisture. What you're trying to accomplish won't be successful unless you can cool the air. A canister of any size will slowly warm up and still allow moisture to remain in suspension, only to wet the air to your cabinet. When air is released to atmosphere, it expands, where it cools quickly and releases the suspended moisture. Cooling is needed, along with slowing the velocity of the air, plus a place for the water to accumulate. That's the beauty of RSG's design. It's large enough in diameter to provide slow air movement, plus has enough surface area and heat conductivity to expel the heat. The larger the pipe size chosen, the more effective it will be. A cooling fan provided for the coil face would certainly be useful as well.

How I wish I had a chiller.

H

[curtis cutter]

I have been turning my non synchro mental gears on options for a cooling system for a while. I want to run this by folks to get an opinion prior to wasting time.

What if I were to take and old home A/C condenser and removed the refrigerant coils and replace with 3/4" copper? I could assemble the copper in such a way that the condensed water would migrate downward to a catch tank at the bottom. After the catch tank the air would continue to the shop.
I would control the large condenser fan with a thermal switch attached to the incoming air line.

Thoughts?