air drier on compressor?

[jiall2]

I’ve got 2 cheap air driers on a soda blaster system and still have moisture problems. Any reasonably priced driers out there? Thanks for any help.

[auldscott]

I have long used a homemade gadget to remove liquid water and mist. It won’t remove water vapor but I have found that vapor doesn’t cause trouble when you are blasting.

I put it about 6 feet away from the soda blast gun, and it has a dedicated (dry inside) hose that is not used for anything else.

It is made from a two foot long piece of 3" diameter Schedule 40 PVC pipe. One end has a cap bonded to it, and the cap is tapped 1/4" NPT. This is the outlet. There are four stainless steel hose clamps around the outside, roughly evenly spaced.

The other end has a cleanout bonded to it.

There is a piece of hardware cloth wedged in the pipe, down at the outlet end.

I stuff the pipe loosely with wadded up paper towels, then screw in the cleanout cap. The air inlet is near the cleanout end, drilled and tapped into the side of the pipe.

Depending on how humid the day is, you might have to change the paper towels once or twice after hours of blasting, but I have never had all of the paper towel material get wet through.

[johnny-infl]

Jiall – you did not mention what pressure you are working with.
prior to the air dryer/filter, you should have the pressure reducer at the tank
to work at below 60psi at the air filter entrance.
any threaded metal fitting into PVC is a loaded bullet waiting to happen.
any pressure above 60psi into PVC is a pipe bomb waiting to happen.
yes, it is commonly done by the cheap DIY auto and hobby shops all over the world.
and yes, they can – and DO explode sending sharp shapnel shards all over the place that can maim and blind a person.
research and caution should be at the top of your list !!!!!!!
just bite the bullet and spend 50 to a hundred bucks for the real deal rated at 125psi and be safe.

jus my Dos Centavos

.

[amuller]

I have to agree with Johnny–using PVC for compressed air is generally considered unsafe. You could make up the same setup out of galvanized or black pipe and it would be safer. As also said, the liquid separator should be downstream of any pressure reducing valve, as the lowered pressure will cause lowered temperature and tend to condense liquid moisture out.

[auldscott]

Thanks to those who cautioned against using PVC under air pressure. I have never had any problem up to 90 psi but quite right, my advice carries unnecessary risk. Metal is better!

[drifter]

Make sure you drain your compressor tank regularly. You’d be surprised how much water can collect in the tank.

[jimparrott]

Ideally you should have 50′ of air line, 25′ minimum between the compressor and the separator. This allows the air to cool and condense, allowing moisture
to be separated. Living in South Louisiana with high humidity, doing this has made a world of difference in my air system. Hope this helps.

Jim

[1946zephyr]

quote Johnny_inFL:

Jiall – you did not mention what pressure you are working with.
prior to the air dryer/filter, you should have the pressure reducer at the tank
to work at below 60psi at the air filter entrance.
any threaded metal fitting into PVC is a loaded bullet waiting to happen.
any pressure above 60psi into PVC is a pipe bomb waiting to happen.
yes, it is commonly done by the cheap DIY auto and hobby shops all over the world.
and yes, they can – and DO explode sending sharp shapnel shards all over the place that can maim and blind a person.
research and caution should be at the top of your list !!!!!!!
just bite the bullet and spend 50 to a hundred bucks for the real deal rated at 125psi and be safe.

jus my Dos Centavos

.

I second this motion. Good ol’ metal pipe (preferably galvanized ) is the best way to go.

[jiall2]

Thank you all. I’m operating at about 80 – 90 psi and I have a very short air line. I will do some adjusting and try again after I get the system dried out. THANKS

[johnny-infl]

also – the size and CFM of the compressor can contribute to many problems. . . . . . what size are you running ?
this is only my own personal summation that air storage is to blame for a lot of moisture issues.
when air is heated, cooled, compressed, expanded, it does crazy things.
to keep it stable, under a constant pressure, and dry will always be a challange. even for NASA.
a small tank with a small motor and minimal CFM will always give you fits with moisture issues, that is the given.
until you get that under control, you will struggle with any soft, absorbant media, such as soda.
Like Mr. Drifter said: drain your compressor tank regularly.
soda blasting is the new kid on the block for hobbyists ~ just go down to Harbor Freight and pick one up.
but there is very little information available as how to set it up correctly, safely, and efficiently.
#1 is to keep the soda as dry as possible. #2 get the delivery air into the media pressure pot as dry as possible.
#3 have a dryer and collector between the media pot and compressed air tank.
the more filters and moisture traps in the system, the better your success.
I have done media blasting for a living for the past 40 or so years. I eventually went from sand and silica blasting to aluminum oxide.
which will last forever when collected, sifted, and stored correctly.
the hobby media blasters available at the Big Box Stores are fine – as long as the proper air supply is maintained, dryed and filtered.
also, another key ingredient is the orifice of the nozzle. You can not use a 1/4" or 1/8" orifice for soda with less than the required CFM.
if you are using the siphon feed blasting handgun, you will have moisture issues and frustrations, no matter what.
if you are a hobbyist and only perform soda blasting a few times a year, just deal with the frustrations.
if you move up to a more often situation, then you will have to invest in a good, high CFM compressor, storage tank, dryers and filters.
personal safety equipment such as a good hood and respiratory mask/filters should be at the top of your list.
a good start-up system is to cruise CraigsList for an old compressor with a 60 or 80 gallon tank that does not work.
scrap the motor – fix a good access drain valve on the bottom and use that as your air storage tank at 125psi and reduce it down from there.
that will give you the air flow necessary for small projects so you don’t have to wait for your small compressor to catch up to your demand.
a small compressor that runs continuously will get HOT – then when the warm air enters the cool media pot and cools down, it condenses,
then you have the moisture issues.

The MINIMUM equipment that you will need is:
3/32" orifice ceramic nozzle for fine abrasives
Recommended pressure range: 35-90 PSI
Required air flow: 8.5 CFM @ 90 PSI

you will become frustrated very quickly if you use anything less than the required parameters for your system.
also, "sand" blasting equipment will not give you satisfactory results without converting everything over to a "soda" system.

like Daniel Boone always told me ~ KEEP YOUR POWDER DRY !!

.

[Author]

Posts