# Three questions to consider regarding moisture



## JWesleyH (Feb 4, 2021)

I'm retired , old, and confused so please consider the following with that in mind. 
1. Why doesn't anyone take the air from the bottom of the tank? Most shops have someone who can weld and fab up a stand that will raise the tank high enough to attach a 20 foot line (per Ingersol Rand ) at the 1 inch per four feet (per sewer line code) next to a wall with a filter / separator / dryer. Every time it's used all moisture would be purged and then where is the rust going to come from? I've worked at shops that only drained the compressor when the water started to spray out of our tools.
2. Why aren't any of the tanks coated on the inside? With self etching coatings being the norm, if I owned a body shop I would seriously consider coating the inside of a new tank. I've cut apart quite a few rusted out tanks and haven't seen one with any rust proofing yet. 
3. Why not dry the air before the pump? How hard would it be to fab up a simple duct and pull all the intake air from a 12 thousand BTU window air conditioner and also use it to cool the pump?


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## motormonkey (Jul 10, 2016)

1. Consider how much water you get when you drain the tank. If you took the shop air directly from the bottom of the tank, all that water/moisture is going right into the air system, and it would take a very serious and expensive filter/separator/dryer to remove all of it.
2. No internal coating will totally protect the tank. Water heaters are coated, and yet they rarely last more than about ten years.
3. The air that comes out of the compressor before it goes into the tank is hot, compressed, and full of humidity. Cooling and drying the air at that point is actually a very good idea. It is done on the highest end commercial compressors. That would likely raise the cost of consumer grade compressors too much though. There are lots of instructionals and Youboob videos about adding a pre cooler/dryer to a compressor. They usually use some kind of automotive oil cooler or refrigeration coil with a small fan, and a float type water trap. Google it for ideas.


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## stevon (Mar 5, 2019)

JWesleyH,

Question is why do you need rusty, oily contaminated water in your air line? Take air from the top or at least near the top on a side port. Most things are done for a reason usually cost is a factor in manufacturing

Stephen



JWesleyH said:


> I'm retired , old, and confused so please consider the following with that in mind.
> 1. Why doesn't anyone take the air from the bottom of the tank? Most shops have someone who can weld and fab up a stand that will raise the tank high enough to attach a 20 foot line (per Ingersol Rand ) at the 1 inch per four feet (per sewer line code) next to a wall with a filter / separator / dryer. Every time it's used all moisture would be purged and then where is the rust going to come from? I've worked at shops that only drained the compressor when the water started to spray out of our tools.
> 2. Why aren't any of the tanks coated on the inside? With self etching coatings being the norm, if I owned a body shop I would seriously consider coating the inside of a new tank. I've cut apart quite a few rusted out tanks and haven't seen one with any rust proofing yet.
> 3. Why not dry the air before the pump? How hard would it be to fab up a simple duct and pull all the intake air from a 12 thousand BTU window air conditioner and also use it to cool the pump?


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