View Full Version : Harbor Frieght 5/10 gal air tanks ?

03-05-2011, 04:43 PM
HF has coupon for $17.99 for the 5gal air tanks... question was, besides the obvious capacity differences between them (5/10gal) does it really make a big difference for pneumatic props using the smalling 5 gal tanks as reserves vs the larger 10gal ? If you have a 60gal master tank serving up 5-8 small 5gals tanks I would think it would work great and the only thing I can think of is doesn't give you quite the capacity as the 10gal tanks and the master tank having to kick on more. Looking for anything(concerns) that might not be so obvious in using smaller 5 gal tanks...

Allen H
03-05-2011, 08:25 PM
Id go for the 10 gallon, and add a moisture trap after the tank. The maindifference like you said is size.

Dark Attraction
03-06-2011, 09:02 AM
It really depends on what you are powering. The purpose of the air tank is to keep your pressure up at the time when your air demand at the prop exceeds the volume of air that can be sent through the air line. If your prop has only one small valve, the air supply from your line should be enough to power the prop consistently without an air tank. If you have several large cylinders firing off at once and... say only one small air hose between the compressor and the prop, your pressure at the prop will drop rapidly as the air pressure flows through the line.

If the prop is firing briefly, a small tank should be able to hold enough pressure to make the prop function properly through it's entire routine. If the prop has a long operation cycle... like a giant monster, a larger tank might be better.

One more thing to consider... the reserve tank can only compensate for a limited time. If the pressure in the tank drops too far, the air system will now be trying to fill the tank and operate the prop at the same time. If the demand at the prop end is too great for too long, your only solution will be to upgrade the air supply lines between the compressor and the prop.

The moisture trap idea is an interesting one. Unfortunately, these air tanks have the inlet at the top of the tank, and no drain cock underneath. We manually dump our tanks at the end of the season, but I was considering mounting them basically upside down in the future to facilitate a moisture trap and drain.

03-06-2011, 09:55 AM
I was concerned how long it would take for one of the small tanks to refill after an event, at first I was thinking it would be immediate but certainly there's a refill time maybe 5secs + or more depending on amount discharged. I think I'll use them on small cylinders only then, Interesting on the moisture, didn't think it would be an issue but I can see over time causing problems with cylinders, selenoids and needing to keep everything utmost dry.

What do you mean DarkAttr... on dumping your tanks, throwing them away or removing valves to let them dripdry? Could you add a moisture trap to one of those HF tanks easily you think if mounted upside down, mean can it really be done? Have to take a look next time at HF...

Dark Attraction
03-06-2011, 10:11 AM
I just had to disconnect the tanks and turn them upside down to drain the water. It should be very simple to mount the tanks upside down... add a few fittings and a drain cock, and you'd be set for fast water removal.

We have a pretty good filter coming off the compressor, but there is still plenty of condensation that makes it into the system. An air dryer for the system would be ideal, but they can get pricey depending on the flow rate. Our main compressor puts out 53 CFM.

03-06-2011, 11:57 AM
yeah, it seems simple enough then... thanks, that's serious CFM. I have to ask does that feed your entire haunt and how many devices (ballpark) would such a compressor run, I'd think you could do at least 30 or more...

Allen H
03-06-2011, 06:07 PM
On my taks guys I just made a manifold that make the moisture trap sit right, out of some pipe and fittings.
And thanks for helping with the thread!

03-06-2011, 07:04 PM
An interesting thing I discovered this weekend regarding air tanks- I've know for a while that you can convert a BBQ propane tank to an air tank (buy the conversion kits online), but where to find the tanks for cheap? How about FREE? How about as many as I could carry for free? Plus the valves are already removed! Those suckers are tough to get off!

Go to you local propane refill station and ask about discarded tanks!

I was getting my forklift tank refilled and while waiting I happened to look around behind the pump house... PALLETS full of them! Waiting to to go to the scrap yard. I asked nicely and they just gave them to me. Woot!

Probably ought mention what you are doing with them so they know not to give you a damaged tank.

03-06-2011, 08:07 PM
ZombieT... huh, nice idea on propane tank... so you have done it already then correct w/o any issues? if got any pics just curious to see the top nozzle parts.

Allen... if you got any pics too, wondering the most effective way to do this would be, you could just run another piece of air hose like 6" piece dangling and when tank mounted upside down moisture would collect in 6" air hose, at end just have t trap or something, this seems to be the easiest method. At season's end run tank empty using the 6" hose as a drain/air release.

03-07-2011, 12:29 PM
Well, like I said I just got them so- no, I have not completed them yet. Google it- there's tons of info out there about the process. Youtube has several DIY instructionals. The conversion kits are on ebay for about 8 bucks. Personally, I'll be custom plumbing them with black iron and plastic fittings. The only special advice I can think of is- if you are mounting these permanently, mount them valve side down so they don't collect moisture.