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View Full Version : My mind is spinning again. New project is it sane?



cybor462
04-02-2007, 12:19 PM
Ok here goes,, I know this is a little ot but it is a shop question.

I have the HF powder coating system. The gun needs 10-15 psi constant air. Not much but more than the oiless compressor I bought for it (airbrush compressor). this compressor can hit 50 psi but 35 is recommended. The problem is there is no storage cap.

So hence my question..... Could I use a mapp gas or other small cyl. like a propane cyl from a camp stove? I think (not sure) but I think it could handle 35 psi. Does anyone know for sure?

I would place it in line with the compressor and output line so I would have a storage tank where the compressor could then maintain the needed 10-15 psi I need.

Next question, would there be any problem using a propane cyl. (any way to flush it?) and would it handle the needed pressure?

Just thinking off the wall here as I have this new compressor and I want to use it.

Would this tank severely increase moisture?

Rusty Marlin
04-02-2007, 12:57 PM
the pressure is a non-issue, propane is stored at a nominal range of 75-80 psi.

As for moisture... no idea.

pressurerelief
04-02-2007, 02:43 PM
Cybor 462

The pressure is not a problem for a propane cylinder. Most of them are spec'd at 240 psi. Moisture will drop out of the compressed air with this setup. If you want to go really cheap look for an appropriately rated empty Freon cylinder that has both a liquid and a vapor withdrawal valve. Avoid the single fill CFR type 39 cylinders. Use the vapor valve for air storage and the liquid withdrawal for a condensate removal utility. The liquid valve will have a dip tube to the bottom.

Second advantage of using a dual valve cylinder is purging is a snap. Flow a purge gas or air into the valve and vent the residual out of the other. Chances are the gas in the cylinder has a vapor density above one so purge into the vapor valve and vent out the liquid.

Rick

BobWarfield
04-02-2007, 02:43 PM
Why mess around with the propane tank when you can buy portable air tanks really cheaply?

Best,

BW

HTRN
04-02-2007, 02:58 PM
A coupla things - One, is there a chance of ignition with Propane? Powdercoating does have an eletrostatic charge involved.

Second, have you considered Paintball CO2 bottles? Filled almost anywhere, cheap to fill(like $5).. You will need a reg - Palmers Pursuit Shop sells a version of their Stab regulator that threads right onto the bottle, and is meant for Third party apps, also, if you need low pressure, go check some brewerys supplys, as they have low pressure regs for using Paintball cylinders for beer kegs.


HTRN

Evan
04-02-2007, 03:30 PM
A used propane tank will work fine. However, the air will smell like propane for the next few decades. If you want a nice tank and some fun too go buy a Balloon Time helium kit for about 20 to 25 bucks. The tank will take at least 150 psi and you can have fun emptying it. It also doesn't stink. I have two. The tank is the same size as a 20 lb propane bottle.

http://www.balloontime.com/BT_Product_30.htm (http://www.balloontime.com/)

speedsport
04-02-2007, 03:57 PM
use the spare tire from your car, it will hold a lot more than 35psi.

chipmaker4130
04-02-2007, 06:11 PM
Old propane tanks are good for a lot of projects and you can usually get rejects from the gas company bone yard for free. The last ones I used formed the barrell for a gas fired forge.

To make one absolutely safe for cutting and welding, simply fill it to the brim with water and dump it out. Done. Like Evan said, the additive used to impart the distinctive smell will linger for a long time, but there is no gas left.

Evan
04-02-2007, 06:48 PM
Or you can plan ahead as I do. I have about 4 tanks sitting out by the gas shed that have the valves open and have been aging from 10 to 20 years. They're almost ripe now.:)

Note: Change of temp from day to night ensures they are constantly "breathing".

CCWKen
04-02-2007, 07:24 PM
Your compressor and the proposed tank may have a hard time keeping up with the volume required. IIRC, those guns need 3-4cfm to work properly. Otherwise, you might as well grab a hand full of powder and throw it at your part. While the pressure is low, the volume is high and that's needed to suspend the particles so that they charge and cling to the part.

cybor462
04-02-2007, 08:29 PM
Wow, loads of good stuff. I truly like Evan and his tank ripening yard! Sounds like it is a blast sneaking around his house at night!

Ken... not sure if it needs that much as this air brush compressor would almost keep up, it is mainly the surge when I first spray it kicks in and hits the limit since there is no storage. With a storage tank the compressor could easily keep up as it will have a full load to start and I spray small parts so the gun is not being sprayed for any length of time.

I found my 10 gallon tire tank (used it for drag racing) so I will make something work with it. I really wanted a small tank so it would keep the weight down as I use my old yard shed as a booth. Carry the gun and compressor each time I use it. The yard shed is metal (makes a good ground when hanging the part with wire) and I do not care about a mess. It is 10x12 so I have loads of room.

Now I need to find some metric fittings as the compressor head is tapped metric. I could re-tap but there is not a lot of wall left and it is aluminum.

We must overcome! I must get smart! I should ...well I should shut up!:rolleyes:

pressurerelief
04-02-2007, 09:19 PM
To get rid of the odorant in a propane tank rinse the inside with bleach. Let it sit a couple of days and rotate it once in a while. The hypo solution will oxide the organic odorant and kill all trace of odor if done correctly. Rinse with tap water and let dry. We use 12.5% Sodium Hypochlorite (Industrial Bleach) to kill Hydrogen Sulfide liquified gas. Works like a charm.

Rick

cybor462
04-03-2007, 09:36 AM
Rick... that I will store for later use. I decided to use the compressor I already have in the shop. The shed I spray in is only 20' from the shop so I thought I will try the HF dryer/filter/regulator stand alone (real cheap) but it will be better than nothing. I will use it only for powdercoating. I will build a little stand for it and bring it in the shed when I need it. I will hook my compressor hose to it and then run the airbrush hose off it. I think it should work as the powder gun has a filter and my compressor has 3 filters and then this stand alone filter.

The reason I did not use my shop compressor was a moisture thing. It for some reason builds loads of moisture.

I will try this new idea and see where it leads me.

cybor462
04-03-2007, 09:44 PM
Well here is what I finally went with.
http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=1118&CategoryName=&SubCategoryName=

I use it stand alone just for the powdercoater. I still have that first burst of paint when the trigger is first pulled. Am I doing something wrong or is this normal?

CCWKen
04-04-2007, 12:09 AM
Hit the pedal then "squeeze" the trigger just a little. If you have to hold a light trigger to get a good dispersed flow, lower the pressure.