Increasing Airbrush Tank Capacity

I recently got my hands on a very cheap airbrush with a tiny compressor. The capacity of it was just none existent and it spat water while spraying so it was useless for its designed purpose in more ways then one.

This seemed like a good small project to try to fix both these problems.

Step 1: The Airbrush and Extras

Firstly the airbrush i got for very cheap and also got a partial refund for the thing simply not working. So i imagine it was so cheap to make its wasn't even worth the postage back.

Second is another air filter, one small one made to fit onto the airbrush end of the air line. There is a larger one straight from the compressor. However the filters are for taking out the moisture in the air, so water doesn't come out the end of the airbrush and ruin the paint. Because the larger air filter is so close to the compressor, it means the air is heated up from it and some of the water gets through as vapor. Pretty big design fail.

To solve this you will need a filter later down the line, so instead of relocating i got another, smaller one. as well as adding a tank so the air will have a lot more time to cool as well as hugely increasing the air capacity if the compressor. So i added both.

Thirdly another air line, one to go into the new tank and one to exit it.

Fourth is to couple the two in and out air lines and one for the tank.

Lastly, the tank itself. Its from an old boiler and had to be drained of some water. I think it has two different compartments inside since the valve on it was under pressure while the other opening was open and mostly filled with water. I drained to lighten the tank but would not use this second valve at all, all i need to know is that the other compartment could hold the pressure i want. it says 3bar on the tank, that's about 43 psi so over 10psi more then i will ever need which is great.

Step 2: Attaching the Tee

I added this pretty simply, cut a short tube that fit snugly inside to bridge the gap. Added a two part epoxy to the internal bridging tube as well as the two outer parts that need to be fixed to each other, so help air seal the whole thing. I clamped it so it stayed straight and left it to cure for over 24hours.

Step 3: Testing the Concept

It works!

No leaks it keeps pressure and air capacity is so large that it takes a good few minuets for the compressor to fill the tank to about 25-30psi (i dont ever plan to go over 30psi).

The air that came out the airbrush was totally dry, because of the tank the air cools enough and because of the extra filter all the moister easily gets filtered out of the cool air.

This set up isn't perfect however, with the compressor on-top like that is will wobble off over time so not ideal. As well as its taking up a lot more space because of the tank resting flat like that.

Step 4: Making a Stand for the Tank

I made a few measurements and made a small stand to keep the tank up on its side, to save space and have the compressor next to the tank on firm ground or firm table at least.

In the last picture the tank is able to free stand on the, err, stand, but just to make it more secure i did later epoxy the tank to the stand.

Step 5: The Final Overview

All in all i think this entire project got me a half decent airbrush for about £20

I did get an adapter for the tank but the tank didnt seem to be 1/4"BSP as i thought. will have to do more research or will have to sleeve the outside connection with a tube and epoxy like i did on the inside, just encase.

I also added another larger airbrush since the extra air capacity can sustain a larger brush for a good few minuets of continuous use before the pressure drops. As well as modifying the stand for the brushes so it can hold the larger brush and i added quick swap couplers to the end line and the two brushes.