If you have ever built a water-cooling system or researched prices and components you know that it can get pretty expensive. Not everything has to be expensive with water-cooling though; with this guide you will be able to build a cheap watercooling reservoir for around 10 dollars. The reservoir cost me $4, the barbs were $1 each, the J-B weld was $5 and I had everything else.
You can really use almost anything to be the reservoir however I have found that a DU-BRO fuel tank works really well. You can pick one up at your local hobby shop. I would suggest you get the 10oz or 12oz one, you can go bigger but there is really no need.
Your DU-BRO fuel tank is intended for use with a RC plane or car, so it comes with a lot of parts you do not need, however hang on to all of them because we are not going to have them go to waste. Unscrew the 1 screw in the top of it and shake everything out.
I decided to use 3/8″ barbs for no particular reason. I prefer to use 1/2″ because you get a better flow rate but I will not be using this reservoir for anything as I already have one in my system with 1/2″ fittings.
The first thing you will want to do is to make the outlet hole. All you will really need to do is drill a hole in the bottom of the reservoir (opposite side of the hole already in it.) Be sure when you make the hole so that the barb will fit very snugly because get as tight of a seal as possible.
Now that you are done with the outlet you can do the inlet unless of course you decide to make the inlet first. Depending on how and where you are going to mount the reservoir will determine where you will make the inlet hole. I decided to put mine on one of the sides. Make the hole close to the top hole maybe 3/4 of the way up.
You now have your inlet and outlet hole where you will now mount your barbs.