Cool Shirt Cooler Build Version 2
Ok, I am always looking to improve on things….thus the first version cooler will now be designated to the crew chief, along with a “Cool mat” which is in the design/redesign phase.
The idea was two fold…..after chumping at Brainerd, I realized that it was a pain in the rear to try and remove the cooler, drain the water, add new ice, put back in the car, etc during a 5 minute pit stop. Thus, we will now have 2 identical coolers where we can have the 2nd cooler loaded and ready to swap into the car, and not have to mess with the water and ice during the stop. Much simpler. I also didn’t really like the hoses sticking out of the top of the cooler as I found they wanted to kink. Not a huge deal, as the pump seemed to push through it, but none the less, it wasn’t as pretty as I’d like. So I ordered 3 more Engels coolers and a new shopping list for a new design:
–7/8″ hole saw
–9/64 drill bit
–3/8-18 pipe tap
–Various wrenches, pliers, hacksaw
–1 Engel Cooler (Austin Cayak and Canoe ~ $41)
–1/2″ PVC pipe. A foot will do.
–1/2 90 PCV fittings, female/female x 2
–3/4″ ID reinforced vinyl hose. 6 inches is more than plenty
–1 Rule brand boat bilge pump. 300gph (~$25 at any boat shop)
–1 tube of plastic weld
–PCV cement and primer (you could use the plastic weld instead if you want)
–2 Bulkhead cool shirt quick connects with shut off valve. McMaster Carr #5923K24
–Pipe thread sealer tape
–For the hose from the cooler connection to the driver’s shirt connection, you can choose to use either 1/4″ hose or 3/8″ hose. Cool shirt uses 1/4″ hose in their systems, either is fine.
–(qty 2) 5923K43 (1/4″) or 44 (3/8″) for the female barb connections with shut off valve
–(qty 2) 5923K73 (1/4″) or 74 (3/8″) for the male barb connections with shut off valve
–6-8 feet of hose, vinyl or otherwise. Clear vinyl hose runs about 35 cents a foot at the hardware store. I have not been able to source the insulation yet that cool shirt uses for the hoses, but still looking.
So we start with our cooler
With the 7/8″ hole saw, drill two holes in close proximity to each other. The 1/2″ PVC is a tight fit through the hole which is perfect.
Cut a 1 1/2″ or so length of PVC, tap one end to 3/8-18 and wrap the threads of the fitting and screw it in. Repeat.
Next use a little plastic weld epoxy, goo the holes up, and slide the two pipes that you assembled through. I put the end of the pipe just past flush in the cooler wall (sticking out)
From there, cut a piece of hose and insert it on the bilge pump. Use a heat gun to heat the hose enough to slide over another short piece of 1/2″ PVC (you will have to measure about how much pipe you need to make the height so that the pump lays on the bottom of the tank). Assemble your pipes with primer and PVC cement. I laid the pump on it’s side after some advice from others as if you leave them upright, they have a hard time priming and starting the water flow due to air bubbles in the pump. Laying it on it’s side will prevent this. I zip tied the electrical wire to the piping to keep it secured out of the way.
I chose to add another 90 to the return line, just to help guide the water downward into the cooler. Then drill two 9/64 holes to run the electrical wires through. From there, you can hook power to your switch or potentiometer control (I highly recommend using just an on/off toggle, and not the potentiometer for flow control, simpler is better in this case).
Now the key to any cool shirt system is to give yourself as much advantage as you can. When it is 100 degrees out, doesn’t matter what cooler or shirt you use, the ice is going to melt and water will warm. With the hundreds upon hundreds of hours we have logged with endurance racing where the driver is in the car for a minimum of 2 hours, we have learned a few things. #1 is to use block ice. Cubed ice will melt way too quickly. Most grocery stores will carry block ice in the back if you ask them. If you have a way to keep it cold for the weekend (Yeti cooler, or RV with a freezer), then you can make your own block ice at home with tuperware containers, then transfer them to zip lock bags for transport). Block ice has the ability to stay cold for hours. #2 is to run the cooler in stages. Run it for a lap, shut it off for a lap or two (for long endurance races). If you are running short races, then you can probably run it full tilt all the time, and I recommend running it when sitting in the grid for extended periods so you aren’t baking in the sun.