I have had my 250EX for over a year and finally got around to building a cooler for it (still no cart, but that's next on the agenda). I can't believe I took so long to get this done.
I have been using a WP-17 and WP-9 torch until now and I am looking forward to doing some extended welding sessions without toasting my hands or taking long breaks to cool things down.
This was a fun project. Like many others, I elected to use a carbonator as the basis for the design, with the stainless steel tank used as a reservoir.
I owe a huge debt of gratitude to many of the fine people that have posted their solutions on this forum and elsewhere. It helped immensely.
The Procon pump on my unit is rated 125GPH and 250PSI. With that in mind, I decided not to adjust the internal bypass relief valve in the Procon pump.
It is not recommended by the Manufacturer and creates excessive heat build up of the coolant by short circuiting the flow internally within the pump.
Instead, I split the output from the pump, with one 3/8 line directed back into the tank, utilizing an inline ball valve to adjust the pressure.
The other side of the split output goes to the torch water supply, with an in-line pressure gauge.
I installed a cheap (< $4 ) but effective 12V digital thermostat (photo attached) that I picked up on eBay to monitor the temperature of the tank coolant.
Speaking of coolant, I elected to go with a 60/40 mix of distilled water and low silicate auto anti freeze (my welder sits in an unheated garage here in Canada). There will be many who would caution against that choice, but I have done extensive research on this. There are lots of people that have been using ethylene glycol and distilled water for years with no issues. I am not buying into the hype over clogged torch cavities caused by leak sealants in the anti freeze. Each to his own. I have a clear hose that leads from the power cable water return Dinse connector to the input on the cooler. If I start to see deposits or film building on the inside of that hose, I will change coolant. Until then, the green antifreeze is colour coordinated with the Everlast 250EX case!
I circulate the return from the torch through a 7 x 12 transmission cooler. I fabed an air plenum from a piece of 28 gauge sheet metal from Home Depot (it was actually an air plenum end cap).
I am using one 5 inch 120 CFM 12V cooling fan to draw air through the transmission cooler. The exhaust air blows directly onto the coolant tank and pump motor which seems to really assist in keeping things cool.
At first, I hooked up the WP-18 torch that came with the 250EX. Even with the pressure dialed down to 25 PSI, I was getting a flow rate of in excess of 2 litres per minute.
Once I hooked up the WP-20 torch, I had to adjust the pressure up to 45 PSI to get a flow rate of 1 Litre per minute. The smaller coolant path on the WP-20 torch really restricts the flow rate.
The digital thermostat is really a nice convenience and it helps to monitor the rate of temperature rise when the pump is operating.
Bottom line, this thing works great and is much quieter than the 250EX fan motor.
I like that I built it myself and if any component fails for whatever reason, I can replace it and get back to welding in short order.
Regarding the 250EX, I had some anxiety when I chose to go with the unit, but after using it for a year, the anxiety has been replaced with satisfaction. It has been a solid performer. Well done Everlast!Attachment 12872Attachment 12871Attachment 12873Attachment 12874Attachment 12875Attachment 12876Attachment 12877Attachment 12878Attachment 12879Attachment 12880Attachment 12881
