Welding Tips and Tricks

I've been toying with the idea of building a water cooler and I'm just wondering if it is absolutely vital to use a brass pump as opposed to say a cast iron pump with a brass impeller?

I guess there is potential for rust deposits to block the torch's water jacket and have other potentially undesirable side effects when using a cast iron pump but if one was to use demineralised water would this effect be mitigated?

Thoughts?

Flo

There's quite a bit of chat about DIY coolers at the moment.

Take a look at some of Rupe's posts. The build of his epic copper cooler is pretty detailed, and I seem to remember there was discussion of some pump specifics, too.

All the best with this. I get the feeling ill be doing this myself one day soon.


Kym

Hi Kym,

Yes I have read Rupes' thread about his water cooler. It's certainly next level! I don't know whether I want to go into quite as much detail as he has but I guess it's the sort of project that you could either do quite simply or give it all the bells and whistles.

Flo

OzFlo wrote:Hi Kym,

Yes I have read Rupes' thread about his water cooler. It's certainly next level! I don't know whether I want to go into quite as much detail as he has but I guess it's the sort of project that you could either do quite simply or give it all the bells and whistles.

Flo

Yeah, the auto switching is pretty full on. I think I'll just be going with the old sticker above the bench that says 'switch water cooler on!'


Kym

I have destroyed one cast iron gear pump due to corrosion.

Just bought and recieved a Procon pump as replacement. Got a new one from UK for 40£, quite good price I think.

AndersK wrote:I have destroyed one cast iron gear pump due to corrosion.

Just bought and recieved a Procon pump as replacement. Got a new one from UK for 40£, quite good price I think.

Hi AndersK,

How long did it take to fail the cast iron pump? Were you using plain tap water or distilled/demineralised water? Coolant? Was the impeller brass or cast iron as well?

Sorry for all the questions.. and yes that does sound like a good price for the procon pump..

Flo

MosquitoMoto wrote:
Yeah, the auto switching is pretty full on. I think I'll just be going with the old sticker above the bench that says 'switch water cooler on!'


Kym

Haha! Same..

It stood unused for about 6 months then it seized.
Dont remember if I had distilled or tap water. Obviously not enough anti freeze to prevent corrosion.

Gears in hardened steel, probably sintered material,they where still good though.

Corroded area was mainly around the shaft seal so it didnt help replacing it.

I'm in the process of building my own TIG cooler right now. It will probably look like this:
I am using 12V shurflo membrane pumps, which are designed for continous operation.
To be honest, this will be the second version of my cooler. The fist one runs okay, but my pump is at its absolute limit, pulling 1 Amp obove it's specified limit due to my large radiator (small pipe diameter = high flow resistance) I used. Here's a picture of my first prototype:

Best regards,

Alexis

Nice design there. What is that type of radiator?

Im gonna add temp guages too

The radiator of my prototype (second image) is one used for PC-watercooling. It's the model MO-RA3 http://watercool.de/en/mo-ra3-0
The problem with this radiator is, that at a certain flowrate the flow resistance becomes very large and therfore a lot of pumps tend to be at their limit. I used this big radiator with the intention to to be able to use low noise fans with low air flow rates. But the problem with the pump being at its limit was severe, therfore in my new design I chose a much smaller radiator with lower flow resistance but increased the air flow rate using bigger fans. Hopefully this will relieve the pump at its given flowrate.

The new radiator will also be one used for PC-watercooling:
Best regards,

Alexis

Check eBay for a pro con brand of pump. Many of there pumps are adjustable for discharge pressure. And are capable of high head pressure. Plus there very reliable. They come in brass or SS.

What about something like this heat exchanger?

or this one?

The down side of that style of coil is that it has a tube header. You would have a hard time getting even flow through the coil with the low flow rates of a tig rig. Path of least resistance means likely only one small section of a coil like that would be disapating your heat load. What would work best is some sort of single pass coil with only one path for the water to go through.

http://www.ebay.com/itm/NOS-Tecumseh-Re ... SwgQ9VzTof
A coil like this would be ideal.

couldn't be that bad? lol

Your right you would probably have enough mass to take the heat. But it's a common problem in hydronic heat coils if the flow rate isn't correct. I've seen coils like that with 180 deg f water pumped through them that will get a frozen burst in a line of the coil from uneven flow.

Built this in the last year. A member from another welding site was kind enough to give me the part numbers of what he used to build his. Mine is portable and can be used with several different tig welders I have. I also have quick connects on the argon line. The tank I built using 11 ga. stainless.

Alexis

That's a nice looking design and similar to how I envisage mine turning out..


rahtreelimbs

nice work with your creation too! What sort of pressure is the system running at?

Poland308 wrote:Check eBay for a pro con brand of pump. Many of there pumps are adjustable for discharge pressure. And are capable of high head pressure. Plus there very reliable. They come in brass or SS.

That's what I have been doing but I was wanting to explore options.. Just as a point of interest what sorts of pressures and flow rates does a water cooler need to operate at?

I measured it once on a 20 torch and I needed 5 bar to drive 2 l/min through.
I think CK states minimum 1 l/min for that size.

Thanks AndersK. That gives me a baseline. Looks like a procon pump will be in my future..

Flo

This is where I got mine:
http://m.ebay.co.uk/itm/221927366962

AndersK wrote:This is where I got mine:
http://m.ebay.co.uk/itm/221927366962

Cheers mate!

Most of the numbers I saw were around 50psi to drive around a litre a minute through the torch. Torch restriction seems the limiting factor, maybe more so with CK? Don't know how the passages compare with other torches but there seemed enough restriction that even going up to 70 or 80psi didn't make a huge difference.

I also tested it out a fair bit the other weekend, with the return flow via the radiator but fan switched off. I welded around 200amps for about and hour, around 60% duty. Kept checking the temperature of the torch, nothing fancy just against my wrist. At a guess the hottest it got was around 40C, once I stopped welding it was drop to around 30C. The tank holding the 14lt of water or so was up around 30C by the end. As with engine cooling you can have the water pumping too fast for efficient heat transfer (apparently). Just bought a IR temp meter. I'll have to check it properly this weekend.

The Procon I used just happened to be stainless steel. Not intended but just happened to be what was on ebay at the time. You can get them with adjustable outputs. Not sure how reliable or easy to adjust it is but if you just put a tee on pump outlet and have one side to the torch and the other returning to the tank via a needle valve or even a ball valve you can adjust pressure to suit fairly easily. Just a note on the adjustable ones though, if its overpumping and releasing internally it just circulates the same water back to the inlet of the pump. I think its better to bypass any excess pressure back to the tank if you can.