Dielectric fluid for Sinker EDM Where and what to buy

I have been running 3 Swiss EDM machines since the early 60's. My dad always ran kerosene in them and so that is what I have run in them as well. I'm past ready to make the switch. I am looking for advice on what to buy, and from where to buy it. I'm looking for something less volatile, safer for my environment and less smelly. I have had Rustlick 500 recommended, is there anything better to use and why? I EDM steel and titanium mostly, sometimes tantalum, niobium and copper using copper alloy electrodes. I am aware I will need to clean all the old crap out of the system and use new filters. Advice would be appreciated.

Commonwealth Oil’s EDM-244. I wouldn't run kerosene due to fire flare ups. When I got my sinker second hand, the previous owner uses some sort of paraffinic oil in it that scared the heck out of me when it would vaporize and ignite. I haven't had any fire concern in mine since switching to the 244.

jmullett said:

Commonwealth Oil’s EDM-244. I wouldn't run kerosene due to fire flare ups. When I got my sinker second hand, the previous owner uses some sort of paraffinic oil in it that scared the heck out of me when it would vaporize and ignite. I haven't had any fire concern in mine since switching to the 244.

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OK, I appreciate the answer, but it did not really address any questions. Why do you consider the 244 better, and where do you get it for a good price including shipping. I anticipated the side note of advice about fire. I have been using kerosene for over 50 years and with proper care, NEVER experienced any kind of dangerous fire. The flash point of kerosene is over 100 degrees F . If you don't allow the temp of the dielectric to exceed 100 degrees F it will not pose any fire hazard. That said, I understand the threat and I don't need any more information about kerosene. What I said is I'm trying to replace my kerosene with something less volatile, safer for my environment and less smelly. So, who sells it for less and some contact information would be nice.

EDM oil choices

Hi Porschefix:
There are a lot of choices out there; a bewildering number in fact.
They sort themselves into 3 basic classes:
1) Petroleum based
2) Synthetics
3) Vegetable based

The petroleum based ones like Rustlick 30 and Rustlick 250 work OK but are stinky, hard on the skin and degrade over time, but are the cheapest option to buy, other than kerosene.

The synthetics like Ionoplus and Commonwealth are very pleasant to work with by comparison, but cost a lot.

The vegetable based ones are used in the medical industry.
I haven't heard anything about them good or bad from a cost or performance point of view but my wild ass guess is they'll be expensive and prone to degradation and rancidity.

I'd go with Commonwealth synthetic but only because I can buy it easily in Canada; your situation in Texas will be completely different.

A single note of caution though; I'm told that if you switch from a petroleum based dielectric to a synthetic you MUST clean your system very thoroughly before you dump in the new stuff or you'll wreck its performance.

It's a helluva nasty job so I've been putting it off, and I'm facing it with growing trepidation as my Rustlick 250 gets too old to work well anymore.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
www.vancouverwireedm.com
Clarus Microtech Inc. | Facebook

When I bought my old Agie EMT-1 a couple years ago from a shop in Pittsburgh, it came with half a barrel of Rustlick 500 synthetic so I've been using that since. It's relatively odorless to me ( and I'm a wine snob ) and my filters are keeping it clean and clear. It's pleasant to work with except when I shower my feet with it. If you're considering the Rustlick brand here's a link to a Belmont page that compares 3 different varieties of it:

http://www.belmont4edm.com/PDF_SPECS/rustlick_oil/Rustlick_Flyer.pdf

It says that the 250 version is odorless but evidently not, according to Marcus.

I've been using Rustlick 250 for years, and it'd odorless as far as I am concerned. I've also never seen it burn, although when surface flushing, I have occasionally had little hydrogen flash fires, which tell me the flushing isn't complete enough. The MSDS says the flash point is >200 deg.F.

Dennis

I would only add to consider the viscosity of the oil you purchase.
Recently ran into a thin rib burn situation where thinner oil performed better due to a "jump only" flushing strategy.
Was able to move more oil in and out of the cut with the pumping action of jump.
I would also think thinner dielectric would be better for through flushing with small ports.

The only draw-back I can see to thinner oil is a reduction in debris suspension.
Not sure which type of burn that could/would affect... Big surface areas burns perhaps??
I believe the electrical properties of the two different viscosities were the same.
May want to check that if you run big amps...

Jay Crumb
Advanced EDM, LLC

implmex said:

Hi Porschefix:
There are a lot of choices out there; a bewildering number in fact.
They sort themselves into 3 basic classes:
1) Petroleum based
2) Synthetics
3) Vegetable based

The petroleum based ones like Rustlick 30 and Rustlick 250 work OK but are stinky, hard on the skin and degrade over time, but are the cheapest option to buy, other than kerosene.

The synthetics like Ionoplus and Commonwealth are very pleasant to work with by comparison, but cost a lot.

The vegetable based ones are used in the medical industry.
I haven't heard anything about them good or bad from a cost or performance point of view but my wild ass guess is they'll be expensive and prone to degradation and rancidity.

I'd go with Commonwealth synthetic but only because I can buy it easily in Canada; your situation in Texas will be completely different.

A single note of caution though; I'm told that if you switch from a petroleum based dielectric to a synthetic you MUST clean your system very thoroughly before you dump in the new stuff or you'll wreck its performance.

It's a helluva nasty job so I've been putting it off, and I'm facing it with growing trepidation as my Rustlick 250 gets too old to work well anymore.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
www.vancouverwireedm.com
Clarus Microtech Inc. | Facebook

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jmullet, thanks for the +1 for commonwealth, I'm looking into it and several dealers I've spoken with have touted it as being good stuff. I've not seen it costs more and I was offered a discount for 2-55 gl drums +shipping. I'm still shopping around. QUESTION FOR YOU. Why the commonwealth 244 versus the other commonwealth fluids? Any specific reasons?

Marcus, Thanks for your, as always detailed reply. The Commonwealth Euro Supreme has been recommended by a dealer in TX and they stock it, and have plans to keep it in stock.

Rich L said:

When I bought my old Agie EMT-1 a couple years ago from a shop in Pittsburgh, it came with half a barrel of Rustlick 500 synthetic so I've been using that since. It's relatively odorless to me ( and I'm a wine snob ) and my filters are keeping it clean and clear. It's pleasant to work with except when I shower my feet with it. If you're considering the Rustlick brand here's a link to a Belmont page that compares 3 different varieties of it:

http://www.belmont4edm.com/PDF_SPECS/rustlick_oil/Rustlick_Flyer.pdf

It says that the 250 version is odorless but evidently not, according to Marcus.

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I loved seeing the clear green fluid in your machine. What I'm seeing now is the Commonwealth is less costly and equal in quality, from what other people I've talked to have said. Do you know of any reason you would select Rustlick over Commonwealth iffen you were starting over? My question Rich, do you like those light green tennis shoes now? Thank you for your help, my greatest respect to your input.
Ron

JayCrumb said:

I would only add to consider the viscosity of the oil you purchase.
Recently ran into a thin rib burn situation where thinner oil performed better due to a "jump only" flushing strategy.
Was able to move more oil in and out of the cut with the pumping action of jump.
I would also think thinner dielectric would be better for through flushing with small ports.

The only draw-back I can see to thinner oil is a reduction in debris suspension.
Not sure which type of burn that could/would affect... Big surface areas burns perhaps??
I believe the electrical properties of the two different viscosities were the same.
May want to check that if you run big amps...

Jay Crumb
Advanced EDM, LLC

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I saw(felt) the viscosity of the Rustlick 500 in Rich L's machine, it appears to be roughly equivalent to the kerosene I've been using. I agree with your input and will keep it foremost in mind. Thanks for the details

Porschefix said:

I loved seeing the clear green fluid in your machine. What I'm seeing now is the Commonwealth is less costly and equal in quality, from what other people I've talked to have said. Do you know of any reason you would select Rustlick over Commonwealth iffen you were starting over? My question Rich, do you like those light green tennis shoes now? Thank you for your help, my greatest respect to your input.
Ron

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If I were starting over I'd probably go the Commonwealth route because of (1) cost, and (2) I'm not doing anything near the periphery of capability of my machine or of technology. I would hate to clean the machine so that it would accept a different kind of fluid such as vegetable-based or petroleum-based since mine had been used with a synthetic. I wouldn't know what to flush my system with although I would ask what happens, or can happen, when different kinds of fluid are mixed. Are the different kinds of fluids, e.g. veg vs petroleum, somewhat or completely insoluble in each other causing bubbles or voids or troublesome inconsistencies in dielectric constant? I don't at all disagree with the notion of cleaning 'cause I like clean. Are brands mixable within genre? Just asking ...

I'm a bit surprised that all you got were 4 responses to your initial question out of hundreds of views and tens of experts.

My green shoes are hanging on my tank as a reminder to close the damn thing.

Cheers,
Rich

Rich L said:

If I were starting over I'd probably go the Commonwealth route because of (1) cost, and (2) I'm not doing anything near the periphery of capability of my machine or of technology. I would hate to clean the machine so that it would accept a different kind of fluid such as vegetable-based or petroleum-based since mine had been used with a synthetic. I wouldn't know what to flush my system with although I would ask what happens, or can happen, when different kinds of fluid are mixed. Are the different kinds of fluids, e.g. veg vs petroleum, somewhat or completely insoluble in each other causing bubbles or voids or troublesome inconsistencies in dielectric constant? I don't at all disagree with the notion of cleaning 'cause I like clean. Are brands mixable within genre? Just asking ...

I'm a bit surprised that all you got were 4 responses to your initial question out of hundreds of views and tens of experts.

My green shoes are hanging on my tank as a reminder to close the damn thing.

Cheers,
Rich

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Global EDM supply sells a couple of products made by Commonwealth. One is called EDM flushing fluid to be flushed through an already cleaned system before adding the synthetic and another called EDM Ram cleaner which is supposedly a more aggressive stuff to be mixed 20% with the old fluid. I'm still figuring out the whats and whys I'm getting answers to . As far as compatibility with different species, veggie organic vs. synthetic eg., don't know yet, different brands of same species, don't know that either, yet. Not looking forward to cleaning but it could be worse.
Same vein of topic, any idea of a good supplier of hoses for edm fluid use? The usual suspects, MSC, McMaster Carr seem to have hose, is that the best choice?
Thanks for the reply
Ron

How do you know when it is time to change dielectric?. My Eltee came with a tank full of dielectric, so I have no comparison of new vs old.
Has anyone have experience with Sinksyn-1 synthetic? (Synlube-Mi.com). McMaster is distributing it. $100/5gal

Porschefix said:

Global EDM supply sells a couple of products made by Commonwealth. One is called EDM flushing fluid to be flushed through an already cleaned system before adding the synthetic and another called EDM Ram cleaner which is supposedly a more aggressive stuff to be mixed 20% with the old fluid. I'm still figuring out the whats and whys I'm getting answers to . As far as compatibility with different species, veggie organic vs. synthetic eg., don't know yet, different brands of same species, don't know that either, yet. Not looking forward to cleaning but it could be worse...
Ron

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How did the dielectric changeover go? I need to replace a solvent based (EDMS-25) to a semi-synthetic. Cleaning the tank is a collossal task, as it is buried in the most inaccessible spot in the already tight shop. Also worried about hose/seal compatibility etc..



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I went with the Commonwealth synthetic, it has worked out well for me. One thing I've noticed is that, being an oil, it has a higher viscosity than kerosene and hence drains slower from the tank. Not a huge deal. Concern about seals and other immersed organic items is warranted, I have had a few small issues. Door seals I used for years started to swell and soften and I had to find a replacement, valve packing seals have needed adjustment and although I have not had to replace anything there thats not saying they won't be an issue in the future. I also replaced all the hoses as mine were literally allmost 50 years old.
Cleaning the tank is just going to have to be done. I recommend taking the tank and pump out of its location and cleaning out the old fluid, then the solids in the bottom and everywhere else and washing it down with soap and water and high pressure maybe even steam. Disposing of the old fluid I took to the people who recycle my oil and they had no further questions. Solids I assume can go to a landfill. I know getting the tank out will be an issue but just bite the bullet and do it, you probably won't have to do it again. As far as the Commonwealth cleaners, I bought 5 gals. of each and in hindsight I would have only used the Ram cleaner if I had to do it again. It was a good move to get rid of the old dielectric, it has virtually no smell and almost zero volatility. Be prepared to buy a case of filters unless you have a friend who has an extra case they'll never use.
Ron