Coolant foaming bad

[TheCaveman19970]

We have two UMC1000ss at the shop I work at. One of them has been having an issue with the coolant foaming bad. After it’s been running for a few moments it loses pressure at the flood nozzles. In the tank the coolant level drops in the chamber the pumps sit in. It does this even if the tank is full. The other UMC does the same thing as far as the coolant dropping in the chamber where the pumps sit yet it doesn’t foam. The refractometer measures the coolant at 7%. We’ve ordered some anti foam for it but could the issue be somewhere else?

 

[marccongdon]

Could the pump be leaking and blasting coolant around in that chamber causing it to foam? I had that happen once except it just foamed up and made a mess.

 

[snowshooze]

Blaser Swisslube 755 B and the hell with it all.

 

[Digital Factory]

Try bumping up the concentration a few %.

How old is the coolant? Some of the additives get depleted over time. Anti-foam is one of them, but there are others as well.

Certain coolants also just foam worse than others.

 

[rjwalker1973]

Trash around the intake will cause the coolant pump to suck air. That can cause foaming as well.

 

[Pete Deal]

sounds like you’re sucking air into the pump. This will cause foaming. I don’t use that coolant but with my coolant too low a concentration won’t be the cause of foaming.

 

[???]

Not familiar with your machine but on mine the fines leak through into the tank and create a dam which causes the pump to run dry and foam.

I do think there are separate issue's in foaming. In the case of the pump running dry its simply aeration, in the case of good pumps which are fully submerged it's a coolant issue.

 

[rpowell]

We have two UMC1000ss at the shop I work at. One of them has been having an issue with the coolant foaming bad. After it’s been running for a few moments it loses pressure at the flood nozzles. In the tank the coolant level drops in the chamber the pumps sit in. It does this even if the tank is full. The other UMC does the same thing as far as the coolant dropping in the chamber where the pumps sit yet it doesn’t foam. The refractometer measures the coolant at 7%. We’ve ordered some anti foam for it but could the issue be somewhere else?

Several thoughts come to mind:

• If you are using a semi-synthetic, rather than a full synthetic, then it will contain some level of emulsifiers to couple the oil and "oil like" components. Emulsifiers - even the most low foaming - will contribute to foam. You may wish to try a full synthetic.
• Maintaining the correct concentration is alway key to coolant performance. Running too concentrated can contribute to foam as well as skin irritation; running too lean can lead to rust/corrosion and machining issues - especially on non-ferrous materials.
• Oddly, too much defoamer can also contribute to foaming so if you are adding any tank-side perhaps you could reduce the amount.
• Water quality plays a very important role. Water hardness below 75 ppm (especially water that has been treated with reverse osmosis or deionized) can worsen foam, water with 75-150 ppm should produce less foam; above 150 ppm should foam least of all.
• Microbes can generate biosurfactants that increase foaming. Tramp oil also can increase foaming indirectly, acting as a nutrient for microbes.
• If the fluid volume in the system drops too low the residence time is reduced and air entrainment can increase - especially if coolant is delivered under higher pressures. Small diameter pipes and/or sharp bends can also contribute to foam, as can incorrect delivery nozzle size.

 

[rjwalker1973]

Several thoughts come to mind:

• If you are using a semi-synthetic, rather than a full synthetic, then it will contain some level of emulsifiers to couple the oil and "oil like" components. Emulsifiers - even the most low foaming - will contribute to foam. You may wish to try a full synthetic.
• Maintaining the correct concentration is alway key to coolant performance. Running too concentrated can contribute to foam as well as skin irritation; running too lean can lead to rust/corrosion and machining issues - especially on non-ferrous materials.
• Oddly, too much defoamer can also contribute to foaming so if you are adding any tank-side perhaps you could reduce the amount.
• Water quality plays a very important role. Water hardness below 75 ppm (especially water that has been treated with reverse osmosis or deionized) can worsen foam, water with 75-150 ppm should produce less foam; above 150 ppm should foam least of all.
• Microbes can generate biosurfactants that increase foaming. Tramp oil also can increase foaming indirectly, acting as a nutrient for microbes.
• If the fluid volume in the system drops too low the residence time is reduced and air entrainment can increase - especially if coolant is delivered under higher pressures. Small diameter pipes and/or sharp bends can also contribute to foam, as can incorrect delivery nozzle size.

Good stuff

 

[Mr. Atoz]

Always do your best to fix the reason for the foaming, rather than just dumping defoamer in. Defoamer is really a very last resort.

 

[rjwalker1973]

Always do your best to fix the reason for the foaming, rather than just dumping defoamer in. Defoamer is really a very last resort.

I agree. Where I used to work you would think some people drank the stuff how fast they went through it. I would use maybe a capfull a week if that.

 

[pcasanova]

Just making sure you didn't do what I did, new vf3 with the auto coolant refill. adjusting the concentrate
with the refractometer I hit 5 on the scale and thought why am I foaming so bad, after I read into it the refractometer is
in percentage its some sugar level or something and when I read into the coolant documentation it said use a 2.8 factor
to get the percentage on the refractometer. My dumb ass had a 14% ration, started dumping in water and got the brix into 2-2.5 and foaming stopped

 

[rjwalker1973]

Just making sure you didn't do what I did, new vf3 with the auto coolant refill. adjusting the concentrate
with the refractometer I hit 5 on the scale and thought why am I foaming so bad, after I read into it the refractometer is
in percentage its some sugar level or something and when I read into the coolant documentation it said use a 2.8 factor
to get the percentage on the refractometer. My dumb ass had a 14% ration, started dumping in water and got the brix into 2-2.5 and foaming stopped

Trust me you are not the first or last to make that mistake. For the younger folk that may not know. The BRIX scale was originally used for sugar based fluids. Unless you have a refractive index of 1 what you are reading on the BRIX scale on your refractometer is not accurate. Some synthetics can have a refractive index of 3 which means you have to multiply what you get from the BRIX scale of the refractometer. by 3. You can find what your coolants refractive index is on the data sheets for your coolant. Also calibrate your refractometer before using.

 

[Donkey Hotey]

I'm going to just add to the same as others have been saying: it sounds like the pump inlet is starving for coolant.

Haas has changed the inlet screen method a bunch of times but, my guess is going to be that the pump inlet lives in a coffee can sized screen filter. The screen gets gummed up with old coolant and chips, then the coolant can't flow through properly and the pump is sitting inside. It will pump the inside of that screen dry if it gets bad enough. At that point the coolant impeller becomes a blender-aerator and it will turn everything to foam.

Nobody likes cleaning them. If you don't have a solvent tank or some kind of go-to cleaner you use for cutting coolant slime, I've found this stuff to work awesome:

Zep ZUHFD18 Foam Degreaser, 18 oz - Walmart.com

Arrives by tomorrow Buy Zep ZUHFD18 Foam Degreaser, 18 oz at Walmart.com

www.walmart.com

Zep Citrus cleaner. Walmart has it in the automotive aisle by the engine degreaser and carb cleaner. Home Depot sells it in gallons. I use it for cleaning all of my machines and tooling but, especially coolant crud. It smells good and doesn't beat up your hands. For that screen, I'd spray it on, let it sit for ten minutes or so and try to use warm water to rinse it out. It might take two or three cleanings to get it spotless.