FAQs

How to properly mix a coolant?

The ratio or concentration for each operation is different.  Consult with your Tower Sales Engineer on the target ratio.  Once this is established, use the "O.I.L." method.  " Oil in Last"  This applies to soluble oils, semi-synthetics, and synthetic water extendable products.  

For example - if your target ratio is 9:1 or 10%, add 9 parts of water to your container.  Then begin to add one part lubricant concentrate with agitation to get proper mixing.

Using a refractometer, get a reading from the mixed solution.  Every product has a different factor to determine the correct refractometer reading.  

The formula for this calculation is: Refractometer Reading (RI) = Concentration % / Factor.

For Tower's Saf-T-Cool 458, the Factor is 2.2.  So for a 9:1 or 10% solution, the Refractometer Reading is:

10% / 2.2 = 4.5

If your reading is higher, then you have too much coolant concentrate in your container.  If your reading is lower, then you have too much water.

There are a number of mechanical ways to properly mix coolants as well.  Please give us a call, and we will have one of our trained Application Engineers contact you to determine which method is best for your operations.

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What temperature is best for a machining coolant?

Ambient or normal plant temperatures are typically fine for most coolants, however, try to maintain a consistent temperature to avoid any possible piece part variations or twisting. Normally the cooler you can maintain your fluids, the better.  Higher sump temperatures, or coolant used above 110-115F, may indicate you do not have enough coolant flow, over working the coolant, or possibly the coolant sump is too small for the rollforming process. 

Standard rule of thumb:

• Synthetics, having a higher percentage water and no petroleum oil, offer superior cooling over oil containing products like Semi-Synthetics and Soluble Oils.  
• Coolant reservoirs should be at least 10-20 times the maximum GPM value of the coolant delivery pump – provides for 10-20 minutes retention time to cool down, separate chips, reject tramp oils, etc. before being recirculated back to the roll tooling.

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What causes machining coolants to smell over time?

Coolants, like any other water extendible product, can turn rancid over time.  A “rotten egg” smell is usually the result of “Bacteria” forming in the coolant.  Maintaining proper coolant mix ratios, good pH control and removing tramp oil will prompt coolant life.  Besides the foul smell, coolant with excessive bacteria can prompt operator skin issues or dermatitis.

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Is there a “shelf-life” for coolant concentrates stored in the original drum?

Yes, most coolants can last up to 1-2 years if stored properly – typical inside storage in regular plant environment and temperature.  However, if you determine any lost performance from your any coolant which is stored past one year, have your supplier check the remaining concentrate.

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What are the best practices for lubricating cut-off blades?

• Always spray (lubricate) both sides of the cut-off blade
• For difficult or severe guillotine blade cut-offs, try using the same coolant as in the rollformer only at a much stronger ratio
• If greater blade life is desired, consider using a highly compounded, light viscosity straight oil  

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Kleendraw W-4100I currently use the Kleendraw W-4100 in my tubes for bending, will the W-4100 turn to a powder in the tube when heated? if so, at what temperature.

this is a test from brooks

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Lubricant test 1A

Lubricant test 1A 6/13/18 BF

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What is a “Synthetic” coolant”?

A “Synthetics” or “Full Synthetic” coolant is basically defined as a coolant concentrate which does not contain any petroleum oils.  Once the water phase has evaporated, most synthetic coolants leave behind a light, dry-to-the touch residue. 

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What is the best overall coolant to use?

The best coolant to use will always depend on the process, materials being roll formed, your water quality, coolant delivery method (recirculating or spray / once through), tool life, required piece part finish and other environmental factors.  Also keep in mind the residue characteristics from the different coolant chemistries:

• Soluble Oils – light oily film, very machine and piece part friendly
• Semi-Synthetic – very slight oily film on parts and machine components
• Synthetics – dry film residue on parts and machine components 

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How much coolant flow should I use?

For most rollforming processes, the more coolant flow, the better.  Hence the name “Coolant”, it is designed to remove heat from the forming operation, flush away excessive chips, keep the roll tooling and machine clean.  Increased coolant flow takes excess dirt and debris back to the coolant reservoir for easier cleaning and maintenance.

Standard rule of thumb:

• Always deliver flood coolants to both top and bottom working rolls directly at the piece part entry where the material is being rollformed.
• Synthetics, having a higher percentage water and no petroleum oil, offer superior cooling over oil containing products like Semi-Synthetics and Soluble Oils.  

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What is the average sump-life for a coolant?

Coolant longevity will depend on many factors such as maintaining proper mix ratios, water quality, metals machined, plant environment, sump idle time, pH control, etc. – typically the better maintained the coolant is, the longer the useful life.  

Standard rule of thumb:

• Synthetics, containing no petroleum oils, typically offer the longest sump life as where Soluble Oils, containing the highest percentage of oils, normally have a shorter sump life. 

 

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What type of mandrel lubricant should I use?

            It mostly depends on the degree of bending or D of Bend.  That is the center line radius (CLR) of the tooling divided by the outside diameter (OD) of the tube.  Other factors like substrate, tube thickness, OD, and application all lead to selecting the best lube to fit the process.  However, gels, pastes, synthetic fluids, soluble oils, and compounded straight oils are the most common.  Each can fill specific needs within the process depending on chemistry and additives.  Consult a product specialist to help determine which product is the best for the overall process. 

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What is a tube bending gel?

A tube bending gel is water based synthetic lubricant of higher viscosity similar to that of hair gel yet pourable.  It can be clear or opaque and is generally used for its high barrier lubricity and ability to cling to the mandrel during the bending process.  Because it’s water based, the product can be cleaned with a mild alkaline or neutral cleaner if needed. 

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What is a tube bending paste?

A tube bending paste is normally a high viscosity, oil based emulsion.  It is generally used for heavy bending applications due to its oil content, high lubricity, extreme pressure additives and ability to cling to the mandrel during the bending process.  Paste products generally need to be cleaned from the tube using a mild to high alkaline cleaner.

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How do I apply gels/pastes to the mandrel?

Gels/pastes can be hand applied to the mandrel or inside the end of a tube before insertion onto the mandrel. To automate the gel/paste application to the mandrel through the rod, a pumping system is necessary.  Typical applicators that come with benders are fluid based systems that cannot handle the high viscosity of gels/pastes.  A NLGI 1 grease rated pump is normally sufficient to extract lube from a pail or drum and distribute through the mandrel rod.  An electrical or pneumatic signal from the bender is necessary to actuate the pump during each bend.  Consult a product specialist to help determine the best method of application. 

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If I want to use my existing oiling system, what type of lubricant should I select?

Most existing oiling systems are electrical or pneumatic pumps rated for up 1000 SUS viscosity and designed for straight oils.  However, full synthetic fluids can also be used straight or at various dilutions with water.  Soluble oils should be used with caution and only if the emulsion is very stable when mixed with water.  Some pumps can be rated up to 5000 SUS, broadening the range of fluids.  

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Can I weld through the residue after bending and not have porosity?

This depends on the chemistry and amount of the residue inside or outside of the bent tube.  For gels and synthetic products, a thin film can be welded through with minimal to no porosity.  Higher dilution of fluids can make it even easier.  However, with oil based products (pastes, soluble oils and compounded oils), the tube generally needs to be cleaned prior to welding.  Some soluble oils can be welded through if the dilution rate is high enough.  

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Do I need to lube the entire tube and how much should I use?

Lube should only be put where it needs to be which is in the bent areas.  A thin film (like butter on toast) should be used with gels, pastes.  In some cases, more lube is necessary to carry through the entire tube if applying by hand on a multiple bent tube.  In this case, put enough on the end of the tube that can carry through when the collet pulls the tube back over the mandrel.  Automating the process ensures that the minimal amount of lube is used and only at the bend locations.  When using fluids, excess amounts generally don’t help and get pushed out of the tube prior to bending.  If possible, consider MQL fluids and application systems.

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What is MQL and when should I use it?

Minimum Quantity Lubrication (MQL) is used when the bending process is not too severe and a near dry tube is required.  MQL lubricants are traditionally renewable resource oils made from vegetable sources and are very light in viscosity.  The process requires a specific air/lube applicator to inject very little lubricant into the tube.  Some synthetic, water-based lubricants can also be used straight or diluted with water.  Consult a product specialist to see if this process would be the best choice.  

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I’m bending more harder materials and I’m getting tearing, galling, and broken mandrels. What should I do?

As more and more higher strength materials and stainless steels are being used as well as thinner dimensions, the need for better lubrication is evident.  What you have been using and getting by with may not work anymore.  In most cases, a more heavy-duty lube is going to be necessary with increased barrier protection, solid film additives, and or more extreme pressure additives.  In most cases, it’s moving from a light oil or water-based product to a gel, paste, or compounded oil.  Application is key because dry spots can cause the mandrel to stick very quickly with no forgiveness that may have been seen before.  Consult a product specialist to help determine the best fix.  

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Is there a “shelf-life” for gels/pastes and fluids stored in the original drum?

Yes, most gels/pastes last six months to one year if stored properly – typical inside storage in regular plant environment and temperature.  Synthetic fluids, soluble oils, and compounded oils tend to last over one year.  However, if you determine any lost performance from your product which is stored past one year, have your supplier check the remaining concentrate. 

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What is the best overall metalforming lubricant to use?

The best lubricant to use will always depend on the process, metal being formed, application method (recirculating flood, roller coater or spray), piece part finish and desired tool life.  Please keep in mind, the lighter or thinner the material thickness, lighter viscosity fluids should be used to prevent slug pulling.

Standard rule of thumb:

• Straight Compounded Oils offer superior lubricity and highest levels of extreme pressure additives
• HD Soluble Oils offer tremendous flexibility by varying mix ratios – one Soluble Oil product can be used on many parts at different concentrations.  Lubricity only second to HD straight oils.
• HD Synthetics offer extremely clean press operations – in many cases can eliminate cleaning operations prior to welding or piece part assembly.  Offers the best cooling characteristics of all HD forming fluids

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What is the best way to apply a metalforming lubricant?

Application method will depend on the meatlforming process.  Rollcoaters provide for the overall lubricant coverage to the coil feed metal, where an air-less spray system puts the lubricant exactly where you need it.  Flood system works best for applying water extendible coolants where additional cooling is desired. 

• Progressive dies typically apply fluids with roller coaters or spray systems. 
• For larger progressive dies using many stations, the absolute best method is a combination system using a roller coater for lubricant across the entire strip, then re-apply as needed to heavy working stations by airless spray.
• Many transfer press operations use flood application systems throughout the tool. 

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Is there a “shelf-life” for metalforming lubricants stored in the original drum?

• Yes, most water extendible products can last up to 1-2 years if stored properly – typical inside storage in regular plant environment and temperature.
• Straight compounded oils typically

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