Rubber Lining vs. Vinyl Ester Epoxy for Ion Exchanger Tanks

Rubber Lining vs. Vinyl Ester Epoxy for Ion Exchanger Tanks

By Ian Isenegger

A debate often emerges about the best material options for the internal lining of Ion Exchanger Tanks. Two schools of thought address the subject. Some people prefer the long lasting but more expensive semi hard rubber, while others prefer the less expensive but shorter-lived vinyl ester epoxy. Neither is necessarily wrong; the correct choice simply depends upon your circumstances.

The chart below chart was compiled from manufacturer’s recommendations, end user history and my personal experience over the last 10 years will aid in your decision making.

1/4” Semi-hard Rubber Lining 20-30 mil Vinyl Ester Epoxy
Material & Installation Costs:
$38.00-$90.00 per sq ft $26.00-$63.00 per sq ft
Surface Preparation:
NACE #1 – White metal blast cleaning is a requirement of every good lining system. The steel cleanliness is directly related to the long-term performance of the lining system. NACE #1 – White metal blast cleaning is a requirement of every good lining system. The steel cleanliness is directly related to the long-term performance of the lining system.
Method of Installation
Lay up of rubber sheets, hand rolled into place. Lining is adhered to wall with adhesives while in the uncured state. It is then steam vulcanized; the lining is cured into a monolithic system. All welds and seams are stripe coated with a roller. The coating is then generally applied
with a large tipped airless spray pump.
Installation Time
Fair – Rubber installation is a labor intense process that requires a skilled applicator. This can increase the overall cost. Good – A skilled applicator is required, although spray-on application is quicker than with rubber.
Post Installation Cure Requirements
Two Types of Cure:
Steam Cure
24-48 hours of steam cure (Boiler Required). Ready for food service post-cure.Chemical Cure:
Applied on chemical cure rubber, 7 days before service. ChemCure II is FDA compliant.		 Two Stage: 1) 24-72 hours at 75 degrees Fahrenheit. 2) Many lining manufacturers will require an additional 2-6 hours of 180+ degree Fahrenheit dry heat prior to food service.
Flexibility:
Excellent – Rubber is very well known for flexibility. If the internal components of the tank tend to move, stretch or flex, rubber will typically move and flex as well. Poor – Vinyl Ester systems are very rigid. The thickness required for long-term service will
be more rigid than thin film (short life) systems.
Impact Resistance
Excellent – Rubber linings perform exceptionally well under most impact. Rubber will compress
under impact and return to its original state.		 Fair – Vinyl Esters would be more likely chip on impact. Vinyl Esters are very strong and
hard on the surface, but it creates an “unforgiving” surface upon strong impact.
Care and Maintenance
Good – Rubber linings are virtually maintenance free, but they should not be left empty and dry for long periods of time. Inspections are recommended every 3-5 years. Fair – Vinyl Ester linings are virtually maintenance free and can be left empty and dry. No damage can occur while “out of service.” Biannual inspections are highly recommended.
Reparability
Excellent – There are two different types of repairs that can be made. Chemical cure repairs are the most common. Pre-cured linings are also an option and can often be ready for immediate service. Good – Repair of Vinyl Esters “can” often perform as well as an original lining. Preparation is critical to ensure proper adhesion to an existing lining.
Expected Life (varies with service conditions)
10-15 years 3-7 years
1/4” Semi-hard Rubber Lining
Material & Installation Costs:
$38.00-$90.00 per sq ft
Surface Preparation:
NACE #1 – White metal blast cleaning is a requirement of every good lining system. The steel cleanliness is directly related to the long-term performance of the lining system.
Method of Installation
Lay up of rubber sheets, hand rolled into place. Lining is adhered to wall with adhesives while in the uncured state. It is then steam vulcanized; the lining is cured into a monolithic system.
Installation Time
Fair – Rubber installation is a labor intense process that requires a skilled applicator. This can increase the overall cost.
Post Installation Cure Requirements
Two Types of Cure:
Steam Cure
24-48 hours of steam cure (Boiler Required). Ready for food service post-cure.Chemical Cure:
Applied on chemical cure rubber, 7 days before service. ChemCure II is FDA compliant.
Flexibility:
Excellent – Rubber is very well known for flexibility. If the internal components of the tank tend to move, stretch or flex, rubber will typically move and flex as well.
Impact Resistance
Excellent – Rubber linings perform exceptionally well under most impact. Rubber will compress under impact and return to its original state.
Care and Maintenance
Good – Rubber linings are virtually maintenance free, but they should not be left empty and dry for long periods of time. Inspections are recommended every 3-5 years.
Reparability
Excellent – There are two different types of repairs that can be made. Chemical cure repairs are the most common. Pre-cured linings are also an option and can often be ready for immediate service.
Expected Life (varies with service conditions)
10-15 years
20-30 mil Vinyl Ester Epoxy
Material & Installation Costs:
$26.00-$63.00 per sq ft
Surface Preparation:
NACE #1 – White metal blast cleaning is a requirement of every good lining system. The steel
cleanliness is directly related to the long-term performance of the lining system.
Method of Installation
All welds and seams are stripe coated with a roller. The coating is then generally applied
with a large tipped airless spray pump.
Installation Time
Good – A skilled applicator is required, although spray-on application is quicker than with
rubber.
Post Installation Cure Requirements
Two Stage: 1) 24-72 hours at 75 degrees Fahrenheit. 2) Many lining manufacturers will require
an additional 2-6 hours of 180+ degree Fahrenheit dry heat prior to food service.
Flexibility:
Poor – Vinyl Ester systems are very rigid. The thickness required for long-term service will
be more rigid than thin film (short life) systems.
Impact Resistance
Fair – Vinyl Esters would be more likely chip on impact. Vinyl Esters are very strong and
hard on the surface, but it creates an “unforgiving” surface upon strong impact.
Care and Maintenance
Fair – Vinyl Ester linings are virtually maintenance free and can be left empty and dry. No
damage can occur while “out of service.” Biannual inspections are highly recommended.
Reparability
Good – Repair of Vinyl Esters “can” often perform as well as an original lining. Preparation
is critical to ensure proper adhesion to an existing lining.
Expected Life (varies with service conditions)
3-7 years

It is important to note the actual mil thickness of epoxy being applied. There are various manufacturers and types of vinyl esters. Some can be applied thicker, but they do require some type of reinforcement, such as fiberglass. Be sure to contact the manufacturer or read the product specifications before deciding. As you can see, there are advantages and disadvantages for the product that you choose. However, for only a roughly 20%-30% up front cost, you can get a rubber lining that has the potential to last twice as long (if not more). If you would like to know more about rubber linings, please contact Blair Rubber at 800.321.5583.