Cast Iron or Acrylic?
Cast iron is the original and traditional method of clawfoot tub production and has been around practically unchanged for over 100 years. The tubs are very heavy and no two tubs are identical. Most cast iron tubs are painted on the outside and enamel coated on the inside. Cast iron tubs start off life as recycled steel which is blended then melted down and molded. The resulting thickness of the formed cast iron tub is approximately 3/8”. The tub is then brought back to red hot and the inside is sprinkled with enamel dust. Most of the time, this will be repeated 3, 4 or 5 times until the required enamel thickness is achieved. Due to production methods employed, actual finished dimensions of cast iron tubs can vary by around 2% from their drawing size.
Acrylic tubs, depending on the method of production, can be almost as strong as cast iron, consistently finished, more perfect in appearance and relatively lightweight and easier to install. Most acrylic tubs now have two shells of pure acrylic sheet for the inside and outside that are joined together with different types of filler both for strength and heat retention. Finished sizes on acrylic tubs should be extremely accurate as production methods easily allow for this. Cast iron tubs are normally two to three times the weight of a good acrylic tub and generally need at least four people to maneuver into position for installation. Acrylic tubs will need only two installers.
If you are installing your tub upstairs, you will be well advised to give greater consideration to an acrylic tub over cast iron. Upstairs flooring and sometimes even ground floor installations may require additional reinforcing to carry the weight of cast iron tub, this is more applicable in older homes. Most good quality acrylic tubs maintain water temperature better than cast iron tubs. Cast iron is a superb conductor of heat. When hot water is poured into a cast iron tub, some of the heat will transfer into the body of the cast iron. This will result in a heated exterior of the cast iron tub surface which will in turn dissipate into the cooler air. Acrylic is not a natural conductor of heat.
When you enter an enameled cast iron tub after filling, you will immediately notice the cold enamel on your back, this will not happen with acrylic which will only be cool, not cold. If scratched or chipped, good quality acrylic tubs can be repaired by almost anyone. Cast iron tubs will require professional repairs and often will need to be removed from the home. This can be very costly and quite often not very effective.
Summary: Cast Iron Tub
It’s traditional. Some buyers will simply never consider anything else. A cast iron tub will always be stronger than the best acrylic tub. In spite of any drawbacks noted herein, a properly manufactured cast iron tub will most likely be around for 100 years or more. Cast iron tubs are heavy and do not need to be attached to the floor. Many buyers simply consider them to be more upmarket than acrylic tubs and they like the strength and weight.
Summary: Acrylic Clawfoot Tub
Again, not all acrylic tubs are created equal. If you choose the good quality acrylic tub, it will be easy to handle and install plus simple to repair if damaged. It will retain the water heat longer and at a consistently higher temperature than a cast iron tub. A well designed and produced acrylic tub will last a lifetime and if properly maintained over the years, will always look shiny and new. Due to the lighter weight, it will need to be attached to the floor.