The classic, and iconic, claw-foot tub; it is one that many people like to see in a bathroom. It reminds them of simpler times and more elegant design. Yet, it makes you wonder how such a tub can support its own weight on those four claw-and-ball feet. Here is how these tubs are made.
Weight of a Claw-Foot Tub
A cast-iron claw-foot tub can weigh between two hundred and four hundred pounds. A modern acrylic version weighs about half as much. Still, bathtub manufacturers have to balance the weight of the tub on the four claw-and-ball feet. It is actually a feat of engineering that manages this.
In the iron version of this tub, the weight is distributed over the wavy leg portion of each foot. The balls, on which the talons of the claws rest, are actually flat-bottomed, even though you do not see that. The weakest point of the feet is at the "heel" of each claw, but when the feet are cast iron like the rest of the tub, that weakness is of little concern.
In acrylic versions, the feet are still metal, but often have large flourishes at the top of the claw-feet. These flourishes disguise the fact that the acrylic tub is actually perched on the feet, and not welded to it. An inner liner of metal is how the feet are bolted to the tub, and the weight is distributed over the flourishes and then through the feet.
Formation of Cast-Iron Tubs
The cast-iron claw-foot tubs are cast in iron, of course. The tub and the feet are made separately. Then the feet are welded to the tub. Sometimes the feet are also bolted to the tub, and an interior liner of porcelain is dropped in and secured to the cast-iron portion.
Formation of the Acrylic Versions
A lighter metal is used to make an interior liner for these tubs. Then an acrylic tub is formed around the light metal liner. This provides a lighter weight tub to which the classic metal feet can be attached without cracking the acrylic tub. Acrylic is rarely used to form the claw feet because it cannot support the weight of fifty gallons of water and a two-hundred-pound human.
What This Means for You
As a homeowner who is thinking about adding or changing the tub in your bathroom, you now know how these tubs are made. You also know which might be easier to get into a second-story bathroom versus a ground floor bathroom. You also know why it may take longer to make the cast-iron version versus the acrylic version. These are all options to consider and discuss with your contractor.