ROTARY MOULDED HOT TUBS EXPLAINED

The hot tub industry has been enjoying large profit margins for years, lining the pockets of hot tub manufactures and dealers alike. Let’s do the math on this; many hot tubs on the market today are the same price as small cars yet, there are more than 10,000 components that go into a car, a large majority of them have to be custom made in a very costly way, such as metal pressing and castings, yet in a hot tub there are less than 500 components with almost all but one (the shell) being interchangeable between tubs and most being outsourced to other component manufacturers. 

Does this make sense?  No certainly not.  Although cars are made in 100,000 and hot tubs made in the 10,000 there is still a world of difference in the cost of manufacturing. So why do they still cost the same as small cars? The only reason I can see is that there is a whole lot of profit being made somewhere.

The hot tub industry has typically centred round one core shell manufacturing method for years, and this being the most expensive part of a tub is the most important. They are generally made using vacuum moulding where a sheet of acrylic is heated over a mould then sucked in using a vacuum to form the contours of the tub. 

However, there is a new kid on the block that is challenging these methods and causing waves in hot tub world! Excuse the pun!  Rotary moulding, rotationally molded or rotomoulded products have been around for many years in the form of large storage tanks and containers; however this method has only recently been applied to tubs. Rotationally molded hot tubs are made from one single mould enabling them to be made in a one step production process.

The process uses a cast aluminium mould that is filled with thermoforming plastic granules, which is then placed in a giant oven and spun in three axis for about an hour which allows all of the granules to fuse together uniformly around the inside of the mould. Extra material naturally gathers around corners making them extra strong. Once the cooking process is complete, the mould is then taken from the oven and cooled using air and water jets, for around another hour. The tub is then removed from the mould and ready to be fitted out with pipe work, jets, heaters, pumps and controllers.

This fast production time obviously saves lots of money in the production of a tub and therefore these savings can be passed onto the new owner of these tubs. This method of production also has its benefits over conventionally made tubs, as they have no metal or wood sub frames that can rust or rot away, they are resilient to the elements and are very hard to crack.

This tub is now often used as an entry level tub to allow those who may not have been able to afford one in the past to get into hot tubbing!