Most manufacturers use the fiberglass lay-up method of spa construction. This manufacturing method combines layers of polyester resin and glass fiber. A heated acrylic sheet is placed over a spa-shaped vacuum mold. Air is drawn out through hundreds of small holes. When the acrylic cools, they remove it from the mold and reinforce the underside of the spa with resin and chopped fiberglass mixture.
This polyester resin and glass combination can lead to a common problem – acrylic blistering. Blisters occur because of a chemical reaction between moisture from the tub and the polyester resins used in the reinforcing process. Many spas have been ruined because of blisters.
Spas made from polyester resins are blister resistant, but their finish and structure warranties are separate. The salesman points out the structure warranty because it is usually 10-15 years. Unfortunately, it’s too tempting to neglect to mention that the finish warranty is only 1-3 years. You could have a blister problem in as little as one year!
Great Northern® spas don't have the blistering problem that others do because we use epoxy resin instead of polyester resin to reinforce the spa. Epoxy resin does not react with moisture to form the gasses that cause blistering. This means Great Northern® spas are blister proof. Our warranty on both structure and finish is the same - 20 years.
The acrylic provides color, not structure. We measure durability by weight and the thickness of the fiberglass, not the thickness of the acrylic. The acrylic covering is at most 1/8 inch thick and tapers to 15 or 20 thousandths of an inch in the footwell of the spa.
Water is heavy. Water in a spa can weigh one to two tons. What happens when you fill a thin-walled spa with water? The water pushes down and gradually bends or breaks the spa. To compensate for the lack of strength in a thin-walled spa, some manufacturers fill the underside (between the bottom and the ground) with urethane foam. Others require sand or a wood structure underneath the spa. Sand or foam provides support under the benches or seats, lounge area and step. Portable spas often depend on the wooden skirt to support the water. Without the skirt, many of these cheap spas would collapse.
If the spa shell is thick enough, other reinforcement is not necessary. That’s why we’re able to offer a 20-year warranty.
Let's compare two well-known spas. One shell weighs just 95-100 pounds and has 1/8 inch walls. Another weighs 120 pounds and has 3/16 inch walls. Spas with flimsy walls like these require additional support. Great Northern® spa shells weigh 225-260 pounds and have walls up to 5/8 inch thick.
Our spa shells don't need additional support. They're built to last! How can you tell how thick the wall is? It's a little tricky. Try flexing flat wall areas. If you can, try to examine a spa that doesn't have the jets installed yet. The holes will show the spa thickness. Lift the spa shell only. Does it seem too light? If the manufacturer uses foam fills or requires sand filling or wood framing, you know the vessel walls are too thin.
Quality spas have the following characteristics. They…
The art of wood tank building goes back to the fifteenth century. People built barrels and tanks to hold liquids. We build hot tubs the same way that medieval craftsmen built their tanks and barrels. Barrels, wooden tanks, and hot tubs are built from curved pieces of wood called staves. Craftsmen assemble the staves and place metal hoops around them to hold the staves in place. At Great Northern®, we make hot tubs out of redwood or cedar. We coat our hoops with plastic to eliminate rust.
Back in the 60s, the popularity of wooden hot tubs really took off. These tubs were made from old wine vats or 500-gallon water tanks. They became watertight when the wood saturates, swells, and seals the joints. Wooden vessels have always been popular with people who love depth and leg room.
All-wood tubs are no longer as popular as they once were since all-wood construction requires clean, knot free heartwood from old growth trees. Nowadays, no one wants to sacrifice these beautiful old trees to make hot tubs. But, not to worry because you can get the benefits of a traditional, all-wood tub (leg room, depth, portability and good looks) with a modern, plastic-lined tub.
The best-known lined tub is the Rubadub Tub®. Bill Jaworski, a pioneer of the hot tub and spa industry, created it in 1978. These tubs are easy to clean and have the same hydrotherapy jets and equipment as spas.
No. The interior finish on the Rubadub Tub® is made from PVDF, an easy-to-clean industrial tank lining material designed for high-temperature service. Its semi-gloss finish resists chemical and weather damage just like acrylic. Many people mistake PVDF for pool vinyl. Pool vinyl doesn't hold up to the high water temperature you have in hot tubs. BEWARE! Some manufacturers use vinyl liners in their hot tubs. The life expectancy of these liners is only 1-2 years.
Yes! There are several reasons you might want a hot tub instead of a spa. Here they are:
Quality hot tubs have the following characteristics. They…