Galvalume Steel Sub Structure

[fatman]

At the Coleman website the company describes their Galvalume steel frame as being 250% stronger than wood, weather proof, corrosion free and backed by a lifetime structural guarantee.   I couldn't help but wonder how Maax came up with the "250%". When looking at the picture of the frame, it suprised me that it doesn't have any diagonal peices to help give it strength. I also wondered about the "lifetime structural guarantee". Suppose the frame develops a hairline crack, how would it be repaired?  Is this like other "lifetime" guarantees in that a court of law describes "lifetime" as 7 years?

[Brewman]

Any quality spa will have a good frame, be it from wood, metal, what ever.  I'd read Coleman's warranty and decide from that what would be covered.  If push comes to shove, it's what in writing that matters, not what someone says.
Brewman

[bobhol]

 i would bet a lot of other problems would show up on any spa before a frame would fail. To me thats like putting a warranty on a steering wheel instead of an engine.   Bobhol

[wmccall]

In case anyone besides me never heard the term Galvalume. I found this statement on a Steel industry website.

Galvalume is galvanized steel with a Zinc Aluminum alloy coating. As we will see, this coating is very important for any building but its especially important in hostile environments.

I'm always suspicious of marketing people using big words.  Recent history is full of marketing people making up words to sell products.

BTW, this forum is enviromentally friendly running on only hyrdoproplopnyl.  No petrochemicals were harmed in the making of this message.

[Chas]

Steel rusts. Just that simple. you can coat it with zinc, but as soon as you drill it to allow for mounting holes, or scoot it an inch on the concrete, it is open to moisture.

I don't think they will have a lot of problems, but I just don't look at a steel tub frame as being automatically 'better.'

I have worked on 'Wildwater Spas' around here - they are now long gone. They had the same type of frame many years ago - and it would rust out at all the screw-holes where the siding attached. Also - they had to ship with the siding removed because the wood panels just would not stay attached in shipping. I don't know if Coleman has that part figured out.

[spahappy]

Colemans's been using it for three years, no signs of rust.

You'll never scratch it sliding it on cement because of the solid ABS pan bottom.

Coleman ships their spas with the panels on and we've had zero, not one issue in keeping the Duramax panels on.


Spahappy

[BobRex]

I tend to think that 3 years is too short of a time to get the steel frame to rust; I've got a 20 year old galvanized sprinkling can that isn't rusted.  Think of galvalume as the same material that steel trash cans are made of, just a thicker guage.  BTW - All galvanized steel is zinc coated, by definition that is the galvanization process.  And yes, under a compression test, a steel stud is substantially stronger than the corresponding pine stud, but so what?  How much stress do you think a spa frame is really under?

But back to the rust idea.  Given that a spa frame isn't typically exposed to the elements (umm, the water goes into the spa, not the cabinet, right?  ) rust should not really be an issue.  No more so than wood rot would be.
Consider that many inground pools use galvanized steel panels for support, and I don't think rust is an issue there.

If you really want to be safe, one of the manufacturers makes a tp spa with a polymer frame.  That eliminates any concerns over wood or steel.

[poolboy34]

actually steel pool walls do rust.  Condensation is a constant problem between the wall and the vinyl liner.  90% of all the inground pools we sell are polymer wall pools for this very reason.  On many of the steel wall pools we do replacment liner jobs on, it's not uncommon to have to grind the rust off of the walls.  

[BobRex]

Location, Location, Location.....  Is the steel vs. polymer pool thing a regional issue?

I was thinking of a putting in a pool a couple of years ago.  At that time I talked to 4 different dealers, 3 sold galvy steel walls, one sold polymer.  All three of the steel dealers claimed that because of guage and the coating, rust would not be an issue.  These were also the more popular dealers in the area.  my neighbor has a steel pool and was told the same thing, so at least the dealers are consistent.

Now when you grind off rust, aren't you removing the galvy layer, thereby esposing raw steel to the earth?
That will rust!

Or maybe the cynic in me should just consider that the dealers are banking on either the homeowners or themselves will be long gone when the liner needs to be replaced in 15 years.  Nawww, that couldn't be the reason  :-/

[poolboy34]

we sell both polymer and steel wall pools.  Rust on a steel wall is a fact of life, as is calcium buildup due to the constant presence of condensation.  And yes, in recent years technology has significantly reduced the risk of rusting to steel wall pools.  Polymer wall pools aren't usually as popular due to cost.  polymer walls cost more, but they also stronger then most steel wall pools because polymer walls don't come in as great of lengths as steel wall pools come in.  Steel wall pools can have panels up to 10 ft long.  Usually steel wall pools only have braces at the joints.  Polymer walls go up to a 6 ft panel, and have braces every 2-4 ft, which makes for a stronger pool wall and support area for the decking be it concrete, pavers, etc...  In the next few years polymer pools will begin to become more popular as the price of steel continues to rise at a rather sharp clip.

[windsurfdog]

Colemans's been using it for three years, no signs of rust.

You'll never scratch it sliding it on cement because of the solid ABS pan bottom.

Coleman ships their spas with the panels on and we've had zero, not one issue in keeping the Duramax panels on.

 
Spahappy

SH,
Ditto on all counts for my LSX except for a light bit of rust along the cut edges.  Since I live in a salty coastal environment, this might be exacerbated.  bubba stu was going to try to secure and send me a piece of the galvalume that Coleman uses so that I can put it in my LSX cabinet and compare.  If he's having trouble securing it, maybe you could.

[spahappy]

I'm planning my show booth and requesting a piece to show.

I'll try to get two, PM me your address so it can go from Phoenix to N.D. and back to Florida LOL

Spahappy

[windsurfdog]

I'm planning my show booth and requesting a piece to show.

I'll try to get two, PM me your address so it can go from Phoenix to N.D. and back to Florida LOL

Spahappy

SH,
Sorry I didn't get back to you sooner.....killer couple of days at work....sent you an email.
Best to you and thanks....

[BubbleLuvr]

Although by no means an expert, I feel that unless a wood frame is pressure treated, the Galvalume is going to last much longer, rust or no rust.  That given, both will probably last longer than you will own the spa.

On a different note, and something that I have been thinking of due to my construction of a composite aircraft is the full-foam vs. partial foam as related to frame structure.  

I have wondered if maybe full foam (since it seems most tubs have open cell structure, therefore less insulation  property) has nothing to do with thermal insulation or even bracing of component plumbing, but as structural support of a shell laminate that does not have enough structural integrity to maintain rigidity when placed in a frame structure with limited or no foam.  I think the fact that Coleman has a frame with a non-full foam process, may lend to credibility as to the shell's structure and materials.

Like I said, I am no expert, but would be interested in other people's thoughts on this.

[Chas]

HotSpring uses the foam for both structure and insulation. As such, they have engineered the system to maximize both:

They use a computer-controlled robotic arm to apply a very dense (30 #) foam to the back of the shell. This is done in a temperature and humidity-controlled enviornment - people don't go into this 'tunnel.' This layer is only about an inch thick.

Then the tub is put on the 'line' and all the plumbing is done. After a huge number of QA steps have been taken and tests done, the cabinet is fitted. The tub then goes on to the foaming area. A less-dense foam (#10) rigidizes and encapsulates the plumbing and adds a 'beam' component to the sides of the tub.    

Then the larger cavities are filled with a mixture of 1 and 2# foam. The 1 pound foam expands rapidly, while the 2 pound stuff does so more slowly. The result is no air pockets or other voids. These air voids are not generally bad from the standpoint of insulation properties, but they can amplify the sound of equipment, and they may weaken the overall strength of the system.

The final step is to seal the bottom of the spa by pouring on a layer of 60 pound density foam. This sets up more slowly, but ends up with a shell that is hard as rock. I handle these tubs with forklifts all the time, and the forks do not go through this stuff.