Our Coverstar auto cover roll up tube corroded and fell apart (6 years old). The regional parts supplier said this is common with salt pools and recommended extruded aluminum for the next roller tube. I'm hoping this one lasts longer! Should I be hosing the mechanism off with fresh water or something?
salt corrosion
- Thread starter Serious1
- Start date
mguzzy
Gold Supporter
What was the old one made of? ... Can you post pictures? I hear these claims that salt pools cause all kinds of corrosion.. the salinity is just not that high. I see you are in Ne, do they salt the roads there in the winter? I would imagine you would get more corrosion from that than your pool at 3400ppm.
I'm in Nebraska and they use some sort of beet juice deicer concoction for the roads.
mguzzy
Gold Supporter
I wasn't sure if NE was New England... I hear the beet juice deicer concoction makes a good mixer with vodka.
It definitely looks like something caused by the water, there is no corrosion on the other aluminum parts., What is the chem levels of your pool, The pH and alkalinity, etc?
It is pretty common for equipment suppliers to blame failure on salt, while not mentioning that salt is just sodium and chlorine, the normal sanitizer used. As Mark noted, some of the aluminum components are unaffected. There are significant differences in performance between aluminum alloys. Look first to your chemistry balance.
The new part is an anodized roll up tube because they had so many issues with the other part. The only other corrosion I see is rust on the bottom of the rail over the steps. Water is always balanced, PH runs a tad high which I control with muriatic acid. Currently the pool is still winterized so I won't be taking readings until I open.
mguzzy
Gold Supporter
Is the unit bonded to the other components of the pool?
www.troublefreepool.com
Bonding vs Grounding
Electricity and water don't mix. Learn a few basic tips how to keep your family safe when dealing with electricity around your pool.
www.troublefreepool.com
- May 23, 2015
- 24,481
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
If those components are galvanized steel, then what you have there is “white rust” (zinc hydroxide). If those components are aluminum then that’s a form of aluminum corrosion caused by chloride attack. There are screws and bolts all around the drum; if they are not properly matched to the drum material then you can get galvanic corrosion from that.
The drum and shaft need to be made from an appropriately rated aluminum alloy and, if they were smart, they would anodize the aluminum surface to give it added corrosion resistance.
Rinsing the cover off with fresh hose water as it is rolling up is probably a good idea. Chloride of any kind is not good for metals and, as the water evaporates from the rolled cover, the chloride concentration gets much higher.
The drum and shaft need to be made from an appropriately rated aluminum alloy and, if they were smart, they would anodize the aluminum surface to give it added corrosion resistance.
Rinsing the cover off with fresh hose water as it is rolling up is probably a good idea. Chloride of any kind is not good for metals and, as the water evaporates from the rolled cover, the chloride concentration gets much higher.
