Hundreds of dips later, the walls of the tub were starting to get soft. I found that these were due to micro-holes/punctures that allowed the water to seep in and get absorbed into the insulating foam. An overhaul was required so I figured it was a good time to cover over the exposed metal. After a lot of research, I settled upon the U-pol Raptor truckbed liner in white colour. This requires a mix with the hardener in order to activate the paint
After doing research on what types of paint was suitable, I purchased everything and went to work.
Then I realized I knew nothing about painting!
What is a hardener?
What surfaces can I paint on?
How do I prepare a surface before painting?
Thanks to google and youtube, I managed to figure some steps out:
Step 1) Draining
I use the siphon method to empty out all the water in my tub. With a long tube completely immersed, I cupped one end of the tube and brought it out of the tub below the existing water level, and the water would get pushed out.
Once it's almost empty, the tub could be flipped over for a complete wipe down and inspection of damages/holes.
It was here I realized all the little puncture marks on the walls and water seeping out of them.
Step 2) Silicon
After stripping out the existing silicon, some of which shrank and peeled after much use and contact, I decided to use this beautiful looking clear silicon. You'll need a silicon gun / caulk gun to use it with, available at most hardware stores. NOTE: Smoothing it over corners incorrectly may cause the surface to lose its smooth transparent appearance and become a bit rough looking. But it fit my purpose and I was going to paint over it anyway so it was not a critical outcome for me.
I also took the chance to inspect rust spots forming at the exterior corners of the ice tubs.
Scraped out what I could, silicon application on all openings and painted over them to prevent further rust. Not a very professionally done job in my opinion but it's what I could manage alone within a 10-day down time window between training sessions.
Step 3) Surface prep
Bare aluminum like mine may not adhere to the paint and a quick painting like that may cause everything to peel and bubble during use.
Using sandpaper, I rubbed down the existing surface to my best ability to rough up the surface and prepared it for the next layer.
Epoxy primer was then used to spray the entire aluminum surface. One spray can was good for two light coats for two tubs. The primer adheres to the aluminum and allows the paint to then stick to it nicely.
NOTE: Watch for the fumes! I wore my snowboard goggles and N95 mask but still the primer spray was quite overwhelming. I ended up taking a deep breath, hold and spray, then run to the corner to breathe again.
Step 4) Painting
Masking tape on the edges. I used the wrong plastic type which left ugly marks upon removal! So use the paper type of masking tape to prevent this outcome.
Painting is rather straight forward. Waited an hour for the second coat.
Step 5) Curing
This was something new to me! Paint drying alone was not sufficient to ensure the best result for usage. Online information suggest 30 days for typical paints to cure/harden for use.
The Raptor guidelines suggest seven days' wait, which was what I did. Who knew seven days without an ice bath would be so antagonizing...
After a few days the paint had a nice satin type sheen to the finishing, looking better with each passing day.
I left the cover open and pulled a car cover over as it was the rainy season so the balcony where these freezers were located were subject to constant downpour with high humidity.
Step 6) Fill it up!
T-1 day to my first class after the overhaul, I started filling the tub up.
The water looked absolutely beautiful.
Minor leak from the drain hole, which I simply wrapped white Thread Seal Tape around the plug to seal from the outside yet keep it removable. The inner drain plug has silicon applied so it would not come loose.
No time to turn on the freezer yet, so ice cubes were sent over.
Happy Hoffers getting first dibs!
Will be spending the next few months filtering, refreezing and observing how this paint handles the water/ice, especially where the solid ice meets the wall.
So far, some walls are still soft as I could not completely drain the internals, but the two coats of paint are very flexible and strong, so I'm crossing my fingers that they provide sufficient insulation to keep these tubs in usable condition for another few years.
Hope this overhaul post has provided you with some information that might help with your own repainting plans. Let me know in the comments if you have any questions, or send an email anytime.