View Full Version : repair insulation layer on old solar HW tank?
edddo
18th February 2021, 02:54 PM
The solar HW system is as old as the house so the writing may be on the wall - however it works very well and I would like to get a few more years out of it.
The tank sits on the roof in the weather.
It developed a rusty crack in the outer skin several years ago ( before we bought the house) and it is now about 2 feet long and no doubt lets the weather in and reduces its thermal efficiency. It exposes the insulation layer ( fibreglass?) to the sun and rain.
What might be some options to repair it and keep the weather out?
Ideas?
168841
168842
thanks
windsock
19th February 2021, 07:04 AM
What is the condition of the water cylinder? Is it made of copper or stainless steel?
FisherX
19th February 2021, 09:21 AM
If it is just the outer sheet metal rusted away I'd use expander foam in a can to make up the insulation you might have lost and shape it to conform with the tank. Prep the sheet metal with sanding and rust converter. Then a couple of layers of fiberglass to seal it all back up again.
(The Bositk Expanda foam is good for 90 degrees and the Sika Boom foam is good for 80 degrees. Should have enough temperature resistance for a hot water tank).
4bee
19th February 2021, 10:25 AM
[QUOTE=edddo;3065218]The solar HW system is as old as the house so the writing may be on the wall - however it works very well and I would like to get a few more years out of it.
The tank sits on the roof in the weather.
It developed a rusty crack in the outer skin several years ago ( before we bought the house) and it is now about 2 feet long and no doubt lets the weather in and reduces its thermal efficiency. It exposes the insulation layer ( fibreglass?) to the sun and rain.
What might be some options to repair it and keep the weather out?
Ideas?
168841
168842
thanks
IMHO that has the appearance of a Tank water leak inside the cladding so it may be that the rest of the Sheet metal cladding is knackered.
Just a thought while looking at your images. I hope I am wrong.
Maybe you could drill a small hole in it near the bottom & see if any water drips/pours out. [B]NB. Be careful to use a very short drill bit though. If so it will need more checking as any sign of free water could still be rain that has entered over time.
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