How much percentage of sulphamic acid in solution would be needed to flush an outboard cooling system. There are expensive flushing products like salt away and salt off and I suspect they use sulphamic acid as their main active ingredient.
317200cookie-checkOutboard seawater cooling system.
I don’t know anything about those products. If they are using sulphamic acid then it must be to remove scale – magnesium and calcium carbonates – stuff that always builds up eventually in industrial cooling systems.
It’s an excellent chemical for this purpose, as it’s as strong an acid as you can get without being strong enough to damage any metallic components. It was used as the active ingredient in Easy Off bathroom cleaner, as it won’t damage even active metals like aluminium.
So essentially you can use it as concentrated as you like. I’d try 1% and let it soak. It takes a while to work. And you can increase the concentration later as needed