Manifolds 454s Cleaning

[northern]

I just finished redoing the manifolds on our boat. They were replaced 6 years ago. Since then we put on 1000 hours. There was no corrosion on the elbows or maniflolds on the engine. Took them to the rad shop had them soaked in their tank, sand blasted and painted. The elbows were plugged up but there was no heat problem. The heat exchangers were also done. Both had tubes that were starting to plug. The boat has an 8KW QuickSilver generator made by Generac. It has not been touched since new in 1989. The tubes were 99% pluged off it took two hours in the rad shop tank to clean out. The bad part was I needed the end flange and the exhaust outlet. Both I got thanks to a posting I did on the generator a few years ago. The two parts were 800 if they had been for a car they would have cost 100. But a new generator installed would have been 12,000. The unit has 950 hours on it and works well.
We boat in the north west so it seems the cold water does not rust thnings out as quickly as in the south. The boat stays in salt water all year and we flush out the system with fresh water.