Any idea why they called them "black iron"? I've wondered about that for years.
The success of black iron fuel tanks on boats depends entirely upon the installation techniques and maintenance. ...They corrode (rust) due to two principle causes: water running down the filler hose and sitting on the top of the tank and bilge water accumulating on the bottom. The first is readily fixable by making sure that the caulk around the fill fitting is sound.
The second is tougher and can't be easily fixed. Boat builders often set the tanks on a plywood platform or set them on a bed of foam (which is worse). The foam collects water which lets it eat away at the steel...David
We replaced the steel tanks in our last boat after 16 years for the exact reason you mentioned. The builder had used foam to support the tanks with minimal drainage. Other than the areas of the tank that were in contact with the foam, the tanks looked great.
Our current boat has steel tanks that are 26 years old and so far so good. Talking to other owners of the same make, it appears that most of the tank failures have been from the inside which in my opinion is preventable.
Anyone know about black iron fuel tanks on a CHB? Good, bad, ugly?
Thanks, James
The downside is I reduced my cruising range to around 300NM instead of having 1200NM....I can live with that because of the other advantages.
Just cut out my mild steel tanks that had bubbling rust just about all over them...especially where water got under the insulation glued to the tank.
Though after cutting them out...they looked like they would have lasted another 10 years at least with no maintenance at all they were so thick.
But I am much happier now that I can see through my poly tanks, I don't have 2" of sludge on the bottom any more, working around them is so much easier and I halved the space taken up by the tanks so I really improved engine room layout and storage.
The downside is I reduced my cruising range to around 300NM instead of having 1200NM....I can live with that because of the other advantages.
Not a lot, except I understand they don't like biodiesel - it eats into them apparently. However, if I had to replace my tanks, which are stainless steel, I would go for smaller volume fuel grade plastic, like psneeld. Then they can be made to shape, are light and easy (relatively) to install, and are corrosion proof to just about everything you could expose them to.Then what are the disadvantages of fibreglass tanks?
Especially on a boat like mine in which the steel is curved to conform to the rounded hull.
Would really like to hear more about this and photos of your project would be great.........
Get a flash light. Look at the tops of the tanks. Do you see water or evidence that water had been running down fittings and sitting on top of the tank? If the tanks have very little exterior rust and you maintain the boat, then they will probably last a heck of a lot longer (decades). Most tank failures on CHB/Taiwan Trawlers are from the outside in due to rust deteriorating the outside of the tank, eventually eating through the thin layer of steel.
I am unaware of CHB's ever being built on top of foam. Also, CHB tanks are usually well above the bilge, most likely the bottom of the tanks will never see water creeping up from the bilge, so again, fittings and screw holes in the teak deck are the usual cause of failure. Get your flash light out and inspect the top of the tanks yourself.