Long story short.. Pulled both motors and Got the bad tank out today, found small pin hole in bottom, washed bottom of tank to look at pitting couldnt see good so took pressure washer to it and while washing it found a total of 3 holes in bottom at that end.. Question is.. Tanks are 10 years old, 140 gal al. The marina called the original makers and got est of 3k each ( two tanks, sure both need replacing) could I have new bottoms welded on or should I bite the bullet and replace both with new?
Back with gas tank issues..
- Thread starter hackalar
- Start date
Maybe look at poly tanks. Much more economical. You can google "custom poly fuel tanks" or look here
http://www.boatfix.com/shop3/store/listItems.asp?strSearch=fuel+tank
http://www.boatfix.com/shop3/store/listItems.asp?strSearch=fuel+tank
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I worked for a place that re-did steel tanks like that. No problem. I've welded and Brazed tanks on my Pickups without a problem. I put some Diesel in the tank and let it sit for a day and never had a PUFF!
That pitting is worrisome. If you cut the Pitted parts off, then you can inspect the inside of the tank for more pits.
If you find more, get the new tanks. If you don't find more, have somebody put a new Al bottom on the Tanks.
That pitting is worrisome. If you cut the Pitted parts off, then you can inspect the inside of the tank for more pits.
If you find more, get the new tanks. If you don't find more, have somebody put a new Al bottom on the Tanks.
If it were me- I'd get all new tanks. I wouldn't want to have to worry about future tank issues. Maybe it is something wrong with the metal in the tanks or who knows but I'd not want to pull my motors twice and all new tanks would surely be cheaper than pulling motors twice! Poly tanks rated for gas could be ok but I would do a LOT of research about E10/E15 as it relates to poly tanks first, assuming you are gas powered? If diesel, I'd go poly. When I eventually replace mine, I will go with poly tanks on the trawler.
You have done the hard ($$$) work by getting the tanks out. Go ahead and renew the tanks. It will cost just about as much to have the old bottoms cut off and new bottoms welded in place. Then you would have a weld seam around the perimeter of the bottom of the tank(s) with increased chance of failure in the heat affected zone. If you renew the tanks you have NEW tanks, if you repair the tanks you have a patched fuel tank that could start leaking again a week after you install and close everything up. You need to find the source of the moisture that caused the pitting and correct that.
Thats correct, they were replaced before for the same reason in 2001... this is the second go around..
The pitting is coming from the inside. There is no moisture where the tanks are sitting. I know the owner before me NEVER used the boat, i can only think that it sitting as long as is did with have full tanks most the time did the damage over the years...
if the tanks had to be replaced already at 6 yrs and now again at 10 yrs there is a water drainage problem under the tanks. you need to configure the tanks to sit on sleepers above the deck they are on now so that they are normally dry. the pitting is from water and or poor bonding of the tanks. they have to stay dry under them and be properly bonded to the electrical system of the boat.
no matter which way you go you have to address the underlying problem or you'll be at this again soon.
no matter which way you go you have to address the underlying problem or you'll be at this again soon.
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No matter what you decide, do a search on 'How to Install an Aluminum Fuel Tank . . . . So you Don't Have to Do It Again' and read it.
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Exactly. Why go through all the trouble of removing the tanks, and then proceed with a band aid repair at that point.
Also, 3K for each tank sounds a bit high. Shop around to local custom fab shops and I bet you can do better.
Also, don't forget to coal tar epoxy the tanks.
Before putting the new ones in, solve the bigger issue of why they are rotting out to begin with. You have a mositure issue some where, either that or the original and replacement were not installed properly to begin with.
New tanks usually run around $10 per/gallon then you have removal & installation labor cost.
If these tanks are only lasting 6 to 10 years there are issues that need to be addressed and resolved. A tank installed correctly should last at least 20 years.
Absolute,
"Suckin Sludge & Havin a Gas"
If these tanks are only lasting 6 to 10 years there are issues that need to be addressed and resolved. A tank installed correctly should last at least 20 years.
Absolute,
"Suckin Sludge & Havin a Gas"
tugboat kevin
Active member
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we send them to a good local metal fab shop they replace the bottom and sometimes a few inches up the sides they also reinforce the bottom edges a 3000 dollar tank cost about 200 to repair and pressure test and the repaired tank is better than new we coat the outside and fix the reason it corroded these guys are good and their welds are butter smooth and terminated correctly to prevent cracking its easy to clean the tank to remove fumes just fill with water and dawn soap, make sure the pickup tube is ok and no screen inside it!
If you end up having new tanks made make sure you use a marine grade aluminum. (5086) At $3000.00 per tank I am thinking you could do better with a good fab shop. And at $6K ..............I would buy the material and a dam nice welder and do it myself. All of the cutting is easy. A good Skilsaw and a carbide blade. Some fittings, and some plywood for the mockup. Also pressure test the tank. You only need 2 - 5 lbs of positive pressure. I would most likely use 3/16 thick material. The hardest part is the welding it so you dont twist the crap out of the tank. You need to back-step the welding.
Oh and the only way to really find the holes is via pressure test.
Oh and the only way to really find the holes is via pressure test.