Performance Boats Forum banner

Fuel Tank Removal & Replacement

11K views 19 replies 10 participants last post by  Azfng 
#1 ·
Hey all,

Considering the purchase of a 74 Rogers Bonneville 18' that needs a fuel tank repaired or replaced.
Was wondering how difficult it would be to remove the fuel tanks?
I understand that a they are glassed in, but not sure whether that means they are encapsulated in glass or is it that the bracket mounts are glassed to the hull? Can they just be unbolted or do you have to cut them out?
What options would I have for replacement tanks?

Thanks...
 
#2 ·
I am by no means an expert here but I had to replace my fuel tank(bow tank) awhile back. It was secured with metal straps over the top as well as being glassed in. The glass was just a few 2"X6" spots that were more of a bracket. I just cut those down, pulled tank and replaced. Not sure if all boats are like that but that was my experience.
 
#3 ·
Are they saddle tanks along the sides of the boat under the gunnel or under the bow? Are they aluminum or are they made out of fiberglass?

Regardless of the answers to the above questions, the job is totally doable provided you're somewhat mechanical and have some tools.

As far as replacement tanks, you could try imco https://www.imcomarine.com/ they're based out of San Dimas and can make any tank, any size.
 
#7 ·
pinhole?

Make sure you take a good look inside. Usually debris sits on the bottom and over the years moisture starts playing a roll in the corrosion process. Once removed and cleaned out, quite possible more failure areas to see/experience. Been there-done that. If repairable, there are also some aircraft quality fuel tank sealers on the market better known as a [sloshing compound] Today's modern fuels may not be compatible with the sealers though so suggest doing some research on the products.
 
#8 · (Edited)
Make sure you take a good look inside. Usually debris sits on the bottom and over the years moisture starts playing a roll in the corrosion process. Once removed and cleaned out, quite possible more failure areas to see/experience. Been there-done that. If repairable, there are also some aircraft quality fuel tank sealers on the market better known as a [sloshing compound] Today's modern fuels may not be compatible with the sealers though so suggest doing some research on the products.
Went through the same issues with my aluminum tanks last year. Pulled both tanks and had them professionally cleaned and coated with Red Kote. I think I payed $150 a tank. I had a local reputable radiator shop do the work.

Here's the product. Damon Industries Red-Kote Gas Tank Liner
 
#9 · (Edited)
gas tank removal

I just removed one of mine a week or 2 ago. In my situation it was much easier than I expected. These tanks had nuts glassed into them. There were fiberglass angle brackets glassed to the floors. Then 5/16 studs into the tanks with nuts. So I had to loosen the locking nuts, screw out the studs with an Allen wrench. Disconnect the filler and supply hoses. Remove the seats and slide the tank out. Sorry, looks like the pictures added out of order. My intentions are to buy used stainless tanks. Then weld together stainless bolts with a tie bar holding them at the correct on center dimension. Then glass in wood blocks that are hollowed out for the bolts and tie bar. This can be seen in the thread by dryhoze1 about his 69 Sanger wood deck build around page 9 I believe.
However these tanks were mounted and can be mounted in many different ways. This boat is a 1970 Taylor flatbottom.
Darin
 

Attachments

#10 ·
I have done this job on a 76 rogers Bonneville. first of all if they are the original gunnel tanks ,they are not aluminum, they are steel, thus the pinholes. there are 4 tabs off the bottom of the tanks that are glassed on , simply cut the glass ,remove the tanks .grind the excess glass .
I replaced mine with custom made aluminum tube style tanks . If I did it again , I would spend the money and buy the proper shape replacement tanks. they are available.
 
#11 ·
RR,
Thanks for the info.
Knowing the tanks are steel, like you say, makes sense in terms of corrosion creating small holes…
When you installed the aluminum tube tanks, what did you have to do get them mounted?
I've taken a look at the Imco tanks. They have brackets that mount to the tank, but I am not clear on how to get those brackets mounted to the hull?
Custom built tanks sound like the best option, very pricey though.
I am not much on fiberglass work. Would any of the options require glass work?
 
#12 ·
Just to be clear, Aluminum tanks, like mine, will get microscopic pin holes and without putting fuel in them or pressure testing, you simply cannot see any sign of the problem. I believe that what happens is sediment that sits in the tank for a period of time will just eat at the soft aluminum metal kind of a dissimilar metal reaction thing. The leak in my tank looked as if the fuel was weeping from the metal without a hole, but there was a hole. If you do aluminum again you might want to think about the coating.
 
#13 ·
today's pump gas

One thing I forgot to add. And I suppose the subject is more about the tanks than gasoline. But the more I learn about today's pump gas, the more frustrated I get. We live in Michigan and all the pump gas has 10% ethanol unless you pay a considerable premium for 100% gasoline recreational gasoline. Which I do run in everything but my daily driver. I run it in pontoon, lawn mower, grass trimmer, leaf blower, snow blower and ski boat. The ethanol seems to be particularly hard on small engine lawn equipment and outboard motors, the older the worse. The worst part to me is they used to have to label the gas pumps as to how much ethanol was in the gasoline. Well now the government here has said the gas stations have to have 10% ethanol or E-10 and the pumps DO NOT have to be labeled as such, which is very misleading. They used to have to label if it contained anything but 100% gasoline. And to make it worse I hear the government is planning to mandate E-15 and later E-20, which will be 20% ethanol. Now I hear from reputable sources in the auto industry that the ethanol gradually over time eats about everything but stainless steel. Viton is a better material for a seal, O-ring or hose, but it is double or more the cost of rubber. The ethanol also gradually eats or dissolves aluminum and brass, probably the 2 most common metals in a fuel system. Now you may not see this in a couple years time, but over the years, yes. Some hoses it hardens and makes brittle and some it makes soft. I am told the ethanol gradually eats away at resin too. So I would probably never run a fiberglass or aluminum tank of I didn't have to. But I understand cost frequently becomes involved. Now previously someone mentioned a coating from a gas tank place. I'd think that's definitely something to consider and certainly a way to keep your boat on the water. I'd ask if their coating withstands ethanol.
Also it was asked about how to mount the Imco tanks. Traditionally the method was to drill through the bottom of the boat and seal up the fasteners with silicone RTV or something like a 3M 4200 or 5200. If I was to go that route I would certainly seal up the holes by maybe drilling a size over and coating the holes with resin using something like a Q-tip for an applicator. Personally I've trended towards drilling as few a holes as possible through the bottom of the boat. So I decided I like the wood block and hidden bolt method, just my opinion.
Darin
 

Attachments

#15 ·
you must use the straps to allow movement . the boat flexes a lot when running through wake and chop.
I couldn't accept the idea of drilling holes in the bottom of my boat, even though it is commonly done.
I made aluminum plates ,contoured to the bottom of hull .drilled several holes in the plate, welded "u" shape brackets that the tanks sit on, to the plates , and welded a strap along the back connecting the two pads togather The straps sit in the groove right in the corner were the bottom meets the side .
used 3M panel bond to glue my bracket down ,the holes were for the panel bond to bite into. covered / buried ,the brackets in body filler with a carbon fiber paint job. no holes in the bottom of my boat

 
#16 ·
RR,
That is a killer looking install!
The 3M panel bond, I'm guessing it's like construction adhesive?
Just so I'm clear: You glued your fab'd bracket to the hull & then bolted the tank brackets to the 'u' buckets in your bracket, or is everything glued together with the hull?
 
#20 ·
I removed the fuel tanks from my 74 Rogers Bonneville today, and since they are dated 1-80, they have been changed at least once; considering this the originals could have been steel. My leak came from a tear/crack where the mounting strap was attached to the tank. The removal was pretty easy only taking about two hours. However, I do have a lot of clean up and prep work to do before I install new tanks. I do plan on having Imco build another set of tanks so the install should be easy. Any suggestions on the reinstall action is welcome, I would like to avoid the possibility of another crack. Also, I might as well replace the floor too while I'm cutting and grinding, nothing better than the smell of fresh cut fiberglass.

Text Font
Floor Bumper Flooring Room Automotive exterior
Table Wood
Floor
I
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top