Aluminum fuel tank repair ??

Streetwalker · 11-21-2003, 05:07 PM

I pulled the fuel tank out of the Olympic I recently bought. It looks pretty good, except for some small areas of corrosion that have left some small "craters" on the bottom. The tank was very difficult to get out & I would like to get those spots repaired before I re-install it. Do any of you know where I can get this done for a reasonable cost??

Chaps · 11-21-2003, 05:18 PM

I'd give strong consideration to having a new tank made. Once those start going back to nature (pitting, corrosion) it is very difficult to guarantee a repair (if you can even get someone to do it). The fact that it is hard to get in & out provides an even stronger reason to go new. Edwing builds his own tanks, probably other boat builders as well so that would be a place to start.

BOTTOM TIME DIVER · 11-21-2003, 05:18 PM

It can be repaired but it must be done by a welder that is qualified in marine tank building.
I have heard of a few "blowing up" due to the lack of proper evacuation of fuel. even after a good wash job they will still explode. due to the corrosion,I would suggest a new tank....after market builders can ber found in the backs of saltwater fisherman and national fiaherman.

good luck

lingslayer · 11-21-2003, 05:32 PM

Someone with experience welding fuel tanks will just fill it with Co2 or Co2/Argon mix and have at it. The gases are heavier than air and displace (purge) the air. After that the fuel residue (fumes) can't burn in the absence of O2.
I've seen it done many times.
Jamie

Onokai · 11-21-2003, 06:44 PM

I suggest a new tank. Hve you considered the new plastic non corrisive type???. They speak highly about them at www.powerboat-reports.com. You may have to subscribe to get the info. I would send them a e-mail asking for plastic tank sources. I have been reading about these new tanks for years.Many new boat come with them now. No corrosion ever for your life. Why go old school aluminum?? PS I have two boats each with aluminum tanks and wish I had the new non corrisive plastics.Mark

ONOKAI

Streetwalker · 11-21-2003, 08:40 PM

My first thought is to replace it, but if it can be effectively repaired I'm OK with that. There isn't much pitting, but while its out I want to get it handled. I have a friend whose alum. tank started leaking, but his boat is 30 yrs old. This is an 88 gall. tank, what do you all think I'm looking at to replace it cost wise. I also have a 21' sled that looks to have a custom built tank & wonder if any of the alum boat builders are certified & would build me a tank??

[ 11-21-2003, 09:43 PM: Message edited by: Streetwalker ]

Sturgeon Tom · 11-22-2003, 07:05 AM

If it is very small pitting you wet sand the area and buy liquid solder and spred it over the pitting. I have done this before and it worked great.
If you are going to get it welded it is cheper to have a new one made. I went though this with my last boat. Moton Marine was the cheapest in the north west and did an outstanding job.
I could find no one in the Portland area that would weld an existing tank. I would have had to send it to Seattle and you have to drive it there as no one will ship a tank that has had gas in it.
I hope this helps.
st

[ 11-22-2003, 08:09 AM: Message edited by: Sturgeon Tom ]

Beer Waggin · 11-22-2003, 12:15 PM

Street-
My first question would be why is the tank pitted? Is or was it set in place with foam? If it was, I'd rip all of that foam out of there and mount a new tank. Alum generally pits because of lack of oxygen. Moisture gets into the foam, gets on the tank and then stays there!
Sounds like you're at least lucky enough to have access to the tank without haveing to cut the deck. :smile:

Deepslayer · 11-22-2003, 03:57 PM

Street I had the same problem on a tank about tweleve years ago. In fact on two saddle tanks. I got a fiberglas repair kit and patched them up. Ten years later when I sold the boat the tanks both looked good as new!
,Ed

Onokai · 11-22-2003, 04:32 PM

One other thought. Try JB weld- it's sold at hardware stores and is great stuff, after a good sanding and cleaning. Mark

ONOKAI

treegolfer · 11-22-2003, 04:50 PM

I was going to purchase a 4 year old 23' Boston Whaler this past summer until the surveyor found the fuel tank was badly pitted. All advice I got was that the tank should be replaced and all estimates I received were $4000 dollars and up. Needless to say, this boat never looked that good after that and I purchased a different boat. Have trouble believing that a manufacturer with the reputation and experience Whaler has would put out a product with a problem like this. I was advised that if the fuel tank was not replaced,I wouldn't be able to insure it since it showed up as a difficiency on the survey. Personally question that, but this is what I was told.

treegolfer

Streetwalker · 11-22-2003, 09:36 PM

Nor riv Dave,
The tank is shimmed off the bottom & its not easy to get to, I just got done removing the back deck & want to make sure the tank is good. I'm not willing to put it back in untill I'm sure that it's either repaired well ( looking less likely ) or new. I'm a little stumped as to why it is pitted also, there is air circulation around it.

Mark Mc · 11-23-2003, 07:39 AM

You'll want to read this article on Dave Pascoe's website (I believe this fits within the link-posting policy):

http://www.yachtsurvey.com/fueltank.htm

Streetwalker · 11-23-2003, 07:15 PM

Mark,
I read that one a week or two ago & intend to incorporate some parts of it, I allready have a flat deck to set it on so that helps & I dont intend to use fasteners this time, just some strategically placed cleats that will be epoxied into place. The thing thats got me stumped is that other than the fasteners it looked like it was properly installed & had about 1/4" clear underneath it. The pitting isn't bad but it was alot of work & will be alot more getting this tank in & out.

Miss B Haven · 11-24-2003, 08:00 AM

Kamloops- I'm surprised you haven't commented on this one. [img]graemlins/lurk.gif[/img]

I'd replace it. If you have one area of visible corrosion I'd be afraid of more waiting to show. I'd never trust a patch for long either. Especially on a gas boat. (I'm sure that's what you have.. .right?). Leaking Diesel is one thing, leaking gas is a bomb!

If the tank was easy to get in and out maybe I'd try to get it patched and see (maybe not). If not- why go to all the trouble of pulling and then reinstalling a piece of crap that might end up killing you. Not the place to take short cuts IMHO.
Have you taped that tank out and then checked the Catalogues and web for an off the shelf tank that would fit in the hole? The price of those is a nit compared to the labor to R&R one in most boats. You've already done the worst/most expensive part!
Good luck!

kamloops · 11-24-2003, 08:23 AM

Mel,

It's kind of like a bad dream that you wish you could wake up and it would all be over.

I would not screw around with a pitted "gas"tank. Replace it. I would be surprised if you could even get a welder to go anywhere near a gas tank, I had a tough enough time finding a certified that would even talk to me about filling a pit in my tank. And their diesel tanks.
I got to get rid of this wireless keyboard.

Anyway, my tanks were inspected 5 years ago and found to be clean and structurally sound than reinstalled back after a complete cleansing.

To make a long story short, I had a tank fail after 21 years of use. The offending hole was on the bottom of the tank with zero access. The tanks were installed on the outboard hullsides next to the engines, on the stringers with glass with wood mounting blocks. Steel straps were used to secure the tanks from movement. When the tanks were reset they were not mounted correctly, they should have been water tight, moisture got under the tanks and rotted them out.

Two new tanks are to be built and installed, hopefully sometime early next year the nightmare will be over.

[ 11-24-2003, 09:42 AM: Message edited by: kamloops ]

rojo · 11-24-2003, 08:35 AM

There is a process for repairing tanks, but don't think I would use it for a boat.What we did in a radiator shop was hot tank the gas tanks then repair the bad areas and then pour in a product that hardened to form a tank liner, this process worked great. Was used mainly for cars that were being restored and where owerners could not find replacement tanks....Roger

Streetwalker · 11-24-2003, 08:38 AM

I pretty much came to the same conclusion after the first post especially given that the back deck had to come out to get this one out. Working on getting prices now. Have done a search & not been able to find one that matches my dimensions yet, so will probably have to have it made.

11-24-2003, 08:41 AM

Fuel tanks can be safely welded but it takes lots of preparation. On aluminum tanks if you have a problem in one spot you have more that you don�t see. Kamloops tank was so rotten that I was able to poke a screwdriver through it with no force.

Captn · 11-24-2003, 10:15 AM

I have had this problem. It is easy to say make another tank, but the fact of the matter is that the tank is put in place and the boat is built around it. My 96 gallon tank had pitted due to salt water that was not able to drain. Don�t ask the question about how the saltwater got there to begin with because I don't know (not sure I want to). With time the normal drainage that would have gone into the bilge, was blocked by debris and the gas tank was compromised.

Talk about a nightmare, now you have a stick of dynamite looking for a place to explode. The boat becomes worth less than zero, as instead of having a net value, it is now a liability.

Long story short. I took it to Britons boat repair here in Salem. They had to use dry ice to contract the tank enough to remove it. The tank had to be etched, and then the welder patched the holes. A 24 hour pressure test was done to make sure there was not another pinpoint hole that may have been over looked. With the tank passing the pressure test, the tank was epoxyed on the bottom and half way up the sides. Some of you may know what kind of epoxy this was, but it was a very slow curing, it took over 2 days. The tank was reinstalled, and no problems at this point.

But for any of you that have not removed a gas tank, you cannot believe how tight they are installed and what it takes to make them fit correctly.

I hope this post has been of some help. Like I said, been there, done that. One of the low points of my boating life.

Onokai · 11-30-2003, 11:05 PM

Streetwalker. I think with the new link rules I can give you this info as no sponsers sell plastic gas tanks. Two manufactures are Moller(330/405-3688 and Inca (615/350-7290. From what I have read this is the way to go.This info is from a non advertising publication Powerboats reports Forget about all other materials for gas tanks in boats. Mark

ONOKAI

Streetwalker · 12-01-2003, 06:21 AM

Whaler man
Thanks for the info. But I have a new tank being built right now. I've done alot of research on what makes them go bad & how to properly install a tank to avoid those things. At first I thought it was properly installed but after looking more closely, the builder did not install it right. It was shimmed up but the "shims" were not completely sealed to the tank & were of a material that compressed only allowing about 1/16"-1/8" of air space underneath. With normal deflection, this probably allowed the tank to come in contact with the floor when loaded with fuel. When I stripped away the shim mtl, the areas that were completely sealed looked brand new, while the areas that were not were corroded as were what looked to be contact points where the tank touched the floor.

SeaJayOR · 12-01-2003, 11:42 PM

I've replaced 2 tanks on my older '75 Bayliner, though on a much smaller scale. I did not have much luck finding someone to contsruct a tank. The first was a 17gal aluminum. When I went to replace the 2nd tank Overtons only had the plastic. So now I have one aluminum and one plastic, both made by Moller I believe. I like the fact that salt does not corrode the plastic tank.
CJ