Fuel Tank Replacement

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
I am planning on replacing the fuel tank in my '84 Offshore during the offseason.
I have pumped out as much fuel as possible, guess the next step will be to remove the "hatch" over the tank and see what is involved in the removal.

I am doing this as preventive maitainance.......assuming it's the original tank.

Looking for any suggestion/hints on this project. I have already replaced the fill line and plan on replacing the line from the tank to the engine.

I have heard about "plastic" or fiberglass tanks as an option.....any opinions on this? I know about the ethanold issue.

Thanks in advance.........
 

mashenden

Well-Known Member
Joined
Nov 3, 2010
Messages
45
Reaction score
1
Points
0
Location
Urbanna, VA
Please post details on measurements and anything else that you find.

I recently removed the forward floor hatch on my '93 Seafarer with the intent to add an aux tank. My plan is to add the aux tank then hook it to my new motor, allowing me to use the boat and give me more time to draw down the gas in the old tank. I will first run some old gas in an old lawnmower, then maybe in a car until it is mostly used up. The last of it I plan to dispose of responsibly. Also the current plan is to go with a plastic tank, specifically the Moeller 58 gallon fuel tank, model #032558 (aka FT5899).

I have included the overall dimensions as well as the reduction in width because of the lip around the opening along with a few other tid bits from an earlier post, below.

I used a utility knife with a hook blade to remove enough of the old caulk to pull up the floor hatch. I suspect a regular utility blade would also be fine, but would require the user to be more careful becasue it would be easier to slip and cut yourself. Lightly using a chisel worked good to clean up the remaining caulk after the hatch is out of the boat.

mashenden said:
In regards to adding an aux tank, has anyone ever put a Moeller 58 gallon fuel tank, model #032558 (aka FT5899), into a Seafarer, preferably something around a 1993 vintage?

This tank measures 44.0" l x 21.5" w x 15.75" d with another 2.25" needed at the top for the fill connections making the overall depth that is needed to be approximately 18".

The forward bilge area in my '93 Seafarer measures 55.25" l x 26.0" w x 21.0" d. The opening restricts the width to about 23.5" but could be trimmed out another .5" to .75" if really needed. It is also worth noting that:

  • While the depth is 21", the V part of the hull cuts into the bottom part of that area a bit on either side so a depth of 21" is only possible for a width of about 17.5", then each side tapers up about 4.5" at something like 20 degrees.

    While the length of this compartment is 55.25", about 42.75" is the full depth then toward the aft, the remaining 12.5" in length has a platform built across, which I understand to be for the fresh water tank if it had one. This restricts the depth in this area to about 19".

Other factors are the fill and vent lines (preinstalled when the boat was built - yeay :)) which enter the bilge compartment on the starboard side at about 17" up from the bottom as well as the PVC pipe for running wires from one side of the boat to the other that is also at about 17" up from the bottom, and is approximately 25" aft of the compartment’s front wall... in other words cutting across at about pretty much dead center of the opening, which is not ideal for sliding in a tank.

So all of that said, it appears this tank would fit both the width and depth without modification and would fit lengthwise if I either trimmed the platform out a couple of inches, which appears to be an easy cut or built the rest of the bilge up to this level. The two complicating factors appear to be 1) possibly cutting out the side to side PVC pipe temporarily so the tank can slide into place and 2) the existing fill line is 2" diameter, while this tank has a 1.5" diameter inlet. Assuming no other complications this seems like a reasonably good tank selection.
 

BobP

GreatGrady Captain
Joined
Apr 27, 2005
Messages
4,746
Reaction score
6
Points
38
Location
Long Island, NY
Model
Sailfish
No reason to replace if nothing wrong with, inspect surfaces before ordering new, clean it up with scotchbrite.

Look for pits, if shallow & few together (ie. spread out- Ok to stay)

If holes, new tank only.

Suggest WEMA sender.
 

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
Removed the tank this morning......found some pitting under the neopreme.......looks like a replacement(?).

PC050041.jpg
 

duabrown

New Member
Joined
Dec 17, 2010
Messages
3
Reaction score
0
Points
0
If your tank has developed a leak, or otherwise damaged, it will need to be replaced. This can be done by the average mechanic. Be patient and make sure you have security in your mind at any time. Natural gas is highly flammable dangerous if ignored.
Work in a clean, organized areas. Clutter can cause accidents.
If you are working indoors, make sure no lights or other sources of flame or sparks exist.
 

cgmiller

Well-Known Member
Joined
Oct 16, 2005
Messages
311
Reaction score
0
Points
0
Well..what did you decide to do? When I pulled the leaking tank out of my 1988 21 Mako in 2009, it looked out until I cleaned it off and willed it with water...had about 15 leaks..some looking like a water fountain. No question it was done..leakes all over ..,y buddy pulled the tanks from his 1989 230 gulfstream a few years ago and he had isolated corrosion where something was toughing the tank. He filled the holes with jb weld and then epoxy coated the tank and put them back in...I will pull the tanks in the 1990 230 that I just bought this winter/spring so I can get a look at them and peace of mind....after 20 years, they need to be cleaned and inspected..if I am going to make the effort to yank them, they will get epoxy coated and hopefully I can put them back in w/o having to buy new ones, which would cost about 800 bucks each..the 86 gallon tank I had made for the mako was about 700 bucks....
 

cdwood

GreatGrady Captain
Joined
Apr 1, 2006
Messages
578
Reaction score
0
Points
18
Location
Hamilton/LBI N.J.
While I'm not a big fan of "repaired" tanks at least have it pressure tested to determine the integrity of the repair.
 

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
I decided to replace.........dropped the tank off with Phil at Alloy Metals in Farmingdale last week, he already called and said the new one is ready.

Will probably pick it up this w/e..........too cold to play under the covers right now!!
 

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
Replacing the fuel fill hose was a real PITA!!

You can try to connect the new hose to the old at the tank and use the old hose as a snake.
I tried this but my old hose was so dry rotted it fell apart.

It's not an easy job........good luck!!
 

Got Grady?

Well-Known Member
Joined
Feb 25, 2010
Messages
98
Reaction score
2
Points
0
Location
By the sea by the sea by the beaut.......
I guess you are talking about the hose to the front tank which is the one i cant get out. The hose to the rear tank was a piece of cake. So can you give me more info on how you did the front hose. I got the front hose unhooked from both ends and all the silicone off ut cant get the hose to move either direction. I called grady and all they could say was pull like crazy till it comes loose. Not much help to say the least. I was considering cutting an access hole in the starboard stringer next to the fish box to try and get more leverage. They said it might help or it might not. Can you tell me more about how you did it? I have a feeling the hose will pull apart on this one too. Help a brother out with how you did it.
 

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
It was about 5 yrs ago so I don't remember exactly how I did it.

Like I said the old hose broke apart and cam out in pcs.
I have an access plate on the starboard side right by the fish box.
I was able to get my arm in there far enough to do the job but I do rember being quite bloddy by the time I was done. I fed the new hose from the tank end and secured a piece of maybe 10 ga wire so I was able to pull it through....try putting some dish soap on it to let it slide.

I would NOT cut the stringer!!!

Good luck, if I remember anything else I will add it........
 

Got Grady?

Well-Known Member
Joined
Feb 25, 2010
Messages
98
Reaction score
2
Points
0
Location
By the sea by the sea by the beaut.......
66

Well that is not very encouraging is it. I have already made a mess out of my hands. The gentleman I talked to at GW did not even flinch when I said something about cutting a hole in the stringer close to the fish box. He just said to get as high up as possible to ensure I was above the foam and to cover it with an access plate when done. I worked at it for an hour today and cut a 3 inch round hole in the stringer right at the corner of the fish box. The hose is about 16 inchs away from the stringer so I used some stiff wire and a piece of 100 lb test line with a loop in it and taped it to the wire. Then I pushed the wire over the top of the hose so the loop would fall over the hose and then used another wire to hook the loop and pull the line back through. I attached some rope to the line and pulled it back around the hose. Talk about fun trying to hold a light into a 3 inch hole while working 2 pieces of wire and hooking a loop 16 inchs away on the far side of a hose while laying on your stomach hanging your head over into the tank locker. I ran out of time but I can now pull the hose from both ends and the middle so hopefully tomorrow it will come out. I almost wish the hose was rotten enough to have come apart. I have pulled and pushed and it has not come apart yet. Anyway thanks for at least trying to help.
 

'84Offshore

Well-Known Member
Joined
May 5, 2005
Messages
375
Reaction score
2
Points
0
Location
Long Island, NY
Keep at it.......you'll get it. Just don't loose your temper like I usually do...:)
Sounds like you are going at it somewhat like I did.

Good luck and let me know how you make out!

If your old hose is that strong, maybe you can attach the new one to the end of the old one and use it as snake to pull the new one through............just a thought.
 

Got Grady?

Well-Known Member
Joined
Feb 25, 2010
Messages
98
Reaction score
2
Points
0
Location
By the sea by the sea by the beaut.......
Success, had a helping hand today. With the rope around the hose at the access hole that I had cut in the stringer next to the fish box the old hose came out pretty easy. I drilled a hole through the end of the hose at the gunnel and tied another rope to the end of the hose. We then pushed and pulled and used the middle rope to keep it from getting pulled under the fish box. Attached the new hose to the rope and pulled it back through again using the middle rope to keep the hose from going under the fish box. Old hose out new hose in less than 90 minutes. My hands and arms are a mess but it feels good to have it done. Thanks for the input.
 

MikeyThumbs

Active Member
Joined
Apr 2, 2023
Messages
27
Reaction score
4
Points
3
Age
40
Model
CHOOSE
I decided to replace.........dropped the tank off with Phil at Alloy Metals in Farmingdale last week, he already called and said the new one is ready.

Will probably pick it up this w/e..........too cold to play under the covers right now!!
I have an 84' Tournament 170 that needs fuel tank replaced.. Coincidentally I live in Farmingdale too, any chance you remember about what you paid for the new tank to be made (i know it was over 10 years ago..). I'm hoping to use the same shop once I get the tank pulled.