Fuel Tank Support
 

As part of the restoration process of my 23cc I removed the fuel tank for inspection. Here is what I've found.
http://www.casdvm.com/photos/DSCN2942.JPG
http://www.casdvm.com/photos/DSCN2944.JPG http://www.casdvm.com/photos/DSCN2946.JPG

The support structure for the tank consisted if 1/2 inch plywood with two layers of woven roving on top. The bottom of the plywood (facing the bilge) was bare wood. When I stood on the structure it felt solid except for the ends were the rot had really taken effect. Part of the reason it felt solid was because of the keel it rests on. Notice from the pics that decay is not just limited to the ends of the wood. The wood shims that kept the tank sliding from side to side were rotton as well. They were screwed into the stringers. The fuel tank itself looked good on the top and sides however the bottom had severe pitting were it rested on the moist wood. This week I will be getting a new fuel tank built as well as rebuilding the support structure for the tank. Here is area all cleaned up .
http://www.casdvm.com/photos/DSCN2979.JPG

I apologize for taking off all the pics I put in earlier posts as I'm re-doing them into web galleries and I accidently deleted the folder they were in. Here is the link for two of the folders I have up right now. John R if you want to put some on "the boat Zone" you are welcome to what ever you need.

Strick
http://www.casdvm.com/photos/Hardtop/
http://www.casdvm.com/photos/TransomCap/

Re: Fuel Tank Support
 

Strick - seeing that you already have your own stuff, no need for me to put them up in TBZ. However, before, I was downloading what you were posting into my "OtherProjectsInspiration" folder on my hard drive. So, if you're missing any of your other pics, let me know - I probably have them [img]images/icons/smile.gif[/img] ...

Re: Fuel Tank Support
 

Strick,

Just curious what year is your seacraft, I am in the process of stripping a 1985 down, and shortly going to inspect my tank, I have yet to look to see if my support is glassed on both sides

thanks,
KBG

Re: Fuel Tank Support
 

KGB,

Strick has done this the real right way. Just figure on removing everything like he did and installing a new tank. I went through this this spring and removing more is better. There's no cutting corners on that job.

The only thing I would do different is have 2 tanks built instead on one 135 gallon. It would be easier to manage weight distribution.

Have fun!

Re: Fuel Tank Support
 

Strick

When I pulled my 100 gal fuel tank in '95 only the rear corners of the support floor was rotted. Mine WAS glassed on both sides however. The shimms were ok also. I then Installed a new 135 gal tank which gives added weight up forward and improved the ride. I also installed a 15 gal fresh water infront of the gas tank up against the forward hold with an access hatch in the aft wall of the hold. Something for you to think about.

I made the new floor out of marine ply and glassed and gel-coated both sides. I made new shimms out of teak and screwed them between the (6) 90 degree angle supports off the tank and the stringers.

Re: Fuel Tank Support
 

Strick....I can relate

What a mess under the deck ..... 27 years of slime !!! [img]images/icons/shocked.gif[/img]

http://www.imagestation.com/picture/...2/fa472e9a.jpg

http://www.imagestation.com/picture/...9/fa472e98.jpg


But I didn’t have the fuel deck supported by the centerline stringer....Even though the deck was real rotten ...it didn't need that support apparently ....but I cant see that it would hurt I do think the brunt of the weight is loaded on the edges attached to the stringers/hull bottom where the deck is tabbed in.

Otto ... How would you do it different ??? One forward one back ??

Re: Fuel Tank Support
 

I pulled my tank and the aft edge of the wood tank platform had very little mushy. The rest of the wood seems as solid as a rock - I jumped on it a bunch - not even a creak. I'm going to leave it.

I would like to know how you re-fasten the tank back down ?

It was originally held in place by pcs of plywood being wedged between the fiberglass sides and the angled aluminum meant to hold the tank in place.

However, wherever the wood had touched the aluminum, whether the angled pcs or the tank itself - there was mild to severe galvanic corrosion. I want to avoid that in the future.

I have epoxy coated and awlgripped the tank ( probably overkill, but I had the spare supplies ). Also, I glued down 3M, 3/4", closed cell, adhesive strips on the bottom of the tank for cushioned support and to let water drain.

Once the tank is in place, how should I keep her firmly in place ?

Re: Fuel Tank Support
 

I went through the same thing when I did my boat. I went with a 120 gal. fit real good and I didn’t loose the hatch in front of the center consol. I moved my tank forward of the bilge area now the back of the tank is in line with where the stringers make that 90 degree angle into the bilge area. By moving it forward and increasing the size from 100 to 120 gal. plus putting freshwater tank and oil tank and batteries under the center consol and above the gas tank the boat rides much better.
FellowShip

Re: Fuel Tank Support
 

This is how i installed the tank, plus i also had two 90 degree plates welded to the fron and back of tank and screwed them into the gas tank deck.
http://www.yachtsurvey.com/fueltank.htm
FellowShip [img]images/icons/wink.gif[/img]

Re: Fuel Tank Support
 

Strick:

I continue to be amazed at the amount of work you are doing and the quality of it; makes me want to take a sabatical (sp.?) from my career and go to town on my '78 23' Sceptre. If this is of any help to you and the rest of the CSC members, I had the exact same problem on my boat. After cutting out the delaminating/rotting "floor" of the fuel tank compartment, and cleaning up the mess and painting with Interlux BilgeKote, I fashioned a new "floor" out of Starboard (3/4"). However, instead of making the floor an exact replica of the original, I cut it to rest directly on top of the keel stringer, with the width varying from the aft section to forward section (wider aft, narrower forward) to conform to where it meets the inside of the hull. Also, where it meets the hull, I cut the edge at an angle to conform to deadrise, so that where the Starboard meets the hull I have two flat surfaces mating, instead of a "hard point". When I mounted the Starboard floor, I bedded it down heavily with 4200 on top of the keel stringer and where the edges met the hull. The purpose of this was to pick up rougly an additional 2-4" of height in the compartment, allowing for larger tanks. The new tanks I had fabricated (replaced a single 80 gal. with one 65 and one 45) have a "V" section at the bottom. That is, there is a flat pad at the bottom of the tank approx. 6" wide, then sections on either side that follow an angle parallel to the deadrise until they meet the vertical sides of the tank. When installing the tanks, I did not foam them in. Instead, they sit on the Starboard floor, in turn resting on the keel stringer, and lag bolted into the sides of the compartment. This design allows plenty of air circulation around both tanks, with all bilge water running underneath the now-sealed Starboard floor. It also allowed for an additional 20 gallons or so of tankage due the increased height.

I know I should have probably fabricated a proper floor out of an appropriate cor material and glassed it in, but my skills in that area are lacking. Also, I will admit, it was a major PITA measuring all the various dimensions in that compartment. However, I believe I kept all the measurements and "blueprints" I created if this would be of use to anyone.

Happy Holidays,
Chris

Re: Fuel Tank Support
 

Abl,
You did it perfect. With epoxy and Awlgrip your tank is virtually impervious to corrosion on the outside. It is the absolute best way to do it. If you don't have tabs on the tank sides you can foam it in with cross members over the top to keep it from lifting in the foaming process. Make sure to lay down strips of 1/4 inch starboard or hard rubber strips under the tank to allow drainage.

Re: Fuel Tank Support
 

I have built a new aluminum tank from 5052-H32 marine grade aluminum for my boat ( we are metal fabricators), and was thinking about taking it to a shop that does the spray on bedliners. It is supposed to be impervious to anything, and not harmful to aluminum. Anyone have any experience with this, have you tried it? Previously I have always painted with zinc chromate several coats to protect the aluminum like is done on aircraft parts.

Re: Fuel Tank Support
 

Once again thanks for all the comments.. I really appreciate it because it helps to stimulate my gray matter to come up with new ideas.

John R - thanks for the back up support. I still have all my pics but I'm just a little dis-organized as to were they all are. Glad to see that my pic's made it to your Projects/ Inspiration folder [img]images/icons/wink.gif[/img]

Capt Chuck- We must have a different design to our boats. My tank sits right up against the forward hold (the stepdown compartment in the consel) so there is no room to put a fresh water tank in front of the gas tank unless I do away with the stepdown compartment and make the floor inside the consel level with the main deck.

Kglynn- 1975 model

Otto- right now all my buddies are killing ducks and catching stripers and sturgeon and I still would rather be working on this damm boat.... go figure.... my mother must have dropped me on my head when I was a baby.

Scott- yea it's good that we are checking everything... there used to be a head in the stepdown compartment in the consel and I could see were the previous owner had done a sloppy job of removing the plumbing and glassing over the area so I decided to remove the stepdown compartment and take a look at the patch job they made to the hull and sure enough it did not look to good so ground out the area and epoxied over it just to be safe. Here are a couple pics of that.
http://www.casdvm.com/photos/DSCN2980.JPG
http://www.casdvm.com/photos/DSCN2983.JPG
http://www.casdvm.com/photos/DSCN3005.JPG

abl1111- I'm going to do it just like Fellow ship posted from the Pascoe site (had it saved as well). That Pascoe knows what he is talking about. He says dont use any rubber strips on the bottom of the tank (to keep it from sliding) so when I pulled my tank out sure enough it had rubber strips stuck to the bottom of the tank and when I pulled them off there was severe pitting into the aluminum. That was the only place were there was corrosion on the whole tank... right were each rubber strip was. Foaming in the tank will keep it secure however often times water will find it's way into the foam. So make sure there is a way for the water to get out. Good that you coated the tank and I may do the same.

Chris- I'm self employed so I get to take a day off when ever things are slow. I decided to use high quality 3/4 inch plywood for the tank to sit on. I'm glassing both sides with a layer of 1708 and will make a bed of cabosil along the edges were the base meets the hull and also will cabosil it to the keel stringer. Then I will glass it up the sides of the stringers. I decided to go with the wood for the extra weight plus I did not feel like driving the 2 hours for composit [img]images/icons/rolleyes.gif[/img] Upon thinking it over I think it is a good idea to keep things as light as I can in the rear of the boat (by using composit) and add a little extra weight in the middle (with the wood)

Strick

Re: Fuel Tank Support
 

Ha Strick
I also went with ¾” marine plywood with lamination on both sides. I almost had a problem that I thought I would worn you about. By increasing the thickness of ¼” with glass lamination and by placing the gas and air filler 90 degree pipe approx at the same location as the old tank I had a very tight fit of the deck on top of the tank. The guy that made the tank for me made those 90 degree gas fill a little too high and my top deck would have rubbed against it. I was going to put a air vent in anyway so I decided to put my air vent right on top of the 90 degree filler hose locations just to be safe.
FellowShip [img]images/icons/cool.gif[/img]

Re: Fuel Tank Support
 

Thanks Fellow-Ship... it's a tight fit in mine as well. I finished glassing in the new tank support last night so I'll take a measurment today with the top deck on (also has 3/4 inch marine ply) before the welder starts making the tank so I can give him. Have to figure hoses, clamps etc... for a maximum height [img]images/icons/smile.gif[/img]

Strick

Re: Fuel Tank Support
 

Looks familiar....

http://seacraft.snetsol.com/inside.htm

Re: Fuel Tank Support
 

Capn Chuck,

I've been at it for almost three years now. Why you ask it's taking so long? Primarily money issues, but also not much free time. I have another 4-5K that I need to put in to be ready for launch.

I am pretty much done with all the rough work; transom replacement, rebuild of front fish well, rebuild of fuel tank area, patching and fixing holes of all shapes and sizes. I have already purchased the paint I will be using to paint the outside of the boat as well as the cap and deck of the boat. I have rough sanded almost all surfaces that need paint. I have also rebuilt my console more to my liking.

Already have a new Fuel tank ready to go. I bought a brand new in box 2001 225 Evinrude last fall.

Things I still need:

Hydraulic steering
Rewire the boat
Electronics
Leaning post
All the rigging for the engine including prop
Misc. items....

I really haven't updated my progress pictures for some time. You can see some of the originals at http://seacraft.snetsol.com

Re: Fuel Tank Support
 

Rich

Boy you really have had your hands full [img]images/icons/shocked.gif[/img] By the pics you have done a great job. What year is that wiring detail from?.

I guess I have been lucky as I am the 2nd owner of my boat and have owed her since 1985, so I have been able to stay with it and not let severe damage set in. [img]images/icons/wink.gif[/img]
I still will be inclosing the transom and installing a bracket. I'm starting to get some bleeding at the engine bolts and motor well cap. After 25 yrs I know it's time. [img]images/icons/frown.gif[/img]

[ December 18, 2003, 04:20 PM: Message edited by: capt chuck steele ]

Re: Fuel Tank Support
 

Hey Strick ...Are you replacing those "level platforms" (used for the batteries) towards the stern of the bilge where the big stringers go outboard 90 degrees??? They look similar to mine ....as in the color is dark ...making me think they are rotten ... I know Fellowship found that when he took his apart.

Ironically I have that space under the console for the head ...BUT .... its nothing more than an empty void with the deck inside the console...I cant figure out why they would have wasted that space ....But I wont !!

Rich …those wiring diagrams are pretty neat !!

Re: Fuel Tank Support
 

Hey Strick - when I pull my console off to see how forward the tank goes, if I have enough clearance, I want to put that console well in. I might want your old one [img]images/icons/grin.gif[/img] [img]images/icons/shocked.gif[/img]

Re: Fuel Tank Support
 

Rich

How far along are you in the refurb? Are your pictures up to date? What kind of damage is shown starboard side forward hold? Your layout is the same as mine.

Re: Fuel Tank Support
 

I tried to print that wiring diagram - anyone know how to format it so it is printable ?

Re: Fuel Tank Support
 

I got those wiring diagrams from some guy at Tracker Marine. It took two months of being a complete annoying ass for him to finally break and he sent me hard copies in the mail. I scanned them with a pretty crappy scanner and I had to make the image size real big so it could at least be legible. I don't know what help they would be for me because i don't have that particular panel.

Rich

Re: Fuel Tank Support
 

Tracker is not very customer friendly. Nice concept, huh? As they moved on short notice to NC this year, all that stuff must still be in boxes someplace. I wish somebody would by SeaCraft from those guys and bring the company back to it's true legacy.