That old topic...I am replacing my Tank
 

Hello Guys-

I am soon to begin the one winter project I need to complete on my '83 23' CC, put a new tank in before next season. I am still on the original tank, so I figure that I better do it now, rather than have it go on me in June...

I have never done anything like this before, but I don't expect it can be as hard as building the pyramids, I hope.

So, before I begin, what advise can you offer me on this project??? I have read all the archived material I can find on the subject, but still know little on what I will have to do.

First I'll need to unwire anything that prevents me from moving the console, then remove the console to have access to the deck, open up the deck and gain access to the tank.

I believe the tank is foamed in, so I will have to remove that somehow... someone on here used a chainsaw, but I am sure there are other ways too.

Remove the tank and bring it to a fabricator.

Once out, I figure I will need to inspect stringers and any other potential probelm areas which I may see with the tank out.

Once built, I'll need to replace the tank and foam it back in place, right???? How the hell does that work and what should I use????

I could really use a few words to point me in the right direction. I figure I will start removing some wiring soon so that I can move the console for access....

Thanks for anyone who might be able to get me started!!!! [img]/images/graemlins/smile.gif[/img]

Re: That old topic...I am replacing my Tank
 

You might want to read this article:

How to Install an Aluminum Fuel Tank

Re: That old topic...I am replacing my Tank
 

QUOTE: I believe the tank is foamed in, so I will have to remove that somehow... someone on here used a chainsaw, but I am sure there are other ways too.

I recommend that you use a blade from a Bow saw.[tree trimming saw] Use just the blade. It's about 18in long. Wrap one end with cardboard and duct tape. It's long enough to go to the bottom of the hull and is VERY agressive so it will cut fast.



QUOTE: Once built, I'll need to replace the tank and foam it back in place, right???? How the hell does that work and what should I use????

Clean the alum well and sand the tank with 60gt on a DA sander. Then roll on 2 coats of Coal Tar epoxy. I rolled a thin coat of regular epoxy on top of that on mine. Use 4lb density foam to refoam it in. You can get 4lb density from FGCI.com

Re: That old topic...I am replacing my Tank
 

The artical by Dave Pascoe is good, but it has falts in it too. His whole deal stems around getting air moving thru your bildge. On big boats that is possible. On these SeaCrafts it's not. He talks about water getting traped in the foam and working on the alum. So don't let water get in there and protect the alum if it does.

Re: That old topic...I am replacing my Tank
 

Your loosing me. [img]/images/graemlins/confused.gif[/img] The 23's have vents on both sides fore and aft just for the purpose of hull/bildge ventilation.

Re: That old topic...I am replacing my Tank
 

That's not how I read it. The whole deal stems from not ever letting water stay in contact with the aluminum for long periods, as in wet foam against the tank. Space for air is needed, not necessarily active air circulation.

Also, I'd be concerned about using coal tar if he is corect about carbon being cathodic to aluminum and causing galvanic corrosion.

Re: That old topic...I am replacing my Tank
 

How much of this stuff do you think I'd need??? Again, you're dealing with a clueless person!!! [img]/images/graemlins/laugh.gif[/img]

Also, am I correct in thinking that this foam stuff is the only thing holding the new tank in place? No straps or anything? I am sure I'll see things more clearly once I open her up, but I just don't know how it all comes together.

Re: That old topic...I am replacing my Tank
 

Hey Hopper ...How ya been ??

Can speak for all ... but my tank had tabs welded right on it that were used to anchor it into the stringers …and that dreaded foam

Don’t know about the "newer" boats but most of the older ones had vents forward and aft (unless closed in during a restore) Those vents allow air flow into and throughout the bilge ...Edit ...I see thats what Finny already said

Re: That old topic...I am replacing my Tank
 

Hi Scott-

I'm doing fine, thanks! Got time now to read my favorite sites and do some boat fixin' if it doesn't get too damn cold!!!

Ok, so the tank has welded "feet" (for lack of the proper term) which are then fastened to the stringers I would assume, is that right? I would guess as long as I don't have any rot going on at that point I can refasten with the new tank.... hmmmm.

I appreciate the help guys, I am also sizing up this project and deciding if it is too much for my limited experience!

-Hooper

Re: That old topic...I am replacing my Tank
 

Good to see ya around !!!

Actually those tabs are up at the top of the tank ... When you get under the deck yours may be different

They had a 90 degree piece of aluminum along either side ...so you could fasten it as much as you wanted ...If you had room, tabs on the bottom might not be a bad idea

Wet foam killed my tank ...only down on the bottom 2-3" of the sides ...It held the water and corroded the tank (no coating). The three builders I have talked to (in NJ) either include or offer epoxy coating.

Re: That old topic...I am replacing my Tank
 

Scott--
The last tank from S&P was real nice. The
epoxy coat was a option from them.

What did you end up getting?

Rodney

Re: That old topic...I am replacing my Tank
 

Hooper, you shouldn't have to worry about rot, your screwing right into the stringers. Just be sure to repair the old holes and you'll be fine. You will find rot underneath. There's a plywood sheet under the tank thats most surely rotted. Thats an easy fix.
Good luck.

Re: That old topic...I am replacing my Tank
 

While it is true that the SeaCrafts have vents, is there a way for air to get around the fuel tank? Isn't the tank intombed between the stringers and bulkheads, so no air can get to it.
Rubber has carbon in it. Coal Tar epoxy is used in offshore metal protection. It will not react adversily to alum.

1gal of partA and one gal of partB will give you 4cuft. That is if you don't do it in cold weather. In cold weather it will not expand correctly. In warm weather you need everything set up where your going to do your pouring. You pour part A in with part B in small measured quanities and stir for about 45sec. You better be pouring it then. Ideally you will have "L" brackets welded to the side of the tank to lag bolt it to the stringers too.

Re: That old topic...I am replacing my Tank
 

Rod ...I just talked to them a couple weeks ago ... They had a pretty good deal...I just have to pick a size
I’ve seen the tanks in the shop at various stages ..Looks like they do excellent work ..not to mention build for several boat manufacturers

Did you get the electromagnetic sender in the tank??

Re: That old topic...I am replacing my Tank
 

Bobby ... Here's a picture of the bilge ...no bulkheads forward or aft


http://www.patmedia.net/scottfish21/...k-in-bilge.jpg

Re: That old topic...I am replacing my Tank
 

That's a much diffrent layout than Brand X boat's have. [img]/images/graemlins/smirk.gif[/img] I'll have some pix's latter.

Re: That old topic...I am replacing my Tank
 

What in Gods name are you talking about?? Please don't make the mistake that many pleople do by thinking Mako's are the same as SeaCrafts. I have two and they are completly different boats, but that configuration Scott showed is the same in all 23's.

Cheers.

Re: That old topic...I am replacing my Tank
 

This obvisly doesn't apply to the 23 SeaCraft, but is a typical setup for a lot of diffrent boat's
http://www.classicmako.com/test/chaparrel/

Re: That old topic...I am replacing my Tank
 

Gordon

I just replaced my tank over the summer. Not that challenging of a project. I used a long blade in my recip. saw to loosten the foams grip on the tank. The tabs that were screwed into the inboard stringers were all stripped out so when I bought my new tank I just eliminated then. I bought a 136 gal tank from SP tanks in NJ. It cost $850 including shipping and a two part epoxy coating. I had a wet and partially rotten floor where the tank sat on so I cut this out and replaced it with new 3/4 plywood and glassed it on both sides. Once I dropped the new tank in, I glassed in a aft bulkhead which serves to stop the tank from moving aft. This Spring, I plan on adding only a small amount of foam about halfway up both sides to stop any lateral motion. That way I hope to minimize the impact of any any water entering this area. I even drilled and epoxy coated a few weep holes along the aft end of the tank deck to allow any water to drain into the bilge. I'll try to post a few pictures and you are welcome to stop by,take a look and have a beer. Dink

Re: That old topic...I am replacing my Tank
 

Scott,
I got the standard 12v sending unit. With the Yam
gauge it reads 1/8 tank when empty. I guess that
gos on the May "To Do" list. [img]/images/graemlins/mad.gif[/img]

Re: That old topic...I am replacing my Tank
 

Thanks Warthog, just so I am clear, you're talking about the foaming process right, not coal taring right?....

Re: That old topic...I am replacing my Tank
 

I really appreciate all the advise you guys are able to provide me.....

Scott - On those tank tabs, are you saying that the deck then bolts down into the tabs on the top of the tank rather than the tank bolting down into the stringers, right?

Finster - You wrote to be sure to repair the old holes in the stringers... Can I fill those with a West System epoxy and bolt into that? Or should I pick a new spot just off of the old one?

Dink - I may just have to take you up on your offer to jave a look at you setup! $850 for 136 gallons doesn't sound too bad, I was going to contact a place in Norwood that I heard of, have them give me an idea on price.....

Re: That old topic...I am replacing my Tank
 

hey hoop i had mine built at capeway welding in plymouth. there at 9 apollo 11 road phone #5087476666..hes a good guy .i now a couple other people who have used him as well with good results.my tank was 120 gallons cost was 880.

Re: That old topic...I am replacing my Tank
 

QUOTE: Thanks Warthog, just so I am clear, you're talking about the foaming process right, not coal taring right?....

Yes were talking about the 2part foam. [img]/images/graemlins/grin.gif[/img]

Re: That old topic...I am replacing my Tank
 

Hoop,

You can do either. Just whip up a cavisal mix and your good to go.

Re: That old topic...I am replacing my Tank
 

Have built many tanks, use aluminum alloy 5052-H32, at least .090" thick. I had been alodine coating the tanks and then painting, but recently have been taking to a company that does truck bed liners and coating with bedliner material. Just my two cents worth.

Re: That old topic...I am replacing my Tank
 

Hoop-

Give Kentfab Engineering in Norwell a call. They make a lot of aluminum tanks and they are CG certified. There is also someplace in Rhode Island called Bruno's or something like that.

Ed

Re: That old topic...I am replacing my Tank
 

The pic that scott showed is the way my 75 23cc was set up. No bulkheads on the front or rear of the tank. There were 4 90 degree angle legs that were screwed into the sides of the stringers. There were some wood shims between the legs and stringers. Most of these were rotted and barely holding the tank however to my suprise the tank was secure. I like Pascoes method of securing the tank with runners under it to allow for air circulation

http://www.casdvm.com/photos/Gas%20Tank%20Support/

however after I glassed these runners in place I found that the tank was 3/4 inch too high and I could not get my deck hatch back over it. I then proceeded to remove the glassed in runners and my solution to secure the tank was to 5200 it to the deck. It is solid and not going to move. It may be a pain to get out later but then again it's a pain to remove a foamed tank and I did not want to put screw holed into the sacred seacraft stringers [img]/images/graemlins/grin.gif[/img]

Strick

Re: That old topic...I am replacing my Tank
 

Guys-

Thanks to you all. I guess the only thing to do next is begin the process. Have to say, I feel a bit like I am fishing a new stretch of water as I have not much of an idea what I am going to find! But I'll get started after the 1st of the year and hope for the best.

I am sure I will learn much along the way!!!! [img]/images/graemlins/ooo.gif[/img]

Thanks, Gordon

Re: That old topic...I am replacing my Tank
 

One option that you can do, not sure if it was mentioned earlier, is have the new tank made about 1/4" shorter in heihgt. Grab an old 1" garden hose, slice it into two peices long ways. Use the garden hose close to the front, back and middle of the tank to lower it, leaving the garden hose under the tank. this should give you about 1/16" to 1/8" of gap under the tank. Weigh the tank down. When i did it it took about three of us standing on the edge of the tank. Pour the foam mix. CAUTION: as the foam begins to expand it will start to fill the 1/16" to 1/8" gap under the tank and tend to push it up, hence why you need to weigh it down. Normally the first couple of pours will do this but once the bottom foam had formed, the foam will work its way up, and not the tank. If done correctly, not allowing the tank to come up, you should end up with foam cushioning the bottom of the tank, which will help prevent cracking or breaking. Cut any excesss foam, and the excess hoses.

Cheers

Re: That old topic...I am replacing my Tank
 

While that worked for ned2nav, it would be best to clamp the tank down. I did it by screwing 2X2's across the tank and into the deck. I will fill the screw holes with epoxy. If your tank is close on the measurements to get the max size tank, the movement of the foam could cause you having to remove the tank and start over due to the foam lifting the tank and then the hatch not fitting corectly.

Re: That old topic...I am replacing my Tank
 

Guys-

What about using a material like Starboard or SeaBoard as the platform for the new tank instead of fiberglassed marine plywood????

Any reason why that wouldn't be a good idea???

-Gordon

Re: That old topic...I am replacing my Tank
 

Hoop

I dont know how you would attach/tab/secure it to the bilge floor and stringers ...not a whole lot will bond with it ...plus that bonding agent then needs to bond to the fiberglass in the bilge. A sheet of 3/4" is big bucks (I'm guessing easy over $250 for a full sheet ) as compared to plywood and fiberglass

Re: That old topic...I am replacing my Tank
 

Gordon

Send me a E Mail and feel free to stop by anytime.

Dink

Re: That old topic...I am replacing my Tank
 

It's too slippery, too heavy, too expensive and nothing wants to stick to it. You would be better off with the marine ply glassed on both sides then you can glass that to the sides of the stringers and hull. I'm sure there are other ways you could figure to secure the tank but why re-invent the wheel [img]/images/graemlins/grin.gif[/img]


Strick