Gas tank questions
 

I'm getting ready to pull up the foor in my '78 23cc. It's been sitting for a number of years and the motor is shot. So while I've got the deck up I want to take a good look at the tank. Any chance it's still good? Do I have to remove it to properly inspect?

Tank
 

You won’t be able to inspect the bottom and that’s most likely were there would be corrosion . since your in there I would pull it and clean it inside and check sender. Get it all checked and done so you don’t have to go back there

To answer your questions....1. slim chance, if it's original very slim chance, 2. Yes sorry gotta remove it, getting it out that's the tough part.

There are some post of guys building a wood rack or tripod kinda thing over the tank to lift it out with come along.

Unfortunately, opening up the hatch is a whole new world. How it all started for me. Hatch needed to be recored. All fuel lines upgraded to new methanol standards ($10/‘). The “$10/gallon” rule of thumb seems to be of the Baby Boomer era, especially with new tariffs on the aluminum. Go at least .125 thickness over standard 0.90 (should in theory last longer). The foam around tank will reflect where water held and corroded tank worse than where foam was not in contact with aluminum. Cut it out using a sawsall, but be careful determining if there is a floor in the hold. My ‘79 20 had beautiful gel coat finish inside. Be careful. Otherwise, not a bad job. As said, triple your time, money and beer budget. Or BOAT: Bring Out Another Thousand. A pic may help you see how to raise, pitch console out of the way without disconnecting or removing. Hope this helps.

Vezo

Oh and the Coal Tar Epoxy

Two best suppliers should be RDS aluminum, Perry, Florida or Sunshine Tanks of South Florida, original builder of Potter era SeaCrafts.

Vezo.

RDS Fuel Tanks
 

Maybe 12 years ago I ordered a tank from RDS made to my drawing duplicating the original dimensions. Looked good and have been satisfied. However discovered the bottom had some downward bow to it due to weldng distortion. I ground down any high spots where it would sit. But also had to grind the access hatch to avoid interference with the fuel fill elbow. Also put a rubber strip around the hatch to raise it slightly. Maybe should have requested a smaller height dimension. Just FYI

Agreed. Once you send them the measurements, they develop a mechanical drawing, including fitting locations, email it back to confirm specifications. Once you sign in agreement, they’re building it and you’re paying for it same with Sunset, I believe, but they have specific drawings for you to approve.

Vezo.

IIRC...

Thanks guys, I trailer my boat so gassing up isn't a big deal and my fishing and playing is all inshore therefore I don't need a big tank.I plan to put a Honda 250 on the back.What's the opinion on tank size keeping in mind that the bigger the more money.

MY '78 23'er has a 144 gal tank, the previous owner had a V-6 OMC looper and needed all the gas he could carry for his grouper fishing. If I were to replace my tank I'd go with a 100 gal mounted as far front as possible. My 250 ToHondaSu gets 3.8 to 4 mpg at 28 to 30 mph, so a 100 gal is more than enough.

The only way to test in place is to pressure test it with about 3-5 psi of air pressure. If it hold pressure over night you may be good for now but still on borrowed time. Better off to just replace it. It could be pitted badly and still hold air but if you have one little pin hole the air will work its way out overnight. You don't want to have to come back a few years latter from now so best to change it out while in there. Even if it hold pressure it may be full of varnish. I have cut open good looking clean tanks to find a brown/yellow coating on the inside. You can run dual filters / water separators but better off to install a new clean un-corroded tank that you know is varnish free.

75-100 is what I was thinking.I'm not sure what size the current one is,I guess i'll find out when I pull it.The boat had a second tank in fro t of the console which I removed years back.I don't want to negatively affect the benefit of a big tank of gas(weight) on the ride by going too small on the tank.

In my case the tank is so long it comes all the way to the bilge, so it was easy to figure out the capacity L x H x W / 231. Because the tank is never always full, weight is changing as you use gas I would not worry about the ride too much. In my case I would like the weight as far front when sitting at rest. Going from a 144 to a 100 gal takes two feet off the rear of the tank I now have, which is around 250#.

Dug up a few more pics for you. Original tank to me had clearance issues with my 90* fill below hatch. Solution? Remove core of hatch. Just the beginning of your issues, pulling one hatch. Liquid Encouragement.

Third pic, Vezo Part I

Vezo

I don't understand that. When I got my tank from them, probably 20 years ago, I told them what I had and they already had the specs. Got it shipped to me (well to a local business) and it fit great. It was already primer painted and I also painted it with resin.

RDS has the exact drawings and plans for ALL of the fuel tanks they made for Seacrafts from 1968 onward. They are NOT, however, listed by Seacraft model. Tell them the date of your boat manufacture (not the model year!), the tank model number if still available, or tank dimensions, capacity, and fill-neck location and direction. They were able to exactly duplicate the tank for my '71 Seafari for me back in 2006, and also just got one this year for my '88 18'.

The 49 gallon tank (47 gallons usable) for my '88 18' retails for about $830.
It was a bit less with my West Marine Associate discount.

Yes Sir, I have had 9 tanks built to spec, over 3 years, for Jersey Speed skiffs from them. I had no idea that they had the original specs. I thought that Sunshine Tanks were SeaCrafts number one builder. I stand corrected. I just paid $1284 for my rectanglular 70 gallon, .125 Aluminum, 2 baffles, one fill, vent, pickup, sending unit, and coal tar epoxied. Yep. Florida tax, for South Carolina pick up and deliver myself...

Shop hard.

Michael.