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cat told me the new engines weigh the same, but it can,t be. i need to raise the boot stripe about 1 1/2 inches mid ship. does that make sense? it's just too close. the old boot stripe is painted on. what do i remove it with. looks like imron....awgrip...... tape it out and respray??????? any help is appreciated. thank's

In the same dilemma. Added Cummins and bigger fuel tank. Advised here to add weight at the bow to counter. The guys on the site are skeptical. Going to try the weight and if that doesn't work raise the water line. Hate to do that because of the look at the chine. If the weight forward raises the stern and keeps the original lines, cool. If not
s#*t!

Mikey,
That weight is not going to raise the stern. All its going to do is drop the front water line down also.

If the job was done correctly, the boat should not be that stern heavy.
Lower in the water yes. Just raise the water line. Fact of life.

Dont forget to fill it full of fuel and some other stuff before you try to change the stripe to see how she sits.Just 2 cents

Guys,
I filled the new 225-gal tank when we set it in the water this summer. Bruce, I don't understand the "If the job was done correctly." I put the Cummins as far forward in the engine compartment as possible and still have enough room to get one hand in to replace belts, barely. She still sits about two inches lower than originally in the stern, so am I just sunk, pun intended? This will most likely be the only time her tank will be completely full unless I decide to go to A.C. for the rendezvous. Don't like the chine below water with a boot stripe, it looks a bit strange.
Well, if that's the worst I have to suffer . . .

Mikey,
You sounded as if the bow was sticking up in the air, thus my comment.

What your stuck with is what your stuck with. You add weight without adding displacement, boats go down.

Just consider yourself the owner of a low rider custom.

Those who's chines are up in the air like a Palm Beach nose, are still pushin gas fumes.

Mikey-when you feel how much better the boat handles with the added weight, the stern chine depth will stop bothering you. Walter

Bless you my sons. decision made, screw it. I gots what I gots, and am glad of it.

mikey look at the picture i posted of the 31 bertram "phoenix".the the edge of the chine at the stern just touches the water.i spent a lot of time experimenting with how the boat should sit in the water.i have the same weight engine as you have with a 231gallon tank.i had this boat running straight as a arrow at 38knts it is now detuned and proped down to 30knots.the boat handles offshore at it`s best in waves above 3' when the chine just touches and 5' and above you want that chine 2" under like 504 cummins or 3208 cats which is like adding two thousand pounds with 3208cats with cast iron gears compared to cummins 6bta.with the chines just touching the bert was on top in 5seconds at 34 to 35 it rode on the bottom chines with giant rudders keeping her on track.at 32 knot i could turn the wheel (5 turns) in a effort to flip the boat and she turnat double it`s lenth actually better than the ceter console 32' that was used as a chase boat along side.trust me do not add weight to the front as a matter of fact emtpy the bow ( v-berth)as mine was.no anchor locker/no rail -nothing.

Mikey

The chines on my 75 FBC with the old 454's and 220 gals of fuel used to just touch the water when full of fuel. I am assuming when I finish with putting in the 270 Cummins it will be about the same. Mine was listed as weighning 10,000lbs in the old Bertram Spec sheets. Tony Meola

The discussion about the weight of the engines and the amount of fuel in the tanks causing the boot stripe to be...as I understand it under water? I have 370 Yanmars and a 225 gallon fuel tank. I never store diesel fuel in my boats fuel tanks. I only try and keep about thirty (30) gallons on board, to crank and run the main engines and the generator, every week or so. Fuel up with fresh fuel when I make a trip. The water line of my bottom paint is the same as the FBC with gas motors, docked next to me, and I have about 1.5" of bottom paint showing above the water line,

J Clark wrote:I never store diesel fuel in my boats fuel tanks. I only try and keep about thirty (30) gallons on board... Fuel up with fresh fuel when I make a trip.

That seems to be the opposite of most of the advice I have read, which is to keep the tank full when unattended to avoid condensate moisture (and the algae that comes with it).

If you don't mind sharing, what is your reasoning for keeping your tank empty?

Starting diesels up and running them at the dock is no good. It will gumm them up. They need to run If you are worried about the charging batts get a solar panel. Leave your tanks full and treat them if you have to. This is my opinion and the way I do it, you may see fit to do your own thing.

The company that takes care of my engines and fuel, also owns a company in Charleston SC, that maintains all of the fuel storage tanks at the old Naval Base as well as the fuel storage tanks at the State Ports.
The benefit of fresh fuel is better than the minute amount of condensation that may or may not form in a almost empty fuel tank. Condensation comes from rapid temperture change? Only if water ie. moisture is already present. Full tank of fuel...full tank exposed to fuel degradation. There is no such thing as algae in fuel! Asphetane is the first by product of fuel break down, and is often called algae. Algae needs, light and moisture to grow, can you imagine an algae that grows with neither, and in diesel fuel? This is just one company's opinion. They are petro chemist, and also have advised me about fuel stablizers and additives, they say most of the stuff is just kerosene! I can put you in direct contact with one of thier service people, they know a lot more about it than me.
My boat runs great, besides what's the difference in running a generator under load at the dock as opposed to under load...under way.

J Clark wrote:There is no such thing as algae in fuel!

Sorry J, but I gotta' take issue with that statement... There are over 100 types of bugs that can live in fuel including not only algae but also bacteria and fungus. These microorganisms need warm fuel to flourish and grow but cold temperatures will not kill them, they simply hibernate in the cold.

Condensation creates more water in a fuel system than we give it credit for. Diesel also holds more water today than it did just a few years ago due to the growing use of cracked fuel. This provides an excellent oxygen supply for these critters.

Br,

Patrick

Well, you can load up a diesel genset at the dock by turning on stuff like the heat or a/c, no real issue. Now with the diesel mains you cannot warm them up enough to do much good at the dock, even goosing them up to high rpm that will usually just annoy your neighbors. You have to un tie and run at cruise for about 10 minutes to get the engines up to the point that the oil and fuel systems shuck all the water that gathers from sittitng.

My Cummins 6BTA 250s will take a full 10 minutes at 2400 RPM cruise underway this time of year to come up to full temps, 185 to 190. Most of the time I don't have time to unbutton AJ and do that, just run her for 10 or 15 minutes at the dock, but that at least circulates the oil and mostly the fuel, keeps the crud from getting too bad in the Racors.

I keep the tank full all the time, pure physics.....no air above the fuel level, no (or little) water condenses into the tank. Diesel fuel is pretty sturdy stuff if you keep the bacteria (not algae) out of the infterface between the fuel and the thin layer of water in the bottom of the tank. After all, that oil done been in the ground for several million years before it got pumped out and semi-refined into #2 diesel...not like gasoline, diesel is pretty tough stuff.

UV

Pat is correct about the bugs in diesel, and Vic is correct that they grow best in the interface of water and fuel. There is no water spec on diesel from the refinery - they don't care. I've tested diesel fuel in the lab and found 100 ppm water, routinely. Most diesel is still produced by distillation, but Pat is correct again that a lot of heavier material resulting from catalytic cracking of crude to make gasoline is blended in, and diesel quality is defintely less than it used to be. Asphaltenes are heavy components present in minute amounts from crude oil on through the process. There is no good analytical method to quantify asphaltenes, unless is has been developed since I retired from petro-chemical research a little over a year ago. They are not likely to be a problem in marine diesel fuel.

I know people who swear by both keeping tanks low in winter and keeping them full. Either way, good filtration and additives are needed, and the Algae-X units do seem to help. Interestingly, Algae-X is one of the sources of the information that asphaltenes are the big problem in diesel fuel, not algae or bateria (maybe they should change their name?). I've had discussions with their folks about this, most that do the talking seem to be sales guys, not chemists.

anyone ever consider flooding a tank with nitrogen to keep it dry? Bill