My 1975 SeaCraft 25' Seafari rebuild thread

[Terry England]

Originally Posted by Bigshrimpin

Terry - Any idea on the size and location of the water ballast tank?

"Axe" Conner or Dave (Cattle Egret) they have PHD's in 25' Safari's.
Gillie, Skip or Island Trader Ter might know. They are real old and people seek them out to find the meaning of both Life and VDH. They ain't on top of some mountain in Tibet though, they's usually "sett'in on a Dock in the Bay", like Otis Reading.

[FLexpat]

You might be able to find something in Carls patent on it.
http://www.moeslyseacraft.com/uploads/1/1/0/5/11051379/lit-pat-ballast-3503358.pdf

[flyingfrizzle]

Originally Posted by FLexpat

You might be able to find something in Carls patent on it.
http://www.moeslyseacraft.com/uploads/1/1/0/5/11051379/lit-pat-ballast-3503358.pdf

Yea, I have read this multiple times and will install some ballast water tanks to the boat. I bought a triangular tank for the race boat and a few 12v solenoid valves to control the water flow in and out of the tank. I not sure if the tank I got now will work on the 25' seafari but will fit nicely in the 27.5' race hull. I may just fab up an aluminum tank for the 25' so I can utilize the space better. Im not sure if I will do one tank or two with the orifice between the two like drawn, One with pumps and valves would help with weight ballast but the idea of the two will help plane the boat better allowing the weight to gradually shift from the front tank to the rear and then empting out as speed builds. The idea of being able to add weight as you need it is nice but to get the water transfer right between the tanks and the outlet for the self stabilizing while bringing the boat on plane is ingenious! It would take some trail and error to get the flow rates right between the tanks and out the exit but if done correctly I believe it would really help the stabilization of the vessel. I will at minimum have ballast tank that I can pump water into and out of via pumps and solenoid valves for control but not sure if I have the room to implement the whole system as shown in the patent.

[cdavisdb]

There is a huge amount of room under the deck, between the main stringers, from the forward tank bulkhead to the forward bulkhead, more than sufficient for any water tank you might design. I think it should work real well. Need to be real careful with reinforcement to handle the weight and slamming.

[Bigshrimpin]

Originally Posted by FLexpat

You might be able to find something in Carls patent on it.
http://www.moeslyseacraft.com/uploads/1/1/0/5/11051379/lit-pat-ballast-3503358.pdf

It's a beautiful mechanical design. Unfortunately It doesn't show anything about size, weight, or specifics regarding the 25.

If you compare the 71/72 25 seafari's to the 73/74/75 25's

There is a big difference in the cockpit/cabin stepdown. There is a LOT of empty space below the cabin floor on the 71/72 25 seafari's. I imagine this is where the tanks would have gone had the 25 been built by potter to moesly's specs.

[flyingfrizzle]

Originally Posted by Bigshrimpin

It's a beautiful mechanical design. Unfortunately It doesn't show anything about size, weight, or specifics regarding the 25.

If you compare the 71/72 25 seafari's to the 73/74/75 25's

There is a big difference in the cockpit/cabin stepdown. There is a LOT of empty space below the cabin floor on the 71/72 25 seafari's. I imagine this is where the tanks would have gone had the 25 been built by potter to moesly's specs.

It would of been sweet if it had the size of the orifice between the tanks and said the volume of the tanks. There are a lot of unknowns there still. That's why Im leaning towards a single tank just for weight ballast. Like Big said there is a lot less room under the floor in the later 25's than the first ones built. The good thing about the latter ones is that you can stand up in the cabin and have a ton of extra head room. Im not sure how much extra depth I have but it looks to be 8" or more over the others. There is still a lot of room in the storage compartment that a bladder tank could go but I am hoping to find room under the deck even if it is a shallow tank custom built to fit the contour of the hull. Welding aluminum is not a problem for me so I could build a odd shaped tank and add some foam coring under it for support and then glass it in solid so that it don't bounce around and support it well.

[flyingfrizzle]

Getting geared up to get back rolling on the seafari. Went about 6 hours away to pick up power for the hull this weekend. Found an awesome deal on a second pair of 2.5 mercury 200 hp efi outboards. (Second to the pair recently picked up for the race hull) I know I know this boat would do better with a io but I'm going to give this pair of out boards a chance. They were in good shape, compression was 125 at the lowest on all 12 holes up to 129 psi as a high. Very good numbers. Came with all controls, cables, harnesses, full gauges that look new, props and every thing to rig and run. Hour meters were very low for the year. Best part was they were only 2k! Came with 17p counter rotation mirage props, what pitch do yall guys think the 25' will need. I have standard rotation 19p & 21' mirage wheels and wonder if I may need to get a counter to those 2) if the 17p's are to little pitch. Like to get the rpms at least to 6000.

[flyingfrizzle]

Pics:

[Bushwacker]

Originally Posted by Bigshrimpin

Terry - Any idea on the size and location of the water ballast tank?

Check with Carla! She should have access to the design info! Skip said Carl had planned to use a bladder tank, which eliminates the need for a vent line! Otherwise, you would need a fairly large vent line to be able to quickly fill and drain the tank. I'd put it as far forward as possible up below the bunks to get the maximum leverage/trim change from it; I'd vote for largest size bladder that would fit, but you wouldn't necessarily have to fill it all the way. You might also want to mount a decent size fresh water tank up there too, since your CG will definitely be higher and further aft than what Connor and Dave are running. They could probably give you good advice on tank size!

[cdavisdb]

Frizz, you have a very interesting problem; wish I had the technical skills to answer, but I think Blue Heron does.

You are going to like 400 hp. Mine is 300 and I'd like a bit more.

CG and roll is the big issues. If you know the weight of the new engines(and bracket?) and how far back from the transom they will be, Dave can calculate the for and aft CG effects. Putting in a water ballast should be able to remedy any issues fore and aft and he should be able to calculate the ballast needed, as well. Vertical CG might be tougher, especially since the engine weight will be both higher and farther outboard than an I/0. Still, having a bunch of water weight low in the bow will help the vertical CG, damping down the roll. How all that will play out in the real world might be pretty different from what the calculations say, just have to try it.

The worst possible result would be for the boat to develop a snap roll. Mine rolls, (how could it be otherwise?), but it doesn't snap. A friend of mine owned one years ago with twin outboards, and a hard top and a tower (I kid you not). It had a viscous snap on top of a extremely wide roll, even after they took the tower off. His wife, who was a pretty good boater, refused to set foot on the boat after her first experience.