1987 Sea Sprite 225 SSB transom re build.

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

Uhmmmm...

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

ok! cpl questions, once Im done filleting and tabbing and wraping the stringers with glass I want to paint the bilge and transom. Whats the best paint to use? I've read Rustoleum Enamel? and how do I figure how much floatation foam I'm going to need? I'm just trying to get a ball park on how much more $$$ I'll need before its ready for carpet!

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

I wouldn't paint the transom yet. You'll want to tab the deck to it. Rustoleum is good stuff. It's what I used and it's holding up really well. Here's how to calculate for your foam. Measure your stringers at their Highest point. Since your stringers slope back to front take 75% of this so if the stringer is 10" tall figure it's average height is 7.5 inches. Measure the area you want to fill at it's widest point and it's longest point. All of these in inches. Now multiply these 3 numbers together to get cubic inches and then divide by 1728 to get cubic feet. Example if the area you want to fill is 7.5 inches deep by 24 inches wide by 84 inches long this would be 15,120 cubic inches divided by 1728 which would be 8.75 cubic ft. This won't be exact but will get you fairly close. The 2 lb foam from USComposites is some good stuff.

Hope this helps.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

ok! so heres what I came up with as far as a figure for foam. I have 4 stringer pockets 2 on each side of the tank. One stringer is 14" tall and the other is 11" tall so I used 12" as a round height number. The pockets are 11' long = 132" and the pocket width is 10" for the most part. So 132 X 12 x 10=15840 cubic Inches divided by 1728 =9.16 cubic ft x 4 pockets =36.66 or 37 cubic ft of foam needed? A 2 gal kit does 8 cubic ft @ $83.99 per 2 gal kit = $480.50 with shipping! DAMMMM! I had to sit down for a minute!

 

[jbcurt00]

Re: 1987 Sea Sprite 225 SSB transom re build.

37 cubic feet at 60 pounds per cubic foot is over 2200 pounds of flotation.

is that enough or not enough?

Based on the weight of your boat, motor and gear.

some components add bouyancy gas is only 6 pounds per gallon wood floats seat foam floats Etc

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

I see Urethane Foam , Expanding Marine Polyurethane Foam has an 80lb kit that does 40 Cubic ft for $264.00 + shipping is that correct?

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

37 cubic feet at 60 pounds per cubic foot is over 2200 pounds of flotation.

is that enough or not enough?

Based on the weight of your boat, motor and gear.

some components add bouyancy gas is only 6 pounds per gallon wood floats seat foam floats Etc

Jbcurt00 Im just looking at replacing what was removed from the boat!

 

[jbcurt00]

Re: 1987 Sea Sprite 225 SSB transom re build.

the 80 pound kit sound like a much better deal.

I understand you're putting back what was taken out but they may have used foam that supported 75 pounds per cubic foot.

I'd like to at least hope that the foam I put in would float the boat. because we aren't going to swamp the boat to confirm it. We'll only know when it does or doesn't when something happens

 

[GT1000000]

Re: 1987 Sea Sprite 225 SSB transom re build.

Jbcurt00 Im just looking at replacing what was removed from the boat!

If you can add a little more, it won't hurt...

I see Urethane Foam , Expanding Marine Polyurethane Foam has an 80lb kit that does 40 Cubic ft for $264.00 + shipping is that correct?

This is correct, assuming you get full expansion, which depends a lot on the temps you have when pouring it...
This amount, if you used all of it would give you approximately 2400 lbs worth of floatation...
Like jbcurt00 mentioned, some things in the boat are naturally buoyant, but having more of a safety margin is always a good thing...IMHO

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

If you can add a little more, it won't hurt...



This is correct, assuming you get full expansion, which depends a lot on the temps you have when pouring it...
This amount, if you used all of it would give you approximately 2400 lbs worth of floatation...
Like jbcurt00 mentioned, some things in the boat are naturally buoyant, but having more of a safety margin is always a good thing...IMHO

So increase the weight of the foam or find more places to put it?

 

[GT1000000]

Re: 1987 Sea Sprite 225 SSB transom re build.

So increase the weight of the foam or find more places to put it?

No real reason to increase the foams flotation capacity, which would obviously cost more, and if you don't need the additional floatation, there is no need for it...
BUT, if you can add more than what you would need in empty places, that is a plus...
As an example, if your boat requires 2000 lbs. of floatation and you have room to add the additional foam to say, give you 2200 or even 2400 lbs of floatation, then go for it...
If as another example you need 4000 lbs of floatation, but can only achieve, say 3000 lbs of floatation with the available space, using 60 lbs per cubic foot foam, then you might have to look into getting 75-80 lb. per cubic foot of floatation foam...
Does that make sense...???

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

Yes perfect sense, but Ive over figured just so Ill have enough, if I put back exactly what was taken out that should be sufficent right? I cant think of any available voids I can get to with the floor out unless I foam in the tank and I dont want to do that!

 

[GT1000000]

Re: 1987 Sea Sprite 225 SSB transom re build.

Sounds like you got it covered...:encouragement:

 

[jbcurt00]

Re: 1987 Sea Sprite 225 SSB transom re build.

37 cubic feet at 60 pounds per cubic foot is over 2200 pounds of flotation.

is that enough or not enough? Based on the weight of your boat, motor and gear.

I again understand that you are putting back what you took out. But the specs for your boat might be of interest, and relevant to this discussion:
1987 Sea Sprite by United Marine 225 Cuddy Cabin

3400lbs +/-

You can't really float 70% of your boat... Unless the remaining 30% is less dense then water (8lbs/gal +/-). That is a dry weight, no gas, no water in the water tank (if equipped), and no oil/lube in the motor. Some of that is more buoyant then water, like I mentioned before, is 30% of everything in/on your boat? I don't know.

That's using the # 2400lbs of flotation from the 80lb kit AND getting 100% maximum expansion for 100% of the foam. Neither is likely, you won't get 100% of the expanding foam IN the boat below decks and there will be some left in each of the 2-part mixing cups, the shipping containers & on the mixing tools.

Look thru a recent foaming on another thread, not 50% waste, but some:

Started foaming, that's a treat.

I only used 75lb foam as an example, because whatever foam they did use, isn't what's available to us as DIYers. I have NO info on what type of foam SeaSprite may or may not have used. But if you're using 60lb foam, in the exact same areas that were foamed before, it would appear that the manufacturer HAD to use a different buoyancy foam. Or the USCG would have barred their sale in the US.

The 2200lbs +/- wouldn't seem to be sufficient, nor the 2400lbs.

 

[GT1000000]

Re: 1987 Sea Sprite 225 SSB transom re build.

The foam might have been a structural component as well.
I only say this because according to the USCG regs., only boats Under 20 feet are subject to the floatation foam requirement...
This is an excerpt of page where this info is located...

Monohull inboard, inboard/outboard boats and airboats less than 20 feet in length must comply with a flotation system called Basic Flotation 
Monohull boats under 20 feet in length and rated for more than two horsepower must comply with the more sophisticated flotation system called Level Flotation. 
Manually propelled boats and boats rated for outboard engines of 2 HP or less must comply with the Modified Level Flotation requirements.

Here is a link to the actual page...Flotation - Applicability
Figuring out the actual flotation requirements for a given boat requires calculations based on Coast Guard formulas and are actually only required to be followed by manufacturers, not backyard boat builders.
All that being said, I personally would rather go to the trouble and expense of adding this "Insurance policy" to my boat in the unlikely event that I should ever need it...
Here is a link to figuring Basic Floatation...
Flotation - Basic Flotation
Here is one link to the formula for figuring Level floatation...
Flotation - Level Flotation
Here is a link to figuring the Modified Level Floatation...
Flotation - Modified Level Flotation
And here is the table of contents pertaining just to floatation and all its formulas, requirements and uses...
Flotation - Table of Contents
It is long and drawn out and somewhat complicated, but if you want to learn all about it, this is the place to start...
Have fun!

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

The foam might have been a structural component as well.
I only say this because according to the USCG regs., only boats Under 20 feet are subject to the floatation foam requirement...
This is an excerpt of page where this info is located...

Monohull inboard, inboard/outboard boats and airboats less than 20 feet in length must comply with a flotation system called Basic Flotation 
Monohull boats under 20 feet in length and rated for more than two horsepower must comply with the more sophisticated flotation system called Level Flotation. 
Manually propelled boats and boats rated for outboard engines of 2 HP or less must comply with the Modified Level Flotation requirements.

Here is a link to the actual page...Flotation - Applicability
Figuring out the actual flotation requirements for a given boat requires calculations based on Coast Guard formulas and are actually only required to be followed by manufacturers, not backyard boat builders.
All that being said, I personally would rather go to the trouble and expense of adding this "Insurance policy" to my boat in the unlikely event that I should ever need it...
Here is a link to figuring Basic Floatation...
Flotation - Basic Flotation
Here is one link to the formula for figuring Level floatation...
Flotation - Level Flotation
Here is a link to figuring the Modified Level Floatation...
Flotation - Modified Level Flotation
And here is the table of contents pertaining just to floatation and all its formulas, requirements and uses...
Flotation - Table of Contents
It is long and drawn out and somewhat complicated, but if you want to learn all about it, this is the place to start...
Have fun!

Thanks GT! I sat down last night and figured what all I have left to do to get her back in the water, I'm not one to cut corners or do shoddy work but I figure if I replace the foam I removed, plus whats left under the cuddy that I didnt touch Im hoping that will be sufficiant. I agree with everything you said and added insurance/more foam would be the way to go but as it is its gonna be about $300 to replace what was removed. Im on a somewhat tight budget and Im still looking at about $1500 to finish the project and thats if all my seals, bellows,gaskets and such are still useable... I think you a heap for all the info, its guys like you that dig through this stuff and keep guys like us ligit! Thanks again...Lee

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

When tabbing my stringers is it necessary to over lap the ends of the tabbing as I go?

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

I would, about 2 inches.

 

[Lwarden]

Re: 1987 Sea Sprite 225 SSB transom re build.

WOG can you give me some kind of layup schedule for my motor mounts? glue em in with PB, tab em with 1708= 2 layers, then what? I have 1708 and 1.5 oz CSM

 

[Woodonglass]

Re: 1987 Sea Sprite 225 SSB transom re build.

Motor mount need to have bulk. I'd tab em in with CSM then a Layer of 1708. I'd do this 3 times. Yep I said 3 times!!! I'd extend the first onto the hull 3" then 6" then 9"