[Davalos]

Not sure if you will have this problem but on my little 8.5 ft. cat, at top speed on plane with my 6hp Evinrude, water tends to hit the front of the outboard shaft and splash up the front of the motor shaft between motor and transom and come over the transom a bit between the two motor clamps on transom. I think a slightly wider motor deflector and a slightly different exit design at rear of cat hulls might improve or eliminate this problem. At lower speed it is not a problem. I know you mention that this is only for going shallow on the IRL (like where I spent most of my younger days) but you know a top speed test will be done at some point so I hope this helps in your design thinking.

I appreciate the information. I do know water splashes around quite a bit back there between the motor and the transom no matter what kind of boat you have. The fact is that my transom cause all the way up to the bottom of the motor clamp and is 3 ft wide in that area. The diverter I have at the bottom of the transom is going to be dead even with the anti-cavitation plate. I am just not visualizing right now how water could possibly splash into the boat. I am not saying you're wrong. I'm just saying I don't know how water could get into the boat with my transom setup

 

[KWGator]

I appreciate the information. I do know water splashes around quite a bit back there between the motor and the transom no matter what kind of boat you have. The fact is that my transom cause all the way up to the bottom of the motor clamp and is 3 ft wide in that area. The diverter I have at the bottom of the transom is going to be dead even with the anti-cavitation plate. I am just not visualizing right now how water could possibly splash into the boat. I am not saying you're wrong. I'm just saying I don't know how water could get into the boat with my transom setup
View attachment 171709

Here is a photo I borrowed from the internet of a very similar outboard to mine, since my 6hp is 5 hours away from boat so I cannot show it on my boat. Arrow points to where water flows over my transom when at full speed on plane.

I hope your design doesn't have this problem but I wanted to point it out in case it helps.

 

[Davalos]

I understood that water is coming over your transom from between the clamps as you stated in your post. But I am not understanding is how is the water getting there to begin with. I would love to see a picture of your anticavitation plate in relation to the bottom of your hull or diverter. I would bet my right arm that something is not lining up properly and causing that water to come over your transom.

 

[KWGator]

I will try to get some photos of hull this weekend and share. It is filthy and needs a good cleaning anyway.

 

[Davalos]

Do you have any napkin sketches? I like cats in most sea conditions. You will sacrifice draft for ride, but most will absolutely slice through chop with how sharp the bow entry usually ends up.

Update: got my biaxial fiberglass layer up. Hoping to do some test runs this weekend.

 

[Davalos]

 

[KWGator]

Weather was bad last weekend so I was not able to take any photos of my hull. I will try to this weekend.
Hope your tests are successful and maybe can include some videos for how she performs.

 

[Davalos]

Weather was bad last weekend so I was not able to take any photos of my hull. I will try to this weekend.
Hope your tests are successful and maybe can include some videos for how she performs.

I will do my best to get her ready. I am anxious to see what she will do in terms of what I am trying to accomplish.

 

[MudSkipper]

Nice looking and interesting rig. It seems like that front spray shield could be added or removed as needed. If I could put a 50 on it, I'd be happy just zipping around.

 

[Davalos]

Nice looking and interesting rig. It seems like that front spray shield could be added or removed as needed. If I could put a 50 on it, I'd be happy just zipping around.

Thanks. I already took that spray shield off permanently. As for the 50 hp 4 stroke Tohatsu outboard, there are at least 200 boat manufacturers that do a really good job at making go-fast boats between 15 and 17 feet that you would feel right at home in. I don't want to compete against them. I am trying to create something that IMHO does not exist, or that there are very few of.

 

[Davalos]

Thanks. I already took that spray shield off permanently. As for the 50 hp 4 stroke Tohatsu outboard, there are at least 200 boat manufacturers that do a really good job at making go-fast boats between 15 and 17 feet that you would feel right at home in. I don't want to compete against them. I am trying to create something that IMHO does not exist, or that there are very few of.

Getting ready to round off my inside corners. I make my own profiling tools, so I can easily do whatever shape of radius I want.

 

[Sublime]

Getting ready to round off my inside corners. I make my own profiling tools, so I can easily do whatever shape of radius I want.

Yep, but for those reading that haven't done much of this, the angle at which you hold whatever tool you come up with can greatly change the size and thickness of the fillet. Definitely some technique involved.

 

[firecat1981]

Yep, but for those reading that haven't done much of this, the angle at which you hold whatever tool you come up with can greatly change the size and thickness of the fillet. Definitely some technique involved.

Absolutely, no one likes a wavy fillet. I usually keep a variety of craft sticks around to do it at about a 75 degree angle.

 

[Davalos]

Absolutely, no one likes a wavy fillet. I usually keep a variety of craft sticks around to do it at about a 75 degree angle.

No wavy fillets here. And I apologise to the poly people for violating your rules. That poly based fairing putty I used on my boat is sticking to everything. To epoxy, my shoes, the aluminum mixing board, acrylic, small children...
Filleted and sanded the entire bottom of the boat in 3 hours. Not bad.

 

[Davalos]

No wavy fillets here. And I apologise to the poly people for violating your rules. That poly based fairing putty I used on my boat is sticking to everything. To epoxy, my shoes, the aluminum mixing board, acrylic, small children...
Filleted and sanded the entire bottom of the boat in 3 hours. Not bad. View attachment 172451

Question: has anyone put their polyester fairing putty in the fridge prior to use? I used a 100:1 MEKP ratio, and still only get 3 minutes working time. I was working in the shade, and it isn't too hot today in Central Florida. Obviously, I can't use any less than 1% MEKP. Looking for some advice here.

 

[firecat1981]

Mix it up and spread it out thin quickly. If you have it in a pail or cup it will kick fast.

 

[Copahee Hound]

Question: has anyone put their polyester fairing putty in the fridge prior to use? I used a 100:1 MEKP ratio, and still only get 3 minutes working time. I was working in the shade, and it isn't too hot today in Central Florida. Obviously, I can't use any less than 1% MEKP. Looking for some advice here.

I had success putting poly RESIN in the fridge before mixing in q cells, so I don't see why putty would be any different. I'm also not very experienced with poly, so take my opinion with a grain of salt

 

[Davalos]

Mix it up and spread it out thin quickly. If you have it in a pail or cup it will kick fast.

I did that. I had it off my board and onto the hull within 1 minute. Kind of like I do when I am working with 5 minute drywall mud. But some of it started kicking before I could even fair it out completely. I really like that fairing compound. It is just a bit too fast for me.

 

[Davalos]

I had success putting poly RESIN in the fridge before mixing in q cells, so I don't see why putty would be any different. I'm also not very experienced with poly, so take my opinion with a grain of salt

Thanks. I don't have a ton of experience with poly either. But I can tell you that I would much rather fair and do cosmetic repairs with poly than with epoxy. It is ready to sand in 15 minutes. And it sands like a dream. I will never do non-structural repairs with epoxy again.

 

[MudSkipper]

As for the 50 hp 4 stroke Tohatsu outboard, there are at least 200 boat manufacturers that do a really good job at making go-fast boats between 15 and 17 feet that you would feel right at home in. I don't want to compete against them. I am trying to create something that IMHO does not exist, or that there are very few of.

Hey man, again nice job. I was not asking you to change anything on your boat and there is no need for you to compete with others. I just want to hang a 50 and go for a ride. That's all. Zoom Zoom.