Spirit of Australia

[785boats]

That's cool! You could always just epoxy a few brass tubes in between those fins. I did that on a seaking 180 esc. Or just get a watercooling plate on ebay and attach that instead of the fins. I am working on a few projects here as well so I always check this thread for inspiration. I like that this boat is made of wood too, makes it more special.

The brass tube was my thinking too. The cooling plate is part of the splashproof case so I don't think removing them would be very easy, without destroying the spashproofing.
Wood is my favorite material for building boats.

I've added the rear ski & given the hull a coat of sealer.
I also added a piece of foam to the underside of the cowling, & carved it out, to offer a smoother transition from the inlets down into the hull. There was just a sharp 90 degree shoulder there before.

[785boats]

A couple of coats of sealer. Some filler Some high build primer putty paint. A lot of sanding, & copious amounts of Mercury cider, and she was ready for a coat of white primer.
Isn't it amazing how once you get it painted white & out in the daylight more little cracks & gaps in the joints show up.
It looked perfect in the shed at night under the lights.
I'll rub this primer back, fix any imperfections, & give it one coat of gloss white then take it for a run.

[grsboats]

Sweet....congrats Gill

[golfito]

I was impressed!

[TheShaddix]

This looks amazing! Super clean lines.

[785boats]

Thanks guys.
Unfortunately the weather turned stormy yesterday afternoon with rain bucketing down, so I didn't get to paint the gloss coat.
Hopefully it will be fine today & I an get it done.
I remember reading somewhere that an EDF boat needs at least a 1:1 thrust ratio.
The stated max static thrust of the EDF on 8s is 5.4kg. The boat as it stands now, ready to run, is 4.37kg. That's about a 1.2 :1 thrust ratio
That allows a 20% margin for losses. I believe most of the losses will be in the intake ducting. Hopefully it will stay below 20%.

I don't think I've ever been more apprehensive about a maiden test, than with this boat.

[boredom.is.me]

So close!

[785boats]

My computer is not working properly so I am posting this from my phone.
She had her first test runs a couple of weeks ago.
It ran well, even though not quite fast enough.
I can't post links from this phone, but if you go to youtube & search for 'bensboat', Pete has posted a couple of videos on his channel.

I've since made a smaller thrust tube and that has increased the thrust from 4.04kg to 6.2kg.
Without the cowling installed the thrust went from 6.1kg to 8.2kg.
So the inefficiencies of the cowling loses 2kg of thrust.
We always knew it would be a problem, even though I made the openings 20percent larger.
The boat runs at what I consider to be the perfect speed without the cowling installed.
No video unfortunately.
So I intend to cut some cheat vents into the cowling to allow more air into the edf.
I will make sure to get some video of the next session.
A bit more speed & I will be satisfied.

[golfito]

I took the audacity to upload some of his videos.

I did not resist the temptation to see them ...
Thanks.

[golfito]

[golfito]

[Fluid]

Great job Paul, it performs better than I expected. Gorgeous looking on the water.



.

[srislash]

She's great. Seems to run well in the rough too so far. But that always gets worse with speed, it may stay good though as it runs over the water rather than using the water for propulsion.

[785boats]

golfito.
Thanks for posting the videos.

It was a pity that the signal kept cutting out but that was because the receiver was crammed in amongst the battery cables & the esc. That's been fixed now.

Fluid.
Thanks. It will look better with the paint job finished & the graphics all applied

srislash.
I'm glad to say that it was running fast & stable when I removed the cowling. It even cornered fine at the higher speed.

[golfito]