efficient 10m displacement powercat (build thread)

I tried a soft start first - didn't limit the current low enough and still tripped the inverter... hence more extreme measures were required

 

Nice work, so you went with electric after all. What make is that compressor? Did you end up with lithium batteries? I gave up on the idea as the price went up so high. I should have stopped off in Norway when I was in Europe.

 

Compressor is a bauer pe-100 - they make a 3 phase version but I picked up this one (single phase) second hand, used once
Didn't go with lithium batteries as the price was double after the dollar crashed.. I still would have liked to, maybe I'll upgrade to lithium if these AGM batteries die...

 

Yeah I just got some more AGMs too, much to my disappointment. Lithium would be much more efficient at powering very high loads like a compressor and cooking appliances. Nice find on the compressor. I need to keep my eyes open...

Hey is your boat built to commercial survey standard?

 

Nup, never be fuel efficient if that were required..survey boats are overbuilt to buggery ... It's built to recreational ISO standard tho

 

I bet you could sell those!

 

I knew it would make it somewhat heavier, but the difference is that bad hey? Do you have any idea exactly how much heavier? Fishing charters seem like a good and fun way to make money.

 

So back to bottom paint - im thinking of trying the super slippery coatings like interlux intersleek pro or the hempaguard x7 etc... ive noticed that these are difficult to buy as they are typically used on commercial boats and professionally applied at slipways etc...

There doesnt seem to be a great deal of information out there from recreational users which makes it hard to decide if the extra expense is going to be worth it... i figure it must be worth it if commercial ships are favoring this option over traditional biocide coatings?

 

Your boat looks ideal for nosing up on the beach.. the intersleek(dont know the hempel) is not easy to patch in nicely. It does work well, things will grow on it but barnacles will push off.
You could use a combination of hard antifoul & copper epoxy for contact areas(crap at antifould but not going to rub off on sand so easy).
Jeff

 

Good point on the beaching jeff- i guess that puts all the slippery coatings out if I want to beach the boat? What else can I use - any recommendations would be appreciated...

 

Ok so without any further recommendations on the antifoul, i decided to put the semi hard antifoul on by hempel - the hempel olympic 89650. Cheap and cheerful, it will do for now...

In the mean time, we got a crane in and lifted the boat up and dropped it back down on some 200L drums in preparation to paint the underside and antifouling. I asked the crane operator how much it weighed, he said 2.9 tonne. So i was pretty close in my estimations and design goals. Im about 200-300kg more than what i would have liked, but i figured there would be some blow outs due to unforseen items - i know i under estimated the weight of the paint for one - there must be over 100kg of paint on this thing by now...

Trying to splash in about 2 weeks time, which gives me 2 weekends to finish the painting and antifouling heres a couple more pics...








Anyone wanna take a guess at what the top speed will be? I have a reasonable idea based off michlet calculations, but ill wait till last before adding my prediction

 

Did you pay for this project by selling scrap metal? I have no idea on power boat speeds so I will just say fkn fast. I can finally see the hull shapes on the real boat. I like the almost non existent rocker. I will be even more impressed once you do the antifoul and the splash pics line up perfectly.

 

What prop pitch did you select ?

 

Ha Dennis - well spotted on the scrap metal i pay a young guy once a month to come and scrap all the old air cons I remove as part of my business...

I marked the center of gravity on the boat for the crane operator. I have a spreadsheet which accounts for every peice in the boat as i built it, both location and moment. The center of gravity should be right over the center of buoyancy and it will float level as per the designed waterline and buoyancy distribution of the hull shape. So far everything is lining up just fine

Prop pitch is 13 7/8 x 21" - i didnt select this they came with the motors. I figure I'll just run those first and then re pitch after seeing how it goes...

 

That surprised me, till I read that the gear ratio is 2.59:1. That is highly unusual for a motor that size, but suits your application I think, it must be running the same box as the bigger engines.