Advice for a beginner - saltwater offshore electric

[Keebert]

Hello all - boat newbie here!

I’m a looking for some shopping advice here because I am working in Trinidad where there is little in the way of RC shops and what there is, is very expensive (read 2x to 3x the US price).

The benefit of living on an island is that you’re near the sea and it’s pretty calm here so there are plenty of places to boat but they are all seawater. In the mornings the sea can be very smooth with barely any ripples so it's pretty smooth out there but not glass. Also, the occasional passing boat will throw up wash that adds quite a bit of chop.

Most of the local guys seem to run 1/4 scale cracker box boats with weed-wacker type gas engines. I would like to run something that can handle some chop but is electric. So now to my first question – how small can I go without being too small for offshore? 30”? 20”? 15”?

Here's a shot I took a few days ago of a gasser:
http://farm9.staticflickr.com/8488/8189709500_f42059e518_c.jpg (http://www.flickr.com/photos/13392981@N03/8189709500/)

My 6-year old son is the motivation for the boat adventure – he wants something to race with his dad. I'm going to have to build two - one for me and one for him. So, I would like a boat style that is relatively user friendly and suitable for a small kid. I have seen some self-righting boats like the Danvo Avenger – are these a good choice? And can I get something in that style that will be large enough for offshore? Or should I go for a regular v-shaped design or cracker box style?

I have a crackerbox plan scaled to about 17" in length which we're going to build for fun (maybe out of foam board) just so that my son can get some building experience.

Another thing I want to do fix a set of running gear so that I can buy a bunch on a trip back to Houston (e.g. motor, esc, batteries, props) and then make hulls from plans scaled to the equipment I have. I have no idea what a decent set-up is so once a size is fixed (I'm leaning to around 20") then I'll need recommendations on the gear.

Thanks for the help! I'm probably more excited about this project than my son is!

[Meniscus]

Keebert, welcome to the forum! You'll find there's a lot of experience here on many different subjects. With regards to your running conditions, I believe it really comes down to whether or not you have swells, vice ripples. Many of us run in rough conditions, but the swells are a major concern as it tends to really stress the electric components as the model bounces from the top of one swell to another.

Are you focused on running a V type hull or are you interested in other types like a catamaran, hydro, etc.?

[Meniscus]

On this website you'll find a video of what a self-righting "eco" hull can do in a very small size. However, there are many more options out there. http://www.minicatracingusa.com/eco.html

It all just depends on what you want to do and what your desires are.

[Keebert]

Thanks for the reply - I'm not focused on a particular style although I do like the flat bottomed crackerbox style a lot. Ideally I would like to have different body shapes but all with the same running gear.

There is little in the way of swell so I don't think that is a problem. My concern is if a smaller size boat can handle the slightly rougher water state that the sea is naturally in due to tides etc.

[Keebert]

Here's a photo of the typical conditions - that's a gas powered hull (about 50" at a guess) for scale. Can I run 20" boats in these conditions?

http://farm9.staticflickr.com/8490/8199859560_22586deef9_c.jpg (http://www.flickr.com/photos/13392981@N03/8199859560/)

[Fluid]

There is little reason to run a 20" boat today. Most of the better RTR boats are 26"-30", and these are probably the most versatile choices for you. The Aquacraft Revolt is a very nice RTR vee hull, the Proboat Miss Geico a great catamaran. There are plenty of others. These boats can come with 2.4 radios, motors and ESCs set up for two 2S packs and can run in the mid-30s or more depending on the prop chosen. Their drivetrains can be moved between multiple hulls and some are usable for boats up to 35".

The biggest problem with running FE in salt water is leaks. You can wash off the hull and runing gear with fresh water after each day of running, but if much water leaks into the hull you can damage all the electric components. Extensive leak testing in the bathtub prior to running in the sea is mandatory.



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[Keebert]

OK, I guess "ouch" is the response from my wallet. The Revolt or Miss Geico is going to cost me $600 here in Trinidad and if I get one each, that's $1200.

The reason I wanted to get something smaller is that I can fit 20" hulls into my suitcase so I can buy them in Houston and bring them back, pay the taxes and still not have to spend a fortune. E.g. vac-u-vee jr with hardware ($90), motor, ESC & battery ($100), radio & servos ($100) let's me get two 20" boats for the price of one 30" RTR locally.

[martin]

As Fluid has said you need to make sure your 100% water tight, even more so on salt water. I run on salt water all the time & theirs nothing like salt water for shorting out electrics if it gets in them. Fresh water you can sometimes get away with re shorting but salt water is a different story (horrible stuff ), just take extra precautions re being water tight regardless of salt or fresh water. You get no second chances with electrics.

[BILL OXIDEAN]

Salt will corrode EVERYTHING from drive shafts to hardware. DO NOT I repeat DO NOT let so much as a drop hit ANY electronics. Certain shortage. If Any gets in your lipo its curtains.
Best electric boats I've seen run in salt water conditions are eco boats.. Salt water is super boyant, and tough on any size boat..

If you run in salt, flush the entire boat, cooling lines, jackets, etc with fresh water immediately after each run. Remove the shaft and flush the stuffing as well as the shaft.

[siberianhusky]

Bill's got it right, I've run a lot in salt water at my cottage, After the fresh water flush of everything I would spray WD-40 in, over, on and through anything metal, even inside the motor cooler.
I store the drive shafts is a plastic bag after cleaning, with a good spray of WD in the bag.
WD 40 isn't the only option, but I buy it in bulk non aerosol and fill up my own pump style spray bottles. Then spray it until it's dripping off the parts. Good stuff for this. The WD stands for Water Displacement.

[Rob7trinidad]

Hi Keebert,
I'm pretty new to this Electric Boat stuff. We migrated to Trinidad from the UK in August 2012, and I bought a Miss Geico boat just before Xmas. Yes, it's a bit expensive to buy here, but it is a lot of fun. I'm just getting to grips with it and the meticulous cleaning involved with Salt Water running.
I have a 4yr old son and 6 yr old daughter, and was thinking of getting a couple of Aquacraft Reef Racers for them to use - as these look like fun.
For some reason after my last run with the Miss Geico, I was unable to blow fresh water through the ESC cooling tubes, whereas previously I could take a sip of fresh water and blow that through the whole cooling tube system. Can anyone explain if this is the righ thing to do, and if I have a problem with the cooling tubes which is preventing me from blowing water through the system. Should I unscrew the protective casing for the ESC? Any help would be appreciated.
Keebert, if you want to get in touch locally, please reply and maybe we can race boats?
Rob

[mappo]

double post

[mappo]

x
Hi Keebert,
I'm pretty new to this Electric Boat stuff. We migrated to Trinidad from the UK in August 2012, and I bought a Miss Geico boat just before Xmas. Yes, it's a bit expensive to buy here, but it is a lot of fun. I'm just getting to grips with it and the meticulous cleaning involved with Salt Water running.
I have a 4yr old son and 6 yr old daughter, and was thinking of getting a couple of Aquacraft Reef Racers for them to use - as these look like fun.
For some reason after my last run with the Miss Geico, I was unable to blow fresh water through the ESC cooling tubes, whereas previously I could take a sip of fresh water and blow that through the whole cooling tube system. Can anyone explain if this is the righ thing to do, and if I have a problem with the cooling tubes which is preventing me from blowing water through the system. Should I unscrew the protective casing for the ESC? Any help would be appreciated.
Keebert, if you want to get in touch locally, please reply and maybe we can race boats?
Rob


Hi Rob,
I run all my boats in salt water out of Bequia St vincent, just be sure to coat all metal parts in corrosion X. and rinse with lots of fresh water. i also put my batteries in bicycle tubes and seal with silicone.

[Rob7trinidad]

Hi Mappo,
Very lucky to be in Bequia..! Beautiful island. Went there many years ago.
Thanks for the response, as well as the innovative battery protection method..! I usually wash the boat down thoroughly in fresh water and clean the flex-shaft before applying marine grease everywhere, which seems to stop any corrosion. I am a bit concerned that the cooling tube around the ESC may be blocked. Do you usually flush the cooling tubes out with fresh water as well..?
Also, I find that the humidity can quickly start to tarnish metal. Do you keep your boats covered and boxed, when not in use?
I noticed this morning that the water outlet nozzle showed some signs of rust already...!!
Rob

[rabosi]

I use a large plastic syringe (similar to those food flavor injectors) to flush out cooling lines. You get considerable water pressure with the syringe. I also wash all external hardware with fresh water, wipe dry and apply corrosion x. I also think it's important to do a submerged bathtub test to be sure no water is getting into the hull. Don't overlook the antenna tube. You could also make an adapter so you can connect a faucet to the cooling lines to flush.

[mappo]

Thanks Rob i do count my blessings. glad you love the island.
Every outing i flush my cooling system and clean the flex shaft and grease it, then i spray corrosion x on all metal parts, dry everything and cover just to keep the dust at bay. salt water is very insidious, it takes just 10min before rust starts accumulating on some metal parts. i mostly use aluminum on my cooling system to avoid rust. If you saw rust on your water outlet, that is because the metal is made from 304 stainless which is prone to some rust, i have seen some at times on my Miss Geico cat.

[martin]

Even the stainless screws will show spots of rust if run over a period of time on salt water, most of the 3mm screws used are A2 grade bolts which is not intended to be used in salt water. I change mine for A4 grade stainless bolts which is intended for use in salt water.