unclecrash

Ya I know all about that my friend who owns LHS has been using the alchol method for sealing boats for years. Theres lots of ways to skin a cat. I have heard about heating. i dont think in a sealing situation for inside the boat Its going to hurt it sure will protect it better than what he has now. I also never seen anything about alchol which I think in my opinion evaporates a lot faster then the thinners they are saying not to use. And this isnt a repair where the wood is all rotted.

piper_chuck

My Feedback: (12)

Their tests included alcohol. The bottom line is thinning epoxy with a solvent (alcohol, acetone, laquer thinner, or whatever) has been shown by people in the industry to have negative effects on the strength and waterproofing capabilities of epoxy. This would be particularly true if 40% solvent were added. [X(] Rather than trying to convince you, I'll leave it to the readers to decide whether to pay attention to the results of controlled studies by well known manufacturers or dismiss them as you did.

unclecrash

Not too worried my boats will be floating long after Im gone. I dont think the water is going to get through the epoxy with the acrylic urethane over it. I think you could be worrieing too much

piper_chuck

My Feedback: (12)

I'm not at all worried about your boats, they're your responsibility. I just want to ensure that everyone else who reads this thread gets complete information.

unclecrash

Good for you I think your still a bit red behind your ears from the words we had

cyclesoul

riteo, save it for another thread boys. Personally i'll take experience first information second. Information is all well and good, but without experience it means nothing.

Ron Olson

My Feedback: (1)

I see first hand all the time what a solvent can to do wood. On my job we use wood wedges to remove poly laminations (it would take me all night to explain my job) and it quickly eats through the cellouse fibers.

cyclesoul

Made a stand for it out of foam, clad in styrene, works well! epoxied the insides of the hull, set up the radio box, removed and sealed the engine (has a brass conrod[X(] never had a nitro engine like that before!)Put in some floatation. Bought some minature taps for sprinkler systems to block off the 3rd hose on the fuel tank and enable me to fill the tank. I think I will also put one in the cooling line so that i can control the flow of water to the engine.

Descided against water cooling the pipe for now, Its a little difficult to put a water pickup on the hull with the over hanging transom, something to think about anyway

Ran the first tank of fuel through the engine in the backyard, heat cycling it, to try and minimise the swimming i will need to do on its first run!!



engine ran fine and didnt stall once, was hard to get some temperature into the engine actually so i fitted one of the little sprinkler taps to the IV setup. Worked well.

cyclesoul

ran it yesterday afternoon in a pond not far from my house, its not a very big pond, probably 50mx20m but definiatly big enough for the first run! Quite a few ducks in there when I got there, though as soon as I started the boat they scampered which was one less thing to worry about. So i dropped it in and we were off! quite a bit of cavitation but with a bit of patience it was up and running, very sluggish on the rudder until it got to full lock and then is spun round within its own length! but at the same time not enough lock to turn effectively at low speeds. hmmmm. This is when it stalled the FIRSt time, lucky its summer here! After 4 more swims and 2 times up the bank (rudder doesnt work to well when the prop is cavitating!) I called it quits cause the engine wasnt getting any coolant.

In a straight line it went very well and didnt need much throttle to really scoot along with a little rocking and a little bouncing

When I got back home I realised that the strut was above the rear transom height and pointing upwards!( I think the seller put it up high to avoid damage during transport!) This would explain the cavitation and posibly the loosness in the turns. even with the prop at this height the rudder barely reaches the same depth as the prop. So im thinking that the rudder is to short, would you guys agree? Also the water pickup in the rudder is about a 5mm from the top of the prop, not so good for a surface drive me thinks!

So I think I need a longer rudder with a deeper water pickup and a longer arm on the servo to get more turning, though with the longer rudder, that problem may sort itself out!

Ron Olson

My Feedback: (1)

I prefer to have my rudders at least 1 inch (26mm?) below the prop itself, not from the hub. I clarified that as someone mistook what I had typed before.
A clearer, closer shot of the transom would help.

cyclesoul

thanks ron, I was thinking it was a little short. I will get better pictures when i get a new camera. Ive been looking at them, just a matter of finding one at the right price! The pic above was with my mobile phone, thats why its crappy!

Ron Olson

My Feedback: (1)

It's the lighting in that shot as the strut and rudder are in the shadow.
It is better than some shots that I've had to try to figure out. Some were like they were shot in a coalmine at midnight witout a flash.
Actually it's not too bad for a cell phone shot.

jhocheung

hi cyclesoul,
hope you still remember who i am ^_^ and dont get angry with me

Thanks for the information you provided and sorry for the bugs and error. i think i will do my best to solve the problem. Tell you one thing, you are the first person to test this boat (Beside me ^_^.)
Rudder seems to be the problem. hmmmmmm..... not too hard to fix i guess and i think the radio is also very nasty to fix due to limited space. i may put in a fibreglass box but than again it will cost higher and looks less pleasent. agree?
This week i am going to put in a bigger engine and see if the stablility still in place.
My biggest concern about selling the almost RTR boat is that it must not be too fast and the cost is also a concern for me as well.

cyclesoul

Yes i remember and no im not angry!! The boat is very good for the money and at the price i paid for it i did not expect it to be perfect! For me this hobby is as much about working on them as it is driving them, Thats why I bought your product instead of a brand name RTR!

I was just about to send you an email to let you know about the rudder length, It really needs to be at least an inch longer. As for other aspects of the hull, yes the radio box is tight and it is hard to get a good seal on the edges under the top of the hull. A fibreglass box would be more water proof and also lighter (both a bonus!). If the hull hatch was just an inch wider it would make the boat signficantly easier to work on with better access to everything( something to think about for the future!) All of these things are a balance of cost and performance for you and only you can decide that!

I think its performance is adequate for an rtr boat, but yes i will be putting a bigger motor in it for sure. What motor are you going to put in it? Ive measured it up and a .21 is going to be a tight fit with the end of the crankshaft butting up against where the flex drive enters the hull, I think I will fit a os cvr18 or a marine version of the traxxas 3.3 (if they bring one out!) so that i dont have to fiddle around with moving the engine mounts, maybe you can put a water cooled head on some of the aftermarket engines designed for Traxxas trucks as a lot of those fit to the small block mounts. HAve you put on a longer rudder?

Ben

cyclesoul

Ron if you look on the first page, i think its the third or fourth photo that shows the rudder and prop set up. In that you can see that the rudder reaches the same depth as the prop.

Ron Olson

My Feedback: (1)

That shot shows the rudder fine but not the prop as it's almost the same color as what the boaqt is sitting on but I would say that the rudder is on the short side but where the water enters should be fine.
I can see where a wider hatch opening would help also as I've built a few boats where I had to modify some tools just to get at some spots.
An adjustable strut would be a nice addition also.
No RTR boat is perfect as some people like their way of setting up a boat differently than someone else does.

cyclesoul

yep it is a little hard to see ron, so i took another pic with my mobile phone, should be crystal clear now! Also it does have an adjustable strut, and in this picture you can see that i have lowered it nearly 10mm lower from where it was before!

Ron Olson

My Feedback: (1)

It's a wonder that it would even steer once the boat is on plane as there wouldn't be much in the water.

Sean Bowf

NM

Sean

cyclesoul

yeah ron as i said it was really sluggish on the rudder until at full lock where there was a slight pause them wham! round shed go in its own length- like a jet boat! lucky I was still only using half throttle to be kind to the motor.

NM?? whats that mean sean??

Bought a new rudder today it is nearly exactly an inch longer than the last one, so according to ron that is the ideal. Its blue though, not a massive fan of anodised colours, but it should go with the colour scheme of the boat pretty well. was only $35 aussie dollars, seems like a good deal to me. It also has the kick up feature that i read on alot of threads that my previous rudder didnt have (though as Its that short, it wouldnt have been hitting too much!!). So until the rudder gets here the boat is in dry dock.

HannSumm

let us know how u get on with this man

cyclesoul

well the longer rudder finally came in and it is now installed!





Runs considerably better now with plenty of steering and it is really cutting in the turns. Still running it quite wet as i like less cavitation if I can help it! Scooting along quite well, though the engine is still tight and rich it was just starting to come on the pipe with a good surge at the end of the last tank (tank number 4) so next tank I will lean it off some more and see what she can really do with this engine. I have ordered a OS TZ .18 from tower (they were $60 off plus discount for spending over $150 after I added a header!) which should make it hammer! Then it will be time to play with props. Here's some more still shots

cyclesoul

I'm definately going to put a bevel on the end of the exhaust, it stalls way to easily with the slightest splash of water when slowing down! about 60 degrees should make it harder to get blocked off.

I also added a lexan spray guard to stop grease getting sprayed all through the inside of the hull from the end of the flex shaft and sealed around the flex shaft to stop water entering the hull. I was going to epoxy it in but changed my mind at the last minute, as I was thinking it would be hard to remove if it was epoxied in there when it is worn and needs replacement, so I just siliconed it in there and it seems to be working well so far.

I saw in another post about cooling heads that a member on here - sleepy- had converted the TZ with the CVR head before, I am waiting on his reply to a pm to see how he went about it. Im just a little concerned that brass or alloy piping wrapped arount the cooling fins wont supply enough cooling in an enclosed hull, we will see i guess. While im on the subject which would work better brass or alloy tube? Im thinking alloy as it will transfer the heat much quicker, does anyone agree?

cyclesoul

Since my last post i have put a bevel on the end of the exhaust to stop the boat stalling if it comes off a plain and when slowing down and that has worked really well. I also broke the pullstart spring, man do these engines have a crap quality spring in them, snaps everytime you try to bend it. After a lot of hassle with that i found that a spare spring from my RE.32 truck engine would fit and with a little help with the spring shape from my LHS (cheers adam your a champ!) I was back in busines with a near indestructable pullstart!

I added some ballast to the back of the boat (4 aa batteries! all I had at the time!) and moved the fuel tank 10mm further astern to bring the cog within the balpark 30% range and this has helped alot with the balance ofthe boat. im still playing with the strut height and angle as well and have yet to find a good compromise of speed v's control.

I had my first blow over with these mods as it was a real gusty day and it was running at least 10-15kmh faster into the wind than with it as the air got under the hull. It was like slow motion as it skipped across a few bumps and accellerated as both a gust hit it and the prop caught more air I kept it pinned as i wanted to see if the engine would rev out even as the bow started to rise up to about 45 degrees and then wam! over she went, flipped over on her roof and then right side up again. Looked mad and my mates were stoked telling me to do it again! No damage, only about 150ml of water got in the boat to, so it wasnt to bad at all.

I also cut 10mm off the header to hopefully bring the engine onto the pipe earlier in the rev range as it is only happening at the end of the tank at the moment when the boat is lighter. This was working well, but i think I need to cut a little more off to make it happen more consistently, not just into a headwind! Fun was stopped by the pipe blowing off the header then by one of the header bolts stripping, can you get 3mm helicoils[:@]

Finally got some action pics too. This was before the pipe was shortened, you can see the difference when heading into the wind (pointing to the left) and with the wind (bow to the right)




I still have the TZ .18 to put in there, but i would like to get the boat set up with this motor before I nearly double the horsepower!

cyclesoul

one more