Slayer-RCU

Pro,

I have decided to add a couple of rear sponsons to the boat, balsa formed with a fibre glass coating for strenght. The water contact area is approx 1 inch wide x 3 inches long. After the failure with the centre ramp, these should work alot better... Just waiting for the glass to dry.

Slayer

Slayer-RCU

Hi,

Well I have finally been able to spend sometime working on the boat, I have finished the rear sponson thingies (refer attached pics), They have been designed to have the boat sit flat as I noticed before they were fitted, the hull had a slight twist about 3mm, this could have caused the RH turns.... anyway this is fixed now.

This was my first attempt at fibreglassing and lets just say the amount of sanding I had to do will not happen again. The next step is to repaint the hull, put it back together (A might convert the full moving elevator into a conventional type elevator), redo the CoG and put it in the water - should be this weekend.

Last Pic inthe next post,

Slayer

Slayer-RCU

This is the underside of the boat, with the hole highlighted from a couple of posts ago.

Slayer

TERBObob

My Feedback: (21)

GREAT ! ! !
Now ... when you get her back into the water .... make sure you post some pics or a vid of her running [8D]
( gotta LOVE those vids )

pro27

Slayer..........
Looks pretty good!
Looks like you should have enough area at the rear now to keep the transom up off the water (less drag=more speed) and allow more of the hulls weight to be carried up front to help with the blow over problem.

Yea...the twist in the hull could explain the other problem you have. It doesn't take much, even 3mm to make a difference in how it rides and handles. A 3mm variance at rest, multiplies to a greater effect the faster you go. IE., Like when driving a car at 20 mph and you turn the wheel 1/4 turn, the car eventually follows. At 60 mph, the same 1/4 turn will set you into the ditch real quick.

Thanks for keeping us updated and look forward to the results!

Slayer-RCU

Well this is the next installment.....


Have just returned from the dam with a bag of red fibreglass and balsa..........No the boats ok but those damm rear sponsons no longer exist. What can I say I put it in the water look good....applied throttle water everwhere...looking even better...boat stayed at walking pace however it look good, after a few attempts at getting the boat to run no joy so off came the rear sponsons and about a 3000% improvement in performance happened although some of the old problems have returned plus 1 new one- a binding throttle cable.

The next step is to fully return the boat back to its original condition(alot of sanding) and add ramps in the tunnel..

I am happy no video of this exists...

Cheers
Slayer

Slayer-RCU

Well after a bit of sanding and the like, the rear sponsons things have been totally removed and the boat now has two ramps sitting in the tunnel section of the hull, the ramps are approx 8 inches long x 3 inches wide, leavinf a gap of about 4 inches between the inner edges of the ramps, once these are blended in, I will fiber glass them and throw it back in the water.


The throttle problem has now been soreted out as well.

See Ya

Slayer

TERBObob

My Feedback: (21)

HA HA SLAYER ...
I was there ... hiding in them bushes and I got a video of it ....

( only kidding ... )

Hey ... that REALLY stinks that after all that time , she ran like poop ! Hope like heck THIS time she runs PREMO !
Please keep us posted on the results ...
( especially since you are doing what I am doing , but further along than myself [8D] . I've got mine ALMOST built ( just the wood part ) .. still got LONG way to go .. )

Slayer-RCU

TERBObob

The kids thought it was great, their Edge hovercrafts (9.6 Vdc, plastic, straight out of the box) were out running it [].....anyway here are some pics of the new ramps (still under construction) and paint job.

TERBObob

My Feedback: (21)

I bet "Dad" felt "real" good then , huh ...
I know the feeling .
( don't ya just love it when your little ones show you up ??? - )
Now , about the ride pads ... Looks good . I think you might have it this time . More coverage on the bottom rear section yet tunneled for lift and airflow . Very nice ...
And as I said before ... GOTTA get some pics of running .. ( even if she IS slower than those TYCO type RC's ... LOL )
But hopefully this time you got her corrected and she will run a like a "raped ape" ( or is that a Grape Ape .. ) ( Grape Ape is an old kids cartoon that was about a giant purple gorilla and a talking dog that was his "owner" , in case you didn;t get that "intelligent" cartoon over there ... )
P.S. just a little jealousy here with you and all that WARM water ... here its probably frozen more solid that the ice cubes in your freezer ... AND cold as HECK .. Highs today were in the single digits ( farenheit ) an with wind chill - minus 15 to minus 30 below zero ( farenheit - I think thats how its spelled ... )
Get that baby sanded , finished , and get her out on the water and let us know the results .

Slayer-RCU

I'll start typing for the second time...don't know what happened but my text was just wiped.

I didn't get to the dam this weekend however I decided to run the boat in our back yard (yes in approx 40 degree C heat).

Figure eights are the go as the yard is fairly small and once again the boat turned to the right in very tight circles but turning to the left was a different story...hmm a torque reaction to engine rpm and prop..I think so. I constructed a wedge to sit between the engine mount and firewall (?)..yea I know I could have used a few washers on one side.

Anyway I fired it up and success the boat now turn both right and left.

A few of interesting points I found out:

1. The boat only scraped the paint on the rear of the sponsons - no paint of the rear ramps, if this transfers to water the boat should go like a rocket and

2. If you run into a bush the prop will cut a circular path through it and cover the boat in plant bits which stick to the boats paint work really well (refer pics)

3. Testing doesn't always require water.

Until next time

Slayer

TERBObob

My Feedback: (21)

( shhhhhhh.... don't give away all your secrets .... ! NOW everyone will know , that when the wife says "GO OUT AND DO SOME YARD WORK , AND WHILE YOUR AT IT , TRIM THOSE BUSHES " , now all will know how you do it ?! LOL LOL LOL LOL

Anyway ... nice job on getting her corrected , but hey ... next time ... leave the hedge-trimming to the professionals ....

( hope she works as well for you on the water as your dry run . )
Make sure first , that you didn't get too much of those bushes down that ole carb throat ...

banks04

My Feedback: (9)

I am new 2 boat building and was wonder what do u guys use 2 waterproof a boat.Im biulding a dumas big swamp buggy and the directions say 2 use epoxy but wouldnt that b heavy if i coat the whole inside with epoxy.If any 1 could help i would really appreciate it thanks[&:]

TERBObob

My Feedback: (21)

There are LOTS of water sealers you can use , but , the epoxy is the most commonly used ( and most readily available . ).
When applying , just don't go gobbing it on thick ... I use a paint brush myself when applying and it comes out pretty good with minimal sanding ( but then again , that also depends on how smooth you get the wood first - )
And added weight ? yep ..
How much ? Well , that depends on how "thick" you lay the epoxy on .
Mix it up , get your paintbrush out , and start "painting" it on in THIN layers ....

pro27

To go one better, along with TERBO's technique.
After applying the epoxy, I use a spreader/scraper, such as an old credit card or other plastic card about the same size, to scrape and spread the epoxy into an even thinner coat. This makes the epoxy go A LOT farther and helps reduce the weight buildup. It also helps reduce the amount of sanding.

pro27

Almost forgot......[X(]

Use a long setting/cure epoxy. If all you have access to is lhs stuff, go with a finishing resin type (20 minute) or 1 hour set times epoxy. If you have the money and source, go with West Systems.

Slayer-RCU

Banks,

I used a poly fibreglass resin.. has work well so far...

Good Luck with your project

Slayer

brother

Hey Slayer, Made it to the pond... didn't get to run full throttle tests. Ran into a problem with the carb flooding. I mounted the fuel tank a little too high, when I ran it yesterday morning I didn't have any flooding but then I only filled the tank about half way. Going to have to drop the tank about 1/2", I did manage to get the boat up to 3/4 throttle for a longer stretch and it appears to plane fairly well. The boat turned out being a little heavier than I wanted, I think it's about 5 to 6 lbs. That's ok, it was built mainly to test the hull design, over all it did well. It turns very sharp for having air rudders, even at higher speeds, it doesn't seem to slide much. Odd I would think the hull would lend itself to power slides, at 3/4 throttle it turns in about a one foot radius, that's a 180 degree turn. Anyway I am going to lower the tank and run somemore tests and then I will start on building the new hull for the K&B 65. Brother

Fluid

Epoxy works very well as a wood sealer/hardner, and you don't need to buy special resins, etc. Get some 20-30 minute epoxy in the bottles ( cheaper that way ) and mix some in a styrofoam cup. After the epoxy is fully mixed up, add about 1/3 as much isopropyl alcohol ( drug store, get the 98+% stuff ) and stir it in well. Now use a cheap 1" paint brush and brush it onto the interior of the hull like any other kind of paint. When it cures it will seal completely and not add too much weight at all.

You can use the same technique to seal the exterior, but you'll need to use a filler afterwards. Sand the epoxy lightly with 150 grit, then spray on a few coats of primer (epoxy based hobby stuff ). Sand smooth and repeat until you like the finish, then shoot on a few coats of final paint and you're done!

banks04

My Feedback: (9)

Thanks alot for the info guys i cant wait to get this thing finished

brother

Eh Fluid, Sounds like this technique would work well for glassing over a foam core. Most of the alcohols I've seen are only 91% isopropyl; is that good enough or is there any other thinner that can be used with epoxy? Brother

Model_Mann

[]please help me[] im a poor(not money wise the other poor) 16 year[&o] old trying to build an electric air boat ive tried and failed[:@]many times. i would like it to be for all terain ( snow, water, ice) i have a speed 600 motor, airplane servos,a cheap speed controll, a lot of pink styrafoam, and a lot of time on my hands.

please help me

TERBObob

My Feedback: (21)

Ok ... but whatcha need help doing ? LOTS of GREAT guys here with LOTS of SUPER info ... just be a little more specific and I can almost guarantee a GREAT answer !

Model_Mann

any info would make me a joyfull 16 year old. lol
i need body ideas/ body plans
i need ideas on how to mount an electric motor
HOW TO MAKE IT GO REALLY FAST IN SNOW, WATER, AND ICELMAO

TERBObob

My Feedback: (21)

LOL .... ok , here we go ...
First , we need to know WHAT electric motor you plan on using ( why ??? different torques and RPM's and battery requirements - which means either more , or less battery weight , which in turn , defines the size of the boat and prop )
Again , a little more info .