Ok…I started asking a few questions about hull building and I actually made some promising headway…
SO I will move forward with a build log of a scratch built boat that will fall with-in the RG65 class rules. Since this is an untested hull design on this small of a boat I have no idea if its going to be a fast boat. It is a planing hull design, but in full scale it has movable ballast(crew)
The hull I am choosing is an untested and never built in the model RC world. I am choosing the venerable two person Dinghy the Albacore. many years ago I owned one and sailed and occasionally raced. I have since sold the albacore. Several years ago I acquired the hull measurement numbers for the albacore and plugged them into freeship and got a hull. I attempted to make one for the footy class, but was never satisfied with the way it looked. so it never even hit the water.
So I dusted off the program copied it into to autocad and shrunk it down from 14 feet to 65cm…
my plan is to make a foam male plug. Id like to make 2 hulls. one will be fiberglass or carbon or kevlar. and the other would be in wood…Not sure if the foam plug will hold up to two boats…
Id like to go with the traditional sloop rig, but since we are limited to 2 channels I wont’ be able to have an overlapping jib.
I am torn as I’d like to have and open transom from the more modern dinghies, but I like the transom and the transom hung rudder to be more in line with the “look” of the albacore.
So I think my first hull will be the more modern open transom, and the second wood hull(if I build it) would be scale with transom hung rudder, which means that the hull would have to be shortened to fall within the rg65 rules…
the Open transom is still a pipe dream. A more standard solid one peice deck with hatch openings is much easier…So we’ll see.
I have cut the foam stations bonded them together together and sanded the plug to the basic shape.
I think you’ll have problems making the transom hung rudder version conform to class rules. The hull length has to be 65 cm +/- 0.5 cm and the rudder must not extend aft of the transom.
Yeah martin I read some more…into the rules and though that…
actually the rule read that the overall length of the boat cannot exceed 65 the length rule makes no mention of the hull…and the second rule is that the rudder rmust not extend beyond the hull. but the apendix diagrams do show pretty specific. so if I do build a wooden albacore, it will be scale with the rudder but won’t be rg class legal…
Well I got the cloth from defender yesterday…
after putting the shrink wrap on the hull I found some areas that did not look symmetrical…so I took the wrap off and did some more minor sanding.
I should be able to lay up the hull tonight I got a hot knife through micheals craft store… mildly impressed with it function but for 13 bucks after coupon, I don’t expect it to last…
on a whim I started cutting foam for a blue splash as well…
Craig, let me lay this one up this weekend along with the albacore, and I’ll bring the finished product by one day for lunch and we can compare. and see how good I did…
Went sailing tonight with the bathtub, I mean soling, did alright walter was there so I could at least compare speed…
laid up three layers tonight… west 206…so I guess we’ll see how it turns out in 10 hours… took 3 pumps of the epoxy…hopefully I didn’t go too light, everything was wet and I used a rubber spatula to smooth and spread it around.
ok finally did some more work. Sanding and primer, and more sanding and more primer… 140 grams… the hull is almost ready for internals and deck fitting, cutting hole for keel, ect…
well I made some more progress… added a keel trunk, keel, rudder and rudder tube. I am also building a stock maritime carbon fiber hull at the same time.
and have scavenged keel, rudder and electronics from my delta rigged round ranger… Still have not trimmed the foam plug to make the deck mold for the albacore…
out of extreme complexity, and laziness, mostly laziness, I’ve scrapped my idea of trying to make a canting rig…
the stock maritime hull. Black Magic… is complete and ready to sail. rigged it with a set of cut down victoria sails…Hence the V on the main… Micro magic vang/ gooseneck 885grams RTS yes I know the jib club is too long…
also pulled the albacore deck out of the mold. not a great piece of work, but should be passable.
Well had shakedown cruise today. floated on the proposed waterline and was was sailing well before I got hit by a victoria and broke the midship thwart with holds the turning block for the main and jib sheet. will have to rethink the attachment to the hull…
so in good winds and 10 minutes of sailing I had just about chosen to make this boat my boat for the season…then I pulled it out of the water and it had 1/2 cup water sloshing around… :scared: so need to fill up the bathtub and try to find the leak(s) I think it may be between the rudder servo and deck. the servo is exposed and I did caulk around the servo but probably did not get it completely sealed. Another design flaw. the open deck has a negative slope so it is not "self bailing… all the water flows forward to the keel trunk. and sits so I need to figure out ow to reslope the cockpit, or cover the entire cockpit… which is easier???
so I also sailed the Stock maritime hull… I was not impressed. the balance is fine, sits on the waterline. but with the narrow bow(no reserve bouyancy), it is also very short. it really wants to try to submarine. It may be a good light air boat… but heavier wind is not this boats friend… if I moved the weight further aft so I had an immersed transom, then maybe when under power the sharp bow would not want to plow as bad… (maybe I have my next delta rig candidate) but it did not take on any water…
a few pinhole leaks in the hull. and more than a few int he deck. I was expecting some porosity in the deck as a result of only going with two layers of glass and me squeeging off too much epoxy… Kinda hoping that primer and paint would fill some gaps.
the bulk of the water did come in through the poorly sealed rudder servo. no leaking around keel or rudder.
SO
First step is the Hull… wile it will be hard, not impossible, but hard… to locate all pin holes… should I just do a light sand and then lay up more primer? and let the sandable primer seal the holes? skin cote the entire hull with body filler and then re sand and re paint.
Light Sand, turn the hull up side down make up some epoxy, thin it a little, and then “paint” the outside with the thinned epoxy to build up a new layer…, sand and then paint???
Deck, ad a third layer of glass/epoxy,???
I don’t plan on cutting out the open transom/deck and redoing. I’ll spend my time on making a new boat…and making the needed changes…
With enough epoxy I know I can fix, but I wan to fix it with the least amount of weight as well…
Hi Marc, bummer with the pin-holes, I’ve got that tee-shirt too many times
Try and keep sanding to minimum as will promote more pinholes if the fibre has not been completely wetted out.
To keep weight down to complete minimum, my bet is to make-up small amount of “low viscosity epoxy” and rub it into pinholes with finger tip to seal pinhols.
Best water test is to fill “empty hull” with water, then watch where the water droplets start appearing on outter hull where you can see everything, which can’t when float testing.
i agree that sanding need to be kept to a minumum or I’ll be chasing my tail…
I did fill the inside of the hull and that how I know I’ve got pinholes… I guess I can use a pencil and mark the holes as the drops form…and then star plugging…
just not sure how to handle the deck although the deck will not be under water(hopefully) water will find a way in…
would you suggest that the thinned epoxy brushed onto the deck or another layer of wetted out glass to solve the deck problem…
For lightness & the deck being mainly for waterproof & aesthetic smooth finish I’ve used same method of finger pressure-in “light weight filler” (not epoxy) and after light 600 grit sanding, light coat of filler primer to check smoothness (can be lightly sanded again) then coat of paint.
Epoxy coating the deck will not guarantee plugging pin holes & from my experience only makes it heavier and your back to where you started…pin holes still there.
at this point aesthetics are out the door… I just want it “water proof” but not overly heavy…Maybe removal of the deck and redoing would be the best for the deck… or just focus on the deck area near the sheer line, IE areas where there will be likely continued water contact…hmmm
