Now the sea trial has been a reasonable success, and the new mods have been done, (not tested but have to be an improvement) it was time to start making it look pretty😀 Major rain and wind (24mph ave with 35mph gusts) the last few days and 20deg C, but today, blazing sun and 28deg C so ideal for painting. Disassembled everything, cleaned up and painted the aluminium beams with an etch primer, then black enamel to finish them. Hulls were primed with an epoxy enamel primer, then a first coat of the sunset yellow epoxy enamel topcoat was applied.

Showed up a lot of minor areas which needed re filling, but that can be done once the first coat is completely dry. It's going to take a few coats to get it all done, but it's looking ok so far. Thick undercoat will fix most of the minor problem areas, or maybe body putty. Colour is almost exactly the same as on the full sized boat which was good. probably take a week to finish the painting, then should be good for another test.

JB

Finally got a chance to give the cat a test, but couldn't find a decent place to try it which was sheltered, as an 18mph wind was on shore and the tide was out. After driving round the local beaches and estuaries, I finally spotted a large tidal pool at one beach which was just deep enough for a test.

Wind was going from around 2 to 20mph in gusts and rotating 180 deg, so not ideal, and the useable water was only about 30ft wide by 80ft long, so not a lot to play with. Cat sailed ok, but the rudder servo was doing odd things (found out it was the servo extender not working with a new but bad digital servo) and getting intermittent rudder of only around 5deg each way. Had fun anyhow running up and down the puddle, and found out what needed changing, which was the point of the test.

I found the mast was too far forward, and it needed a lot more rudder. I have now shifted the mast back 45mm and changed the rudder servo (now without extender). Rudders are good for movement now, as I have changed the cable from the crossbar to a horn on the side of the rudder,- now has about 40deg throw each way. I have also shortened all the servo/battery leads now to make them fit better in the compartments, as there was a bit much spaghetti previously. Boat looks to have reasonable speed and is very light on the water (only weighs 2.6kg) It will be interesting to see what difference a proper sail will make.

I'm disassembling everything at the moment and will be painting it in anticipation of the problems being sorted. Painted the servo bays with acrylic paint to waterproof everything. Reasonably happy with it as a first test, as it's always a gamble designing as you go.

JB

Almost ready to give it a try. Winch, rudders, etc all sorted, just doing a few wiring mods to make things fit better, plus on/off switch and charging point (want to leave it closed up, to save undoing screws every outing) Mainsheet was fun to work out and set up, but a lot of choice words helped get it done 😎

Winch sits in the port hull, servo, RX and 4 cell NiCad square pack sit in the stbd hull. The lead for the winch comes through the aft beam to protect it. Compartment covers have sponge seals, but still some proper waterproofing to be done round the winch and rudder cable . I have to completely disassemble the boat to paint it once it's all finished, and make a proper sail (using the land yacht sail to test it with)

JB

Almost ready for a basic test. Rudders, tillers, gudgeon and pintle sets made, rudder blades made and glassed, link bar made, mainsheet pulley system worked out, rudder blades and centerboards painted, and centerboard tops and tillers varnished. Also made a rudder servo link which took a bit of experimenting with. Winch and servo/batt/RX compartments will eventually have waterproof lids, once I figure out where everything will fit.

Addition, --the pulleys are made from 16mm nylon bungee/shock cord buttons (for tonneau covers, boat covers etc) turned down on the lathe, with a brass tube sleeve and 3mm screw into a 3mm tapped hole. I was looking for small pulleys in the hardware store and spotted them. Almost exactly what I needed.

Was hoping to test it sooner and test the winch layout at the same time, but the winch did not arrive from Ali Exp, as the seller mucked me about, (think he was doing something dodgy) so ended up getting a refund from Ali Exp after waiting 15 days for the guy to ship it.

Have now ordered one locally which was supposed to come today, but the courier failed to make an adequate effort with the delivery. I stayed home specially all day so I didn't miss him, but he never knocked on the door, and just left me a card to collect from the base. Now I can't pick it up till Monday, and have to drive 12km to pick it up from the branch which is only a few kms from where I bought it, so I paid $15 for shipping for nothing. Couriers and the mail service here are becoming 3rd world ! Quite often they will knock once, and if you don't get to the door in 5 seconds they are off. So basically held up for 17 days because of shipping problems !

Vid of mainsheet system working, (substituting rubber bands for winch) Took a bit of thought, as it has to work across the boat. Basically a sideways version of the continuous loop system.

JB

A bit more progress,- decks glassed, gunwales taped and faired, center beam attached (trial position) filler pieces under front and rear beam mounts to make up for the edge tape. I used cotton sewing tape as it was easier to tape round 90deg and stayed bent better than glass which always tends to want to straighten out.

Still had to keep working the tape till the resin had cured enough for it to stay put. Dynel cloth is better than glass for edges as well, but the tape made it easier to get a neater edge. Centerboards are glassed each side with very fine finishing cloth. The boards are wider than would be normal, as I will need to experiment with the CE for balance between the mast, sail and centerboards to get a slight bit of weather helm which cats need. I can cut them down if necessary and adjust the centerboard case to suit once sorted.

Sail in pic is from my land yacht, but I'll use it for a test. I plan to temporarily attach fixed straight rudders and lash the boom in the center for a water test to check if the current position is anywhere near correct for balance.

JB

Hulls glassed last evening, and re-coated today . Centerboard boxes were previously filled with balsa plugs in their exits, which were sanded back flush when fairing the hulls. Now glassed over and will be cut out when the glassing is complete.

Decks will be glassed next, then gunwales will be taped to join the deck and hull surfaces so as to completely waterproof everything.

Centerboard blanks have been made from 2 x 2mm pieces of ply ea, cross grain laminated to prevent warping. They will be sealed with thin resin once shaped

JB

Been busy lately with yard work, fitting roof racks to the car for my new kayak (rescue vessel) etc, but finally got round to the exciting part ! Hulls are all faired now with a few coats of epoxy using West fairing/filler powder and mahogany dust to make it easier to sand, (the dust is to give it some colour so I could see where to sand to. Hulls are screwed to pieces of 100x50 timber with cross pieces screwed to them, so they can be screwed to the table to keep the hulls straight while glassing.
This was necessary, as the ply decks had twisted slightly over the length (about 2mm) in the 30c heat lately. Once glassed they will stay straight, (the cross beams will help as well.)

Used an orbital sander and long boards with 60 grit paper to knock the filler back. Cloth will go on in one 1200x300 piece for each hull.

JB

Trying the land yacht sail to get an idea of some proportions, and work out where the center of effort will be. The cat sail might end up being taller and narrower in the foot. The mast on my 18ft cat was 25ft, so I thought I might try following those dimensions, scaled for the model. Might be able to make both sails multi purpose for both models. I have to put another chain plate pad just behind the center beam, (for possible backstays) but need to find where the beam will need to end up first. Designing as you go is interesting🤔😐💥

I've also made a dolphin striker for the mast load (not that there will be much-if any) but it will be also be used to locate the mast with a pin. Normally the mast doesn't go through the beam, but sits above a short compression post, (see in pic) but in this case anything goes. This should enable the boat to use an unstayed mast as well.

JB

All of the beams have been adjusted to the correct width, holes drilled for the front and rear beams, and the holes reinforced and waterproofed with epoxy forced into them and spread with a wooden skewer. I have also epoxied in reinforcing plates for chainplates if I decide to go with a fully stayed mast. Haven't decided yet, but they will be there if I need them.

Been experimenting with various epoxies and their effect on polystyrene foam. The resin from the local f/glass shop is fine, (pic 3) also a brand of Chinese resin which is marketed by an Australian company, and sold here by a Korean $2 shop. I found that another Chinese brand of epoxy resin eats foam, so I'm assuming it's more like a polyester, --smells nasty as well. Still have a couple more to test,- another variety of the Aust one, and a US marine resin, made by PC products, Allentown PA (never seen it before looked interesting so bought one to try. ) apparently can set under water, has anyone used it ?

Goes to show, you need to test these Chinese glues before using them on anything. I find them generally ok for most things, but foam and plastics (like ABS) are another thing.

JB

Have now made the center beam, but need to make a few width adjustments to the mounts on all 3, now I know what the width between hull centers is going to be, with the hull tapers. I always seem to build 3 steps in advance, then go back 2,- happens when you design and build on the fly. Hulls now have 2 coats of Zinsser water based sealer, and are ready for sanding and a few coats of acrylic paint before glassing.

I want to get everything tested for fit and ready to screw together once the hulls are finished.

JB