Model Yachting

Building the Pond Yacht "Catnip"


August 5, 2014

Hi, to those following my builds. Last week was a downer, giving up on Footloose, but it was the best thing to do at this time. I know that I will return to that project and do it in a way that is more satisfying. Meantime, here I am with the shop cleaned up and getting ready to start my catboat build. I have half a dozen plans and have made up a table of proportions from which I will draw the boat.

Before I really begin, I wanted to get better equipped. One of the problems I had with Keep Clam was that a bread and butter boat really requires a special kind of clamp to do the glue up job efficiently. I've seen some professional builders use what, for lack of a better term, I call a "bridge clamp". It may well have another name. I have never seen them for sale, so I had to make myself a set. That has occupied my last two work days.

A bridge clamp is quite simple, really. All it is a two pieces of something strong enough to take the clamping pressure, long enough to span whatever you are clamping and deep enough to have one piece on the top and one on the bottom. They are connected by pieces of threaded stock long enough to accomodate the depth of the item being clamped. The clamp pieces might be steel angle iron. That's especially good if a lot of power is going to be applied. However, I think wood is more common and is, of course, what I work with. I dug around out in my fancy wood supply out in the shed and yarded out two piece of very heavy, hard lumber, one of black locust and one of osage orange. These were actually purchased for bow making, but since I am not doing that any more, they are now just an appropriate wood for my needs at this time.

Both of my planks were true one inch or 4/4 lumber. Yesterday I cut blocks 1 1/4" wide out of them. I cut several each at 9", 11", 13" and 15". These lengths, allowing for the nuts,bolts, and washers on the treaded stock, will provide clamps with working capacity of 6", 8", 10" and 12"... enough length to span the beam of the bread and butter stacks of most any boat I might realistically care to build. Each block was then drilled at each end to accommodate the 5/16" threaded stock I used. They were then all sanded and each pair installed on pieces of the threaded stock I cut to 12", which is undoubtedly excessive but I can trim when I have some experience using them. Finally, this afternoon, I assembled the finished clamps.

Here are pix:


Here you have it. Wood blocks connected by treaded stock.



This was the clamping of Keep Clam... it was a mess, with several types of clamps used, some of which didn't reach all the way into the middle of the hull. The result was some rather messy glue lines.



Here is how the bridge clamps would work in glueing up a boat stack. Obviously, more would be used, spaced all along the stack. This is just a few scrap pieces of wood to give you the idea.



This is the lift pieces of Keep Clam, ready to glue. Picture seven of the new clamps spaced along this stack, neatly accommodating all of the steps from short pieces to long pieces, and all kept level. Much better, eh?


I'm not going to keep track of hours. It was a nice idea, but it'll get done when it gets done. Since I am also intending to try to do more of the hull work with the bandsaw, I may cut out a mock up in styrofoam to make sure the cuts will work as I think they will.

Stay tuned.



August 7 - 14

Great morning's work! Started out by needing to get those clamps organized and off my work table. As noted, they are in graduated sizes, so I cut a long trapezoid of board that was 11" at the wide back end and 6" at the narrow front end, with enough extra on the wide end to screw it to the bottom of the set of shelf/bins behind and over the table:

With that taken care of, I decided to go straight to making Catnip. As indicated above, this is not a project from plans. What I've done is establish the average proportions of six different catboats, i.e. ratio of beam to length, hull depth to length, mast height to length, etc.

Gaff Catboat Build


If length is considered 100% then beam is between 40% and 50% and hull depth (less any keel - most are centerboarders) is between 10% and 12%.

For 24" boat, beam is 10.5 to 11 inches. Hull depth is 2.5 to 3 inches. I have basswood that should clean up to roughly 1.75 thick. Add .75 for bottom and .50 for deck to give 3 inches. Or, use an extra lift of .5 between deck or bottom and main hull lift.

For 18" boat, beam is 8 inched + -. Hull depth is 2.75 + -. Use basswood at 1.75 plus a 3/4" piece for bottom and 1/4 for deck.

Boom is generally length of hull + -

Mast quite variable, from 100% if gaff has high lift to 150% if gaff lift is not so high. Obviously choose shorter if there is going to be a top mast and topsail.

Use three piece plywood for keel with fin opening or centerboard. For 24" boat, use two pieces of 1/4" and center piece of 1/8" to allow for 1/8" aluminum keel

In the process of doing that, I just plain got my eyeball somewhat trained to catboat hull appearance. So, I yarded out a piece of masonite, drew a set of 2" squares on it, 12 squares by 3 squares, and then sat down and sketched in one half of a hull. Next I dug out one of my old basswood planks that happens to be just shy of being true 8/4, i.e. 2". Because the hull depth of a catboat is very shallow and the sides are not very tapered on many of the designs, this one lift template will probably build the whole boat. I used it today to cut a right and a left main lift. I plan to build each half of the boat individually, then glue them together with a plywood keel between, then shape the hull (not much will be needed) by doing one half as if it were a half hull model, then establishing station templates based on that to make the other side match. Here are today's pix:


Here is the masonite template. I drew the outside and then the inside edge. The template is actually lying on the 3/4" board that will become the bottom in tomorrow's work. The thick plank I worked with today was, fortunately, wider.

Note that this board appears to be just barely adequate. In fact, it's fine. I'll draw the outer line, but then draw another 1/4" in from that one and that's the one I'll cut to. That will give a little curve or shaping to the bottom, though this will end up being essentiall a flat bottomed boat with just a bit of rocker to it.


Here is the unplaned edge of the thick plank. As noted, it was wider than needed and I was able to make a very straight, smooth table saw cut to remove one inch from one of the rough sides. This still left more than enough width for the lift. The cut off material will become the spars.


This shows the two sides of the primary lift.



Note the squared ends left on. This will provide surface for clamps to join the two halves. Once the halves are joined, the squared ends will be worked off. The bottom and the sheers will be similarly constructed, resulting in three, possibly four layers to arrive at the thickness I want. Then the new clamps will come into play to do the horizontal gluing of the layers together.



This is the two cutouts from the inside of the lift. Note the knot I had to accommodate. I bought these planks more than 15 years ago to build ventriloquist dummies. I could often find a good plank with a knot or two and get it at a better price. The vent figure heads were small enough that I could easily work around knots. Not so much so for boats! However, I think I might be able to get another 18" catboat hull out of these pieces.


Can't wait to see what tomorrow brings!




A good morning, but with a false start or two. The project worked in my mind during the night, as they will, and I decided I was plannning to do things in the wrong order. So, this morning's work was pretty simple. I cut out 3/4" thick pieces for the bottom and was thinking of same to do sheer lines on the top. However, it became apparent that I was stacking wood too deep, so I went ahead with putting the bottom on both half hulls. The new clamps work really great, but... I need to remember to put wax paper between the clamps and the work so I don't have to clean glue squeezings off of the clamps afterward and I realized I could have used more smaller lengths. Finally, it was apparent I went way overboard on the length of the treaded stock. Once this boat is finished I'll make up another six small clamps, 6" and 8", and cut all of the treaded stock down to a more practical length.

Today's pix:


Here's the first side done. Doesn't this look a lot better and more manageable than the glue up of Keep Clam shownw above?



Here's the second side done. Note I learned from the first side to protect the clamps with wax paper. However, not having it made the first side pic clearer.





Upon examination after glueing, I decided that the 3/4" bottom was very heavy. I bandsawed the inside shape out, leaving the hull depth the same. In this process, I left a strip of wood in the center to act as a kind of keel plank, since I intend to screw the keel fitting to the bottom. The actual bottom will now be 1/8" plywood, glued to both the sides and that center strip. I think this will work well and knocked something over a pound off of the hull weight. This morning I glued the plywood bottom on.


I'm kind of making this up as I go, but it's going to be interesting. Obviously, it will be a flat bottomed boat, kind of a catboat sharpie. I think I will add a full length outside keel plank though, for lateral surface stability.


While I took a couple of days off from building, Keep Clam and I had a bit of an adventure. I decided to try string sailing, i.e. letting the boat go but with a thin fishing line on the bow. Theory is to let it do a broad reach as far as it will haul the line, then tug the string to cause it to jibe and sail back. I reasoned that if this works well, I could sail on quite a few bodies of water that are otherwise too big for free sailing... Like Puget Sound! So, KC and I went over to the beach and did some sailing on the deep briny, as it were. It worked pretty well, though I learned some things. Don't go at extreme low tide... the line picks up seaweed. Go prepared to wade to get a decent launch (my shoes are still drying.) I fastened a spinning reel to a short rod... wrong. Use a spool type reel like an old bait casting reel. It will keep the line from tangling much better than a spinning reel does. Finally, you don't want a short pole, you want a long one that will let you keep the line up as much as you can and that also doubles as a handy boat pusher and catcher at the shoreline. Still, even with these handicaps, KC got two good long runs in about 50 yards off the beach and showed she is capable of handling some wave action. Great fun!



August 15-14

As you see, a few days have passed. Mostly this time was used to obtain and set up a Grizlly roll around dust collector. The extremely fine sanding dust from balsa and basswood is really brutal. I used to have a big double seperator collector before I downsized the shop. I didn't want to go there again because of space considerations so I thought a wall mount unit would be good. Unfortunately, that turned out to be more of a problem than a small floor roll around. The same model machine came as floor or wall mount, so, since I had gotten the wall version, I had to build my own floor roll around base, which was kind of fun and worked out well.

This morning I rigged up the dust collector and the belt sander and attacked the hull to achieve the shape I wanted, basically a cross between a catboat proportioned sharpie and a moderate dory. I sanded the hull to true and then sanded in a 10 degree slant on the sides and stern.



Propped up on scrap block.







August29, 2014

It's been a busy two weeks. Unfortunately, not much of it involved with building Catnip. Life erupted around us in several time consuming ways, including the brutal murder of our van, which resulted in a time consuming effort to first resurrect it (not successful) and then replace it. Buying a car is one of life's significant experiences... right up there with annual physicals. Really not conducive to a boat building mood.

Anyway, one key Catnip development was discovering that I had very nearly ruined my effort. When I cut the hull out, I cut it vertically. Later, as shown above, I decided to give it a nice belt sanded 10 degree slant. The end result is, to me, quite attractive and should improve seaworthiness. However, in handling the hull, I discovered that I had so closely come to going too far in at the bottom that when held up to bright sunlight, I could see light through the thin wood at the juncture of the bottom and the side in one spot. Ouch! That problem sat on the bench for quite awhile while I dealt with other stuff, but I finally got back to the boat. I cut some nice flexible strips of bamboo from old bow stock and glued and clamped them on the inside of the bottom along the thinnest area of the sides. This will be visible in one of the pix below. I also learned that if I replicate this boat, I'll cut the slant in on both the inside and outside with the bandsaw right at the start.

I had been giving some thought to just how I wanted to handle the keel and rudder. Traditionally, catboats are mostly centerboarders with very long shallow rudders. Building a model centerboard is not too difficult, but subsequently repairing it would be a nightmare. A long stern hung rudder would be a delicate piece looking to be damaged in normal handling. For these reasons, I decided on a keel and below hull rudder. I wanted the keel to be removable so that modifications to it, if they proved necessary, would be easier. Since making that decision, I have gained some experience with an RC Laser that is the epitome of quick set up and disassembly and travels in a neat carry case. ( See " Laser Yacht "Popeye" ) After experiencing the convenience of the Laser's set up, I will make a few more adaptations in Catnip to provide the same here.

Today I got in a really good morning's work:

Laid out the deck and marked the deck attachment brad positions as well as cutting out the waterproof hatch opening. Here again, stealing an idea from the Laser, I constructed my hatch by buying a 2.5 qt. plastic paint bucket with pop off lid, cutting it at the shoulder and then cutting a matching hole in the deck. The bucket top will be silicone sealed to the deck and the pop off lid will provide a simple water proof closure. The bucket is quite large at 6", but with an 11" beam, Catnip can handle that and it will provide very easy access to add or service RC gear.

The deck work was followed up by keel and rudder work, moving the project right along. Here are the pix:


Deck supports installed. Look closely at the far inside bottom edge and you can see the bamboo strip I glued along the side to reinforce where I sanded too far in. Same treatment was done to the other side. The sides thicken up considerably fore and aft, so this fix should be good.


Here the deck, still slightly oversized, is sitting on the hull with the hatch inserted in its hole, though not level or sealed at this point.



Good shot of the hatch base inserted in the hole, which was scroll saw cut in just slightly undersize and then sanded to a smooth fit.


Here's the keel. I debated on how thick it should be. Obviously, thinner means less resistance. However, the easiest way to get a readily removable keel was to use an aluminum channel. These are available in 1/4" and 1/2", specifically made to match plywood in those thicknesses. I decided that 1/4" looked a little wimpy on this stout workboat, so went with 1/2". The channel is screwed to the bottom, the screws going through and into the 3/4" bottom/keel support inside. (See pic through the hatch, above.) The keel itself will be retained in the channel by two pins. The weights are 9 oz. M-24 boat zincs. The keel is cut from 1/2" pine, rather than the basswood I made everything else out of. I felt that that the pine would be just a bit more able to stand up to the knocks that a keel takes. I may make a new keel shape. I'm not real happy about the notched effect where the keel joins the rudder. I think I will deepen the rudder and make it fair into the keel more smoothly.


All in all, a real good day's accomplishment. I think I can now see this boat going into the water within two weeks.




Sept. 2, 2014

The project has moved into its second month. A disappointment, but it couldn't be helped. Over the past couple of days I did manage to get a coat of sealing paint on the inside and today I got the deck glued down and the edges sanded in. The deck was left slightly oversize till this point. Here's where things are now:


Deck clamped. Note the 3/4" pieces of wood directly under the clamps. These are loose pieces, with a sheet of wax paper under them, that serve as pressure spreaders so that you don't end up with a wavy glue line.


I'm throwing this picture of the finished clamping step set aside to dry in so that I can make a shop point. Note the two shiny new 1/2" wrenches. Whenever I come up with a good way of doing things that benefits from a special tool, I make it a point to buy that tool, even if I have one, and keep it with the related items, in this case, the clamps. I also buy a backup, so that when the one I'm using crawls out of sight on the workbench I don't have to delay the work while I try to find it or go buy another so that the first one will come out of hiding. (I am assuming that you realize that there is no such thing as an inanimate tool, and most have attitude.)



Deck glued on and edges sanded in. Note the interior painted white. This included the underside of the deck, the idea being to seal so it's protected from moisture.



Here you see the evolution of the keel. The top one was first and I was thinking in terms of a separate keel and rudder so that the rudder could be further aft, increasing its power. However, I've learned that the waters I sail in are rife with floating seaweed, which would hang up on the rudder. I came up with version two to deal with that problem, but didn't really like the line from the rudder into the keel and the reduced rudder surface that resulted. That led to version three, which is not quite a graceful as the second one but provides a bit more keel area and a bit more rudder surface, which will help given the wide beam of this boat.

Note the piece of 1/2" aluminum channel above keel 1. It is wide enough to have two good sized screws inside the channel fastening it to the keel plank inside the boat. You can see on the top of keels 2 and 3 the two half moon cuts made so that the keel can sit flat on the bottom of the channel, the cuts being where the keel channel screws are. The keel willl be held into the channel by two through pins so that it can be easily removed.



Sept. 3, 2014

Some more good progess today. Rudder post hole is now all the way through and the mast step receiving hole is bored. Keel now has its edges rounded and sanded and the first coat of paint is on the deck. I'm down to single items like this now, and the painting is going to take several days as I wait for each coat to dry. Here's pix:


Keel is now sanded to round edges. Not razor sharp as they are on the deep keel racing models, but about right for cruising yachts. You can see the keel pins at the top, in the aluminum channel. These will permit easy removal of the keel.




Here's a better shot of the keel pins. They fit quite snugly and being put in from opposit directions are unlikely to vibrate out.



Here's the deck with both rudder post hole and mast step receiving hole showing. The mast step hole is 1 3/4" deep and receives a 5/8" (20/32") brass tube.



Here's the tube in the hole. It will be cut off about 1/2" above the deck and in turn receives the foot of the mast, which will be fitted into a 19/32" tube.




Sept. 6, 2014

Still making slow but steady progress. The painting is being done in steps, by piece and color. Deck and bottom are white, sides and keel are red and the weight bulbs on the keel are white. Can't really do anything that involves wood working or making sawdust, like doing the spars, until all the painting is over. Here's how that's shaping up:



It's going to be a sharp looking boat under sail! Don't miss the white weight bulbs at the right. The sail will also be red.


Sept. 8, 2014

Painting progess is slow, but it is happening. Here you see the hull basically assembled. To be honest, the rudder was temporarily sstuck in for the photo. It needs at least one, maybe two more coats. However, by Wednesday, I should be doing spars and rigging.


Pardon my conceit, but this is going to be one spiffy looking boat. I think it will certainly get noticed!



Sept. 10, 2014

Nise stuff today. I cut a slice off a nice piece of 3/4" select pine for a mast, trimmed it to just over 5/8" for the brass mast step tube and cut it to 28 1/2" above the deck. If you refer to the table of average measurements for a catboat way back at the beginning you'll see that this is roughly 110% of boat length and toward the bottom of the mast height range. I sanded this to round and fitted the step into the 10/32 tube that mates with the 5/8" tube installed in the boat. Came out a nice looking mast. Because of not having stays, catboat masts tend to be thick and somewhat stubby looking.

Next step (because I just couldn't resist it) was to cobble up a sail plan on paper. In keeping with the whole approach to this boat, i.e. not a kit and no specific drawn plan, I designed the sail by the simple technique of laying out the spars, drawing a pattern within them, then adding the required luffs. A gaff sail requires luffs at the leech, the foot and also the gaff. After drawing these in, I cut the paper sail and scotch taped the rig together on the boat to get an idea of what it will look like.


Here you kind of see both the fascination and the scariness of the catboat... all that sail area in one piece! If you get the light on the screen just right, you can see the two reef lines I've drawn in. I'm debating reef lines versus actually installing roller reefing. The reef lines would be sexier but the roller would be a lot more practical.



Here it is on the boat. when I cut the cloth, I may modify this a bit. I think I want the finished sail just a bit smaller to fit on the spars, so I'll draw it at least 1/4" smaller all around, then add on for the seams. I may also modify the gaff to have a higher peak.


Tomorrow I plan to make a quadrant and install the rudder.



Sept. 12, 2014

Two pretty good days work. I probably made more of it than I should have, but I'm happy with the results. Yesterday was devoted to improving my knowledge of threading and the equipment for doing so. I wasn't happy with the results I was getting with my very old and very cheap tap and die set, so I went off to Tacoma Screw and got some advice and purchased a new handle and several appropriate dies for threading the brass shafts I use on boats: 10-24, 12-24 and 10-32. What a difference new high quality dies made. I also cut out my quadrant, again using the scroll saw. I tried for a heavier guage brass though and pushed the saw harder than it liked. My cutting was pretty rough and irregular and I ended up doing a good bit of filing to get a decent form. I also made the quadrant 10% larger than the last one as the rudder is larger.

Today I threaded a whole new shaft, installed the rudder tube, shaft and quadrant as well as the brace pins for the rubber band and a heavier duty traveler than I used on Clam. All of the through deck items were also epoxied in, including pulling the mast step and reinstalling it with glue. This was for sealing as much as for strength. I got the first coat of varnish on the spars and also made up the center cover artwork.


Here's the quadrant. I went an extra step this time and instead of just ending the ends, soldered in brass pins.


Here you see the quadrant installed, with a rubber band stretched between two brass posts, one right at the edge of the "deckhouse" and the other at the stern. You can see the brass pins riding between the strands of the rubber band. At the stern you can see the traveler.


This shot shows how I dealt with the paint bucket lid that went on the deck insert. I cut a piece of white plastic to cover the printing on the lid, then did my own artwork, copying a cat outline from an icebox magnet and doin my own lettering, which is actually better than I usuall do. You also get a good view of the quadrant with its pins in the rubber band.


Tonight and tomorrow morning I should be able to get more varnish on the spars, clean up the unbelieveable mess and be prepared to start on the sail.




Sept. 13,2014

Good full day's work today. I got all of the spars fitted out. Man, there are a lot of fittings required for a gaff rig! Got a nice gooseneck made. And.... got the sail sewn! I think it came out pretty well. I carried the boat out into the yard where there was some wind and the sail seemed to fill quite smoothly. I still need to do the running rigging and fit an effective boom vang. That big sail and boom need it. Actually, the sail came out smaller than it might have. I decided to go ahead and use the paper pattern I had made. I found I had plenty of the red material so I figured it wouldn't be a bad idea to start out with a slightly smaller sail. If it proves fully adequate, fine. If not, I get to make another sail, which is fun. Tomorrow should see a finished boat and I have scheduled sea trials at the pond on Monday.


Here she is, just about six weeks from start. When I finish the rigging tomorrow, I'll take some closeups of some of the brass work I did. I did several things I hadn't done before.


This wasn't a planned photo. After I pulled the table into the shop to close up, I turned around and caught the light behind the sail, and, of course, couldn't resist "Red Sail in the Sunset".




Sept. 15, 2014

It is done! Yesterday and today were very productve with respect to rigging and metal work. In a couple of hours I will have it over at the pond for a first sail and on the water photos. Meantime...


Gooseneck and Murphy pin. With the addition of the tube inside of the eyes, the

Igooseneck is rigid enough to serve as an adequate vang. I achieved a superbly smooth mast step slide fit so the mast is removable. However, Murphy says that inevitably, a need to lift the boat out of the water by the mast tip will arise, thus, a pin in the sleeves so that when that occurs, the boat comes along with the mast.


I added slide to the traveler.


this shows the gaff slide and the sail hoops, all soldered brass rings.


Here is the sail drawing. I'm not quite happy with the leading edge, but it does seem to draw soothly. We'll see how it actually performs. That is the key question. Remember, this hull is something I dreamed up. It is not from a published plan.







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