S45 Construction Keel: trunk , alignment, support

Here is how John Fisher built two Star45 keel trunks. First he make a aluminum mandrel that is the same size and shape of the top of his keels. Next he waxed the aluminum and then put a single layer of wax paper over the mandrel.

He used a light spray of 3M 77 to stick the ends together on the second one. The first one had a pc of tape, which is now a part of the trunk.

The mandrel with waxed paper is wrapped with glass which he again used 3M 77 to hold in place. He has not verified that this doesnt have any long term effects to the glass so use at your own risk. John used 2 layers 3.2 oz glass with glass tape on the top and bottom edges to help add some stregth. Usually he would add kevlar, but that is not allowed in the star's. One the glass was in place John wet the whole thing with resin. If you dont have any way to vac bag the trunk, just let it cure and remove the mandrel. The trunk weighted in at 1 oz.

John has a food vacuum sealer so he put a release paper over the top (wax paper with holes in it), then breather cloth (he hasused paper towels in the past), and then into a food saver bag for the night.

To remove the mandrel he used a hammer and a vice. He knows that sounds severe, but that is what it took to get the mandrel back out. He started by placing the mandrel into a vice with smooth jaws. The jaws were just far enough apart that the aluminum would fit between them, but not the fiber glass wrap. Then he tapped the mandrel out. He points out how much force it took for him to get this apart so you can design your keel top with this in mind.

Photo 01- mandrel before prep
Photo 03 -mandrel with glass, ready for resin
Photo 04-keel trunk in food saver bag. You can see the resin going into the breather cloth.
Photo 05 - keel trunk off the mandrel, note the tape. 2nd trunk used3M 77 instead.
Photo 06 - Trunk on the keel.





The following picture shows the way that John aligned the keel on his second boat.
Since the keel is plate and 1/8" thick I laid a straight edge on it and
aligned it with the pc at the center of the transom. I did this on both
sides to make sure it is centered as well.

To capture the top of the keel box he added 2 1/8" X 3/8" spruce blocks
to the top of the keel trunk and glued them to the king plank. The photo also shows the glass tape He used to reinforce the
radio tray.

John Fisher photographer

===

here is an alternative keel trunk (from Uncle Dave)

I poked my camera down into the Sirius 45 and snapped a couple of pictures showing how the keel is attached to allow it to be removed and another installed.

The keel is a aluminum fin with my flat bottomed bulb. The keel trunk is assembled over the keel fin before mounting the trunk in the hull. The trunk is pretty simple. Two pieces of 1/8 ply on either side of the fin. Cut flush across the top of the fin. Height is determined by the amount of the fin to extend into the hull. Length is determined by the shadows or braces to support the fin. A filler pieced goes between the sides so that fin can be slid own and out of the trunk.

Before gluing the trunk up it is very important to coat the insides of the trunk to make the sides of the trunk as water resistant as you can. The the fun part is placing two mounting bolts through the sides of the trunk and thought the keel fin. I think the two bolts in the picture were 1/2 long 3/8 inch dia.



I placed a heavy wire through the both the bolt heads so I could turn the nuts on the other side.



With the nuts removed the two bolts simply push to one side and the keel fin mounted or removed as the case may be. In my models the height of the fin inside the model is low enough for a swing arm sail control to fit properly. I use Probar (now Dumas) SCU's.

Before building the deck I simply dropped the trunk (with keel fin) through the slot in the bottom of the hull so the trunk rests on the keelson. The hull being fiberglass the trunk if filleted with the bottom using some auto body resin-paste. I think I also used the resin paste to mount the keel trunk in my wooden models (memory escapes me its been years). The ends of the trunk are braced to the chine to with stand leverage forces from the heavy keel bulb and sailing stresses.



When the two bolts are tightened they not only hold the keel in place they also pull the sides of the of the trunk tightly together. With the tight fit one should expect the keel fin may stick in the trunk if some sort of lubricant (silicone) isn't used.

Construction Star 45, building rudder and installation

Here are some photo's showing one way to build a rudder quickly and easily. The quick overview is cut out the shape in a thin material, tape the sides together, insert the rudder shaft, fill the inside of the rudder with epoxy. This takes about 10 min or so to do. Followed by installation in your boat.

John Fisher

Lay out the rudder shape on a sheet of 1/64 ply. On other class boats John used a single layer of a 6 oz carbon fiber layup, so you could also lay up some fiberglass for use on the star. To do a glass layup, just take a sheet of 6 oz or heavier fiberglass, a sheet of lexan or plexiglass, and some resin. The first step is to spread resin on the plexiglass, then apply the fiberglass and then make sure it is all wetted out. Once cure flex the plexiglass and the layup will pop off.

Shows the two sides cut out of plywood, these could be fiberglass instead. Straight sided shapes like shown and the star plans are easier to make.

Tape the two sides together with masking tape. With curved shapes He taped them together then insert the shaft and resin. If you use straight sides on the rudder you can tape one side and then open it up like a book, apply resin, then close and tape shut. The open book method uses less resin but only works with sq or straight sided shapes.

Note the bend John put in the shaft to prevent it from turning inside the rudder.

Shows the top open to pour in resin. John uses a syringe to pour in resin once the shaft is in place. You can add micro balloons to the resin if concerned about weight.



Installing Rudder in Star 45

John Fisher photographer

S45 Construction Deck(s), Hatches

from John Fisher:
Attaching deck to hull

John Fisher photographer

Hull with deck mounted:

John Fisher photographer

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HATCHES:

From Phil Geren:
The simplest hatch cover solution I have found for Star 45 is to cut a piece out of Presentation Cover vinyl, which cut-out is shaped like the hatch opening but 1/4 or 3/8 of an inch larger on all sides. Then, apply electrician's tape (1/2 or 3/4" wide) all around the perifery, so that half the tape is on the vinyl and half is hanging over the edge.

Presentation Cover vinyl which I get at Office Depot is about 15 cents a sheet; it is about 0.008" thick; it is slightly over 8.5X11" in size; a full sheet weighs about 16 grams; it is stiff, but flexible; it is crystal clear, but if you want it opaque, just wet sand it with #400 grit wet or dry sandpaper.

Position the hatch cover over the hatch so that the tape extends evenly past the hatch opening an equal distance all around, and then just press on the tape to stick it to the deck. It's waterproof, durable.

You can make spares and stick them to another piece of vinyl and carry that with you to the races. That keeps spares nice and flat and keeps the tape's sticky side clean for future use. A set of these hatch covers usually lasts me all season. At lunch, I take one cover off to allow the boat to dry out, sticking the cover to a dry vinyl sheet to keep the tape's sticky side clean.

Photo is Star 45 #778, freshly rebuilt for the Nationals this year, and a set of covers on the floor next to her.

Phil Geren photographer

--
from Uncle Dave:
I pulled one of my old Star45's from the attic and have it here in my workshop. It has a fiberglass Sirius 45 hull, a aircraft ply deck and aluminum keel fin. Unfortunately it is not one of my finest examples of workmanship or painting. However I'll suffer the embarrassment and use if to show some one style of hatch construction.

Carrying around a model around out of the water is no big deal. Taking a model out of the water can be something else. You first need to hang onto the model. Then find a place to take hold to lift the model. This is one of the reasons I have used easily removable hatches. You can grab the model through the hatch, fingers under the deck and pick it up. Of course a thin ply deck the model deck and hatch construction needs to be strong enough to withstand pulling on the deck and lifting a twelve pound plus model. Therefore I braced my decks around hatch areas.

First I built a flanged frame for the hatch to sit in that also extended under the deck and attached to the deck bracing.


Then I built a hatch cover based on the size of the hatch. Initially the hatch cover was made to fit very loosely in the hatch. I then took some silicone (tub seal or similar) squeezed a bead around the shelf/lip of the hatch. The covering the hatch opening with food wrap poly sheeting I'd push the hatch cover in place down into the silicone. This made a nice water tight gasket around the edge of the hatch. After waiting a day I'd remove the plastic, trim and silicone that showed topside. With the silicone dry, pop the hatch cover in place and check the fit.



I placed a strip of magnetic tape on either end of the cover and on each end of the hatch frame.



When the hatch cover and hatch mag tapes touched they pulled together. This magnetic tape is neat stuff you can pop the cover in place and it will stay put.

Typically I made my hatches about 4"X5" giving me plenty of deck to the sheer.


I heavy weather if the model might go over on beams end I'd cover the seams with tape just to be extra watertight. A 4X5 hatch gives room to get inside, adjust winch, radio etc, and to remove any water that got into the bilge while sailing.

S45 Construction planking the bottom

Photograph by John Fisher

Photograph by John Fisher

Since it was requested here are a couple of photo's of planking the
bottom of my two wood/glass stars. photo 01 is the bottom of the first
star about half way done. Planks are 1/16 X 3/8 balsa. These were cut
from a 48" long sheet. Weigh your balsa before buying it. I would not
use a 3 X 48 sheet that weighed in at more than 22g. It takes 3 sheets
to cover the bottom and you could add another 1 to 1.5 oz by using
heavy balsa.
I started in the middle and worked to the outside. I sprayed the
shadows with kicker, then put down a plank, then added super fast CA to
hold it down. If the kicker was not dry enough it would cure before it
wicked into the joint which would cause the next plank to not fit
correctly. I had some variation in the planks, but once they were
glassed the bottom smoothed out quite a bit.
If I were to do another one I would add the half frames. I will be
adding them to the DXF files in the next couple of days for anyone
wishing to cut a set.
Picture shows the bottom after it was completely planked. On the
second boat I got a nice pattern on the bottom since the balsa sheets
had different grain structure. I sanded the sided flush and got the
bottom relatively smooth, but not perfect. With the balsa planks they
were flexible and if sanded too much you get thin spots at the frames.
The glass smoothed out inperfections. If doing a hard wood bottom the
planks should fit better than what I did with the balsa.

====

From: "John Fisher"
Subject: Photo's of star 45 double diagonal planked

Here are some photo's of Sherwood Jones Star 45 with double diagonal bottom planking. He used two layers of 1/16 planking. The planks are 1" wide. He then covered it with 1 ½oz glass. Weight is about the same as mine with the 1/16 longitudinal planks and two layers of 3.2 oz glass. Just goes to show that there are multiple ways to solve a problem.

S45 Construction -- Sirius 45 drawings, set 2

Here is a second group of Sirius 45 drawings from June of 1981. They are early drawings for the Star 45 class fiberglass hulls I produced in the 80's. Those hulls were sold under the name "Sirius 45". Since then the Class drawings have gone through three major revisions. There are current official drawings are avaible from the AMYA store. These old drawings should still meet the keel and standing rigging specifications since they do not offer hull offset dimensions. IMHO they can be used with wooden models built using laser shadows which meet the class specifications. The Sirus 45 keel is the Mainwaring Keel found on the current Class drawings.

These copied drawings can be printed out and overlap to enable you to paste them together.

Star 45 Construction --Sirius 45 drawings, set 1

Here are a group of Sirius 45 drawings from June of 1981. They are early drawings for the Star 45 class fiberglass hulls I produced in the 80's. Those hulls were sold under the name "Sirius 45". Since then the Class drawings have gone through three major revisions. There are current official drawings are avaible from the AMYA store. These old drawings should still meet the keel and standing rigging specifications. They do not offer hulloffset dimensions. IMHO they can be used with wooden models built using laser shadows which meet the class specifications. The Sirus 45 keel is the Mainwaring Keel found on the current Class drawings.

These copied drawings can be printed out and overlap to enable you to paste them together.








Here is a keel on a Sirius 45 S45 model.

Star 45 Construction; JF Covering a wooden hull with fiberglass

From: "John Fisher" racer577 at citystar.com

I have used the 3.2 oz satin weave on 7 boats now. The first was a single layer and now that hull is 4 or 5 years olds it is showing wear and tear. I went to using 2 layers to help with durability and to have more material for sanding. Another thing I like about the cloth is that is drapes very nicely and easily will cover the hull with one pc. On my 10R's I have used 2 yards folded in half to do the hull. On the star I was concerned that it would be too wide for a single yard. I ended up with more than enough material so I cut it on the diagonal.

The glassing starts by laying the glass over the hull. Then I smooth it out so there are no wrinkles. This may take a couple of min. Then I repeat with the next layer. Once the glass is smooth, time for epoxy. I used the 209/105 west systems combination. I used about 10 pumps of material.

I start applying resin to the middle of the bottom with a cheap paint brush. Then I work my way out to the edges of the bottom. Next I do the sides. You need to use lots of resin and dont pull too much or you will pucker the cloth. Once everything is wetted out I go back with a squigee and remove the excess resin. Dont get to carried away or the cloth will go dry again. If in doubt of how this should look practice on a spare block of wood first to get a feel for how the cloth looks as you take out resin.

I did the glassing at about 8 pm and with the 105/209 the resin is still green at 7 am the next morning. When green the glass can be trimmed with a #11 blade in a hobby knife. Then wait another day or two until sanding for full cure. I dont like to do much sanding, instead I try and do most of my fairing by using a thick primer and sanding most of it off between coats. For a clear boat I use polyurethane for a top coat.

S45 Construction John Fisher's first hull off the board August 12, 2006

John Fisher writes: "Well, the first hull came off the board this morning and it was 17 oz with all the frames. So with 1/16 oz balsa planking and 2 layers of 3.2 oz satin weave glass I came out pretty close to the 16 oz. I would have liked to be slightly lighter, but this is pretty good. The second boat should be lighter since I used lighter balsa. If you are going to build a star in this manner take a scale to the store when you buy your balsa and weigh it. The bottom planking sheets I used varied from 14g to 32g for 1/16 X 3 X 48. I didnt use any of the 32 g sheets. The first boat sheets were about 22g each and the 2nd boat was 14 to 15 g per sheet and there are 3 sheets for the bottom. So that should be a 1/2 oz difference between hulls."

"I am sure that I could make the frames lighter. On my 10R's I used .150" wide frames and on the star I used the 3/8 wide per the plans. I am sure I can thin them down to 1/4" or .200 without loosing much strength and it should drop the weight by another oz or two."

John FIsher




I am planning on using thinned west epoxy to coat the inside. I will do it one the keel trunk and radio tray are installed. Radio tray will be a sheet of ply with holes for the servo's.

I will use a carbon rod for a push rod for the rudder.

Deck will be thin ply or fiberglass.

2006 Augst 13, BTW:
The planking was 3/8" wide strips of 1/16 balsa. {John} sprayed the frames with kicker, then put the planks on, then hit with a drop of 1 sec CA. Might not have to use the kicker in houston, but here in CO there is just no humidity to kick off the CA. {John} did not taper the planks and any gaps were filled by epoxy when the bottom was glassed. Took about 1 hour to plank each boat.

Star 45 Construction notes (1) Getting Started

"John Fisher" is building Star 45's. He has provided a series of photographs taken as he builds the model from scratch.
These are posted to the blog along with his notes to help builders assemble the Star 45.

In the following posts you will find comments, notes. and his photographs

Photo's showing the building board and the first couple of steps for putting the frames together.
Building board is 3" wide 3/4" MDF that is glued/screwed together.

The notched balsa template is glued to the building board using a straight edge
to make sure it stays straight.

The vertical part is installed once the stern section is assembled. These parts keep the shadows sq and vertical.

Photo showing adding of the stringers, rails and chine.
For the single chine version, there is only one pc of material for the chine instead of 2 as shown in the photo's.

Photo showing the 1/8X3/8 spruce for the chain plates. This needs to be installed before the rails go in.

Photo showing the two keel pcs going in these are 3/8 by 1/8. He used balsa, but could be done with spruce instead.

Photo showing adding the rails. Notice that the rails are made of two pcs. 1/4X1/8 for the first one and then 3/8X1/8 for the second. You need to start both at the transom. Start at the transom with the rails and stringers. Start one side and go forward to station 9 or 10, then do the same on the other side. Then go all the way to the front with one side. Starting both sides at the same time keep the transom from twisting.

Photo showing the bottom stringers. 1/8X1/8.

Photo showing all the rails and stringers installed, ready for planking.

Photo showing adding the side planking and sanding to get ready for bottom planking.
He used 1/16" balsa for my hulls since he will be covering it with glass.

It probably will work the same if you are using harder woods, but you will probably want to trace the outline onto the wood and cut close to shape before gluing it on.

Photo showing side plank after being glued on. John used thin ca and glued the 4" wide plank on.
Make sure it is located correctly before starting gluing.
Note the small patch on the bow of the back boat. John did not have the plank far enough forward.

Photo showing the planks after being trimmed close to the stringers.
John used a # 11 Exacto to trim the balsa planks.
Go slow and take multiple passes here. You don't want to remove too much material or you will get a gap when the bottom is planked. Also trim the rails close at this point.
The rails/side joint will be finished once the hull is taken off the board.

Photo showing the close stringer sanded to fit the side and the back stringer still need to be sanded.
John used a sanding block and sand the sides to match the bottom curve. Balsa sands really easy so this is pretty quick. He used 220 grit paper

Photo showing both hulls with sides matching the bottom curve and ready for planking.

Photo showing the bow sections after sanding and ready for bottom planking.

==

http://groups.yahoo.com/group/Star45/ for discussions with other Star 45 sailors.

S45 Construction bow details - sides planked-- ready for bottom

"John Fisher" is building Star 45's. He has provided a series of photographs taken as he builds the model from scratch.

S45 Construction Planking - transom detail -

Two hulls with sides matching the bottom curve and ready for planking.



View of Transom construction.

S45 Construction sanding stringers P05

"John Fisher" is building Star 45's. He has provided a series of photographs taken as he builds the model from scratch.

Photo shows the close stringer sanded to fit the side and the back stringer still need to be sanded. John used a sanding block and sand the sides to match the bottom curve. Balsa sands really easy so this is pretty quick. He used 220 grit paper.

S45 Construction trimming planks P02

Photo 2 shows the planks after being trimmed close to the stringes. John use a # 11 exacto to trim the balsa planks. Go slow and take multiple passes here. You dont want to remove too much material or you will get a gap when the bottom is planked. Also trim the rails close at this point. The rails/side joint will be finished once the hull is taken off the board.

S45 Construction installing side planking P03

Photo 3 shows a side plank after being glued on. John used thin ca and glued the 4" wide plank on. Make sure it is located correctly before starting gluing. Note the small patch on the bow of the back boat. He did not have the plank far enough forward.

S45 Construction rails and stringers installed

rails and stringers ready for planking.

S45 Construction adding bottom stringers P22

Photo 22 shows adding the bottom stringers. 1/8X1/8.

S45 Construction Keel pieces P-20

Photo 20 shows the two keel pieces going in these are 3/8 by 1/8. John used balsa, but could be done with spruce instead.

S45 Construction adding the rails p-21

Photo 21 shows adding the rails. Notice that the rails are made of two pcs. 1/4X1/8 for the first one and then 3/8X1/8 for the second. You need to start both at the transom. Start at the transom with the rails and stringers. Start one side and go forward to station 9 or 10, then do the same on the other side. Then go all the way to the front with one side. Starting both sides at the same time keep the transom from twisting.

S45 Construction 1/8X3/8 spruce for the chain plates P-17

John's photo showing the 1/8X3/8 spruce for the chain plates.
These need to be installed before the rails go in.