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7/09/2006

GRP, Vacuum bagging, Fiberglass, Carbon Fiber , Dynel

Stuff you need to know:

Breather fabric is a lightweight, polyester blanket that provides excellent air passage within the vacuum envelope while it absorbs excess epoxy.
60" wide x 2.7 yd, 60" wide x 10 yd. 60" wide x 200 yd rolls:

Release Fabric is a tough, finely woven nylon fabric treated with a release agent. It is used to separate the absorber, breather and vacuum bag from the laminate in vacuum bagging operations. Excess epoxy bleeds through and is peeled from the cured laminate along with the release fabric. Peels easily and leaves a smooth textured surface, ready for bonding or finishing. 60" wide x 2 yd,. 60" wide x 10 yd rolls

Vacuum Bag Film is a Clear, heat-stabilized, modified nylon resin film, tough, stretchable film for high vacuum pressures. 60" wide x 2 yd, 60" wide x 10 yd,60" wide x 20 yd. 60" wide x 333 yd rolls:

Vacuum Bag Sealant; a mastic tape sealant for airtight seals between vacuum bags and molds. Easy to work with around difficult angles, patching small leaks in the system. 1/2" wide x 25' rolls:

Techniques Book on Vacuum Bagging, West System publishes this definitive guide to the principles and application of vacuum bagging techniques for laminating composite materials
with epoxy.

Fiberglass Mat is a Chopped Strand Fiberglass Mat, Offers great conformability with low cost.

Veil Mat 0.09 oz/sq ft

Fiberglass Mat, 3/4 oz/sq ft, 1.5 oz/sq ft, 2.0 oz/sq ft

Fiberglass Cloth 4-, 6- and 10-oz per square yard.

Dynel Fabric is a popular laminate fabric with great abrasion resistance used for museum-quality restoration work on wooden boats. It's strong and supple like a true woven fabric, with no fibers to irritate your skin.
Size Weight, 5 oz

Carbon Fiber lightweight, strong composite can strengthen any project while adding minimal weight.
Plain Weave 5.8 oz
Twill Weave 5.8 oz
Unidirectional 9 oz

Carbon Fiber Tape a unidirectional reinforcing tapes are used
to improve tensile strength and stiffness in one direction with minimal weight.

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You can learn a lot about boat building by reading catalogs for example: www.jamestowndistributors.com/
Many of the same materials are also used in model boat building.

The Jamestown site has several links to model builders, AMYA and other organizations

7/06/2006

Star 45 R/C model sail boat Hulls, tips tricks | Class rules

Billie Geisler's comments on building Cedar Hulls,2006 August 1:

I build hulls from cedar rather than balsa. I find a clear, straight grained dog-eared fince picket at Lowes, Home Depot, etc. I cut the rough edges and flats off with a 10 inch table saw, rough cut the planks for the hull, then use a 3 inch table saw from Micro- mark to cut the final planks. I think that cedar is stronger than balse, and I don't think it soaks up as much epoxy. Epoxy is weight. My hulls weigh about the same as a fiberglass hull, and don't oil can.


The plastic sacks that the newspaper is in when it hits your drive is useful as gloves. The epoxy doesn't disolve them. Also, you can cut up the newspaper plastic sack and use to keep the hull from sticking to your clamps. These sacks are also good for picking up dog crap off your lawn, or any other nasty stuff. Just check for holes before using. :-)




AMYA Star 45 Class Rules, 2006, 1.0 Hull:

1.1 The Star 45 Class establishes as their approved plans a set of lines and drawings as the approved reference and construction plans for the class. These plans are scaled and appropriately modified for the use of modelers building a 45-inch model of the Star Boat. Existing plans supplied by kit manufacturers, etc. are grandfathered. New molds, plugs and scratch built models shall conform to the approved plans and specifications.

1.2 Hull length will be 45 inches (plus or minus one half (1/2) inch overall. (NOTE: this does not include any chain plate for backstay attachment, or 1/4 inch bow bumper if used. However, if the chain plate is attached to the transom or overhangs the transom, it may not extend beyond the transom more than 3/8 of a inch.) Hulls may not be less than 11 inches nor exceed 12 inches in beam when measured at the widest point on the deck. (Rubrails are not included in measuring but will not exceed 1/4 inch of thickness/width.)

1.3 In the event of a builder choosing to scratch or hand build a Star 45 Yacht, the builder must adhere to the class approved reference and construction drawings, as obtained from the AMYA Ships Store, as in the builders ability. A second consideration in scratch building is to ensure that safe and sound building practice be maintained.

1.4 All hulls will be constructed of wood or fiberglass or a combination of wood and fiberglass and be a minimum of 16 ounces when weighed before attachment of the deck and keel. This weight must be
verified by another member of the Star 45 Class using the Class Measurement Form.

1.5 Decks shall be constructed of wood, fiberglass or plastic laminate material.

1.6 All hulls shall be the standard hard-chine hull. Hulls may be built with a sheer at scale height or with a sheer no more than one inch higher than scale (when measured at the point of maximum depth of sheer.)

1.7 All fiberglass and wood hulls will have a name plate permanently attached to the inside of the hull so as to be seen when the hatch cover is removed.

1.8 At or before its first Sanctioned Regatta the newly built model yacht must be measured using, as reference, the approved measurement form and signed by not less than the owner of the model yacht and one other member of the class. This measurement form shall become, with the registration card, a permanent record of this model yacht.

1.9 The AMYA Star 45 Class recognizes and approves the molds and manufacturer and/or kit packagers of Star 45 molded hulls and kits in existence at the time of approval of these specifications. These sources will be approved sources for the class. New manufacturers will be directed to submit the first of their product to the Class Secretary for approval.

1.10 No maximum weight is specified, however, no yacht will weigh less than 12 pounds when fully rigged ready to sail. This means with all gear, rigging, sails, radio components, batteries and ballast placed and secured on board.

1.11 Bow Bumpers are mandatory for all class registered STAR 45 yachts. Bow bumpers are limited to three eight's of an inch (3/8") overhang. Bow bumpers shall be excluded in the overall length measurement, whether recessed in or otherwise attached to the bow stem. Bow bumpers must be of resilient fabrication to minimize damage to another yacht in the event of a collision.

Star 45 R/C model sail boat | DECK

Phil Geren on Staining Wood Deck Materials:
I was planning to stain planks prior to assembly, then use CA first, to get things fitted together and in place, then cover with 0.25 oz. fiberglass cloth and "thinned" (MEK or IPA) epoxy. Flex Coat epoxy people (fishing rod mfgrs) recommend heating the epoxy surface with a heat gun (hot air) prior to it's hardening, to release bubbles and smooth the surface, like what you see on fine fishing rods.

AMYA Star 45 Class Rules, 2006, DECK

8.1 Deck construction shall be limited to wood, plywood, fiberglass reinforced plastic or plastic
laminations (Formica). It may be covered with any material. Thin plastic films, such as MonoKote,
are not allowed for decks except as coverings.

8.2 Hatches are not restricted in size, location, number or style, as long as deck strength and
integrity are maintained.

Star 45 R/C model sail boat | Sails

AMYA Star 45 Class Rules, 2006, Sails

2.1 Sails may be of single or multi-paneled construction. Sail material shall be unrestricted.

2.2 All sails are to be cut to comply with the following maximum dimensions when measured by the procedure as outlined in the "AMYA Regulations". Dimensions shown are measured 'Edge of Cloth" to "Edge of Cloth" and are in inches.

2.3
MAIN JIB
Luff 62.75 42.50
Foot 25.50 15.75
Leech 65.50 37.00
Roach 2.00 0.50
Head 0.75 0.75
Foot Round 0.50 0.50

2.4 All sails, main and jib, will be cut with either a straight head to clew leech with no roach, or a fair
curved head to clew leech with the maximum roach point occurring approximately one half the distance from the clew to head. Divide a straight line from the aft corners of the Clew and Head into four (4) equal sections. Then, for the Main Sail, maximum offset from edge of cloth for the Roach at the quarter points to be 1.75" and the offset at the mid-point to be 2.0". For the Jib, the offset at the quarter points to be 0.375" and at the mid-point to be 0.50". Sails cut with a straight leech at the maximum roach allowance are prohibited from use on the Star 45 Class Yacht.

2.5 The mainsail gooseneck or attachment will be attached to the Mast between 0.50 inch minimum to 4.0 inch maximum measured from the deck.

2.6 Battens are allowed on the mainsail but are restricted to 4 in number, equally spaced along the leech and may not exceed 8.50 inches in length. Battens are not permitted in the jib sail.

2.7 Sailmakers must conform to the above measurements.

9.1 Each yacht shall carry on her main sail the class 5 point "STAR EMBLEM" and an assigned AMYA registration number. The star shall be at least 2 inches in size (measured from point to point across the flat of the star) and positioned above the registration number. Registration numbers shall be at least 3 inches in height and at least 3/8 inch thick. Both star and registration numbers will be placed on the upper half of the mainsail on both port and starboard sides of the mainsail and shall be positioned so as to be easily read from either side.

Star 45 R/C model sail boat | Mast and Boom

AMYA Star 45 Class Rules, 2006, Mast and Boom

3.1 Masts shall be made of wood or aluminum. Swing rigs, rotating and permanently bent masts are prohibited.

3.2 Masts shall not exceed 3/4 inches square when measured at the thickest point of the mast. Maximum mast height shall be 70" when measured from the deck, inclusive of the crane. Rotating wind indicators and burgee staffs are not included provided the backstay is not attached to them in order to circumvent the 70" maximum mast height specification.

4.0 BOOMS:

4.1 The main boom and jib club shall not exceed 5/8" when measured at the thickest point. Booms and jib clubs shall be constructed of wood, aluminum and/or fiberglass.

Star 45 R/C model sail boat | Rudder

AMYA Star 45 Class Rules, 2006, Rudder

6.1 Rudders may be constructed of wood, fiberglass, plastic, plastic laminates or metal. The exact shape is not specified, but they may not exceed 4 1/2 inches at the hull (fore and aft) 3 inches at the bottom, (fore and aft); and may not project more than 7 inches below the hull when measured at the post..

Star 45 R/C model sail boat | Keels and keel-ballast bulbs

AMYA Star 45 Class Rules, 2006, KEELS AND BALLAST BULBS


7.1 Keel will be of the style known as drop, and will be of the FIN and BULB type.

7.2 Keel fins may be solid or hollow and constructed of reinforced plastic, plastic laminates, fiberglass, wood or metal. (Note: Strength and integrity of the keel fins must be maintained whether built solid or hollow.) Keel fin shape is not specified but must follow the general shapes outlined on the reference drawing. However, keels will not be less than 6 inches nor more than 8 inches long (Fore and Aft) at the keel/hull junction, nor less than 4 inches nor more than 6 inches long (Fore and Aft) at the keel/ballast bulb junction.

7.3 Keels, keel fins and ballast bulbs may be removable, however, they may not be changed, interchanged, substituted or otherwise manipulated once any heat or series of heats in which scores will be compiled, has started. Mechanically movable keels or ballast bulbs are specifically prohibited from use in Star 45 Class Yachts.

7.4 Ballast bulbs may be constructed of any material not prohibited by the AMYA. The actual shape is left to the builder's discretion, but will not exceed 9.75 (9 3/4) inches from the front of the keel bulb to the rearmost point of the keel or bulb.

7.5 Total drop (length) of the keel fin/ballast bulb combination will not exceed 11.5 (11 1/2) inches when measured from the keel/hull junction, before any fillers or streamlining is added.

7.6 Ballast may be made from any readily available material, such as poured lead, lead shot, etc. (Note: When using material such as lead shot, the mass must be solidified through the use of a bonding agent such as fiberglass or epoxy resin, plaster of paris, poured over and through in order to create a solid mass.)

7.7 Race directors may elect to use a template based on the construction plans to determine the keel length (depth).

7.8 Keel depth shall be measured from the center of the keel fin at the hull to the bottom of the ballast bulb. This measurement is from the edge of the bottom of the hull as it meets the side of the keel and should be determined during construction and before any fillet or fairing is added.

7.9 The Star 45 Class specifically excludes radio equipment, sail controls and batteries (power cells) from being considered ballast. This specification defines ballast as anything carried aboard the model for the main purpose of changing the weight distribution of the model and/or weight of the model. Ballast shall be fixed in place by gluing, fiberglassing, or bolting (bolts and screws).

7.9.1 Ballast may not be removed or relocated during any one regatta. The use of Velcro or similar quick release fasteners is prohibited as methods of mounting ballast.