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5p June 1984 9 aving finished planking, it is a temp- tation to have a little sand at it to confirm that it will finish smooth, and there is nothing really against at least rubbing off the corners. Do this with glasspaper pinned on a hard block of wood and sand only across the planks, without a great deal of pressure. If you find an obstinate spot, where a harder piece of balsa has crept in, put your other hand inside the hull to support the planking from the other side. Don’t do much more than rough sand at this stage. One of the points to take note of, with this or any similar structure, is that the planking shell is firmly supported at each shadow position but will ‘give’ between shadows. It is possible to sand thin at every shadow line because of this, which is one reason why initial sanding (or rasping or whatever with harder planking) should be across the planks, i.e. round the hull rather than along it. Bow blocks The bow blocks should be added, first trimming any overhang of the planking at Bl, using a razor saw or sharp blade. It is worth marking a cutting line on the outside, using a narrow strip of card aligned with the bulkhead at centre and deck edge and running a pencil or ball point round. This will help prevent cutting too far back and thus leaving a gap to be filled; it isn’t vitalif a gap does have to be plugged, but it is more satisfying to produce a neat fit. It is also good practice at working accurately, which may be essential in other jobs. Sand to cut plank ends nicely flush to the bulkhead face. Either lin. or in. balsa can be used for the blocks, and it should be as soft as you ean find. About 12in. of lin. or slightly less than 24in. of ¥,in. will be needed, 3in. wide in either case. Start with the top lamination, which will enable lower joints to be seen easily (still working upside down, of course), and first trim the end of the block or sheet to fit exactly the angle between B1 and the ply stem. This should be 90° each side, but if it isn’t, crack the stempiece glue lines (refer back to where it said cement lightly in place!) and straighten it up. Trace the full outline of the bow on to the block and cut, leaving a reasonable clearance outside the traced line. Cut a second, making sure the aft edge fits, then cement both in place, holding with pins, and leave to dry. Note that the top surface of the block must at no point be lower than the deck line of the stempiece; it will later havea slight camber sanded into the top face to match B1. with a single light source, turning it to move the shadow line, is also helpful. Cover Choice Now comes achoice. Ultimately the inside of the hull is going to be tissue covered, by brushing thin varnish over, laying tissue (or nappy liner!) panels in place, and brushing When set, remove pins and fit the second more varnish through the tissue. When dry pair of blocks and again leave to dry before this stiffens the planking to a noticeable fitting the third, etc. The prototype used degree, and it will thus be helpful in sanding three lin. laminations and scrap to fill up the exterior. It means that the jig and the small remaining depth. Leave to dry shadows must now be removed, but it is thoroughly before trying to start shaping. worth tacking some temporary straight This is initially done with a sharp, long crossbeams in (only two or three) to prevent bladed knife, but don’t try to prise great the hull from springing inward at the lumps off, and don’t try to carve down to inwales. near finished shape. Just remove the The alternative is to finish the hull general surplus — with very soft balsa it exterior with more sanding — it needs to be does, It takes little effort to sand it down. an even surface rather than a super smooth however, make a lot of dust and is not one — and to defer removing the shadows recommended in the lounge. Wear an old until the outer hull reinforcement has been coat and sand it outside, where the dust can added. We followed the latter course, but the float away. former is probably just better on balance. How you carve/sand this block is a On the prototype the outside was sanded to measure of your eye and your skill as a finished shape (using light pressure only, modeller. It should blend smoothly into the and that discreetly) and the transom plank planking without having to sand the ends trimmed. It was then given a coat of planking down appreciably and should drop polyurethane varnish, which when dry was smoothly from the slightly blunted deck line again lightly sanded off. The hull shape was to quite a sharp V at the forefoot; you should then examined to make sure that there were sand away the corners of the ply stempiece no serious ’umps and ’oles. It was also to fair in with the V without reducing the extent of the ply profile. The deck-edge line should flow in a smooth curve, too. Nothing looks worse than a lumpy bow, but ifa little patience is used a pleasing shape should result. Itis often a good idea to leave this sort of job not quite finished overnight, so thata fresh eye can be brought to it. Looking at it Left, the hull covered with 15 denier nylon(!) – one leg of a pair of tights. Pins hold the cut edges in place, the cut being necessary with the fin in place. Wrinkles in the nylon sand away during the first two undercoat rubbing down stages. Above: deck beams in position, and the first undercoat on the hull. The overall shape is beginning to be clearer but readers must decide if the aim of nice looks is being achieved. Displacement is only 6/b. but this allows about 4lb. of lead. C.G. is 19\,in. from extreme bow. for the impatient! Model Boats 334 weighed at this stage and with the shadows still in place and including the ply fin, the total was a bare 12o0z. (say 340gm). The next step was to draw over the hull one leg of a discarded pair of ladies’ nylon tights. To do this it is best to remove the hull from the jig and either cut off the shadows to the deck camber line or remove them altogether and fit some temporary cross- braces. It would be a lot simpler if the fin was not glued in and could be withdrawn, as trying to stretch the nylon over the fin is taking it to its limit. There are two courses open, the first of which is draw the toe of the to tight over the bow and stretch it up as far as Bow blocks of really soft Tin. balsa laminated in plac e, with scrap for the small bits. Blocks must extend and rough-sanded; note the fin, then cut through the gathered part to (or outside) the stempiece and planking. Second pict ure shows the blocks carved enable it to be stretched over the rest of the stempiece is ‘sharpened’ as part of this process. or so above deck, the tube hull. This sounds somewhat easier than it is, venient places and are strong enough, but if projecting ¥,,in. marked on the ply by because the cut nylon immediately pulls used it is probably as position can be were shadows balsa away. however, it can be persuaded back pressing, when the outline is being well either to reinforce the tops or remove and pinned to the hull, overlapping the pencilled, or a centre line can be drawn on nal. conventio is them and fit beams, which edges aft of the fin. It tends to pull up in the ply and the tube position established by the If the boat is to be used for vane sailing scollops, so a lot of pins are needed and there of the loads will measurement. Then, when drilled, the deck most : one-piece be can deck will still be lots of wrinkles along the edges. can be slipped over the projecting tube anda be taken by the %4in. sq. central stringer, so These are not important and sand away at single stout pin, or thin veneer pin, tapped deck two only you could get away with later stages; the main thing is to cover the through the deck into the stempiece, beams, to reduce the unsupported area, balsa and avoid extensive laddering of the They enabling it to be replaced accurately in the nylon. An alternative approach is to pull the leg on over the bow, split it just a little to cover half-way along the fin root, pin in place and varnish that part. When dry, cut off surplus nylon and use the other leg of the tights to repeat the process from the stern end, pinning an overlap which, again, is unimportant and will sand smooth later. Once the nylon is in place paint it thoroughly with polyurethane varnish, brushing well in, and leave to dry. The pins can then be removed and the hull very lightly rubbed over with a worn piece of though three or four would be better. ean be cut from hardish xin. balsa and need only be in. deep so weight increase would be minimal. Take the curve from the drawings of the shadows. On a heavier yacht it would be normal to notch the inwales and halve the beam ends into them, but in the present case no real load is to be carried and a well glued butt joint should be adequate. enough to accept fingers, radio components, etc., with the stringer in the centre. Use harder wood for a deck beam fore and aft of the hatch; planed pine lath is usually about ¥/,,in. thick and is ideal, since it is light but reasonably strong. It need only be 34in. deep in the centre and not much more than //,in. at each side. Two pieces about ‘,;in. * Vin. or so should be cut to form the fore and aft edge on glasspaper to remove any fuzz. Now flow beams ata before they can be eradicated. The interior can now be varnished and tissued if this was not done previously, prior to fitting one or two deck beams. The tops of the shadows will serve if they are in con- June 1984 line. Alternatively the beam positions can be marked by measurement and pins pushed through the ply. Replacing the deck will enable the pin positions to be checked and you can be sure that when the hatch is cut out it will correspond neatly with the prepared frame. Access If radio is to be installed some form of access hatch is needed. The radio will be in the region of the boat’s C.G., roughly where the fin trailing edge enters the hull, anditis recommended that the centre deck stringer is left intact, so a hatch should be large a thorough coat of oil undercoat, again brushing well into the nylon, and when dry lightly sand round the inwale top surface which will cut through the unpainted nylon and allow the area covering the deck side to be removed. After this first undercoat has dried hard the wrinkles can be sanded down, although another two coats will be needed same position during further work. For example, it is helpful to place the deck on the hull and, by peering under the edge, mark the hatch beams fore and aft. The hatch width is easily measured from the centre strips, half jointed into the cross- distance giving the access you personally need. A couple of balsa beams forward and possibly another aft will complete this stage. The deck is cut from ¥/;,in. (0.8mm) ply and our practice is to draw round the hull on to the ply (rolling the hull to bring each side in contact in turn) and cut the ply with scissors, leaving at least !/,,in. to be trimmed off once the deck is glued in place. If the backbone and stringer are drilled for the rudder tube and the tube epoxied in, Those builders who like something of a gesture towards scale appearance can fit an optional cabin structure in the modern style of sweeping smoothly up from the main deck: this is shown on the plan. A crossmember seals the after face, the top is /;,in. ply and the sides are swept down in a curve to the cockpit line. The cockpit area is outlined by a thin strip of timber and the deck inside this strip can be painted black, dark brown, dark blue, etc., to suit the general colour scheme. The effect is quite pleasing at a few feet distance, and the deck itself remains intact and therefore watertight. Some builders will no doubt adapt this, either using the coachhouse top as an access hatch or adapting the cockpit area for this purpose, neither of which offers any difficulty. The only slight complication is that the mast step should be inset into the cabin structure, but this only involves three small scraps to make three sides of a box. Before securing the deck in place(a coat of varnish on its underneath is sensible) plan the radio layout, if any, so that any mountings, etc., can be built easily. If for vane steering, mount the skeg, making sure that it is vertical and dead in line with the fin. Also fit reinforcement to the inwales at the attachment points for the shroud plates, which will screw in place with *,in. screws. Widen the inwales by adding 2in. strips of /, x ¥,, or Y, in. and fit a in. plate beneath the widened area, making sure that soundly glued joints are achieved. Plan the position of any deck fittings off the centre line and glue blocks to the deck underside as appro- priate. Make sure such blocks clear deck beams, etc. Check that you really have finished all internal work before finally gluing the deck in place. 335 came from manufacturers and certainly, in its early days, the new association seemed to follow the trade rather than setting up rules and expecting the trade to follow with appropriate products. However, over the years the association flourished until it had six or seven times the membership of the M.Y.R.A.A. (many of whose members were in both groups) but it seemed impossible to secure any agreement for joint international AMYA (American Model Yachting Association) has been recognised as the U.S. national body by the I.M.Y.R.U. in place of M.Y.R.A.A. (Model Yacht Racing Association of America), thus ending a saga which began back in 1971. The M.Y.R.A.A., which goes back nearly 60 years, was one of the founder members of the I.M.Y.R.U. but, rather like the M.Y.A., did very little officially in respect of classes etc., when radio sailing was — it appeared that a number of influential A.M.Y.A. members had the fear that the cooperation with the I.M.Y.R.U. meant handing control of their domestic arrangements over to the Union, and this fear apparently still exists in some minds. More people have begun to realise that as a national body they have complete control over the sport in their own country, and that only if they wish to compete in I.M.Y.R.U. events do they portion to the number of registered boats in the class is common sense, and an extension of the principle that radio clubs do not vote on vane rules or vice versa, which has worked unofficially but well in the M.Y.A. The formalisation of this and a system of voting according to class numbers has been discussed occasionally, so the Americans should receive little opposition. Possibly this proposal arose form EC12 skippers; 95 per cent of the running its own ideas of competitions. they wouldn’t like alterations forced on them by countries which do not sail the have to follow the internationally agreed rules. It’s much the same as a club Why not, provided that if members wish to extend their activities to national events, then they have to sail to national doubt similar — the association can only take heed of motions put to it by member clubs and there is always a bit of a chicken and egg situation with something new. The association cannot make rules? Two proposals have already been received from the newly-recognised association, one that there would be an upper limit of affiliation fees and number of votes, and the other that in any anything official until it has been decision on rule amendments votes shall be cast in accordance with the number of proposed, with sufficient boats in being to demonstrate that there is sufficient interest, but the clubs are willing in registered yachts of the class concerned, the class has official recognition. affiliation fee is paid. Fees are influenced by, and votes declared (for each class) when the annual general to build numbers of yachts until Be that as it may, the M.Y.R.A.A. found itself accused, rightly or wrongly, of not doing enough to promote radio sailing, apportioned according to, the total number of yachts of recognised international classes holding current certificates, and this may make a with the result that the A.M.Y.A. was formed. From a distance one got the impression that much of the pressure Championship. & South District Met. District Championship Met. & South Rawdon Cup. Event. Open Mayoral Cup. Charnwood Cup. Cup. Trojan Committee Cup. Parks District Championship and Northern Northern Team Championship Midland District Championship. Festival Cup. Nylet Trophy. Cheddar Cheese. Bowl. Jesmond Alpha Cup. Open Event 66 6 12 12 1313 13 13 13 13 20 20 2020 2026/28 27 June 2 3 3 3 336 difference to the U.S., who have tended to Class A R10R M RA RM M R10R A A RA M RM RM RM M RM RM Venue . ge Birmingham Date 3 3 33 Forest New Clapham Bradford & Leeds 109/10 Cheltenham 10 Fleetwood Leicester 10 Fleetwood 16 Gosport Birkenhead Bournville Etherow New Forest Woodspring Newcastle Birkenhead 10 16 17 July Trophy. Waller John Championship. District Midland Northern District Championship. Mug. Currey Dun Trophy. Barnaby Cup Cole MYA National Championship. Nyria Cup. Plant Cup. Welford Trophy. RM RM 10R RM RM R10R RM A ARM Lincoln Keynes Milton Newcastle Gosport Doncaster Birkenhead Forest New Gosport whe Birmingham Leicester 14/15 1515 15 222222 22 Taplin Cup. Fred Parkes Trophy. RA & R10R M Poole Cleethorpes assurance on this point when the class became officially recognised, but if the proposal is adopted (and there seems no reason why it shouldn’t) it would be in effect impossible to make a change in this particular class without U.S. agreement. Consideration and the probable adaption of these two proposals will, hopefully, go a long way towards reassuring those American skippers who may have suspicions that the I.M.Y.R.U. has some sort of take-over deal in mind. All the Union wants to do is ensure that all model yachtsmen can make their own views known, through their national bodies, and can compete anywhere in the world to common rules. That, and the promotion of model yachting, is the sole function of the Union. Windsor Trophy. Event Corporation Trophy Class R10R R1OR Championship. MYA National Maker Trophy. Model MR10R RM Eastern District Team Championship. S. Western District Championship. Open Event. Littlejohn Cup. Ladbrooke Trophy. Northern District Championship and 1 1 1 1 7 88 88 8 Dovercourt Appledore 36R Birkenhead RA Hove & Brighton Bournville Rugeley MYSA Open Event. Sandylands Trophy. 36R RM 10R RA RM 10R RM Red Rum Trophy. RM Spastics Cup. RM Broadlands Trophy. Event. Open District Junior Championship. RM RM Northern . A Championship District Team South District Met. && South Championship.RM Met. 36R Championship. Northern RM Trophy. ParkesDistrict Fred RA/R1OR Event. Open MR36R p.p. Team Championshi National MYA Championshi District South & Met. RM Wilkinson Sword R10R Nylet Trophy. RM Trophy. Thornhill Open A575 Cup. MayoralEvent. Avocet Trophy. Northern District Championship. and 28/3 August MYA National Championship Yachting Monthly Cup. 5 RM RM AMickey Finn —_— Fleetwood Bournville Chiltern M Essex 29 August Venue Fleetwood Hove & Brighton Team Championship. Northern Mickey Finn National Championship. MYA National Championship. Fleetwood Leicester Chelmsford Poole Gosport Birmingham Birmingham Woodley Dovercourt Fleetwood Chippenham class. In fact they were given an 30/1 July 23/24 ~ total EC12 fleet is in North America and 24 Milton Keynes 24 M RM RM RM R10R 6m 6m RM RM RM RM Voting on class amendments in pro- Hinds Cup. Midland District Championship and Macdonald Trophy. MYA National Championship. Tucker Trophy. 17 23 MYA National Championship. Welford Race. Round Hatfield Trophy. Canada Cup. Cup. TamplinCup. Gilbert . District Championship Midland Championship. Met. & South District p. Championshi District Eastern Eric Nuttall Memorial Trophy. Open Event. to ‘buy’ votes by registering every existing boat, which would work out at £2.50 per vote! becoming established. The reason was no Event MYA National Team Championship. ceiling on both fees and votes as, apart from limiting financial commitment, at present it would be possible for a country responsibility. Partly — again, a received impression t will be generally known by now that the quote numbers of yachts in classes registered in total; the number actually holding current certificates could be smaller. If it was numbers that have ever been registered, England would be paying for some 9000 boats! There is a case for a Cleethorpes Cup. RM Mickey Finn A RA SE Birmingham Chelmsford Leicester Birkenhead Cleveland Gosport Broads South Wales Birkenhead Gosport Danson & Hove Birkenhead Cleethorpes Chippenham Birmingham Guildford New Forest Woodspring Leicester Chiltern Fleetwood Lynn Kings Etherow Gosport Cleethorpes Model Boats
