Forum Replies Created
Hi I was pleased to receive my Spring Mainsail as always a good read for all GP owners. But I was hoping to see more details about the rule change which allows for deck holes for spinnaker storage and launching.
My questions are:
Can the hopes be cut into decks of existing boats? Both glass and wood?
What stiffening is needed under the decks in this high stress area?
Will there be revised drawings issued and a requirement for a measurement check and and endorsement on the boats certificate? As is required when modifying the mast step in series 1 boats.
The idea looks good but I would like to see more information and detail about the changes needed to the construction to accommodate the holes
I will wait for the Spring Mainsail to see if any details given if not I will contact David
Some interesting thoughts, not going to cut any hole until some clear instructions and plans available.would be rather strange for a change to the rules that can not be applied retrospectively to older boats. This would be a first where old boats could not be kept up to date. The pictures we saw in the January news letter were of a glass boat, which builder had made the modes and was it a new build with a modified deck moulding? As the pictures showed what appeared to be an after fitted moulding trimming the openings I feel that some more details need to be published – Spring Mainsail?
in the original Series 1 GPs the floor boards were 75 to 100 mm wide slats with gaps, in later years most owners changed to floor boards from ply wood with no gaps each board being 300 mm wide so could be cut from half a standard sheet of ply. The single sheet without gaps meant that things didn’t get lost so often. The boards were there to serve two purposes to spread the crew loads so that the bottom panels were not bearing foot loadings, second they provide a space for water from spray and waves to be without wetting the crews feet. The bottom panels of Your 1974 GRP boat will be relatively weak compared to plywood and as such floorboards are needed to help spread the crew foot loads.
When boats are weighed the floorboards are included in the weight, the rules say that the floorboards must not be used to make up weight in a boat that would be otherwise under weight. The class rules say that the floorboards must be in place for the boat to confirm to the class rules.
Of course new boats built in last 20 years as Series 2 boats both grp and wood have a double floor with buoyancy tank under what would be the floor boards. Some Series 1 boats had risers added to the frames so that control lines could be run under the floor boards.
i think that Chris and Oliver have said all you need to know about swapping fittings and the rig from your wooden boat to an old grp hull. It is possible but may take just as long as refurbing your wooden hull. One show stopper on cost would be if the shrouds supporting the mast are either too long or too short for the grp boat, there are no standard positions for the shroud plates and therefore shrouds are unique to the boat, you may be lucky but you would need to put the mast into the boat and try for length
i have dug out my copy of the plans and on Sheet 3 of 4 the keel to hog bottom ply detail shows the ply under the keel but there should be enough width in the hog, the inner part to clean off the bottom panel and fit it to the hog without removing the keel. I would check the width of the hog along the part you want to replace to see how much of the hog you will have as the landing for your new ply. You will also need to remove the bilge keels, these screw through into the frames. Along the chine the bottom ply is screw glued to the inner chine stringer and the outer chine piece sits in a notch and is planed down to match the bottom ply. You may need to replace part of the outer chine piece just depends on how cleanly you can remove the old ply, it may be best to cut into the inner chine stringer and refinish the outer chine piece to match the new ply.
if you get stuck for buying a set of plans I do have a set of my own which I could trace the details for you, email me at [email protected] if that helps
i have replaced several panels on various GPs. Is your boat a Series 1 boat with buoyancy bags? Up to hull number about 13200 or a newer Series 2 boat with buoyancy under the floor? First I would buy a set of the construction plans from the Association office, for which ever type of boat you have, this will let you see how the bottom panels and the keel are constructed.
The keel piece is fitted after the bottom panels are fitted, so to remove then one would normally remove a section of the keel so that the ply can be removed and the new ply fitted to the hog ( the inner part of the keel). The ply can be replaced between any of the frames I would normally identify the position of the frame and cut through the ply along the middle of the frame so that the existing ply panel and the new ply are supported on the frame, you could also try a half joint where you taper the old and new ply over a length of about 50 to 75mm over a frame. All new ply and joints should be made using SP epoxy 106 resin and fillers and all new wood coated with epoxy to ensure no further rotting. After fitting the new bottom panels refit the keel .
what you are planning is not an easy job but is not impossible providing you have a good work space under cover if possible.
Good luck and let us know how you go.
Hi sorry for slow reply but not been at home. If you email me I will send you a collection of horror pictures too many and bid for the forum email [email protected]
unless your cut down sail has a headboard that is attached to the sail say by the luff rope being left as the old length the answer is no you can’t use the existing wire halyard and hook rack.
if you want cut the sail down I presume you will take out a middle panel and maybe shortened the foot along the boom. The head of the sail will then be about 1 m or so below the top of the mast. I would replace the wire halyard with a 5mm spectra rope halyard and a camcleat, then you can adjust the main to suit your cut down or full sail with no problem
To find the rotten ply can difficult as it is all hidden. The best way is to get your hands into these hidden areas and rotten ply will crumble when touched. Access to these areas involves looking as:
under the thwarts – check that the sheathing glass layer is intact – if not feel the ply under the thwart also look for cracks at point where the flat part of the thwart meets the side of the deck.
under the decks when fitted with through deck sheeting, is the plywood to which the track is bolted secure
Open the hatch cover in the transom knee and reach inside to the inside of the transom, check the piece of ply which runs up the centre of the transom
open the hatch covers either side of the mast and reach in with a screwdriver and try to push into the block under the mast, if sound zero penetration
But as Oliver says if you want a cheap GP 14 wooden series 1 boat with round transom scuppers is far easier to check for condition as you can see every thing the only hidden area will be the front buoyancy tank if fitted. Only other check needed on an old boat is under the mast check that the keel/hog has not split due to having high rig loads applied.
I would back up the warnings from Chris – be very warry when buying a FRP boat that shows any signs of cracking. I had a very bad experience with a Speed FRP boat No 13954 – the plywood reinforcements rotted and left me with some big bills to sort the boat out. Areas where you need to check – under the thwarts front and back, under the decks for the plywood supports to the genoa cleats (if through deck sheeting), inside the transom the rudder pintle reinforcement rots, under the mast there is a block which supports the mast, on the sides of the boat are two pads each side one for the shroud plates and one for the genoa sheet turning block. All the plywood in my boat was either rotten or well on the way to failing.
Superficial gelcoat dings are par for the course and are easily repaired – also open up the forward hatch and look around the front buoyancy tank, if possible have a friend shine a light around the outside of the hull – you may see some thin areas in the lay up particularly along the keel, another stay away sign.
Over a period of 12 months I had all these parts renewed by Steve Parker at a cost of about £2,000 before I decided to call it a day and bought a new boat from SP Boats. I wrote an article about these problems which was published in the Spring 2018 Mainsail – some FRP boats seem to be OK but there are a number of boats with all or some of these problems. Check carefully before buying.
The arrangement described with the elastic take up under the deck is much older than you suggest I had a system under the foredeck on GP 10444 which I rigged with a boom stored spinnaker pole. Other boats I have owned since then have all had an under deck take up system some with the pole stored in the boat clipped on by the crew to a hook on the uphsul/ downhaul and some with the pole stored on the boom mainly newer boats. On my current boat we have added a shock cord loop on the mast under which we tuck the pole to stop it flapping about when it is stored on the boom.
Steve16/07/2019 at 9:57 pm in reply to: Suitable Varnish For Toerail, rudder, deck handles and deck "V" #18557
you mention that you need floorboards, these are essential in the Mk1 grp boats as the hull is not particularly thick being just a single layup of grp, to finish the floor boards you can use varnish with a sprinkle of fine sand while the varnish is still wet to give a non slip finish or you can use a nonslip deck paint from the International range to give some colour to the finish.
Ig is a long time since I sailed a Mk1 grp boat numbers 7039 and 7044 were boats I campaigned when they were in their prime, both had problems with leaks into the side tanks where the tubular ribs pass through the tanks. Also check that all of the screws holding the keel band are in place as these pass through the hull and will allow a significant amount of water into the boat if missing
Steve Corbet16/07/2019 at 9:34 pm in reply to: Most cost effective new boom up cover or best way to make your own #18555
Hi, I have owned a number of wooden and grp GPs and have followed advice the you should buy the best quality cover you can afford. For a wooden or grp boat with wooden decks a breathable polycotten canvas cover is advised so that the wood can breathe if you use. A PVC cover the boat will sweat and the varnish will fail as any moisture in the wood will be drawn to the surface cracking the varnish. I did think that when I moved to a grp boat that a pvc cover would be ok but after speaking to Steve Parker at SP Boats even grp boats need to breathe and he recommends a poly cotton cover. I have bought my last two covers from Sun and Rain, not cheap but very good quality, will last for a good number of years and if you go for their deep sided cover the sides of the boat are also protected from the weather. I also would always use a boom up cover for normal storage and I only use a flat cover when towing the boat.
Remember your boat spends more time under its cover in the club Dinghy park than on the water being sailed so a good cover is an investment
While I would agree with most of Oliver’s advice to get a good starting point rather than trial and error even with an older boat it is worth following the tuning advice given on he various sailmakers tuning sheets. If you have a series 1 square footed mast, the mast must be set hard against frame 2 and chocked centrally in the mast step, attached the shrouds with the mast about 1/3 out of the deck slot, hoist your foresail and tension as normal. Now hoist a long tape up the mast using the main halyard until you read 18’0″ at the top of the lower black band, lock off the halyard, now swing the tape to the top of the transom (not the horse if fitted – old boats) ideally the reading should be about 21’10” plus or minus 1″. Adjust the position of the shrouds until you get in this range. Your should then find the boat is well balanced when sailing with a neutral of tiny weather helm up wind. When finished note the shroud positions for future reference.