I have just about finished wielding a sander (at least prior to the application of a filler)on 511, but having stripped the boat of all fittings find myself in the dumb position of not having a centreline on which to fit things like the jib tack, mast step etc etc. Yes I do feel a little stupid. Thus has anyone got an idiot proof way of finding the centreline??
The jib tack normally attaches to the furler,which is fastened to the tang moulded in beneath the deck.At the stern I normally measure across the transom,below the hull/deck join,as the hull surface is probably more relevant than the deck surface.
Thanks for this. Your comment on the hull being more relevant than the deck at the transom makes sense. I was dumb enough to remove the jib tack (as I am putting in a space frame) before marking the centreline. However, I think I should be able to centre the boat at the bow. From here just a matter of joining up the dots - I hope!!
Position of centreline although somewhat daunting is a state of mind rather than a reality the important thing is that the mast is vertical in comparison with the hull and centreboard. When we fitted out 565 we ran a number if lines through the boat picking up the centre of the case the notional centreline (middle of transom to pointy bit at the front) and a couple of others like cl of boat above deck and below and checked them against the mast gate and gunwales where the shrouds are to go. It was laborious but worthwhile when we put the mast up it fitted the gate with a difference of 0.5mm on the sides and the shrouds were equal. So thats the long answer to the question the short one is measure three , four , five times then fit. Johns comment about the hull is really valid
Thanks for this. Really useful. Looks like I have a few hours with a tape measure to come.
Whilst typing this reply and after a touch of navel gazing at the boat I wonder if you have any thoughts or better still pictures re jenny sheet systems. I have removed the jib tracks - just as well as I think they were about to rip out of the side tanks - and wondered if anyone has gone for a simple up and down via rope instead of fore and aft along a track for the jenny. Former would be cheaper and lighter but I am not sure where to fit the primary take off point. Also I plan to go for the adjustable rig with blocks instead of fast pins. Before I get stuck in do I need to strengthen the boat anywhere (I am putting in a space frame but I think the shroud tension from the U bolt disappears inside the boat forward of the side tanks which is not currently programmed to be strengthened.)
As I said any help gratefully received.
Andy (covered in gel coat dust - the home base overalls do not work, tomorrow it's B&Q's turn)
You definitely need to add reinforcement inside the side tanks if highly loaded fittings are going to be sited there.A large backing plate may suffice or you may need to bond an extra piece of GRP in place.Quite a number of boats use the barber hauler system to control the jib sheets and the latest boat to join the fleet is fitted out in this way,as can be seen in the attached image.I don't entirely understand whether the intention is to connect the shrouds to the spaceframe. Image: http://www.javelinuk.com/e107_files/public/1249246733_18_FT568_s4202263_.jpg
This talk of centrelines led me to looking at 131 and realising the mast step is fitted with its right hand side aligned with the right hand side of the much wider centreboard slot. As this boat is essentially unmodified since it was built ( I've found no filled-in or spare holes ) it looks as if it was fitted off centre when built.
Many thanks for the picture. A real help and one to add to the ever increasing collection.
As regards the shrouds, the space frame will support the U bolts , but the pictures I have seen (and are in the above mentioned collection) seem to show that the adjustment disappears into the boat via a sheeve forward of the U bolt - i.e. so that it does not pierce the side tanks. Do you know if any reinforcement is needed round this sheeve, or would a large dollop of epoxy sufficce?
It would be a really good idea to reinforce the deck moulding locally.If the spaceframe is doing it's stuff there will be some fairly abrupt loadings occurring which would not have been imposed on a less rigid structure.A GRP pad,or better still a block of something like 10G40 Tufnol could be epoxied in place to spread the load.
