Hull, Deck, centre case and splash

Furhter developments on the hull consists of setting in the collision bulkhead, fitting the tube that goes in the bow of the boat, glassing of the floors and the centre case

The collisions bulkhead is a 8mm peice of foam that was made to the shape of the boat right up forward.  The bulkhead goes across the boat and serves 2 main purposes * giving strutural ingegrity to the boat, giving it more stiffness against the waves. Never good if your boat cant take the force of the waves :P  And the bulkhead also serves as structural part for the forward part of the deck to rest on.

There is a tube that goes up at the very very forward part of the boat, it goes through the collision bulkhead and through the nose cone of the bow.  This tube is just a case that holds in the prod which holds out the main sail (may need to check if that is corret)

The floors that i mentioned in my previous post has to be glass to keep it in place and add more stiffness.  Ultimately all the stiffness and strength in the boat comes from the glass thats laminated on so you would want all the parts of your boat to have glass on to get the maximum potentioal of strength of your boat.

The centre case in this boat is shaped like a trapezoid, it is made out of glass and goes right through the boat.  The perpose for a centre case is to hold the centre board which is a part of the keal.  This add balance to the yacht, unfortunatly i dont know too much on the subject so i cannot elaborate on the subject.

The deck has a few extra things to be done to it, theres the 2 mast plate peices, we will just say the "centre case plate" not sure what its really called and the carbon uni's and glassing the rest of the deck.

There were 2 types of mast plates that we put on the deck.  The first on is placed on the aft end of the blister.  This plate is a massive peice of glass made of several layers of glass and is prity heavy but is very strong and stiff.  This plate is about 120mm long and 80mm wide and half of the plate lays ont the blister and half of it hangs off, the reason for that is that the mast sits on top of this plate but the designer wants the centre of the mast to be on the centre of the bulkhead thats in there so therefore the centre of that plates centre is in line with the centre of the bulkhead.  The 2nd mast plate sit in the bulkhead at the very top of the but down the thickness of blister foam so it sits under and its aim is to take the massive load force that comes from the mast and spreads across the top of the bulkhead.

Carbon uni's is a fibre that only has the fibres going in 1 direction.  We put these carbon uni's diagonally down from the plate thats at the top of the bulkhead and runs down to the cockpit sole, there is another peice of carbon uni running across the the boat just above the cockpit sole.  These uni's serve as a load spreader, when load or preasure goes on the blister to the plate under it transfers to the carbon uni's then runs down, under the bulkhead on the deck it carries down underneath but in a mirror image to the top of part, those mirrored peices run down to the hull then the loads gets transfered down there also.

Glassing the rest of the deck deffinately seems like a harder task to do than what the aft part of the deck does because we have to glass the transition from the cockpit sole to the blister and the foredeck which does pose as a challenge but once we started to get it underway it wasnt so hard.  I think that is because we were deffinately more concentrated on what we were doing and learned from our mistake on the transom glassing but it did take a while.  A lot of darts were put into this bag because there is a tremendous amount of shape change in this boat but we got it done successfully.  On the deck we used the ADR resin which is a different type of resin we previously used and has a much longer pot life so we have more time to work with it.

A splash is something that takes the shape of a certain part of the boat so that when you turn the boat over you can place that splash on the ground and rest the boat on the top of it.  The splash is made out of several different meterials includeing double bias glass cloth and a few more things which i cant really remember (i will correct when i find out what they are)

Reflection

For glassing, by the time the team had got to the forward part of the boat they have developed a lot of skill, they could do a better job of the floors and got alot faster and more organised.

The gerder was done very well, they had a good vaccum, there was no spanning and there a good amount of resin on.  They learnt that where they put the hose was not the best spot for it to be.  They placed the hose which had mesh around it directly on top of the other mesh in the stack, this can cause a problem because once the vaccum is turned on there is so much preasure inside that bag that it will force the hose down and may create a dent/hollow in the laminate.  A much more effective way of placing the hose would be to create a dart and put the hose through the tip of that dart so when the vaccum is on it has no direct contact with the laminate.  The flange that was put on the gerder was next to perfect, what they did was they pre wet there glass out and layed it on there peel ply then grabbed a long metal straight edge and put some duraseal over the top so that the sglass doesnt get stuck to the straight edge, so they lay the straight edge down and put the glass over the top and turned the gerder over and placed it on top of the glass and coved it in.  This was a very good method of putting the flange on and i think it turned out perfect.  Thanks Chris.

On the blister which "Ugly Chris" and i were working on had made a mistake when we cut the top side and forward deck peice, we cut the foam but we cut to fit but what we hadnt taken into acount was that becase there was that blister we would hav to bevel the topside so that it can come in and we can plank the foam blister over the top of it.  But because we didnt allow for that we moade a bit more work for ourselves, to fix the problem we had make the first 2 strips lay inside on the top sides which was a harder task.

Ahh now vaccuming the deck, where do i start... we put down the glass on the forward part of the deck, completed that no problem.  Now the transom part and started on that and glassing that was ok, putting the vaccum bag down was the problem.  We put the vac tape down, put the bag over it, turn the vaccum on and watch, but, not a lot was happening, the vaccum was hardly working so we were going around trying to find where there was a hole that air was getting in.  Then "good looking Chris" went over to the transom and realised that there was resin on the vac tape and bag which wasnt sticking together.  After a couple minutes of playing around Chris desided to cut off a part of the transom and try and stick the vac tape to the temporary frame instead which didnt realy work either, not a good evening.  In the end after several attempts by Chris he desided to leave it and see how it was in the morning.  Later on we realised that there was a simple saw cut through the foam and that was the cause of not getting a vaccum.

Hull, Floors, Deck/blister and Vaccum

(A bit of a different layout this week and probably for the rest of my blog because i cant remember what we did on each day anymore : P)

At this point we really split ourselves up and worked on diffierent parts of the boat.  From memory there were 2 hull teams, 1 was finishing the very foward part of the hull and getting that all glassed up and then there was the team that worked on the floors.  Floors are laminated pieces of foam put together going athwartships (port to starboard) in certain parts of the boat.  Doing this creates structural integrity to the hull of the boat so that nothing happens to the boat when it crashes in to the waves.

The other group that was working on the hull were completing the for and aft gerder which goes from the transom to the station 7 bulkhead and goes from the top side of the hull to the underside of the cockpit sole.  The reason we have the gerder is to stiffness to the deck and hull and also that when you walk over the deck/cockpit sole so you dont go through.  The gerder has a flange on the top of it, a flange is a flat peice of glass which layes paralell to the gerder and is dead flat.

This pink foam is the gerder which has the flange over the top.

The deck team which is the team i was apart of, we worked on getting the cockpit sides, topsides and the blister.

The blister is big bubble type roof for the cockpit.  The blister has to be made out of strips of foam and it follows the shape of the deck so the aft end of the blister is larger than the forward end which means that the strips of the blister has to be tapered to fit.  The blister also has a dome sort of shape so not only do the strips have to be tapered for and aft it also has to be beveled on the sides so that there are no gaps when they come together.

The sides are roughly cut oversized and gluing them up to make the length that we need.  The next step was getting cutting the cockpit sides and top side and fairing them to fit.  The topside has a extra 50mm round gthe whole deck.  The reason for that is for he vaccum.  In more datail the vaccumm has to have something to stick down to and if we put it on the edge of the finished measurement of the boat then we cant glass it all the way to the edge, we would end up having the glass too short, so chris designed the temporary frames to have that 50mm lap because he knew that we would need something to put the vaccum onto.

The way that the vaccum works is first of all if you want to vaccum a glassed surface you need to prepare the stack.  The stack consists of and in this order, the surface your going to glass with the glass over the top - the peel ply - perfirated plastic - mesh - and finally the vaccum bag.  The vaccum bag is stuck down to the surface (in this case it is the deck) around the deck with what we call vaccum tape or as chris says (gorilla snot) and you stick the bag to the tape and the tape is fairly stick but when the vaccum is turned on.. it STICKS! very sticky stuff when you have a complete vaccum.  On the vaccum bag you need to create these things called "darts" darts are parts of the vaccum bag where we have created a sort of kink in the bag so that when the bag has its vaccum that the bag dosnt "span" over areas that arnt flat.  Spanning is where the bag isnt pulling down onto the surface, typically they happen in corners, if you can imagine the deck of the boat where the bottem of the deck and the side deck they make a sort of right angle and the bag running over the bottem and the side, in the corner if that right angle is a corner that the bag needs to get right into or else the bag will not pull dow the glass onto the surface of that corner, if the bag isnt quite in that corner, that is called a "span".

Parts of the "Stack"

Peel Ply - The peel ply act as a type of backstop for the excess resin, the peel ply will soak up that excess resin and hold it in the peel ply.  The peel ply also will stay on in the part that you dont need to work on untill you have finished the boat, the peel ply will protect the glass from being contaminated in anyway or scratched.

Perfirated Plastic - The perfirated plastic also acts as a backstop for excess resin and has small holes in the plastic to also any more excess resin to go through and also anyair that is under the plastic.

Mesh - The mesh acts as the final backstop for the resin but mostly its job is to release the air through.  After the mesh is the bag and the next day you have a vaccumed galss surface.

Week 6

Monday- Applied another layer of glass on the forward part of the hull which the team had some trouble with applying because of the rapid shape change of the hull.  Definatelty a bit tougher than the last 3.  Cut and glued together the cockpit sole oversized.

Tuesday- Todays main objectives were to get the cocpit sole fit to size and beveled to the right shape and to get the gerder vaccumed.

Wednesday- Today we had to determain where the bulkheads are and where the transom will come up to by putting the steal straight edges on the top of the hull on the forward side of the frames and further forward more to allow for the thickness of the transom and two sides of resin and glass. also that day we had to get the cockpit sole glassed up on one side because the foam that we used has holes in it. The reason we had to glass one side before hand is because of the holes in the foam, if we do not have one side already glassed or covered we would not be able to get a vaccum.