October 23, 2011
With the integrated forestay chainplate the bow pole tube is an awkward part to fit in the bow. In hindsight it would have been better to do this during the joining of both hull halves but I decided to do this afterwards as I had some various options in mind regarding an extra chainplate for a cutter stay and/or making a provision for a gooseneck for a jib boom. The jib boom didn’t made it but the base for the cutterstay chainplate has been made.
There were two possibilities to get the bow pole tube in place, by sliding it into a slot or by tilting it through a large hole. Disadvantage of the slot is the possibility that the bow deformes and needs a reconstruction afterwards and the advantage of a large hole is a better acces for the laminating work inside the bow area.
So I choose the large hole, although in two steps to keep the possibility to go back to the “slot method”. And so I went from one hole to two holes and, after gathering enough courage, to one large hole. I placed the bow pole at the right angle and distance and discoverd that the size of the forestay chainplate could have been a little shorter, about 20mm., despite the fact everything has been made according to plans. The effect is that the chainplate protrudes a little too high above the deck. Not a good sight and not good for the size of the jib. So I decided to lower the whole bow pole tube assembly with 20mm.
The plans shows two threaded stainless steel studs and together with two wingnuts and a stainless steel strip this holds the protruded bow pole in place. I don’t have experience with a retractable bow pole but I can imagine that pushing the bow pole to its protruded position gives some troubles in the last inches. Two wingnuts turn more heavily than four wingnuts so I decided to mount four studs and I replaced the stainless steel strip by a circular piece of carbon (an offcut of the sterntube skeg)
June 5, 2011
There was some courage needed to cut a temporary hole in the bow. I decided to do that for an easier mounting of the bow pole bulkhead and the bow pole tube. And there is some more work to do inside this difficult to reach bow area. Click in the picture to open the bow pole photo gallery.
More updates and new photo’s in the sterntube and mainhull external laminate gallery.
May 5, 2011
At first I thought of making the carbon bow pole by myself, also as a kind of exercise for making the carbon mast and boom in future. But for practical reasons I decided to buy a custom made bow pole, to save on time and to have a look in the kitchen of a professional carbon mast maker. Thomas Whilkes of Ceilidh Composite Technologies (http://www.carbonmasts.com/), the maker of the carbon bow pole, was so kind to discuss some ins and outs with me about making a carbon mast and the ideas I have to do this by myself.
The bow pole has been made in a female mould with carbon pre-pegs. The only thing I still have to do is making the attachment points for screacher and spinnaker. The bow pole is retractable and slides through a bow pole tube. To make the bow pole tube I thought I needed the bow pole as a mould, but in hindsight it was not necessary to buy the bow pole in this stage, as the outside diameter is exact the same as a 125mm pvc drain pipe. So, instead of the carbon tube I used a pvc drain pipe as a mould for the bow pole tube. With 7 layers of wallpaper I increased the diameter to 128mm for the easy gliding of the bow pole. The mould is finished with two layers of plastic film and a teflon coat between the films to be able to release the glassfibre bow pole tube from the mould. Click in the photo above for some more photo’s about the making of the bow pole tube.
There are also some new photo’s in the picture gallery of the sterntube and external laminate.
January 3, 2011
Im my post of August 12 I announced the engagement of Port and Starboard main hull halves. This trial fit was necessary to get the beam bulkheads on the right place. Since then there was still a lot of work to do, especially in making and fitting the lower folding strut hull anchors which took a lot of time. Last holiday I carried out the last things before joining the halves, like designing and mounting the sterntube with skeg, but also the preparations for a second carbon chainplate in the bow area. This is placed at the front of the anchor well and is intended for a heavy weather jib or storm jib. Since this is not a design feature, I’ve created my own solution.
It was my goal to join the couple in matrimony before the end of my holiday, so today January 2 was a long day to get it done and it worked. Another milestone.
December 24, 2010
I finally made a decision about what kind of propeller shaft support bracket to choose. The plans calls for the fin or P type but in my view these have some disadvantages. First, it is not made of composite but of steel, bronze or brass . This means a different material that sticks out of the hull with risk of leakage as it is a subject for high forces. To me it also looks quite vulnerable but it has to withstand ropes or netting that can be caught by the propeller but also a stone/rock on the wrong place when drying out.
A more solid construction is possible with the reinforcement type shaft support, the skeg with build in stern tube. Advantage it is it can be made as a whole with the hull (all composite) but disadvantage is some more drag, more difficult to make and some extra facilities for the water lubrication. I think I can minimize the drag disadvantage by making the skeg as small and thin as possible with a carbon plate as base. The following picture shows the general idea.
Click in the picture for the photo gallery.
The engine page has been updated too and there you can find two photo’s of what can happen with a P- style shaft support bracket when catching a lobster pot rope.
August 10, 2010
….. which resulted in a lousy vacuum bag. See the lots of tacky tape on the lower side of this vacuum bag.
Making wet vacuum bags in a flat position is not a big deal. But laminating on vertical surfaces or an oblique angle, the resin will drop down and contaminate the tacky tape. With resin contaminated tacky tape is useless and will make it extremely difficult to get an airtight vacuum bag. Therefore it is wise to close the lower side of the vacuum bag prior to the wet hand-lay-up. To remember myself (again) I made a serie of photos (see the gallery) that shows how it must be done in the right order.
Tomorrow I will start the mounting of the beam bulkheads. To be sure of the right position I will do a trial fit of both main hull halves.
August 4, 2010
Abrading solid glassfibres causes a lot of itch ….. but it is done now. It took three days (and four vacuum bags) to be able to mount the now correct lower folding strut anchor assemblies.
In the mean time I also infused the aft cabin bulkhead. Not yet recovered from the shock of a few days ago, I forgot this time a brush that was trapped in the vacuum bag ……
“They” say that the epoxy fumes damage your brain. Would that be true ?
July 30, 2010
Just yesterday I reread Ian’s plans about the lower folding strut hull anchor assembly and noticed this warning again.
While reading I thought one must be a fool not to keep full attention and skill to these critical structural elements …..
Guess what. Pride comes before a fall. Today after I freed the two carbon anchor assemblies from their vacuum bag and was preparing to mount the assembly in the hull, I discovered that the base plate was shorter than the anchor….. F**###(censored) In a fit of madness I had the base plate mounted in the wrong direction. Itself is not so bad were it not that all the UD fibers are now running in the wrong direction. Too bad of all the beautiful laminate work….
Well, after a fresh nose and a cigar I went on with cutting off the base plate and grinding off the excess laminate on the underside of the anchors. This weekend I will do the new laminates and hope to start next week with the mounting of these parts in the hull (which was my intention to do this weekend)
Occasionally I can be a complete idiot ….
July 28, 2010
When working on the starboard half I made all the carbon lower folding strut anchors, but not the complete anchor assembly for this port side. So, before putting in these carbon anchors, I first had to do some unfinished business on the carbon anchors. Cook them in the oven (this time not the one in the kitchen) and making the total anchor assembly.
To speed up the curing (I want to do the lamination too today) the anchor assembly is being heated by a 1500W infra red lamp. Perhaps the standard that holds up the lamp is a bit oversized ….. Click in the photo to see the photo galery.
By the way, the infusion photo galery and infusion video in the previous posts has been updated too.
September 27, 2009
Before moving the mainhull half to the other workshop I still have to finish some things. One of them is the bobstay anchor.
Some time ago I had a look on the composite department of Stork Aerospace and there I learned that they put a lot of effort in saving weight at the ends of airplanes and wings. Not a surprise of course but this reminded me of the quite heavy bobstay anchor in the bow of the F39. In spite of the fact that I prepared the piece of stainless steel to fasten into the bow, I decided to make a much lighter carbon one, almost in the same way as the carbon chainplates.