zondag 28 december 2008

Rudder(case) part 3.

I managed to reshape + laminate the leading edge of the rudder, so I could continue with the rudder case. Couldn't find a proper 4 mm thick plastic to mold the case. Instead I wrapped the rudder with the frontrunner fabric, and put two thin hard plastic sheets on top of that. Tried to mold the edge of the flanges with clay, but wasn't satisfied and instead just used an epoxy fillet (also handy to keep the mold plates steady). Once the case is out of the mold I can round off the fillet on the inside of the case.

It worked out well, although the case may be a tiny bit too 'loose'. I'll probably have to make the plastic block at the back of the case 1 mm less wide, to squeeze the case a bit together.
Couldn't think of a good way to put the glass spacer plate in the center of the molded case, and just guesstimated when I glued it on. To glue the tube properly alligned to the spacer plate, I put the case upside down on the rudder and used a piece of tube as can be seen in the picture below. I'm sure this method is not very accuate, but it was the only way to allign the tube I could think of.

In the meantime I'll also work on the centerboard. I wanted to use western red cedar as a core, but changed my mind when I found out in the Netherlands this is not the 'economy option'. Divinycell is cheaper. I think it's quite a big blade; should be easier to shape and laminate than the rudder.

woensdag 17 december 2008

Rudder part 2: FAIL

I laminated all layers (2 c-layers with the carbon sandwiched in between + extra layer round leading edge and top) in one go, hoping this would give the most compact laminate. Next time I won't, and just do one layer at a time. All the glass in one go is difficult.
Although the laminate itself came out ok, to my dissapointment the leading edge of the board has a much too big radius. I didn't take into account enough the thickness of the 3 layers C: to get the profile right I should have shaped the leading edge much more precise than I did.
I don't feel ready to throw away the rudder. Instead I'm busy shaping the leading edge again, this time hopefully right, and then re-laminate the front end of the rudder. Because I have to remove almost all the glass from the front till the carbon uniderectional, the carbon won't be totally enclosed by C-glass anymore (I mean: the layers under and above the carbon are not connected to eachother anymore on the front side), so the rudder might be less strong. I'll take the risk.

maandag 15 december 2008

Rudder, part 1

I could found enough scrap foam to glue a blank for the rudder. Between the two halves I put some glass to make the blank a bit more stable.
Then I glued in the spar. I used fir (or was it pine?) as a core for the spar. Ian Farrier said that's ok, as long as you wrap the spar with the specified cloth.

Here is the blank with the still unsheated spar.

And here I'm gluing the spar in. Some small blocks under the spar (hopefully) keep it centered in the blank. I put some weights on to keep the blank straight while gluing.

The blank is initially shaped using a router. Grant used the same method. I've never shaped a rudder before, but I thought it went quite well this way.

The routed blank looks like a mess......

...but is actually not too hard to shape. I put some marker lines in the corner of the routed areas, and then it's easy to sand down. Just keep on sanding until the lines start to fade. I mostly used a surform to do the rough work, and a longboard to finish. In this picture the top half is nearly done. I was surprised how small (thin) the board is; because it's so small it feels like every mm mistake really counts - and it probably does.

End result so far: blank with 'HD' insert (mahagony) at front end. At the whole back of the blank, and the low tip of the blade, the foam is removed and replaced with putty. I also made the HD fill at the back with putty. This is easy to do because of the layer of cloth in the middle of the blank.
The rebate for the uni-directional with the spar in the middle of it make up a big portion of the whole board, and it feels like all the careful (ahem) shaping has been waisted. After glassing I'll check if the profile is still anything near the real thing and if not try to restore it with fairing compound.

maandag 8 december 2008

Primer (finally)

I'm finally busy putting high build primer on the top exterior. This time I'm not spraying (too much hassle + needed a lot of thinner) but just rolling. I apply two thin coats in one go: this primer hardens so quickly after applying you only need to wait 15 minutes to be able to roll the second layer without messing up the first layer. I'll sand this layer down (grit 80-120), touch up the last spots (which show much better with the primer applied) and then apply one more layer primer which I'll sand with much finer grit.
One thing I learned is it is easiest to do as much rough sanding as possible within 24 hours. The primer is already sandable without clogging the paper too much, but not as rock solid as it becomes later.

Cockpit area cleaned and ready for primer. I'll try to finish this this night.
The corners in the cockpit-area will be high gloss and very visible. To get them nice and even I put on a new fillet after fairing the flat parts of the cockpit. Not much work and I think it will look quite good.
Some advice for builders shopping for hardware: if you've built up your bow (as I have) you need a trailer-U-bolt with VERY long legs to make it to the inside of the boat. I couldn't find a suitable U-bolt and will for the time being be using a simple eye epoxyed to a piece of M10-rod.

zaterdag 8 november 2008

Interior primed, exterior work

Still busy fairing the interior and exterior. This is taking longer than I thought. It's a lot of surface, with all kinds of nasty turns, corners and edges.

Interior fairing is finished..
....and primed with normal house primer. The floorboards and the lid of the centerboard case will be made of some blue flightcase material I happened to have laying around. Still have to trim the centerboard flange.The exterior is almost covered with fairing putty. Still have to do the cockpit floor and the starboard cockpit seat. I did a rough sanding, and will do one extra run with putty and sanding to finish all the last spots. I won't try to get all the walking areas perfect, as they will be covered with non-skid. Will work hardest on the shiney areas (cabin sides & cockpit coaming & main bulkhead).Detail of the traveler, mounted on hardwood blocks.

zondag 12 oktober 2008

wignet rail cutouts + transom

To make uniform cutouts in the wingnet rails, I used a piece of aluminium angle as a guide for the (metal)saw. The angle is cut off at 45 degrees on my table saw.

By accurately marking the widest points of the cutouts (36 mm wide) and keeping the low edge of the alu guide more or less at a uniform distance from the hullside below the rails, it is not too difficult to get nice uniform cutouts.Although mounting the outboard bracket on the aft panel of the cockpit seat as plans advice is probably the most sensible thing to do, I'm just not ready (yet?) to cut away a big part of the hull to make room for the outboard leg. Instead I'll mount the motor on the transom. The setup will be something like this.

maandag 29 september 2008

main hatch

My first attempt to glue the ply bearing pads for the hatch supports was a failure. The pads have to be (and weren't) EXACTLY level in all directions. Even a very minor misalignment of the pads results in the supports noticably not standing/lying straight and thus not lining up properly for the slide tracks on the hatch.
Also the heads of the 10 mm slide bolts were about 6 mm thick, and together with the insulating nylon washer I needed about 8 mm between the coaming and the supports. Because the bearing pads were (as per plans) only 6 mm thick, the bolt heads rubbed against the coaming.
I hacked the bearing pads off again, and made new thicker (10mm) pads and a MDF jig to glue the pads properly aligned. Overkill? Maybe, but...
....this time the supports alligned beautifully. My home-made slide-tracks and slides also work well. I'm happy. I put some 600 gr glass on the pads to strengthen them, as ply alone will probably wear down (too) fast.
I want to drill all the holes and make all the inserts before fairing the outside of the hull. One of the last pieces I have to make before fairing the outside are the inserts for the mast support. Here is my mold (one sideplate removed): I use the two metal studs to keep the tube at the right angle in the mold.

woensdag 17 september 2008

interior + mast step

With the hull upside down it was time to finish the upper part of the interior. Prior to fairing I made four HD inserts + extra glass for the lifting eyes. Two eyes just in front of the front beam bulkhead, and two eyes at the main bulkhead.

Fairing the interior took a lot of time and it was one of the most unrewarding jobs so far. Despite that I tried not to rush it and to work just as long as it takes to get it right. End result so far (boat is right up again). The interior is primed from the gunwale up. The part in front of the beam bulkhead is finished with polyester topcoat with a textured roller. It looks OK but I'll think about it a little bit longer before I roll the whole interior.
I finally managed to get all the alu to build the mast step. Finding a shop willing and able to sell the alu took a lot of time and effort, and in hindsight it might have been easier to build the mast step in stainless steel, like Tovio did.
I was a bit worried I wouldn't be able to saw the alu, especially the 1 cm thick plate, but it turned out to be no problem. I glued a copy of the plans to the alu sheets and cut all the parts to (roughly) the right size with a jigsaw with a blade especially made for cutting alu and some cutting paste to grease/cool the saw. Finishing can be done with a file (????) and waterproof sandpaper.
Here is a picture of some of the parts put together. As you can see they are a bit rough, I still have to file and sand them to the final shape and I've got to epoxy-glue some extra pieces to the ears. The lightening hole was cut with a normal hole saw and my drill press. It looks good, and it might be handy to tie some things to, but that's it. The weight saving is minimal.

zaterdag 9 augustus 2008

I'm still sanding... (yeah yeah yeah)

Last post I mentioned I enjoyed the sanding of the hull, but that's over now. Sanding this hull is a lot of work, and because of all the concave curves not as easy as the float hulls.
It's nearly done now, luckily. Yesterday I sprayed some high build epoxy primer on the hull.
For the primer I'm using this 'HVLP' paint sprayer for home use. It's probably not good enough to spray the final layer of paint, but for primer it works ok.
After that it's sanding time again, this time not by hand but with an electric sander. The primer is rock hard and sanding it shows imperfections much better than when sanding the relatively soft/coarse fairing compound. I started sanding a part of the hull and it seems I have to sand off a lot of the primer (+ guide coat) to get rid of all the scrathes and other imperfections. I'll sand with grit 80 and after that spray another coat of primer which I will eventually sand with a much finer grit.
When I get tired of sanding I try to work on some other parts. For instance on the slides for the hatch. Using real jib track + slides for the hatch would be very expensive so I decided to try to make it a bit cheaper. Since the slides will only have to bear the weight of the hatch itself, I thought the slides needn't be superstrong. I made a track by sawing a groove in a 2*1 cm aluminium profile. Then I made slides from a thick polyethyleen (HDPE) cutting board.
It's easy to make the tracks&slides if you've got a table saw with adjustable depth of the saw-cut. I think sawing aluminium with a good wood-sawblade won't hurt the blade too much, but to be sure I used an old damaged saw blade (hit some screws with it earlier on).
By cutting the grooves in the slides not at the same height, I angled the sliding track 7 degrees as per plans. I'll glue the tracks to the hatch with epoxy fillets, so I won't need to bother with HD inserts and screws.
Tomorrow I'm going on vacation for two weeks, after that I hope I can get the building up to speed a bit again. Still trying to finish the boat before next summer.

dinsdag 8 juli 2008

Fairing hull

Last few days I and my brother have been busy sanding the fairing compound on one side of the hull. I actually quite enjoy the sanding, I try to sand about 1,5 hour a day during lunch break and then it's a nice break from the office work.
I believe a trick for succesful/easy fairing is to put a sufficient thick layer of faring compound on to make sure you're able to sand the whole surface down to the required end result in one go. Much easier than to start with a thin layer, filling low spots, sanding, filling more low spots, etc...In my experience filling and sanding low spots is difficult without messing up the surrounding area which previously was fair.

Still a lot of sanding to do before this hull side is ready....

After a while I found myself only working with the four tools below: a bigish longboard (self made of cutof sandwich panel with paper glued with contact glue), a smaller and less wide longboard from a marine supplier shop, a brush and a drywall-trowel (hope that's the english word) to put the fairing compound on.
It's difficult to work on the concave part of the hull with the big(ger) longboard, so I ended up doing almost all of the sanding in that area with the small sanding board. As far as I can see now the result is still fair (enough), but maybe defects will show once some paint is on. Anyway, the bigger part of this hull area will never be seen once the boat is finished because it's under the wingnets.
The drywall trowel works really well: it's much thicker (stiffer!) than the normal iron squeeges and after some practice it's easy to put on a layer of fairing putty with a consistent thickness. I only use metal squeeges - they're easy to clean with just a paint heat gun and a scraper. On the first hull half I have used the 'ridge' method to put the fairing compound on, but on the other half I'll probably skip that step and just trowel a layer on.

maandag 23 juni 2008

Port side windows + mastpost

Putting on ridges of fairing compound with a candy bag on the port side. This time I put on more ridges than I used to do, about every 5 cm, and this worked better for me.After the ridges have been sanded flush they are used as guides to put two layers of fairing compound on.
Then it's time to sand with the long board (P40). Notice the bad spot above the front window in the picture below? On this spot there was some not cured fairing compound - apparantly not properly mixed by me. Stupid and some extra work....I'll make sure this won't happen again.
I used a different manner than on the starboard side to mark the cutouts. This time I used the templates to mark the outline of the windows, and then used a flexible batten (and some nails) to mark the cutout (2,5 cm overlap window) in stead of just sliding the templates 2,5 cm up/down. I believe this way the cutout is slightly more 'fair'. Not that anyone will ever notice once the windows are glued on.....
The hardwood mastpost is glued in place, and has to be trimmed and glassed to the cabin roof. I'm thinking about putting a lifting eye in the deck just aft of the mast foot (and two lifting eyes just aft of the aft beam mounts), so I'll probably strengthen this area a bit with UD running up on the aft side of the mast post to the deck + some biax on top of that.
With all the basis components and cutouts done, I'll put the hull upside down and start faring the ceiling and sides of the interior and the outside of the hull.

maandag 16 juni 2008

Doing some leftover tasks

I still had to do the exterior laminate for one beam mount. The other three I laminated while the hull was standing upright on its supports. Stupid: it's much easier to work on the mounts whith the hull laying on its side, like I did with this last mount. You can easily roll the hull on your own.
I have learned it's easiest to laminate the hull-upper folding strut slot corner later on with a light cloth instead of trying to do that while doing the 'main' laminate.

I'm also working on the mast post. It is made of a piece of hardwood. In the picture I'm using soms scrap wood to measure the angle I need to cut the mast post.

Karel Michielsen urged me to strengthen the supports for the anchor well hatch with a filet and a piece of glass, which I thought was a good idea indeed. Here's how I did it.
At the moment I'm also using a lot of time to search for companies to deliver the hardware, masts, sails, etc. I'm having a hard time finding a store to buy the metals and bolts. I bought the 1" stainless steel ball at the ebay-shop of toolsupply (thanks to Grant's blog) but that's about it till now. In the US there are some very nice online stores for small quantities metal, like http://www.industrialmetalsales.com/ and http://www.onlinemetals.com/ in Seattle but the shipping costs of those companies to Europe is very high. Any tips to get metals in Europe (6061 T6 Alu and 316 Stainless) are appreciated!

maandag 2 juni 2008

hatches and cockpit floor

This weekend Karel Michielsen http://home.ozonline.com.au/f41_sail33/ paid me a visit (he was in Holland meeting family). It was really nice to talk to such an experienced builder. I'll try to pass on some of the tips he gave me in this blog. One of those tips was to put a sanding disk (grit 40 or 80)on the angled grinder and use that to touch up fiberglass seams, spills and generally do all other kinds of sanding.
Maybe this is no news for some, but I had never thought of using the grinder for this kind of work. In Holland the angled grinder is considered by most people to be just a tool for cutting & grinding metal and not a sanding tool. Anyway, I did some tests with the grinder and with some practice it indeed is a perfect tool for cleaning up fiberglass, cutting out bubbles and smoothing tape edges.

Anchor locker hatch will lie on some supports cut out of some leftover sandwich panel.
This is how it will look. I'll not bolt through the hinges. Instead I'll drill oversised holes in the hatch and deck, dig out a bit of foam and then fill with HD putty. Then I'll tap a thread to bolt the hinges with short bolts.
I made a small foam coaming for the forward hatch. Has to be touched up a bit and then I'll put some glass on.
Cockpit floor still has to be doubled. Good opportunity to get rid of the scrap foam pieces. Some of those pieces got a little sunburnt during the last two years. The divinycell is apparently not very UV resistant....

woensdag 21 mei 2008

minor progress

Not much progress last few weeks due to a holiday with the family and nice weather (been sailing my hobie 16 instead of building).

It's getting time to start thinking about the hardware/sails. I'm trying to find some affordable sheet tracks, travellers, tracks & slides for the hatch etc. but that seems impossible in the marine field.
In an attempt to save some money I bought a Rutgerson main sheet traveller second hand, but I'm having second thoughts about it. This traveller is very beefy (and heavy) and way overkill for my boat. I'll probably sell it and buy a new midrange Harken traveller.
All interior panels are taped. I'll leave the interior very basic first, and will decide later (while sailing) what works best. I'm happy I chose the centerboard: cabin looks quite roomy.
Cutting holes is always a scary part. I used a lot of time trying to figure out the right shape and came up with this. Still not really certain if this is 'it', but I guess it's better to just cut it and move on..... Now there's no way back.......