vrijdag 28 december 2007

Exterior almost lamiated..

Cabin side + upper hull have been laminated. Now I only need to do the lower hull and the extra layers on the keel and at the beammounts to finish the exterior laminate.
The hull is still light enough to move around on my own.

dinsdag 25 december 2007

Deck laminated

With the hull on the laying on the ground it's much easier working. This picture is prior to laminating. I made three rebated areas for glass overlap with the electric planer: two on the side of the deck and one about 50 cm in front of the beam-bulkhead.
Deck is now laminated with UD in place and plastic on top. With the help of my brother it took about 2,5 hours with preparation.

zondag 23 december 2007

Hull out of frames

The hull is out of the frames and hanging in two loops from the ceiling. Now I have to get rid of all (the remains of) the battens and frames and strongback before I can put the hull on the ground and continue laminating.
I'll glass the deck first, so I can turn the hull upside down without risking damageing the foam.

vrijdag 14 december 2007

Job done

Laminating the lower half of the hull in one go took me 5 hours without any break. Over all I'm quite pleased with the results. No bubbles and as far as I can judge a good resin-cloth ratio.
This is the quality of the laminate I was aiming for.
However, on some spots I just couldn't get this quality. For some reason the cloth kept some wite-ish small spots, no matter how much epoxy I added. The cloth is laying flat against the foam, no bubble. This problem (or is it?) has occured on all laminates till now, pre-wetted or not, pre-coated or not and with and without peelply and plastic. I think it looks a bit like the 'bad' spots Grant (see link section) found when laminating with peelply and plastic.

donderdag 13 december 2007

That is a lot of glass!

Foam pre-coated with a thin coat epoxy (hull-half took one kg epoxy). Carefully sanded 80 grit with orbital sander. Vacuum-cleaned (twice) and cloth is already laying in place smooth. All heaters in the workshop have been turned on this morning to get and keep it at 20 degrees celsius.
Now I only have to take the afternoon off from work and properly wet out this 9 square meters of cloth within 4 hours. Easy enough..........hopefully.

maandag 10 december 2007

First exterior laminate

Cabin side + gunwale area + part of deck are laminated with plastic on top. On the deck I made a rabbet with the electric planer as this is supposed to ease the fairing of the overlap of the cloth. Although I'm not really convinced it is necessary in this spot (deck will need a lot of fairing anyway because of the extra layers glass) it's not a lot of work on a flat surface like the deck, so I decided to go along.

Here is the laminate with plastic in place....
...and here the plastic is removed. The 'plastic without peelply-technique' results in a very smooth shiny surface with the weave of the cloth filled. It's not difficult to sand it 'dull' without sanding (too much) in the fibres.
Lesson learned: don't try to 'plastic' multiple-curved surfaces with one big sheet of plastic, or you'll mainly be busy trying to get rid of creases. The creases fill up with epoxy, leaving a ridge after removing the plastic. It's much easier to work with overlapping 70 cm wide pieces of plastic. Luckily it'ts easy to remove the ridge.
I'm happy using the 'plastic' technique (not a single bubble this time), although like with most things it takes some practice.
Some lessons learned the hard way:
    • It's still important to wet out and smooth out the cloth as well
      as you can before putting on the plastic: with the plastic on it's easy to get rid of small imperfections and air-bubbles and excess resin, but NOT to shift the cloth in a major way, and
    • I hoped it would be possible to use the 'dry-method' with plastic, but that didn't work. On the spots I didn't pre-wet I still had a hard time to get the cloth well adhered to the foam: it just doesn't tack to the foam right away on all spots, and adding more epoxy is of no use. Does this sound familiar to other builders using divinycell? On spots with putty/ply I don't experience this problem. So it's obvious: I should build a ply stich&glue boat!
      Now serious: I'm planning to see if it helps to coat the foam with a thin layer of epoxy and let it cure before laminating so I can use the 'dry method' for the lower hull half exterior.

vrijdag 7 december 2007


Working hard to get the hull ready for sheeting.

I'm pre-filling the edges of the anchorwell hatch with putty. My idea is this will give a better result than digging out the foam after laminating and cutting out the hatch. I intended to use a router to dig out the foam, but couldn't because aera in the forward section is not flat.
Instead I used a screwdriver: I 'cut' the inner and outer outline by pricking the screwdriver in the foam and then it's very easy to dig out the foam. Maybe it would have been even easier to cut the outline with a knive or chisel, but I didn't think of it. Anyway, this was much easier than using the router. Why do I always forget to do it the simple way?
Next photo's show the way I rounded the edge of the deck to the cabin side.

Marking lines at 2,5 cm from the edge. I tapered (??) the flat area a bit at the front of the cabin to end up about twice as small at the start of the cabin-deck edge.
'Fire up your planer' - to make a flat side
Two more flat areas are planed on the edges of the first planed flat area. The 'rounding' now consists of three flat areas. I tried to mark the outline of the two new flats, but that was pretty useless (not accurate enough)
Finishing: sand the four edges of the three flats down a bit, then round the whole edge with diagonal strokes of the longboard (lonboard of course in line with the edge). It came out pretty decent. Maybe some small highs and lows, but I can't fix that in this stage. The foam is too soft: when I fix one spot I'll probably sand a bit too far on another spot of the edge. I'll get it totally right when fairing the exterior with putty.

maandag 3 december 2007

Starting exterior

The last interior panel has been taped. I'll leave the interior for now until I can put the hull upright.
I had forgotten how easy it is to sand the foam (using grit 40). It's actually quite nice and quick work. My twinbrother sanded most of the lower half of the hull in one afternoon. The bow stilll needs some work. By the way, the foam-strip-longboard (see foregoing post) works ok, but so does a much more rigid longboard I made from a two-side laminated foamstrip.
Centerboard case has been trimmed with an electric planer to roughly match the hull. First I'll fill all the gaps, then I'll sand the last bit with a longboard.
Yet another picture of the sanded hull....
I'm also starting work on the deck. In the cutout-areas of the deck I'll put some putty in place before laminating. Afterwards I can just cut the section without having to dig out and fill the foam-edges. Here is an example of the pre-filled edge for the hole in the bow. I use a very accurate festool router to remove approximately 19 mm of the 20 mm foam thickness.

Next I'll have to round the edges of the deck to the cabin-side and the hull. The plans state it can be well rounded, but how? Should I do it just with a longboard and some guesstimating (flatten the corner with a longboard - I mean: sand the corner down to for instance a 3 cm wide flat ridge and then round the two 'new' corners with a longboard)? Or maybe I can do the edges with a piece of PVC-pipe with sandpaper glued within, but it might be difficult to get a nice even corner on a long stretch.
If anyone has a good trick or tip I would be really glad.

dinsdag 27 november 2007

Main Bulkhead, cockpit floor & mast support web

After taping the main bulkhead, taping the ruddermount on the inside and making some flanges I could glue the cockpitfloor. I also glued the mast support web in place (not taped yet).

Cockpitfloor flange + plenty glue

Cockpitfloor glued and temporarily held in place with woodblocks and a piece of wood between the beam bulkheads to keep the floor straight.

Mast support web tacked in place prior to taping.

As I'm almost done taping the interior panels, I have to prepare for the dreaded longboarding. I'm experimenting with a poor-man's longboard: it's just a piece of foam with one layer of tape on top and two wooden blocks as handles. I tried to glue sandpaper with spray glue, but that didn't stick. After that I used ready made wallpaper glue: this works ok but takes a while to set enough. If the longboard works well, I'll make a few so I'll never have to wait for the glue to set.
Once I've done some sanding I'll report if the longboard works. I hope so: it's cheap to make and VERY light.

vrijdag 23 november 2007

Bunktop & Rudder Web

The second half of the bunktop has been glued in the hull. First I had to make a flange in the most forward section, as the underside of the top can't be reached in this spot. I was in doubt if it would be easier to use the alternative for a flange as described in the plans (drop panel in a bead of putty and tape the underside and upperside of the panel only 'up') but decided it would probably be stronger to form a proper flange. This turned out to be much easier than I thougt (nearly straight section).
Flange mold...

Second half of bunktop glued in place. I use wooden blocks with screws to temporarily fix the panel. The screw-holes will be filled while taping the joints. It is very satisfying to put these large panels in the hull - it really makes a big difference in the way the hull looks on the inside.

Glueing the ruddermount with a level to check it's ..ehm..level. It's held in place with some wooden sticks, one screw and the tube (which is held at the right height with a piece of wood clamped to form frame 12).

My plan is to do all the internal taping of the ruddermount before placing the second cockpitfloor panel, instead of doing it later. To me doing it now seems much easier than trying to tape the mount through a temporary hole in the cockpitfloor (as per plans). Or am I missing something here?

dinsdag 20 november 2007

Internal taping

Most of the internal taping and extra laminates have been done now. Instead of using peel ply I experimented using plastic on top of the fabric.
First impression:

  • it's very easy to see where there's air in the laminate, and its very easy to get rid of the air by squeeging the bubble to the edge of the plastic;
  • it's difficult to know for sure, but to me it seems the cloth is much more 'compact' and well adhered;
  • after removing the plastic the surface is very smooth with the weave (almost) filled; it will probably be easy to sand it without sanding too much into the cloth;
  • unlike working with peel ply it's easy to see what is happening to the cloth;
  • the edge of the cloth blends in very nice;
  • the plastic-trick works for flat surfaces and doesn't work in corners (can't plie it without a lot of wrinkels)

The first results are encouraging and I''ll go on using this technique. For now I only used it to laminate on top of already sheeted foam, I'm not sure it will work as well on bare foam. We'll see.

I tried to take some nice pictures, but I wasn't able to get very good ones.
Posting them anyway....

deck stringer glued to roof
laminated with UD + C + P(lastic)
plastic removed
foam bedded for placing rudder web
Laminating the last layer of cloth (UD) on the rudder web, this time in an ordinary garbage bag, heated to speed up curing

woensdag 14 november 2007

Bow and little things

Unfortunately I did not make much progress this week. I've been busy closing in the bow with foam and taping that section. Not much fun: difficult working laying twisted inside the hull. Luckily it's done now. Before I can fit the second half of the bunk top I have to finish the bobstay anchor.

Bobstay anchor: foam with putty insert.

Bobstay anchor: middle section cut.

Bobstay anchor: wow, that is a lot of carbon!
Laminating the bobstay anchor wasn't a big succes. Laminating ('wrapping') pieces this small is still not my cup of tea. To continue moaning: the fit in the hull wasn't very good either. But it's no use crying over spilled milk. Currently the final layer of C is curing so tomorrow I'll glue the anchor in place and be done with it. I decided to try use vacuum to force the last layer of cloth tight around the piece. I used an ordinary shopping-bag and a tie-wrap. This works really well.

poor man's vaccum bag?

I'm also working on the rudder web. I made two jigs to glue the gudgeons exactly alligned.

vrijdag 9 november 2007

Hull joined!

When trial fitting the hull-halves I noticed some gaps, especially in the bow section (ranging from a few mm to app. 1,5 cm). Maybe the upper half distorted a bit because I was not able to support it much (as I had to lift it out of the way), or maybe this will always happen a bit in the areas where there is some tension in the foam and the marine ply insert (because of all the bending).
Luckily this didn't turn out to be a problem. To be sure of a very tight join, and for ease of mind, I thought out a way to clamp the halves together. Here is what I did:

On the outside of the upper half I screwed a batten along the whole joint, held in place with scrap piece of wood which overlap the joint. See the picture below. In the bow section I couldn't use woodblocks, so I only used screws (the joint is not flat in this area). Picture of the extra batten on the outside.
The preparation took about one hour (taking it easy mode) and was well worth it. After putting some putty on the joint it was simply a matter of clamping the battens together - 2 meters at a time, starting from the bow - and correcting any misalignment by screweing some extra blocks to the outside batten to pull the battens in line. See the picture below. By the way: this part had a gap, and needed more clamps than usual.
After aligning and clamping the battens together, I fixed them with some screws and went on clamping the next two meters. The whole process only took about one hour (taking it easy mode).
Result: an IMO very nice joint.

maandag 5 november 2007

We 2 are almost 1

Trial fit of the two hull-halves. A plunge bob is used to put the halves straight on top of each other. I used the beam-bulkheads at gunwale level as a reference point, as they are by far the most accurately placed parts in the hull halfs.
Impression of joined hull (rotated, of course). Looks quite roomy for a relatively small boat.

Bow web - part 2

Laminating the bow web. I did the first layer with one piece of DB. Not a very good idea (duh), just too much curves and overlaps to wrap it nicely this way. No pictures of the rest of the laminating. Let's just say 'wrapping' is not my favourite work. For the last layer I worked with several pieces of bi-axial tape (15 cm wide, I cut it in half for taping bulkheads etc.) and this went much better than the first layer. This tape is really bendable and doesn't fall apart the moment you cut it (unlike the DB cloth I used for the first layer).I screwed a piece of scrap foam to the bow and 'surformed' it level, to make a nice fitting foam insert to place the bow web on top.
I bedded the foam-insert in glue, then glued the bow web on top and used the squeezed out glue to more-or-less form a fillet on the inside. After that I taped on the inside in the still wet fillet, thinking this would give a better bond than waiting for the glue to set and trying to sand in this difficult to reach area.

I wasn't really pleased with the way the bow web looked, as it was a bit chunky and messy because of all the glass overlaps and carbon-tapes. However, after fitting the bow web it became clear how little of it will ever be visible again. Of course I knew that by reading the plan, but somehow it's different to see it right before your eyes in stead of on a piece of paper. The front of the bow web is the only 'messy' place visible. I'll tidy it up after glassing the outside of the hull.