Showing posts with label catamaran. Show all posts
Showing posts with label catamaran. Show all posts

Tuesday, 7 December 2010

setting up bulkheads II

when we first set up the bulkheads we just located them on their correct position, in the right height and perpendicular to the centreline at the base. they were still able to lean for or backwards and to twist between sheer and keel line.DSCN7071

with a temporary keel we stopped the bulkheads from leaning and fixed them plum in position. the laser we used earlier to establish a centreline and to set the bulkheads level was helpful again. DSCN7102

on the picture above you can see the temporary keel in the middle and the sitka spruce keel stringers before they are glued in.

some of the bulkheads, specially the ones with a quite big cut out in the middle and therefore narrow at some places, were not stiff enough to remain straight under the load of the keelstringers. some bulkheads were slightly bowed because the flocoat cured whilst they were leaning against a wall and the epoxy fixed their slight bow. with the help of additional stringers on each side we straightened them up again.

DSCN7099

we clamped the stringers in position and used laser, plum bob and tape measure to do fine adjustments until all bulkheads were straight and plum. in order not having to do all that again we marked the bulkhead locations on the stringers. when it came to glueing the stringers in place all we had to do was to get everything to the marked position.

DSCN7100

to keep accessibility into the hull easy for a long time, we only glued in the stringers on one side of the hull and left the other side more or less open. you are going to see more of that in the next posts.

DSCN7098

this is this weird guy who seems to be on a lot of the photographs i take of the building process. one of the rare pictures where he is wearing more than just the headphones and the glasses…

if you need some nice pottery, he is the man!

Saturday, 24 April 2010

epoxy coating of first bulkheads

all bulkheads were cut for us at swallow boats in cardigan, a bit less than an hour drive from our shed.
they balance nicely between well thought, modern and cost effective boat building and classic looking boats made for sailing.

had them cut by a cnc router saved a lot of time and we now have really precise cut bulkheads. all it needed was cleaning up the slightly rough edges and figuring out how the finger joints in the bigger bulkheads would slide together. ..
I hope we can trust the computers who did a lot of work for us and everything is fair and in the right place when the bulkheads are set up...


on the three bulkheads you can see on the picture above. i tried out an epoxy system commonly used in surfboard building called resin research and is distributed in the uk by seabase in cornwall. according to their website, the resin has:

· lower toxicity
· lower exotherm
· longer pot file
· shorter set times
· lower vapour
· better colour
· better colour stability (UV stability for brightwork)
· better strength
· etc.

we still had some leftovers of the widely used and time proven west system resin. so i made a mix of WS as well to compare it with the RR resin.
i was interested in ease to work, gelling time, pot life, efficiency, etc.

when we have used the resin a bit more, i will post more details on our experiences.
so far i can say that the RR resin is a bit more viscous compared to west system what made it easier to use it with a roller sponge and gave a better finish. it is clearer in colour and doesn't seem to give out a lot of vapours so its smell is much less aggressive than WS epoxy. the RR epoxy had a shorted gelling time than the WS but had a longer pot life and was less exothermic when going of in the mixing cup. it must be said though, that we used the slow hardener on WS and the standard hardener on RR.




Thursday, 22 April 2010

setting up the strongback for the cat

ysbrand and me set up the strongback yesterday.


we started with fixing the short 2"x4" crosspieces you can see to the floor following a centreline we defined with a really tightly pulled dyneema rope.

we used PU-glue to fix the crosspieces to the floor first but to make it a rigid structure we will drill additional long screws into the concrete floor. last thing we want is a moving strongback.
the people who poured the concrete floor did a pretty good job so we just needed a few strips of ply to get everything perfectly level.

Monday, 19 April 2010

Not a lot to see. yet...


Our building shed... an old greenhouse on a sunny hill in lower solva, pembrokeshire. all that insulation created a lot of dust but keeps the temperature quite stable. stable temperature+epoxy=good; dust+epoxy=no good
the man you can see breaking things is Ysbrand. it is his shed, his idea and he will be sailing that cat.