Thursday, June 30, 2011

I'm not Arnie...but I'm back!

It has been more than two long years since I last posted anything here - holy crap! Catori has been sadly neglected along the way. Since then I struggled with a shoulder injury that did not like any form of sanding or planing which pretty much halted building and my interests shifted rapidly to earning a crust when there was no surplus for epoxy and ply. My wife and I own a decorative hire business called Centrepiece which keeps us pretty busy most days and just recently, I managed to start putting some time (and money) into the build.
Luckily, I am supported by Tiffany on two fronts a) it makes me happy and b) it makes me happy! Since the last post, I have...
  • Fitted all of the stringers
  • Dry-Fitted the seats
  • lamined the rudder foil and stock
  • bought an outboard and aluminium for the spars
  • ordered the sails and rigging from Duckworths while the NZD is at a high
  • changed my mind on a raft of small details more times than I care to remember and 
  • started the dreaded planking
I now have my heart set on a launch date before Christmas so the pressure to finish before the framing epoxy is yellow and brittle is real!
Now that I have put paw to pad, I will endevour to post some updated images for all. Until then, happy days and fair weather to all!

Tuesday, May 19, 2009

Bottoms down, frames up and yeeeha!~

This is really exciting!!!!!!

I am starting feel that I am making a boat instead of a jigsaw puzzle now.
The centreboard case, stem and first five frames went in easily but not without some significant levels of anxiety and fear of the unknown mistake! This is me having a steam bath over an old kettle and some flexible hose.

When it came to bending the chine stringer I was very worried about snapping the timber as the bend is quite significant. I decided that I would bend it incrementally in baby steps by applying steam along the length in the vicinity of the frames where "first contact" and the new bend was being made. There is no doubt that this help as after steaming for a few minutes, I could easily tweak a bit more "slack" out of the tiedown I was using at the transom to pull the stringer home.

Anyway, the bend was done then released, epoxied and reapplied and screwed into place with clamps and I went to sleep feeling very satisfied, two nights in a row.
Now I am off to bed with a hot cup of honey, lemon and whisky to ward off the evil winter spirits which have returned with swine to haunt us!

The pics tell the rest of the story. Onwards and seawards!

Transom Assembly

Now, where is my lovely wife with my coffee and that brush and pan...she does such a good job when I need some tidying done in the shed.

Ah yes...the transom...

At the outset I wanted a modified transom area that would accommodate an insulated lazarette locker with a drain for ice and cold storage of liquid refreshments. I was quite concerned that because I was deviating from Johns plans and "flying solo" so to speak I was on shaky ground when it came to this part of the boat so I decided to build the entire transom locker arrangement with frame 6a as a sub assembly on the bench.
The result is very pleasing and in fact I think it made fitting the chine stringer and seat fronts a lot easier for two reasons:

1. I could fit the chine stringer to the ply bottom and trim it before installing the transom and
2. Standing the transom up at the correct angle off line gave me more confidence because there is no turning back when you are epoxying to the bottom plank.

I have since installed the assembly into the boat and put additional drains in. I have drained the ice box (starboard side) and centre lazarette locker into the cockpit and drained the cockpit into the motor well because I dont want holes in the transom. I'm not sure that this was in fact the best option but it is done so time will tell. Actually the transom assembly was pretty time consuming because of all the fiddly bits. I plan to use the centre locker for my grab bag with flares etc. There is sufficient space between the tiller and the top of the locker for the day storage of cell phone, vhf, sunnies etc. or if required a small auxilary fuel tank for the outboard. I have left a small lip to stop things falling off the top of the locker.

Monday, May 18, 2009

Centreboard and Case

I have grouped the activities related to the centreboard and case here so that I can add to this part as the build progresses. I had an interesting time with both the case and the board.
Having decided that the board itself was to be 50mm wide between the cheeks in the case, I proceded to build the case with a 9mm doubler on either inside faces. I put another pair of 9mm ply doublers on the outside of the centre case between frames 3 and 4 which was rebated into the bunk flat supports and the centre case logs on the bottom panel. This effectively give a 3x 9mm ply lay-up stiffened by the centre case logs and bunk flat supports to withstand the lateral loads of the centreboard.
I also installed a centre case bush arrangement with rubber o-rings as shown (the o-ring and sleeve in the pic are not fully seated yet) which virtually eliminates the possiblity of leaks and prevents the centrecase from "pinching" the centreboard which is sandwiched between the inner doublers. The foil is also bushed and seats against the case bushes on either side. I just realise the pic is on its side but if you turn your head you will understand, look funny and get a sore neck like me.

When I shaped the foil itself, I used one side of a NACA 2412 wing ordinates for the profile of the foil. I made a jig for my skilsaw which I used to cut grooves lengthways into the laminated stock. The problem is the jig sagged without me realising it and I ended up with slots that went deeper at the end of each cut...ayeeee!!!!! Step away from the saw, have a wine and go back another day when the head is clear. All is not lost thanks to the miracles of epoxy and a bit of thickener.
When it came to the lead for the board I was keen for a jelly tip so I set about making a mould for the lead. I started by using the offcut from the centreboard as a profile around which I wrapped a thin sheet of aluminium which I crimped closed. I took the mould to a local chap who casts fishing sinkers to see whether he would pour the lead thus saving me a lot of time and hassle. He agreed and I left him to it returning about an hour later to pick up the tip.

My reception when I returned was decidedly "cool". It transpired that the laminated offcut at the bottom of the mould "fizzed" and together with the burning epoxy blew a chasm into the bottom of the mould through which molten lead proceded to spurt all over the foundry! Luckily no harm was done and they all managed to see the funny side of the event. They even agreed to allow me another go using an improved mould design. The second mould was a huge success and the pics speak for themselves.

Oh, I nearly forgot...having bolted the lead tip to the board (I used two 8mm SS threaded rods screwed into the foil to a depth of about 150mm with liberal amounts of epoxy "lube" on the threads), applied two layers of glass to the cheeks and leading edge, I had faired the transition from timber to lead and applied two coats of epoxy to the board while it hung from a piece of wire. When I was taking it down I forgot I was dealing with 14Kg of lead plus the weight of the board and it slipped from the wire and smashed into the floor about two inches from my toe (I was barefoot at the time). I nearly wept with relief and then fear that I would have to start all over again. To my amazement the damage was negligable and I simply filed off the slightly mushroomed leading tip, reapplied some thickened epoxy and hey presto...we have a centreboard! Needless to say I am more than happy with the result.

I still need to do a final sand, dry fitting and paint. I can't do a real dry fit the centreboard to the case until later when I roll the boat or cut the obstructing cross members from the building frame - probably once the planks are in place. She seems to go in ok upside down from the top.

Wednesday, April 15, 2009

Frame #2 position & dimension queries

The position of the notch for the bottom plank on the stem drawing is given as 674mm. Assuming that:
1. The drawing indicating the relative frame positions for all frames is correct and
2. The centrecase is correctly placed at 1775 from the end of the bottom plank but also 810mm behind the forward face of the mast per sheet 3/12 and
3. The stem governs the position of frame #1 physically because the laminated 12mm sides end where frame #1 starts
... then by my estimation, the notch dimension is about 15mm too far forward (or short)on the stem drawing.
This means that when the stem is correctly positioned on the bottom plank, there is a 15mm gap between the end of the 12mm ply bottom plank and the stem notch transition.

This is best illustrated in the picture above.

Having matched the curved profile of the stem to match exactly with the profile of the bottom plank, I was able to bond the 20x20 doublers to the stem before assembly to the bottom plank.
However, the transverse limber hole in the stem at frame 2 creates a break in the doubler and as a result I got the break in the wrong place because I followed the stem drawing alone. In the picture below, the stem doubler was chamfered to line-up with the limber hole in frame #2 which is now correctly positioned forward of the mast. Not a serious thing but it would have been nice to avoid the confusion.

Monday, March 9, 2009

Jigsaw Days

Ok here goes...I arrived home with three lengths of RS 250 x 60 x 5700 Fijian Kauri (Agathis) and two lengths of 150 x 50 x 3000 Kwila. As these were loaded by a fork hoist, I had no idea just how heavy they were until I got home and had to offload them from my roof carrier alone. The Kwila in particular was far from light and I realised that I probably pushed the roof carrier to the limit! The following day I got stuck into ripping them down and discovered that the first plank had some substantial residial stresses which resulted in bowed timber when ripped. Although workable and satisfactory for shorter lengths, the second plank would not be good enough for stringers and had a knot in it midway along so I returned it to the yard where it was exchanged for a clear piece and an extra 300mm of length for my troubles. I drooled over the piles of exotic hardwoods and imported lumber in the massive shed. Some of the ripping was done on a table saw which consists of a piece of ply bolted onto an old cast iron sewing stand with an old skill saw mounted from below and an aluminium angle fence held in position by two G clamps. This worked ok but was a bit dodgy over the portable infeed and outfeed roller stands and I remembered seeing Wilfried Vermeiren's blog which showed how he used his skill saw to rip his stringers and opted to do the rest of the planks that way so the 6m stringers were ripped using the skill saw and a fence on the building jig. Sizing was done with the help of a friend by passing them through my brothers Ryobi buzzer. I like that tool!!! All up I collected five large bags of shavings and sawdust for the chookhouse. The stringers are now bundled and ready to go but having read the horror stories posted by those of you who have had the experience of snapping stringers, I am dreading the day I take them down to use them because I did not get any spares from the process. I will look carefully at my options for softening these nearer the time. I made a small epoxy mixing balance based on the description offered by Joe Tribulato which is very simple to use and is especially useful for mixing very small amounts of epoxy (less than one pump from the West System dipensers) and also for the Resorcinol glue that I am using for laminating and bonding the Kwila. John was most helpful on this topic as Kwila has a lot of resins that leech out continiously making bonding difficult. Freshly planed timber, cleaned with MEK (Methyl Ethyl Ketone) and bonded immediately with Resorcinol is apparently ok. All the frames have been cut and so far I have finished the stem and frames 1, 2 & 6 ready for standing-up. When I lofted the plans and cut the templates, I made a small error on frame 2 that resulted in a slight camber in the bottom profile of the cross piece where it is in fact flat. This had to be corrected by adding a second layer of 12mm ply (I used 12mm insted of 9mm due to the size of the frame for the cross piece) and some epoxy filler. I am now satisfied that neither strength nor appearance has been compromised and I can move on. The 9mm and 12mm plywood I purchased was marine bonded and "boil proof" but is not BS1088 rated. There are some voids in this that will worry me when I start planking and I am going to try and get a credit for those sheets and by BS1088 Gaboon Ply for the palnking and decking. I have raised the height of the building jig temporarily using two lengths of framing timber to save my back during cutting of the ply - this has made a huge difference and if I did it again, I would raise it even more to reduce bending and back strain during this phase. I was also glad that the jig was still moveable to give me flexibility during this phase of the build. It gets pushed around quite a bit to suit the activities of the day. I have also raised the middle and aft bunk flat at the sides by 8mm to assist drainage towards the thru-compartment drains alongside the centrecase when the boat is beached, at anchor or on the trailer. The centreboard lamelles came out slightly thinner (50mm) than the plans but I am not concerned about this and will reinforce the foil with glass later. The case will remain 70mm in width internally and I have designed a pivot pin and Vesconite bush arrangement based on Johns design that will compensate for the reduced thickness of the centreboard. Now progress has been tremendously good thanks to the fact that I am currently unemployed. The plan was that I would budget for enough materials to get started and once employed again, I would be awash with cash for boats and stuff...ha ha! It looks like building will grind to a halt sooner than expected but at least I have enough epoxy and materials to get the boat to the planking stage. Anyway, that's it for now. Lastly, if you guys could please assist me with a decent template for the blog or teach me how to arrange the photos, that would be great. I seem to spend more time arranging the bloody thing to look presentable than typing while in fact I should be making wood shavings and curing epoxy! Somehow the sequence of the photos and where they place themselves appears to be either ad-hoc or non-negotiable.

Tuesday, February 24, 2009

Modelling and Transom Options Explored

I started today by drawing frame 6a and the transom in full scale on the paper for the template. I have known for a while that this would bring me to a crossroad regarding the outboard well and the locker configuration. I have settled on having the through-transom outboard per John's drawings on my sloop rigged Pathfinder, however I am considering an alteration to plan which mirrors the port side outboard detail on the starboard side which I intend to convert to an insulated cold storage locker. (A cold beer never went astray after a hard day cruising!) The middle compartment will lower in height below the hole for the tiller and will be a lazerette for a battery etc. To make sure I understood the original drawings and the intended variation to plan, I created a model using card. This was a very worthwhile investment in time for me, being new to the art of boatbuilding. The excercise was made very easy using A4 tracing paper in a photocopier. The plans were copied (2X for frames drawn on one side only then flipped and joined with magic tape along the CL) and pinned over some cardboard then cut through using a Stanley knife.
Tomorrow Noah will start to cut some wood...Svoopa, svoopaa, svooopaa!