Deck Beams to Bulkheads

It were a mixed boatbuilding bag today, a leap ahead, a major set back and blood spilt on the boat. 

My principle goal for today, was to get the Bulkheads prepared for a 3D  assembly. To achieve this I first had to; fasten the deck beams to the bulkheads, tidy up the bulkheads and at least begin giving them a coating of epoxy sealer. Boatbuilding teaches you a bit about how your mind operates, for me, I have found that I do not enjoy any time away from the project. My first build, fitting out a fibreglass yacht, went well because I was able to fully immerse myself in the build, everyday head down. This time around, being older, I've got baggage, other commitments, but I can only blame the weather this time, a week and a half of wild storms, flooding etc. So after two weeks off the job, I felt like I was "all thumbs", and for quite a while I fumbled about trying to get back into the build. 

My first error was to start chiding myself for not having made a Deck Beam for Bulkhead 3 - it wasn't until I woke this morning that I realised that that particular Bulkhead, being mid-cabin, doesn't actually have a Deck Beam. But this is the sort of stuff I trip over if I'm not there every day, keeping my head in the build. After a few hours I had Deck Beams added to Bulkheads 1, 2 and the Transom and thought things were going well but while preparing Bulkhead 4 I found a fault that floored me. I had measured, cut out, glued floor and cleats without noticing that the Bulkhead was 100mm short. I considered my options (no epoxy won't fill that far), and concluded that such a fundamental error meant I had to go way back at the start and create another Bulkhead, cleats, floor ... Dang, but it's just got to be done. NOTE: I'm not blaming anyone, but more than once I've misread measurements off the Plan and I can't decide whether it's down to my failing eyesight or the author's handwriting. Be careful. 

I decided to keep busy and focused on cleaning up the bulkheads ready for epoxy sealing. To do this, I took the advice from the Paradox Boat Builders Manual and used a "flapper" course sanding attachment on my angle grinder ... the one that I've had for so long that I couldn't even guess where it's guard attachment got to. Well, when you're sanding your Bulkhead, grinder belching out sawdust, as you flip the timber about with your other hand don't put your pinky on the flapper. I did, and that good aggressive remover of epoxy runs, sharp edges and fluffy finish, is also very good at removing flesh. As I stared into a 7mm grove over the first joint of my left index finger, I noted the lovely mix or red and white flesh there. The other side of my brain was thinking still and I rushed off to get some Elastoplast and disinfectant cream before the blood arrived. Yeh, do be careful. But with all significant injuries, there"s that pleasant self-anaesthetising effect that kicks in and you can work for a good few hours before pain sets in. I got at least one side of one Bulkhead sealed before knock off time. 

Ideas from Today.

Don't forget to select a 'good side' before fastening your Deck Beams. 

The whole bevelling of bulkheads thing is not well explained in the plans. Just roll with it and know it's going to create work down the track. 

Flapper is good, just be careful. 

Do what the Builders Manual suggests, and carefully measure up the overall heights of the Bulkheads and Deck Beams before glueing. 

When you stuff up, don't sweat it, just call yourself a dummy and go back and start again. As many builders have found, epoxy can hide a myriad of sins. Strongly too, but if it's too far out, just cut another piece of wood and burn your mistake. 

And, an oldie but a goodie; measure twice cut once. And, make sure you read the Plan clearly. 

 

Bulk Epoxy -Bote Cote

I bought a bulk order of BOTE COTE yesterday, through a local agent I found. BC in an Australian made epoxy and apparently has no solvents and is low allergy. Brushes can be clean out in water and the mix ratio is 2:1. It's quite a bit cheaper than WEST Sysytem. One interesting difference is a product used to thin out the first coat of epoxy. apparently it allows the epoxy to penetrate deeper and act as a moisture barrier and timber preservative. 

I look forward to splashing some about. Today though we're having record rains with houses in the next town being washed away ... so no boat work. 

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While out making my purchases yesterday I came across a waterfront village I'd never seen or even heard of before. Unbelievable, it was like going back in time. Great expanses of land close by the water dotted with slow moving boatbuilding projects. I found two Wharram cats a Pahi 26 and one about 35-40' ? Both in poor condition stripped down and being rebuilt. I suspect that the Pahi won't actually make it given that her owners have "no idea" and only visit infrequently. I dropped in to chat with a local pro boatbuilder who filled me in and he also suggested another brand of epoxy, cheaper still* and "very good" made by Acme Chemicals. (*$200 for 20 litres). Going by the finish of the motor launch he was building, he knows his scarf from his splice. 

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NEW EPOXY (BOTE COTE - Made in Australia)

I've just started using my new epoxy to glue cleats and floor pieces to the bulkheads and so far it feels pretty good. There is little smell, seems to penetrate well and it feels creamier than WEST System. I can only describe it that way, it feels silkier, proof when you're glueing and the pieces want to slide sideways as you're clamping. I'm less worried about dry joints too, cos this stuff spreads well. 

I'll test the strength in the morning I guess, but so far it looks good.

PPS: As of today, 25/4/2015, I'm giving BOTE COTE a big tick of approval. The pot life is fantastic (even with the standard rare hardener), judging from the lack of smell the claim that it's 'low toxic' seems about right too, when you're done working (without gloves) you don't even need to wash your hands, if so soap and water will do, and it's sticks well too. A few days ago while testing out ring nails (I used a few to hold the cleats in place), I coated the nails in epoxy, but because I was only tacking and didn't want the joint to squeeze dry, I only rammed the nails part way home. When I came to nail them all the way next day, they were very difficult to budge. Other joint have shown no sign of weakness, and the manufacturer's claim that it's 'flexible' when set, seems right too because when I bend the plastic spatula to remove old dried epoxy, the blade bends a terrible lot before it breaks the bond. I haven't sanded it get, but from the result so far, I'm not expecting and problems. 

CLEATING

Well this is a really fiddley part of the build, lots of little pieces to go on each bulkhead and you can only do one side of a bulkhead at a time. I just need to get this done before scarfing up the side panels before a dry fit. 

GETTING BACK TO WORK

 AND it feels great to have the school holidays over and be back at work on Quixotic. 

Next step scarfing side panels

I've been dragging my feet not glueing the cleats & the floors onto the bulkheads so far. but yesterday my budget expanded a little so now I can think ahead & to buying a second sheet of marine ply for the hull side. When I loft, cut out then scarf the 2 side half-pieces per sheet of ply, I'll be ready do "dry fit" the hull into 3D. 

I've taken notes on scarfing from various blogs & read the Builders Guide but I won't know what works until I get going on it. My previous build just had side panels butted up together with a backing plate, which in hindsight was easy to accomplish but very amateurish. A good scarf should be strong & straight, just what you need to have under you when pounding away at sea on a dark night. 

IN HINDSIGHT I may have been a little ambitious claiming that scarfing the Sides was my "next step". 

Cleats & co.

Today I finished ripping back all the cleats & bits & pieces that are attached to each of the bulkheads & the transom. Many little pieces there are. 

Next will be to glue these in place. Simple. 

Sven Yrind's "mongrel Paradox"

...  of Matt Layden’s 14-foot coastal cruiser Paradox. I got out the drawings and looked at them. Paradox has a strong flat bottom and a draft of only nine inches. At first look one gets the impression that she cannot go to windward as it seems that she has no means of preventing leeway. A closer look reveals her chinerunners, small two-inch wide horizontal winglets sticking out from the chines for about a third of the boat’s length. But was that enough? Intrigued, I called Matt and he told me that he could sail Paradox better to windward than Dave in his slightly bigger centerboard boat, and he invited me over to see for myself. In October 1997, I sailed Paradox for a month. In 2003 I returned, and again in 2006 and 2007. Each time I stayed for about a month, sailing and discussing boats with Matt. We continue to exchange ideas once a week over the phone, which is very enlightening, as Matt is always one step ahead of me. I am now convinced that the chinerunner concept, created by Matt in 1982, is the greatest innovation for small cruising boats in the last century. The reasons why very few people have realized its advantages are that Matt does not try make his voice heard above the din from the egos in our conservative, self-centered society to promote his idea, and that the principles behind it are complex and subtle, and have been subject to little research and experiment. After a decade studying Paradox, and talking to Matt I have come to understand that the boat’s leeway-resistance comes from a combination of three sources, the chinerunners, the lifting body shaped hull and the large rudder.
Unlike the ordinary cruising boat, Paradox has no heavy ballast keel making her stability obvious. Matt uses less obvious means, like her cruising load kept low and her flat bottom which, a bit like a multihull, moves a lot of buoyancy to lee at small angles of heel. At large angles of heel, Paradox’s righting moment comes from a good height-to-beam ratio and the buoyancy of her superstructure. This shape gives Paradox positive stability at up to 165 degrees of heel. Better than most conventional keel boats Matt uses a lug sail. "Yrvind" is a mongrel, based on Matt’s and my ideas. I am grateful to Matt, and would like to thank him here for taking time to engage himself in my problems.

My favourite photo. Mr Yrvind looks so chuffed with his build. Rightly so! 

Sven went on to successfully sail "Yrvind.com" across the Atlantic Sea then up the east coast of America. He went on to build another design to make a record breaking circumnavigation in a 10 foot boat. His later comments about his "mongrel Paradox" was that it was too heavy & did not have enough room for living aboard in rainy weather. Both these criticisms can be partly attributed to the changes Mr Yrvind made to the original Paradox design. 

For full details go to "Yrvind.com" particularly the period May 2008 to September 2011. 

A Wonderful Paradox Story pt2.

In part one, I wrote about SMALL FRY from Western Australia & how, based on two separate articles, she may have been rolled, dismasted & her skipper lifted off by helicopter & the some years later both were found cruising 400 miles further north. 

I am happy to report that this indeed is what happened. The skipper did abandon SMALL FRY, she was recovered & continues to achieve some creditable sea miles cruising the WA  including a rounding of Cape Leeuwin on the SW tip of Australian continent. 

I posted these findings on the Paradox Builders group site & it's brought up some further discussion & input from a friend of SMALL FRY who provided some of the above information. He also suggested, based on discussions with the skipper, that the rudder may have given away before the capsize & dismasting. Some of the discussion follows:-

> Geoff Davis recently sent me a link to this article.  (See my previous post about Paradox Design) It explains why the Paradox is a very good sea boat.  The Paradox is not overly beamy, is heavy displacement for its size, has a favourable prismatic coefficient which means that it does not hobby horse excessively, the ballast ratio is not excessive and the ballast is not too low down, the rig is relatively heavy which slows down the roll motion. The A/B ratio which is the ratio of boat above and below the water is also good.  Not covered in this article is the fact that the mast will float when submersed, adding more to the ultimate stability.  I have previously built a free standing mast and have used the same calculations to check the design of the Paradox mast.  I think it is strong.  If anyone is concerned about the strength of the mast it might be worth considering a mast tabernacle which will help to support the mast.  I considered this but decided to stick with the plan, mostly because it is so neat. When I questioned Geoff about the capsize he thought the rudder had given way first.  I think it is worth having a good look at how you build your rudder.  Make sure it is strong - there is a lot of force going through it.

> ... the rudder. It also looks to me the most vulnerable part of the boat.... the weakest link. But, to be fair, Matt designed the boat as a coastal cruiser which only ventures out onto the wide open ocean during during reasonable weather.( Posted by: "james hall" flexwing462)

> What are the weak areas of the Paradox rudder? . (Posted by: wyliewesty)

> The rudder is cantilevered from the rudder stock and unsupported for most of the underwater part. Which is not a problem when used as designed. Many other boats have unsupported rudders and they aren't having a problem. But the Paradox rudder carries more load than most other types and when conditions become extreme that load increases, so it and its fixings need to be stronger than most others.( Posted by: "james hall" flexwing462)

> I'm looking forward to reading Geoff's account so that we can understand what went wrong, and why, and the info will help us when evaluating what are suitable weather conditions. ( Jim c/-Jims Times blog)

I recall that Sven Yrvind did a major redesign for his ocean crossing design based on Paradox. 

This is Sven Yrvind's "modified Paradox" rudder assembly under construction minus it's mass blade shown below. Very complex, he later wrote that "YRVIND.COM" "became too heavy". 

 

Paradox Design Principles

There has been some discussion on the builders group about Paradox's design, & one contributor said that Geoff Davis skipper of SMALL FRY had recommended the following article to help explain some of the theory behind his design. 

Beam, Ballast & Displacement by M Kasten of Kasten Marine, Port Townsend. 

From the web article I have snipped the following highlights: 

"Widening the water plane (increasing beam) will increase stiffness,  & reduce comfort & degrade seakindliness.

Adding ballast will make for more aggressive roll motion due to the added righting force. though adding ballast will reduce roll angle, there will be a less gentle "return" at the end of the roll, i.e. there will be a shorter roll period, roll accelerations will be greater, the roll motion will be less comfortable, and the incidence of seasickness will increase.

From research on Fastnet Disaster, those boats with heavier structure, lesser "ballast ratios" & heavier rigs resisted being "thrown" into severe rolling, had a much more seakindly roll motion, were easier on their rigging, did not lose their masts, did not capsize, & did not experience nearly the degree of sea sickness among their crews."

View full article @ www.kastenmarine. com

There was a further comment in the article about the benefit of distributing ballast as far from the centre pivot axis of the vessel. I understand Paradox has billets of lead distributed along its length fairly close to the bilge chine.