The zen of fairing...

I should have known better when I pronounced the fairing process as 80% complete in my last post. In my dreams... Preparing the hull for fiberglass has proven to be a bigger task than anticipated. I'm not complaining, as I enjoy the work and I don't really care how long it takes. My experience building furniture and guitars has taught me the importance of taking your time. Rushing a process almost always leads to mistakes or creates more work downstream. Rushing also diminishes the building experience in an aesthetic sense. Enjoying the ride is my goal! The ride, in this case, seemed at times an endless series of scraping/sanding sessions. The question becomes; when is enough enough? If one expects a professional looking finish quite a bit of work is required. Thankfully, I will be painting the exterior, so I have the option to fill some irregularities. The longboard proved to be an essential tool. The bar I set for overall hull smoothness is similar to that of a professional auto body shop. The result should be smooth to eye and touch from all angles. A word to the impatient: don't try this!

The hull is ready for glass at last, however, I'm going to glass the centerboard, centerboard trunk walls, and transom before I do the hull. I've never worked with fiberglass, so I want to get a little experience under my belt before tackling the hull.

The Centerboard and Trunk 

I'm using mahogany for the trunk. The trunk walls are made from 18 - 2" x 3/4" planks, splined and glued with epoxy. Before glass is applied, an oversize hole is drilled in the location of the centerboard pivot. This hole is filled with thickened epoxy. Later a smaller diameter hole will be drilled for the pivot hardware. This adds an extra barrier to protect the wood from water intrusion. Not much extra work, but it seems like good insurance no matter how the pivot is implemented.

I've rabbited the centerboard logs so no end grain will be exposed when the trunk is complete. I plan to make the trunk top removable as many folks recommend.

The Pivot

Barto specifies the shape and thickness of the centerboard in his plans, however, the pivot details are left to the builder. Whatever approach is used, it should offer long term reliability and ease of maintenance. I spent some time researching what others have done and found a variety of solutions. What I found led me to question the clearance shown in Barto's plan; 3/8" on each side of the board. I emailed him to make sure I had it right. His response was short but not specific; "Don't make it too tight. It is surprising..." With this in mind, I tried to step back and take an objective look at the problem. The following is a list of what I consider to be the minimum requirements.

1. No water in the boat.
2. No water in the wood core.
3. Smooth/reliable centerboard operation in all conditions.
4. Ability to remove centerboard easily for repair or maintenance.
5. All parts replaceable without using a sawzall.

Seems simple enough. I also expect the solution to be serviceable for many years. (At least till I'm dead)

Some centerboard pivot solutions in order if complexity:

A. Bronze rod with epoxy bushings. Removable cover. PROS: Simple. CONS: I'm not sure about the mixed bearing surfaces and the longevity of such. I would guess the epoxy will wear more quickly than the bronze. If so, how would one repair without removing the trunk. A sawzall procedure for sure.

B. Large bolt with plastic/nylon spacer functioning as bearing surface for the centerboard. Seals on inside of trunk. PROS: Simple. Large diameter bearing surface for the centerboard. Addresses compression issues when using a bolt. Everything is replaceable. CONS: My only real concern with this approach would be keeping water from the wood core. I think this concern goes away if the holes in the trunk walls are drilled oversize first, filled with epoxy, and later re-drilled to create an epoxy bushing for the bolt.

C: Bronze rod with bronze bushings. Removable cap. PROS: Bronze on bronze bearing surfaces. Reduced stress on the wooden trunk walls. No compression issue. Everything is replaceable. CONS: More parts. Something must be done to keep water from getting to the wood core. Again, this problem can be eliminated as described above.

There are variations on each theme, but these are the basic solutions I've seen. I chose C because I think it will provide the greatest durability. I'm not an engineer, so this is pure speculation on my part. One of the things I'm not completely sure of is weather it is best to let the centerboard ride back and forth on the pin or inhibit the side play. I'm planning to minimizing the side play initially and see how it goes. The following drawing details my initial thoughts regarding the pivot mechanism.

I floated this plan at the wooden boat forum to get some feedback. Most folks thought the approach was overkill. They might be right. I've since reaccessed the plan and made it a tad simpler by eliminating the locknuts on the centerboard. I've also decided to make the upper portion of the centerboard thicker, decreasing the clearance and making the board stronger at the pivot.

 Fun with lead

I took advantage of the nice weather on Sunday to pour some lead. I admit I was a little uneasy with the idea at first and I thought about using lead shot and epoxy instead, but melting and casting the lead seems like a right of passage for the first time builder. I used eight pounds of lead guessing some would stick to the pan. I fired up my trusty old coleman stove and was surprised how quickly the lead melted. It took only twenty minutes or so to liquefy.

I used a respirator, safety glasses, and big mitts.

Kinda fun, actually!

Smoking hot!

The finished product. I'll encapsulate with epoxy and apply a wood cover. The shape of the recess was designed to not interfere with the shaping of the foil. The weight is 6.5 pounds.

On to the fiberglass...

A sail in the mail...

When it comes to sail rigs it seems everyone has a different opinion. On the other hand, I have very little experience sailing and hence; no opinion. I'm a blank slate when it comes to rigging, so I picked my boat mostly on the opinions of others and the fact I love the way she looks. When I first received the plans I mainly focused on the hull. Gaff, Bermuda, sprit, lug; all gibberish to me. I had to spend some time researching just to understand what I was looking at. Barto's sail plan calls for a stayed gaff rig with 90 square feet of sail.

After a bit of fussing, I decided to stick with the plan for obvious reason; Barto knows what he's doing. We will see if it is as much of a chore to rig up as the balanced lug aficionados claim it will be. Looks cool to me!

I ordered the sail early on because I had a sail maker in mind who works alone and often has a que of work lined up. Several builders with melonseeds recommended Dabbler Sails, a one man shop specializing in small boat sails. The owner, Stuart Hopkins, was very helpful and completed the sail ahead of schedule. He does beautiful work!

Four ounce cream colored Dacron.

Dusty business...

Winter finally arrived on Christmas with several inches of white stuff and the first really cold temperatures of the year. We live northwest of Denver where winters can be quite harsh, however, this fall has been the mildest I can remember since moving here in 1978.
I was lucky to be unhampered by bad weather throughout the fall, but knowing what was coming, I installed a 5,000 watt ceiling mounted electric heater in the shop. Previously, I got by with two small electric/oil radiator type heaters, not adequate when the outside temperature is below 25 degrees. The new heater works great and will allow me to keep the shop at the right temp when I glass the hull.

I glued the last two strips in place on Christmas eve and toasted the occasion with friends, family, and some very stiff eggnog. A hull at last! Christmas morning was spent drinking coffee and planing my next move. I decided the hull will be easier to glass before I apply the skeg. Later on, after the centerboard trunk is installed, I have to flip the boat again to glass the joint. I'll apply the skeg, bottom rub rail, and outer stem at that time.

Fairing the hull

While boat building is new to me, shaping wood is not. I was a professional cabinet maker and luthier for many years, and I've turned a lot of wood to dust. Weather you are building furniture, guitars, or boats, the process of preparing the product for finish is basically the same. I want to be as efficient as possible and use the tool that allows me to remove the most material in a controlled way. Starting with hand planes and spokeshaves and ending with scrapers and sandpaper. I don't advocate the use of electric sanders for fairing the hull. It can be done if you're careful, but it is easy to create dips or ripples that will show up later, after the glass is applied.

  

 

I've tried to keep tolerances tight so to minimize the cleanup effort, but I still need to remove quite a bit of material. I've learned it is best to go incrementally, especially when symmetry is important. I started with a small hand plane at the chines, where the 3/8" bottom transitions to the 1/4" sides. This is really the only place I could effectively use a plane as mahogany is very prone to tearout if one is not careful. Thankfully, the bead and cove worked well to align the planking and I mostly used a cabinet scraper to do the initial leveling.

I worked my way along, starting at the transom and switching sides periodically, being careful to remove material evenly. It is important to constantly feel the surface for high spots and waves, keeping an eye on the symmetry. The key is to keep moving and not fixate on one area.

The cabinet scraper is a great tool if you know how to sharpen it. Lots of folks spend way too much time sanding when they could be using a scraper. For me, scraping is preferable to sanding and, if done properly, leaves a glass like finish. I keep a variety of scrapers in different shapes and thicknesses. The scraper is the perfect tool for dealing with curves.

 

It is important to work in more than one direction while leveling with a scraper. The scraper must be sharpened regularly. A sharp scraper will produce very fine shavings, like a plane. You will know it is time to sharpen when the shavings start to look like dust. A sharp scraper removes material much faster than sanding and provides a smooth finish in one shot.

 

If life was simple one could avoid sanding altogether, however, the scraper cannot adequately deal with the long curves of a 16' boat like the melonseed. To make sure the hull is truly fair it is necessary to use a long board. I could have made one, but I opted for an expensive 3M product with fancy hook/tooth sandpaper. The board is 30" x 4" and it's flexible. A rip off at about $60 bucks, but well worth the money if one factors in the time saved and the excellent results. Using it is a great workout.

 

I'm currently at about 80% with the fairing. Since I began the planking process in October the mahogany has darkened considerably, making it very easy to see the low spots. The emerging hull is an amazing thing, graceful, with sweeping curves and a distinct fish like quality. I love it!
 

 

Happy New Year!