So after all my floating, and recalculating, I ended up locating the keel box right where I had originally calculated it would be. Which was great since I had already installed the main cross beam which now intersects the keel box perfectly! I was still a bit nervous cutting that hole in the hull though...mainly because yesterday it floated so well, it just seemed a shame to put a hole in it! The tricky part today was getting the boat leveled in all directions so I could be sure the keel box is installed straight on centerline, and plumb all around. I think I was able to meet most of those criteria so I epoxied it in position.
Wednesday, December 15, 2010
Well, since it's now time to install my keel box, I started to worry about where to locate the thing. I had calculated a center of buoyancy...but how accurate was my calculation. I really didn't want to attach the keel only to find the boat sits way off it's lines. So I figured the best thing to do was to go float my boat. Sounds simple, but the problem was I didn't have an easy way to get the boat to the marina. Also, it's been nasty windy, rainy weather here in the Northwest. So even if we could use the boat lift, it would be tough getting any useful data with the boat bouncing around in the waves. So yesterday, I decided the best thing to do was to bring the water to the boat! So I built myself a 28'x8'x1' test tank in the shop and filled it up with water. Once word got out about what I was doing, I had no shortage of people show up to help me move the boat into the tank. (I found out later it was because they figured some sort of disaster would likely be part of the evening's activities and it was not to be misses!) The floating of the boat went off without a hitch. With no keel, it floats a bit nose high. So I had the three guys go inside and simulate the weight of the keel. By moving just over a foot forward of the center of the buoyancy, the boat floats level. So with this info and a few more calculations, I will now be able to mount the keel with confidence!
Thanks to Chad, Dan, Dave, Erik, Kris, Michael, and Mitch for the use of your muscles and ballast. Sorry there wasn't a flood or any other disasters to entertain you guys! (and thanks to my wife Denise for taking the pictures so that people would actually believe I went sailing in the garage)
The toughest part of this little adventure was keeping my boys out of the tank today as I was filling it up. They kept trying to convince me we need to leave this thing in the garage all winter long. After we were done with Vertigo, they launched their El Toro dingy and paddle around for a while. Too much fun!
Saturday, December 11, 2010
I've nearly finished fairing the keel bulb plug. I think I may add a layer of glass just as reinforcement so the bondo "egg shell" doesn't crack when I push it into the concrete/mortar mix. My plan is to make a 2 part mold divided into upper and lower parts. The upper part will have the filling ports. My goal is to make this a one piece bulb rather than having to bolt 2 halves together.
I am really fortunate to have the i550 blogs to look at. Even though it's a different boat, it is still kind of similar and I am able to pick up a lot of little tips from seeing what those guys are doing.
Today I also got completely caught up on all my interior joint taping. I also set the keel box on the floor of my boat and daydreamed about what kind of grid system I will use to integrate it into the boat structure. Not having a plan means ultimate freedom..but it also means lots of time just staring at stuff!
Thursday, December 9, 2010
Finally, the keel fin is faired and I'm very happy with how it turned out. So next I built a keel box. This will mount inside the boat on the floor and will, along with a grid structure, provide the support for the keel.
Basically I just used the keel fin as a mold to make the keel box. I did add some duct tape to make the finished box a bit bigger around the leading and trailing edge areas. This will allow a bit of wiggle room to allow the keel to slide up and down more easily. Next I wrapped the keel in plastic sheeting so that the keel box didn't become a permanent part of the keel. Then I began wrapping the keel in Biaxial glass. After 6 layers, I decided to let it set up so I could make sure this thing would slide off.
It didn't. As I mentioned before, I wrapped the keel with multiple layers of plastic sheeting before I began the glass layup. Unfortunately, as I began sliding the keel box off, it slid a few inches and then layers of plastic began to bind up. For over an hour, I tried all sorts of tricks and nothing worked. Not even yelling at it. Finally, I used a razor knife and sit it along the trailing edge. It had enough flex that I was able to pop it free and slide it off. I then pulled off the offending plastic and tape and slid it back on. Perfect fit! Snug but slides easily along the length of the keel fin. I then left it on and added another 4 layers of uni-glass. So I ended up with a nice fitting keel box that is about an 1/8" thick solid glass.
Tuesday, November 30, 2010
One cold night as the snow was falling and I didn't feel like heading out to the shop, I figured I should start thinking about the keel bulb. So I poured myself some wine and I did. And what I thought was, there's no reason for me to re-invent the wheel and try come up with my own bulb shape. Since this project is sort of similar to the i550, I've decided to use the bulb shape someone already designed for that boat..with only ever so slight modification. I found the bulb lines on the i550 forum and downloaded them. The only problem is that the i550 bulb weighs 180lbs and I'm thinking I need this thing to weigh around 550 lbs So I grabbed my calculator, scratch paper, another glass of wine and began measuring, calculating stuff, and running ratios. By some method which my memory is not exactly clear on, I arrived at the conclusion that by enlarging the i550's bulb dimensions by 45% this new bulb would weigh precisely 550lbs. I know when I did the calculations I was pretty confident that they were sound, however, I will consider any weight between 475 and 600 lbs a complete success. And if it's way off, I melt it down, build a new mold, and re-cast!
The first step is to build a plug which I will use to cast a female mold in plaster or concrete. I am building the plug out of plywood and foam which I will fair (arg!! there's that word again!) and cover in fiberglass.
Wednesday, November 10, 2010
Finally finished laminating the keel. Ended up using E glass alternating between 12 ounce biaxial and 10 ounce unidirectional fabrics. for a total of 11 layers. Did a simple hand layup using a brush, squeeges, and a laminate roller. It's a nice thick layer of fiberglass. From what I can tell, it's just over an 1/8 inch thick. Which should be just about right. It also seems quite smooth and true to the foil shape. I'm sure I'll still have to do some fairing, but hopefully not too much.
Friday, November 5, 2010
Got the keel core done today. I'm happy with how it turned out. I thought I would have to do some fairing but it's actually so close that I'm not going to risk messing it up! I would of started laminating but I didn't have enough time to do all 12 layers so I didn't want to start. I have a race ('Round The County) this weekend so maybe on Monday....
Tuesday, November 2, 2010
Got home from work today and had some time to work on the keel fin core. After finishing making the cuts, I spray painted the whole thing dark green. By doing this, it will be easy to see the depth I need to go to as I chisel and sand. By using a chisel and mallet, I'm able to get rid of the wood and bring it down toward the right shape. Then I use the sander to continue shaping the blank. Once I get the foil shape roughed, I'll make a template and use filler to fine tune things. It's fun and I'm feeling quite craftsman-like as I'm using the mallet and chisel to carve this foil shape. Just hoping the finished core looks craftsman like!
On my way home, I stopped by Fiberglass Supply (that place is like a candy store..without the tooth decay!) and picked up the glass I'll need for the lamination. I'm using 12 oz bi-axial e glass and 10.3 oz unidirectional e glass. Probably around 6 layers of each will give me the strength I need and will give the foil a skin thickness of 1/8 inch which will give me the right shape.
Friday, October 29, 2010
The pine laminated very nicely to form the keel blank. I then marked the foil on one end of the blank. My plan was that I would run it through the table saw at depths that corresponded to the foil outline--just like I did with the foam for my practice rudder (yeah I've decided that was just a practice rudder...pink foam is just not gonna do the trick!) The difference,however, is that the pink foam weighed nothing, and this plank (even though it's pine) weighs a ton! I tried the table saw thing but trying to push it through by myself with any degree of accuracy was going to be a dissaster! So I decided to bring the saw to the blank by using my skilsaw. This seems to be working great although it takes a while. I'm using a piece of 3/4"ply as a straight edge that I clamp in place. I then set the depth, and make a run down the blank. Then I unclamp, move a quarter inch, reclamp, reset the new depth, and cut again..and repeat..over and over. It's not hard, and seems to be working quite well...it's just a bit tedious and takes some time!
I had a good talk with the guys at Fiberglass Supply yesterday. Matthew was very helpful as I talked about my keel ideas. The guys at FS are totally cool and are always helping me brainstorm stuff. So it turns out that I don't really need to make this keel out of carbon fiber...even though CF is sooo cool! The biggest advantage to carbon is how stiff it is for it's weight. And in certain situations, this is really important. I'm not that concerned about making the keel fin lightweight. So I can use S or even E glass..and just increase my layup schedule to reach the same strength as the CF. It may flex a bit more..but it will still be strong (at less than half the price as CF) Besides, I'm gonna paint the rudder and keel orange(cause orange is fast!) so no one would be able to see the awesome black carbon anyway. I head off to Seattle tomorrow to work a few nights...so probably work on shaping the keel fin some more come Monday.
Sunday, October 24, 2010
This past week I did no actual work on the boat. I did however help out the boat cause. Since my wife has been very patient with me working on the boat so much lately, I decided to tackle a project for her (building cabinets/bookshelves) Although it took all my days off, she is very happy and I've built up some currency I can cash on the boat project! Truly a win/win situation!
Friday, October 15, 2010
So today I did some more painting. I was able to get 2.5 coats of epoxy primer on the hull. I have to say that after all the sanding, it has been really fun to finally paint. My plan now is to finish a few more coats of paint on the hull. Once the exterior is primed, I will focus on working on the inside of the boat..hopefully finish the inside this winter. One of these days I need to use a real camera to take some pictures instead of my phone which kind of distorts things. Also, now that the boat looks all nice, I guess I should give the shop a bit of a cleaning too..of course that means valuable build time wasted!
Thursday, October 14, 2010
Thursday, September 30, 2010
So last week I covered the decks, cockpit and cabin top with glass, fully encapsulating the boat. This week I was able to fill the weave of the glass. I used 2 thin layers of epoxy slightly thickened with micro-balloons. Of course this meant bleaching, scrubbing, and sanding between layers, and after the second layer was cured. After a couple days of work, I'm happy to say the weave is filled and things are feeling pretty smooth. Next i will fill the weave on the hulls shear panel section. Once everthing is filled and smooth, I will check for problem areas and tackle some little fairing projects. I have to go work for a few days but will hopefully be able to work on the boat a bit next week. I don't really enjoy the whole sanding for hours and hours thing so it is important that I keep the momentum going and get through it! Still having fun though!!
Saturday, September 25, 2010
The one bad thing about West System epoxy is that it sure seems to blush. For some reason during the curing process, a wax like substance forms on the surface of the epoxy. To ensure proper bonding of the next layer of epoxy, this waxiness has to be removed. I've found the best thing is using bleach water and a scrub brush. Then I lightly wet sand with 80 grit and wipe with a rag. This seems to get most of the yellowish-orange "blush" off. This morning, I was able to bathe the whole boat this way in order to get ready to "fill the weave" of the fiberglass cloth. After the wet out cloth cures, it is a long way from being smooth. It currently still has the texture of cloth. I will use epoxy slightly thickened with glass microballoons (to make it a bit more sandable) to fill the woven texture of the cloth and to build up a sandable surface that I will be able to make smooth.
Because the cloth I used was only 38" wide, I ended up having 2"overlap lines where the sheets of cloth would meet. I used the blet sander to grind these down so they will be easier to blend when I begin filling the weave and the final outside fairing.
Well, most of the outside structure is complete and prefaired so it's time to start covering things with fiberglass cloth. Adding cloth adds some stiffness to the plywood, but mainly its to provide a moister barrier and also more resistance to impact and abbrasion. I started with the transom, then the decks and the cabin top. I used 6 ounce e glass cloth for this. I had the whole day off and was able to get the whole boat covered. Wetting out all that cloth took a lot of epoxy. I think I still have enough left to finish the outside of the boat though. I just bought sails for my racing boat and don't want to have to tell my wife I need to spend another $500 on epoxy!
So now my boat is waterproof! I could plunk it in the harbor right now and go float around with no ill effects to any of the wood. Sweet! It's officially a boat!
On my San Juan 24, the cockpit isn't very wide. The boat can heel way over and I just stand on the opposite cockpit moldings and can drive comfortably. This boat has way more room in the cockpit. It's so wide, my feet can't touch the other side when I'm in my estimated driving position. So I figured (actually Erik pointed it out to me...but I'm sure I'd of eventually noticed) I had better add a foot brace thing. It's made of 1/4 inch ply and epoxy and runs down the center of the cockpit. It turned out nice and straight and should be plenty strong to take all sorts of abuse that I'm sure it will see. It also further stiffens the cockpit floor..which may now actually be bullet proof!
Thursday, September 2, 2010
Once I had all the seams taped with fiberglass it was time to "pre-fair" This involves first grinding the sharp edges of the glass tape. There is still a difference in height between the glass tape and the wood surface. If I just went over everything with the final layer of glass, there would be a bump where the tape runs underneath. This would then need to be faired. Instead, I'm fairing all the tape and most any bumps or misallignments now so that all the major bumps are gone and things are fairly smooth and even before the final layer of glass. This will mean the majority of the fairing compound and build ups will be below the final layer of glass which should make it more durable and decrease the chance of chipping later. So now I'm just spending time spreading a light weight fairing mixture along all the tape seams and any other imperfection areas and sanding the whole surface smooth in preparation for the final glass cloth layer.
I'm now devoting all my build time to getting as much done on the outside of the boat before the weather turns cold and the epoxy and fairing compound start taking days to fully cure. Once the weather turns cold, I'll work on the inside of the boat where I can easily keep it heated.
I continue to make progress with an hour or two here and there. I'm having a blast working on this project...just wish I had more time to devote to it!! But it will get done someday!!