Showing posts with label fairing. Show all posts
Showing posts with label fairing. Show all posts

Tuesday, August 11, 2009

Finished and delivered!

I finished the canoe! I really need to catch up and post the final series of pics, but I'll get to that later.

I put the finishing touches on the canoe last week and was ready to get it out to the water for a test drive before I turned it over to the client. The first thing I noticed was just how much bigger than my Bob's Special that this Prospector 16 is. It is immense! Even though it's only a foot longer and a couple of inches deeper, it really seems huge.

I took it out to Northeast Creek to launch at Camp Brewster aboard Camp Lejeune. When I set the unloaded canoe into the water, the first thing that stuck out to me was the fact that less than 1/3 of the hull was in contact with the water. I performed a wet launch, and when I climed in, the stability of the craft was impressive. Even with me climbing over the gunnels, the canoe was incredibly stable and, at no time did it seem like it was going to capsize.

I then knelt in the center of the canoe and heeled it over and the responsiveness was pleasing. I paddled it sideways, forward, and performed turns with the greatest of ease. This is one amazing craft! It will go any direction you tell it to go, and go with ease. I look forward to building one (or two) for my own use soon. But before I can build my own Prospector, I have a couple of other projects to attack.

I will be building a pair of loft beds with desks and dressers next, as well as a set of book shelves. Those projects will show up here as they progress. I also have to get my workshop in order now that I have cleared out some space. I am also currently engaged in building a small cabinet in cherry for a half-bath in my house to hang above the toilet, and will also get pics of that up here as well. Hopefully, I will be able to begin my canoe around October and be ready for launch in the spring.

Saturday, April 11, 2009

Fairing complete. Let's lay some glass!

Fiberglassing the hull is one of the most nerve-wracking (to me, anyway) things to do in the building process. Mainly this is because once started, you have to finish; can't stop until the last coat of epoxy is laid. My concern is that I will get started and find something that I didn't do. I really need to learn to trust my abilities and instincts and. That said, the process is relatively straightforward.

Once the hull is faired and filled, the hull gets sanded with 80 and then 120 grit sandpaper. The 80 grit sanding provides an initial fairing and then the hull gets wetted down with water. The water raises the fibers of the wood that have been mashed down by the scraping and initial 80 grit sanding. Then the final sanding with 120 knocks off the fuzz and provides a good, smooth surface for the glass to adhere to.

Next up, the fiberglass cloth (60z cloth, 60" width and about a foot longer than the canoe) gets laid over the hull. It looks like a sheet draped over it. The glass must overhang all edges at the sheer and the stems.

With the cloth in place, the epoxy gets mixed and brushed on. In brushing the epoxy, enough of the epoxy needs to be applied to soak into the wood and completely saturate the cloth in order to create a good bond. It's important to not leave areas starved of epoxy, as this will either show up as a blemish on the completed hull, and will create weak spots. I don't worry about using too much epoxy at this stage. Runs don't bother me here because they will be taken care of with the squeegee coming later.

Application of the epoxy requires two people (in my shop). I apply the epoxy and my assistant (oldest son) mixes and watches the time for me. Starting at the keel line near one end, I apply epoxy from keel to sheer all the way to the stem on one side; about two feet of the hull. Then I do the same bit on the other side. This anchors the cloth to the hull for the remainder of the epoxying.

Continuing down the hull about two feet at a time, keel to sheer, wet edge first, and side to side, I continue to apply epoxy. I skip back and forth to always overlap the wet edge to ensure the best possible bond.

After about 20-25 minutes, my son tells me to go back and start squeegeeing. At this point, the first section that I applied has begun to set and get a little firm. I use a plastic squeegee (the type used in auto body repair to apply and smooth body filler) and scrape off excess epoxy (and those runs I allowed) and smooth the whole bit. Care has to be exercised to not take too much of the epoxy off which would starve those areas and cause blemishes, but I have to take enough that the glass/epoxy is smooth.

I will continue to work in this way- side to side, spread and squeegee- along the entire hull until the whole thing is epoxied and smoothed from stem to stem, and then it's time to wait. Once the first coat is applied, it will be about 3 hours (depending on temperature and humidity) until the next coat can be applied. I apply three coats of epoxy to the outside of the hull. The first coat adheres the glass cloth to the wood, the second coat fills the weave of the cloth (mostly) and the third completely covers the cloth so that it can be sanded smooth for a final finish of varnish. All three coats are necessary so that when you do that final sanding you don't sand into the cloth. If you sand into the cloth, it will show as a white blemish and potentially weaken the hull in that area.

After the third coat is applied, I like to give it a day or two to cure and then I can turn the hull upright for the first time. This is really exciting for me because it's the first time that it actually looks like a canoe. Once it's turned upright, fairing can begin for the inside in preparation for the 'glass on the inside.

You can see a more detailed series of pictures of fiberglassing a canoe (where I am glassing another canoe) here.


Wednesday, March 4, 2009

Let the fairing begin!

With the stems shaped roughly, it's time to cut the sheer of the hull. The sheer is the line of the top of the canoe as it sits in the water that gives the canoe it's familiar shape. Cutting the sheer is pretty straightforward:Start by placing a batten along the sheer from the station molds and use that to draw a line to be cut to.

Once the sheer is completed, it's finally time to begin fairing the hull. For those not familiar with canoe or boatbuilding, fairing is simply taking the strips from a faceted state from the initial assembly of flat pieces and smoothing the angles to make smooth curves all around no matter where you go.

Note also that I have plugged the screw holes in the outer stems with dowels. This fills the holes first and foremost and it also adds a very subtle design element. The dowels will be visible when the canoe is finished and will be finely placed "dots" that show. I think they will look pretty neat. On my last boat, the only screws I used were on the gunnels at the deck ends. As a result of using the screws there, I had to plug the holes in this manner. Once it was done, I really liked the way it looked and decided that the next canoe would have these screw holes along the entire length for subtle decoration.

Another view of the stem.

The fairing process is fairly involved and takes a bit of time. Steps to be followed from initial fairing to ready for glass are as follows:

  1. Initial fairing- Either by hand plane, hand sanding, ROS with 80 grit paper. Whatever you feel comfortable with. The key here is to take the high spots where the planks meet and knock them down to make the hull initially fair.
  2. Filling- It's inevitable that there will be a need to fill somewhere on the hull. I did the filling after the initial fairing for a couple of reasons. First, by completing the initial fairing, I can better assess the spots that need filling. Second, I am going to sand the hull at least two more times and will be able to clean up anything that needs it on the next couple of sandings.
  3. Second sanding- Again with 80 grit. I know this sounds a bit aggressive, but the filler from step 2. is epoxy mixed with sanding dust (wood flour) and that stuff is hard to sand. I go aggressive to clean that up. However, care needs to be taken in order to not create dips and gouges with the power sander.
  4. Wet the hull- This is done to raise the grain of the wood fibers that may have been mushed down during the sanding processes. It also will highlight the spots where you still have glue that needs to be cleaned up. If you don't get all the glue/epoxy off the hull before 'glassing, those areas will show as light or blotchy. The way I see it, if something is avoidable, avoid it.
  5. Final sanding- This sanding is accomplished with 120 grit after the hull is completely dried out from the 4th step. This will prepare the hull for the 'glass and also knock off the raised fibers from the wet the hull step above. Once this step is complete, the hull is ready for 'glass and epoxy.
Hopefully, with the posts and pics, and now with the schedule I just laid out, things still make sense. I will be completing the sanding and fairing soon and getting to fiberglassing, so stay tuned.