Thursday, September 30, 2010

Two Stabilizers + Seat Preliminary

The two stabilizers are now just about ready for wrapping in glass and epoxy. With a little more sanding to remove the excess resin from the touch-up, they will be all set.

Now if only I can find a source of biaxial tape, I'll be all set!

Meanwhile, I tried an initial setup of the seat back.

This will require some thought as to what sort of jig or bracing will work best to secure the pieces for glassing. If worse comes to worst I might succumb and resort to stitch and glue techniques.

Tuesday, September 28, 2010

Second Stabilizer Cleanup

Tonight I spent an hour and a half with the belt sander carefully cleaning up the excess resin on the four surfaces of the second stabilizer.

First, I had to remove the shrink wrap plastic, which turned out to be somewhat more difficult than expected. Why? Some of the resin had solidified around folds in the plastic and managed to hold it in place. Also, at one end where I had to pinch the sides together and have them rest on the flat top panel, the plastic managed to get pinched between the side and the top piece.

The plastic was strong enough that I could gently pull it out, but of course the plastic prevented the resin from securing that section of the two pieces together.

Anyway, after spending some quality time with the belt sander making everything flush and smooth, I mixed up a tiny portion of resin and used it to fill the gaps.

I also weighed the first stabilizer on a wife-approved food scale. It was 4 pounds, 0.5 ounces. This is before adding the external layer of glass or glass tape and resin.

Sunday, September 26, 2010

Second Stabilizer Assembled

I didn't have much time this week to work on the boat. Still, I glued the short section of the first stabilizer where the side did not quite meet the deck, making sure to apply a clamp there to keep things together.

After the resin hardened I belt sanded off the excess, and smoothed out the other drips I had missed the first time through with the sander.

Today I double checked the fit of the side pieces at their tips and did some touch up belt sanding to get them to meet flush at the ends. The 6 inch wide belt has a bit of an upward curl on both edges, so this makes it a bit of a challenge to not remove material that I really want to keep.

I rigged up a long work board (8 feet by 1 foot by 1.5 inches) on which to apply resin to the stabilizer panels, and lined it with shrink wrap plastic. This was much more ergonomical than a long sheet of waxed paper on the floor of the garage.

After mixing up another cup of resin I glued the second stabilizer together. The only hitch I ran into was that one of the foam bulkheads was a couple of millimeters too tall. I was not pleased, especially since I had just applied resin to it.

After some judicial use of paper towels and the little belt sander the bulkhead now fit much better.

As with the first stabilizer I clipped the bow and stern, though this time I added some force from a C-clamp to the bow clip to get things to fit tighter. A bit more weight was added to various points along the top board to make sure of a good joint.

The shrink wrap used to keep the main workbench clean was much better than the waxed paper to see if the sides and the top and bottom were properly fitting together. I could feel if the sides were pushed in too far or were sticking out too far, and see it as well.

With the second work table the process of applying resin to the boards went a bit faster this time. The resin in the mixing cup didn't get hot, and a second batch wasn't needed to finish the job.

Time spent today: approximately 1 hour.

Wednesday, September 22, 2010

Plastic Bags and Epoxy

When working with epoxy it is good to have something under the thing being epoxied to separate the thing from the table upon which it is sitting. This keeps the table clean from drips and keeps the thing being epoxied from being glued to the table.

I often use something cheap and readily available such as waxed paper. The downside to waxed paper is that it can leave a waxy residue on the surface of the epoxied part, and it sometimes doesn't release properly. Instead, it tears and leaves pieces embedded in the epoxy.

People often use polyethylene plastic sheets or bags instead. It is pretty cheap, and generally available from builder supply and hardware stores. It comes off epoxied surfaces fairly easily. However, it is optically translucent and difficult to see through. Thinner sheets also have a tendency to wrinkle, and those wrinkles transfer into the resin. The resulting surface, even if you smooth out the wrinkles, is dull in appearance.

As I happened to have two kinds of polyethylene available, one from the bag my morning newspaper is delivered in and the other which was used to secure the bottle of resin as it was shipped to me, I decided to see how well they worked for bagging wet resin surfaces.

I also happened to have a large roll of shrink wrap plastic, so I tried that as well. Shrink wrap plastic is optically clear and about as flexible as the newspaper poly bag. The resin bag was a bit less flexible, but intermediate in terms of optical clarity.

The results were amazing: While both poly bags did pretty much what I expected, i.e., dull finish with wrinkles, easy to remove with a bit of tugging, the shrink wrap plastic delivered a superb glossy finish with very few wrinkles. The plastic practically fell off the resin with no effort. Wow!

Even the area where the steel block was used to press against the bag against a test piece of epoxy soaked glass was flatter and shinier than where the poly bag was.

I'm going to see if the shrink properties can stand in as a replacement for vacuum bagging, too. It almost certainly won't be quite as "tight" as vacuum bagging, but it might be adequate.

Tuesday, September 21, 2010

Prep Stabilizer for Glassing

Last night I removed the waxed paper from the stabilizer. As expected, much of the excess epoxy ended up along the bottom edge where it formed into a somewhat flexible flash. Some of this could be removed by snapping it off. Some of the thicker sections were quickly removed on the bench belt sander. I had to take care to not go too long on any given edge so as to not chew into the joint.

The rest I removed with a hand held electric belt sander with an old 80 or 100 grit belt. This actually worked very well, as I paid attention to the direction of the belt and the grain of the wood. It is important to apply sanding pressure against the edges where it was supported by the underlying wood so that the edge doesn't split or fray.

Along one edge the side managed to get glued slightly recessed from the edge of the top. While this could be handled with filler paste and faired smooth I chose to sand the top edge to be even with the side. One way or the other needed to be done so that when the exterior was glassed there would be no cavities.

I then belt sanded smooth the remaining high points of epoxy. This went pretty quickly.

Most of the seams turned out fine. Unfortunately, however, there was not quite enough weight put against the bottom, so the edges did not quite meet in one area. This will be addressed when the glass layer is applied as it should be easily filled with epoxy.

Tonight I think I'll either have to get more waxed paper or, better yet, some polyethylene plastic and put together the other stabilizer.

Sunday, September 19, 2010

First Stabilizer Glued

Yesterday was spent out on the water near Olympia at the Sound Rowers Budd Inlet Race. I took some 650+ photos, and edited it down to 630. They were finally uploaded and posted this afternoon - leaving me a couple of hours to work on the new boat!

First, I replaced the belt in the sander. It was an old, well used 50 grit, and it took two trips to Sears to get a good replacement. The new belt is a 48" x 6" 50 grit, and it is perhaps a bit too quick at material removal. The second stabilizer's tips are perhaps half the thickness of the first stabilizer, and it took only 5 minutes to do all four ends.

Just for fun I weighed one of the stabilizers with the foam pieces. It was about 3 pounds, according to my more or less accurate scale.

The next step was to actually glue a stabilizer together. After lining the workbench with a sheet of waxed paper, I set the top piece on it. I nudged the paint cans towards the piece so that the waxed paper was folded up on both sides of the stabilizer's top piece. This would prevent the epoxy from sticking to the paint cans when they were shoved against that piece and the sides of the stabilizer.

After mixing about a cup of epoxy resin, using a paper hot beverage cup for the container and reused chop stick, I squeegeed the resin all over what is to become the interior surface of the top piece.

I then remembered that I would have to apply resin to the side pieces as well and needed a place to apply resin to the them that wouldn't leave a mess. Quickly I laid another length of waxed paper on the floor of the garage and placed the first side piece on it.

I dribbled some resin down its length on its inward side and squeegeed the resin all over the broad surface as well as the edges. After separating the board from the waxed paper it was put on the top piece on the workbench in roughly the correct position.

The second side piece was then covered in resin on the inward side as well the top and bottom edges. It was placed on the workbench adjacent to the other side piece.

I rubbed the bulkhead foam pieces in the excess resin on the waxed paper on the floor, and put them in place between the two sides of the stabilizer on the bench. The paint cans were adjusted to squeeze against the top piece and to keep the sides flush with it.

At the ends I folded the excess waxed paper over and held the ends together using plastic chip bag clips. These provided adequate clamping action and spread the force over a reasonable area.

At the stern I had two somewhat smaller clips to cover the larger area.

The remain 1/3 cup of epoxy was getting quite warm by this time. In fact, it had actually started solidifying. Rats! It would have been the perfect amount to have finished coating the bottom piece and the remaining edges. I poked at it with the chopstick and it went "poof", with a small vapor cloud emanating from it. It was nasty!

There was a bit of liquid resin below the solid section, so I tried to apply it to the top piece. I only needed a little! This was not a smart thing to do. I had forgotten how gooey this stuff gets when it has begun hardening.

I had to scrape off as much as I could, then clean the squeegee.

Hurriedly I mixed about a 1/4 cup of resin and applied it to the bottom piece. Before placing it on the other pieces on the workbench I took the chopstick and sort of dribbled and painted it on the edges of the sides. It work pretty well, though there were a couple of drips here and there.

The bottom panel was applied and centered. A weight was placed on the section that bends upward at the bow so that the panel would meet.

I noticed that the sides were not quite flush with the top piece. Adding a big hunk of iron to the center section solved that problem.

Hmm, the side pieces were sticking out on either side by a millimeter or two. Adjusting the pain cans didn't solve that, so I added a few C-clamps along the length, lightly closed. Some additional weights were applied at various places to help make sure that there were no gaps between the pieces at the seams.

The whole process took about an hour.

According to the instructions provided with the resin I have 72 hours to finish working with this stabilizer before I would have to sand it for a subsequent application of resin. Tick, tick....

Monday, September 13, 2010

Chamfering Edges

On weekday nights I don't have a lot of time between preparing dinner, interacting with the family, work-related stuff, clearing out more of the family room and, oh yes, sleeping!

Anyway, there is time enough tonight to chamfer the edges of one of the stabilizers on the belt sander, which would probably go faster if I replaced the belt with something a little newer. Still, the plywood is a hard wood and by its very nature it takes longer to remove material.

Here are the front and rear ends of one of the stabilizers, chamfered to about 1.5mm at the edges:

Here is a view of the sides and top, with the bulkhead foam blocks in position. The paint cans are an experimental alternative to making forms. With the nice, flat table surface and the side panels held in place by the reasonably heavy paint cans, force can be applied where needed, and adjusted as needed.

Here I'm holding the two sides of the bow together. When gluing I'll use spring clamps instead of the nylon cable ties that Rick suggested. That eliminates the need to drill holes and then fill the holes later on.

Since the bottom of the stabilizer curves upward at the bow, it will need some weight along its length to make sure that the panel follows the curvature of the sides. For the picture I'm merely holding it in place.

Sunday, September 12, 2010

Bulkheads cut

Progress has been surprisingly slow due to other commitments. Photo shoots at two races pretty well shot the Labor Day weekend and this weekend. Still, it was fun being on the water - even if it was in my slow boat.

The workbench is now cleared of most extraneous junk from previous projects, and the stabilizers have made their way to it.

I spent way too much time tonight cutting the 6 blocks of foam to be used as bulkheads. There was a foam beam left over from a previous boat project that was perfect for the two bulkheads near either end. Unfortunately, it was mostly just a smidgeon too narrow for the central bulkhead, except for a couple of short sections here and there. I managed to mess up a few of the pieces, sanding them just a bit too much on the disc sander. After a bit more care two central bulkhead pieces were finally produced. Sigh...

Saturday, September 04, 2010

New boat

I've been lax over the two years in not posting anything about my pedal boating experiences. Yes, I've been out on the water, but since September of last year I no longer have a fast pedal boat. The Escapade has been my only boat, though I did borrow a Cadence from a friend of mine for the NAOWRC Townsend Challenge race.

Anyway, the reason I sold my fast all-purpose Cadence pedal boat was in order to get a faster racing oriented pedal boat. The 6.5 mph long term cruise speed of the Cadence was not enough to keep up with the most surf ski paddlers, let alone the single and double rowing shells.

So, with the extensive help and advice of an Australian boat designer and pedal boater, Rick Willoughby, I'm starting the construction process of a V15_6m boat. Here is a 3-D rendering of the boat moving at racing speed:

So, after hemming and hawing over whether the boat should be built from foam core fiberglass composite, foam core carbon fiber composite or marine grade plywood, I finally opted for the plywood approach. I figured that it wouldn't be too much heavier than the fiberglass with 4mm Okoume plywood, probably a bit sturdier, and perhaps a lot prettier when completed. It would be cool to go to the annual Wooden Boat Festival in Port Townsend with a fast wooden pedal boat!

After getting the drawings from Rick I sent them to Turn Point Design, a CNC shop shop in Port Townsend that came recommended by the folks at Pygmy Kayaks. If you don't know, Pygmy Kayaks is renowned for their beautiful stitch and glue kayak kits.

Anyway, Brandon at Turn Point Design came up with a reasonable quote to convert the drawing file to a CNC program to lay out and cut the 4x8 sheets of Okoume 1088 marine grade plywood. He indicated his shop had been involved with other boating projects, including Pygmy's prototypes, the America's Cup yachts, etc., and he promised quick delivery so he got my business.

Today he dropped off the panels - for free, no less! - and now construction is about to begin.

Here is a photo of the CNC-cut panels, just after opening up the carton:

Here is a photo with the panels spread out a little:

Here is a close up of the scarfed edges. This should help make for stronger joints on the resulting longer sections of the hull and deck:

Here is a close up of the panel with the hole cut for the stuffing box:

The weight of the panels, according to my more-or-less accurate scale, was 41 pounds. This included a couple of scrap pieces packed with the panels, plus the cardboard wrap. It turned out that Brandon was able to fit everything on 4 panels rather than the 5 he originally thought were necessary. I'm going to have to piece things together without gluing first and see if perhaps he somehow missed something, because both Rick and I can't see how he did it - and still have so much scrap!

After that, then the next step is to do some test layups with the resin and filler putty. I got that stuff from Fiberglass Supply, up in Burlington, WA. They are known for their support for stitch and glue builders, surfboard builders, etc.