March 3, 2012
Frames are done. Next up, setting up the building platform. I have materials on hand to assemble the legs, diagonals and cross-pieces. The leg assemblies will be built tomorrow but final assembly of the platform will have to wait until I can get to the lumber yard on Monday.
Once the platform is put together (but before the stations are set) I need to scarph and cut out the bottom panel. I expect to begin assembling the hull by the end of the week.
Recent work includes gluing up the centerboard blank:
Checking the frames for ventilation and limber holes, completed doublers and smoothed edges:
Not all of the frames fit on the work bench so not all of them are shown in the photo. Due to limitations in the shop, that work bench will be cut down to 16" x 96" (roughly in half) to make a little more 'walk-around' room to work on the boat.
January 10, 2012
Over the last few days I lofted, cut and glued the side-arms for Frames 3, 4, 5 and 6. This leaves Frame 6A and the Transom - along with the Spine/Stem and Seat Fronts - to be completed in the next few days.
The newly arrived resin and fast hardener (particularly the fast hardener) ought to shorten the epoxy cure time and speed up some of the work. The centerboard blank needs to be glued up so it can cure completely while I finish Frame 6A, the Transom, the Spine/Stem and Seat Fronts over the next few days.
I took some time yesterday to true and hone the irons for my hand planes. The system I use is called Scary Sharp and uses sandpaper ranging from 120 grit up through 2500 grit. Setting up the sandpaper takes longer than sharpening the irons but it is exciting to see a metal-mirror surface appear after working up to 800 grit. It is amazing to see a glass-like mirror surface appear after working through 2000 grit paper. Once I am done with the hull components I can have some fun shaping the centerboard and rudder.
January 5, 2012
The mail-person/letter carrier delivered part of my DuckWorks order today - the inspection hatch for F-1 and a piece of stainless that will become the lifting strap for the centerboard.
The inspection hatch installed:
F-1 needs epoxy coating. And, yes, the inspection hatch needs fasteners.
The bottom panel of Frame #5 was lofted and cut out today. The doublers on the foreward side were glued in place.
The side arms will be cut and glued tomorrow.
December 18, 2011
There are a number of notches to be cut in each of the frames. Each stringer - there are 8 planking stringers and 2 chine stringers - fits into its notch on each frame. The frames and the stringers make up the 'skeleton' of the boat. There are other notches in some frames for bunk and seat supports.
Most of these notches measure 1-3/4" wide by 3/4" deep. All of the notches require square corners to accept the stringers and supports. The placement of the notches on the frames makes using a power tool awkward at best, nearly impossible at worst. The saber saw is too unwieldy and doesn't cut fine enough. Wrestling the frames around and through the band-saw would be at least unwieldy if not impossible.
I cut the notches by hand. The following series of photos shows how I do it:
Rough cut (vertical cuts broken out with chisel)
December 14, 2011
Visual Proof of Progress!
The assembly of Frame #1 is complete!
I still have to make the cut-out for the inspection hatch (the one I have is too large for this frame) and coat the frame (including all edges) with epoxy.
The assembly of Frame #2 is progressing but, due to operator error, slowed a bit. The top cross-piece is to be 3/4" thick, laminated from two 3/8" pieces (the plans do not call for 3/4" ply anywhere else so there is no need to buy a sheet of 3/4" ply). Well, I cut two pieces of 3/8" and decided to glue them so that both sides of the lamination would be "A" sides (I am using A-C exterior ply). Unfortunately, the ply had a slight bow, so when (here comes the operator error) I didn't use enough epoxy and didn't wait long enough for it to properly cure, the two pieces of plywood separated (the bows pulled away from each other).
I let the epoxy cure while I decided what to do. I could sand down the cured epoxy and re-glue these two pieces. I could use another sheet of 3/8" ply and cut new pieces. I could buy a sheet of 3/4" ply (and find other uses for the rest of it).
My first thought was to rule out buying 3/4" ply. My next thought was to cut and glue new pieces of 3/8" ply. I didn't like the idea of sanding cured epoxy - dusty, messy and pretty much unpleasant. But I decided to see just how dusty, messy and unpleasant sanding the epoxy would be. So, with a respirator on, the shop-vac connected to the sander and an 60-grit disk on the ROS I found that the sanding job was tolerable and not so terribly unpleasant. Those pieces were sanded yesterday.
The lamination was glued this morning using LOTS of thickened epoxy (over the initial coat of neat epoxy on both pieces), LOTS of clamps and LOTS of patience. I will let the epoxy cure for two days before even thinking about taking the clamps off.
In the meantime, Frame #2 has progressed to the point of needing the top cross-piece complete the assembly. The sides have been glued to the bottom piece. The doublers have been glued in place. Here is a shot of the last two doublers glued and clamped this afternoon.
Notches for stringers and bunk supports will need to be cut. Once the notches are cut, the entire frame will be coated with epoxy.
December 1, 2011
Rudder Glued Up
Last week I cut the lamells (some designers call the pieces to be laminated staves; Welsford calls the lamells; had to look it up) for the rudder blank (to become the rudder blade). Today I glued those lamells together.
The WorkMate is covered with wax paper to catch dripping epoxy. The cauls (the 2x4s sitting on the WorkMate) to support the lamination were covered with packing tape to prevent gluing them to the lamination.
The lamination clamped up in two dimensions: three bar clamps pull the lamells together horizontally; the cauls have two clamps each to clamp/squeeze the lamination vertically. This combination of clamping reduces the tendency of the blank to warp or twist.
Warming Tent Structure:
The top of the warming tent is 3/16" MDF with holes cut for the work lights and 1x2 rails. The top supports two 8" work lights and rests on two (band saw) run-out supports.
Three large garbage bags cut to fit the top structure and held in place with eight spring clamps finish off the warming tent.
Two 100W light bulbs provide the energy to warm the tent. An hour after setting up the tent, the room temperature was 46° F while the thermometer inside the tent (sitting on one of the cauls) indicated a temperature of 90°.
The warming tent will be used when I glue up the centerboard lamination over the weekend. With some minor modifications the warming tent will be adaptable for use with the frame assemblies, too.
November 27, 2011
I've used West Systems epoxy products with some success over the years. My chief complaint is their cost although in recent months I've become aware of another limitation. West Systems uses a 5:1 resin to hardener mix ratio, which is great when using their pump dispensers. The 'other limitation' is that it is difficult to accurately mix a 5:1 ratio in small batches - there just isn't a lot of room for error. There are many times that a small batch - less than a full pump of resin plus a full pump of hardener - is needed. A two-pump batch results in a lot of waste. Oh, and the pumps tend to drip just enough to make a bit of a mess.
I began measuring resin and hardener by weight using a small digital scale. This allowed me to mix smaller batches and reduced waste. I switched to a 2:1 epoxy and bought larger containers of resin (gallon) and hardener (1/2 gallon). Pouring resin from a one gallon bottle isn't too difficult in warm weather - although precise measurement of small amounts is still a bit tricky. In the colder central Michigan climate of late fall, resin does not pour well - particularly for small quantities. It 'glops' out of the bottle almost in clumps. I decided I needed to find another way to deal with my epoxy.
Shopping for relatively small bottles to use for dispensing resin and hardener, I found plastic squeeze bottles for ketchup and mustard. Great! At a buck apiece they were worth trying. I labeled the bottles and decanted resin (into the yellow-topped mustard bottle) and hardener (into the red ketchup bottle). These bottles are handier and easier to bring to the house to stay warm.
Using the smaller squeeze bottles and the digital scale, I am able to mix very small batches of epoxy and minimize waste.
November 19, 2011
Clearly, I haven't just been sitting doing nothing over the last two weeks - I just haven't noted anything here.
Today was a good day. I cut ten 12' stringer pieces (the band saw is a fun to use). These were milled to proper size: 18mm x 45mm x 3,660mm (3/4" x 1-3/4" x 12') (the thickness planer is even more fun). These will be paired with and scarphed to ten 10' stringer pieces (which were also milled to proper size today). I should note that the plans specify 20mm (3/4") stock. The radiata pine I am using comes from the yard at 18mm. When I built the Goat, 19mm was treated as 3/4." A millimeter here, a millimeter there - what difference does it make? Well, maybe none in this instance but I wouldn't want to give away too many.
Another issue I've been thinking about is what adhesive I should use. Epoxy is specified in the plans and seems to be something of a norm in small boat building (yeah, I know, some would disagree). But for small tasks (gluing one scarph joint at a time) epoxy is not only a bother but wasteful. I've seen a number of comments re Titebond III as a good alternative to epoxy. I posed the question on the DuckWorks group. Many responded that Titebond III is absolutely a good boat-building adhesive. Two responses suggested otherwise. One, from a professional boat-builder and friend, said Titebond III is plenty strong enough for boat-building but cautioned against using it as it 'creeps.' This means joints can move over time - not a good thing. The other response came from John Welsford (designer of the Pathfinder). He said, in no uncertain terms, to NOT use any of the Titebond products in building the Pathfinder. He explained why - Titebond is NOT as strong as epoxy, does not fill gaps (requiring close fitting joints) and requires very high clamping pressure.
I will be using epoxy.
November 5, 2011
The project became a bit more active yesterday. I began making sawdust! The lumber I ordered arrived Thursday. Friday I began cutting it up into smaller pieces. The bill of materials calls for chine logs of 18' and stringers of 19'. I could not readily purchase 20' lengths so I have to glue two 10' pieces together to get the lengths I need. I cut the pieces for the chine logs but totally misread the dimensions for the stringers! Fortunately I caught the error after cutting only four stringer pieces (enough to make two stringers) and I have enough lumber left for all ten stringers. Yesterday I milled the chine log pieces to almost finished size and built a router jig so I can make the scarph cuts for gluing the two pieces together. I'll make those cuts and glue the scarph joints today.
I'll have to pay closer attention to the plans...
November 9, 2011,
The scarph joints did not get cut or glued until today. I was setting up the jig to correctly cut the matching angles necessary for good scarph joints. That fiddling involved making new rails (with matched slopes!) and rearranging the bed of the jig to make clamping the work piece easier.
So, while the router jig is shown on the Shop page, here is the first chine log being glued:
Not much detail in the image. The two pieces being glued are 10' long each. That sawhorse is 6' long so the ends of the pieces are supported. The two pieces are clamped into a channel (plywood base with 20mm square side pieces)just wide enough (72mm between the side pieces) to hold the chine log pieces snugly. The mating surfaces of the pieces were painted with neat epoxy before being coated with thickened epoxy and clamped into place. The work lamp is used to keep the temperature of the joint around 70* while the epoxy cures.
An overview showing how the ends are supported.