Tuesday, May 4, 2010

waterproofing

Tuesday 4 May 2010: I've been slathering coats of Target 9300 water-based polyurethane coating on the skin to waterproof it. First doing the hull, then an hour-and-a-half or two later flipping it and doing the deck. This coating has been used by David Mills, aka "stumpy" who posts regularly on the Blue Heron Kayaks' Kayak Builders' bulletin board for some years. David has been using this on nylon fabric. I was surprised to hear that because everything I have heard about nylon is that most things won't stick to it, or will be too inelastic and subject to failure when the nylon stretches beyond the limits of the coating.

By the way, if it seems like I am growing less enthusiastic about updating this blog, it is mainly because the editing interface is terrible, and especially the process of inserting these images, and linking them back to my website is an enormous pain-in-the-ass. I find it so frustrating to manage that I am ready to consider that finding myself in a situation where it might be necessary to resort to cannibalism to in order to survive, would be preferable to finding myself in a situation where it is necessary to create or edit posts using this crappy web interface!  That's all I'll say about this right now because it has worn me down and I am tired of fighting with it....


Anyway, where was I?  A nice long thread was started on Blue Heron's Kayak building forum about fabric for skin-on-frame kayaks. This thread rambled along for awhile and contains a lot of interesting information about fabric choice for skinning. But eventually David gives a nice explanation of the specific water-based polyurethane sealer he has been using for a few years; and how he applies it. Did I mention that there are many who would advise against use of water-based poly? The experience of some who have tried is that it would get soft and turn whitish when it gets wet; or that it might even just peel off in sheets. The only two references I have for positive results using water-based poly come from Robert Morris, in his book, "Building Skin-on-Frame Boats", and from posts on the Qayaq USA bulletin board by Turner Wilson. Robert Morris mentions that an interesting characteristic of water-based poly when used as a sealant, is that it does not stick to wax. So that by waxing the frame, it is possible to prevent the skin from becoming glued to the frame by the sealant. Probably I am crazy, but this idea appealed to me. Just noticing, how springy and alive the lashed frame is when it is bare, made me interested in trying to preserve that feel in the boat after it has been skinned. So the frame had been oiled with tung oil and then waxed with some Meguires paste wax before skinning. 

Another strong motivation for my interest in water-based polyurethane is a desire to find a boat building technique that is less toxic, and that generates less waste. This was a big part of what motivated my interest in skin-on-frame boats.

The Target water-based polyurethane was very easy to use. Since it is water-based, it is very low on volatile organic compounds. Everything can be cleaned up with water. There are no volatile thinners or solvents required. The same brush can be used throughout so there is much less waste. It is very much like working with acrylic paint. In fact, ordinary acrylic paints can be used to tint the Target coating. David Mills has some very nice examples of whimsically painted boats colored in this manner. In fact, I mixed a little titanium dioxide into the layers that I put on the deck. I did that to make it a little more reflective in hopes that would help to keep it cooler in hot weather.

There is a specific technique for using the Target coating successfully that was developed by David in consultation with Target. The technique is to use coating that has been thinned with water to a concentration of 50%. Special care is taken with the first two coats using the thinned sealer, to work the coating into the weave of the fabric as thoroughly as possible. Since David has been using this coating on nylon, that instruction is likely especially important in that case. With the rather loosely woven polyester fabric I am using, it is quite easy to work the coating into the weave. I followed the same procedure, using two initial coats of coating thinned 50%. After that I just slathered on 6 or 7 coats and used the good part of a gallon! I laid down the rice-paper ensos onto the bow with the first coat of full-strength coating.

The second instruction to be observed, is to allow the coating to cure for 72 hours before exposing it to water.

In the picture below, you can see some of the pull-holes that opened up while I was sewing this very loosely-woven, 8 oz. polyester cloth. Over many coats (6 or 7) the Target coating eventually filled these holes right up. You can see how the boat is leaning to one side on the starboard bottom panel and so I can apply a very thick coat of polyurethane and allow it to run up against the center seam which traps it where it can fill in the holes. Neat. I'd like to type some more stuff after this picture, but this crappy editor makes it impossible to get a cursor down there without deleting the image and reloading it. This makes me sad.

Sunday, May 2, 2010

shrinkage


Sunday 5 May 2010: The afternoon was sultry. I spent an hour or two out on the deck in the hot sun with a hot heat gun shrinking the fabric nice and tight. Perhaps I should have used an iron, but I have a heat gun that has pretty good temperature controls and decided to try that. I was quite conservative with it at first, not wanting to burn a hole or catch the house on fire or anything. So it took me a little while to get the proper temperature, and acquire a feel for the skin tightening under one hand, while I was aiming the gun at it using the other hand. I was concerned about opening up the pull holes again while tightening. And my concerns were justified. I also wasn't sure how tight I should make things. So I did enough to take out the wrinkles but didn't get carried away. It is tight, but not drum tight. Set it out in the yard to take some pictures of how things are before I start waterproofing.

Monday, April 26, 2010

skins


Sunday 17 April 2010: Following the method shown in the skinboats school videos,  I roll out the cloth -- 8 oz. polyester from George Dyson -- and sew a small pocket on the bow. Then I unhook this pocket from the bow, walk to the stern and pull the cloth back about 3 inches and sew a pocket there. This is where the trouble starts. I should note that skinboats school uses nylon rather than polyester in the very helpful videos they provide. I'm guessing that their nylon is a little more stretchy than the polyester that I am using. Also this polyester is very loosely-woven. It doesn't take much to open up large pull-holes in the cloth if stitches are subjected to any tension. So I pulled and pulled and opened up ugly holes and backed off and restitched and pulled and there may have been some foul language involved. In fact, I'm certain there was substantial amount of foul language involved. But so far, no cannibalism -- that was right out. Throughout this frustrating beginning, I was coming to understand the nature of this cloth that I have, and decided that a better approach would be to only make things as tight as can be pulled without opening substantial holes. I managed to get the cloth tight enough end-to-end that there are no obvious wrinkles across the hull.

So Monday I rolled the boat right-side up, and started the center seam from the cockpit, forward to the bow. Again, where the skinboat videos demonstrate better ability to pull transverse tension in the center seam to make it nice and tight, too much tension in this fabric opens holes. I manage to find a compromise where enough tension is pulled to result in a reasonably wrinkle-free skin, while keeping the pull-holes manageable. So the skin goes on with little-to-no obvious wrinkles, but it is not as tight as might be possible with a more tightly woven fabric. An advantage to polyester, is that it can be permanently shrunk in the end using an iron or heat gun. So hopefully, it is not necessary to worry so much about getting it quite as tight during the initial stitching. I'll have a better feel for how that works when this is finished:)


Over the next few evenings, I stitch up the stern and then use a blind stitch to roll the excess cloth at the seam over into a tube:



Basic stitching is mostly done. I also steam bent one last thin strip of ash around the cockpit coaming lip to build it up to be wide enough to provide a good hold for a spray skirt. I've put some last little smoodges of wood-flour thickened epoxy into some gaps here and there between the various strips that make up the cockpit coaming lip. It only needs to cure overnight, some finish sanding and stitch holes drilled before it will be ready to sew into the skin.

I've also accumulated the materials to make float bags and ordered 2 gallons of water-based exterior polyurethane coating to waterproof the skin. That will be a bit of an experiment about which more later.

Sunday, April 4, 2010

bones


Sunday 4 April 2010: I only just summoned the will to proceed a bit further this weekend after picking up a cold weekend before last. But the time has come to get this one done. Last week I received 40 feet of 8 oz. polyester fabric from George Dyson. He shipped the day after I had emailed the order on the basis of my word that the check was in the mail. It arrived USPS Priority Mail from Bellingham, WA, 2 days later. Outstanding service. I was expecting that to take a week or two. I unpacked the cloth and rolled it onto a section of 4 inch diameter PVC tubing to let the creases resulting from being folded, to relax.
 
Today is a beautiful day, I took the frame out on the deck and cleaned up the deck stringers. I also cut a small piece of cedar gunwale stock to place on top of the masik to lift the forward deck stringers a bit higher. I put a couple of oak pegs in the the top of the masik to lock it in place and glued it to the top of the masik with some Titebond III waterproof glue.



I lashed all the stringers down and then brushed tung oil on the frame. I may add a lashing here and there to the bow and stern plates, and redo one or two lashings. But I think this is more or less ready to be skinned.


Time to review the videos at skinboat skool:
http://www.skinboats.org/skinboats/sewing_your_west_greenland_kayak.html

Instructions at Cape Falcon Kayak:
http://capefalconkayak.com/howtoskinakayak.html

And the relevant sections of Robert Morris's, Chris Cunningham's, Mark Starr's books on building skin-on-frame boats.


The bones are exhaling tung oil vapors this week and should be about ready for skin this coming weekend.

Sunday, March 14, 2010

i torture the timbers



Sunday 14 March 2010: Over the last couple of weeks I have been experimenting with various ways to fail at steam bending a cockpit coaming from red oak. The process began in the last week of February when I sketched a coaming outline, 23 inches long by 16 inches wide out of poster board. I transferred this pattern to MDF and cut it out on the bandsaw. After drilling holes to allow for clamping, and hammering it all together I had a jig for steam-bending the cockpit coaming.


This jig is taken mostly from Chris Cunningham's book, Building the Greenland Kayak and uses a strip of aluminum flashing that wraps around the outside of the piece being bent to help support the wood and prevent splits from developing.

Though it is not the ideal material, I so far have nothing better to try than some kiln-dried red oak 2x4 from Home Despot. I ripped it down into strips about 1-1/4 inch tall, 3/8 inch thick. The strips were then cut to length -- the circumference of the form, plus 12 inches -- and then the 12 inches at each end are planed to make a long scarf joint where the ends overlap when wrapped around the jig. My first try almost worked. But I was too slow getting it clamped down, and it was a rather cool windy day, so that it came out somewhat asymmetric. The section near one end where I started the bend held close to the form. The other side and far end of the strip had cooled too much by the time I got it clamped and so didn't bend as easily. This resulted in a somewhat lopsided coaming. I may try to fix it with a heat gun. This is a general problem with the approach of bending by starting at one end of the strip and wrapping it around. You have to work very fast. It seems easier to get symmetry by marking the spot where the strip crosses the center of the cockpit at the front, clamp there first and work both sides back together. But that would make it more difficult to use the aluminum flashing to contain the strip. I'm still pondering whether the ability to brace the outside of the bend with the flashing is worth the potential for asymmetry induced by uneven cooling when wrapping around from one end to the other. I used the end-to-end approach with the aluminum flashing for 3 coaming attempts. But when I later tried to bend the coaming lips, I tried bending them from the front of the coaming symmetric around to the sides.

My second try at a coaming cracked right at the front of the cockpit, where the radius is the tightest due to some grain runout there. By the third try, I finally got a reasonable coaming.


This strip was just under 3/8 inches thick and was steamed for about 30 minutes before bending. I glued with epoxy thickened with wood flour and it looks good enough:


I have since failed on three attempts to bend a coaming lip from strips 3/8 inch by 3/8 inch. Two tries lost to grain runout; the third try today almost worked. The strip came out of the steamer very pliable and went around the form quite nicely. But it insisted on twisting so that the top of the coaming lip wanted to twist to the inside by the time it was wrapped all the way around. I was not able to fix the twisting before the strip cooled off too much and I snapped it while trying to get it to lie flat. Probably it would be better to bend the coaming lip around the bottom of the form where it can be braced against the base. I tried to bend it around near the top of the coaming where it would be in actual use but this made it easier for the strip to develop twist as I was bending it.

I finally was able to contact someone at Garman Brothers lumberyard near Annapolis to inquire about obtaining green, white oak. White oak or ash would be preferable for this purpose, especially if it was still green. I guess I'll try to get out there sometime this week to take a look. This is rough-cut lumber used for exterior fencing and construction so it sounds like a job to pick through and find some suitable boards. I may need to buy a planer, or find someone to surface it for me. Guess I'll take a look first to see if I can even find some suitable boards. This stuff is cheap at least. Exotic Hardwoods in Gaithersburg claims to have quartersawn white oak, but it is all kiln dried and expensive.

I also got in touch with George Dyson to inquire about material for skinning. He sent these PDF files describing the various weights and weaves of nylon and polyester fabrics available. I'm thinking about going with an 8 oz polyester skin and water-based polyurethane coating. I'll order the fabric this week. I also need to order vinyl material to make float bags. Float bags are necessary because this kayak will not have any watertight compartments. Inflatable bags maintain positive buoyancy in the event the frame is flooded.

The frame can be finished and oiled at any time and will then be ready to be skinned. If I can just get a reasonable cockpit coaming, everything will fall into place to finish this off.

Saturday, February 20, 2010

installing the masik


Saturday 20 February 2010: By Friday night, I had developed a theory about how to replace the top of frame 4 with the steam-bent masik. I cut away the top of the frame with a Japanese saw and drilled holes near the top of the remaining section of frame 4.


I filed shallow grooves into the top of the gunwales so that lashings would not stand proud there because I want the masik to attach with a rabbet over the top of the gunwale. Then I re-lashed the frame to the gunwales using the holes I had drilled in frame 4.



I cut rabbets into the end of the masik, and then chiseled a groove to lock over the top of frame 4.



I drilled two holes trhough from the top of the masik at each end to accept lashing and lashed it down to the gunwales. It was a little tricky to figure out a way to lash these joints. I didn't want to drill holes in the gunwales, and that little section of frame 4 on one side tends to get in the way of some of the more obvious lashing patterns. But this seems quite solid the way it is and looks like it will do. I could peg the masik into the gunwales but I think this is strong enough.


straightening things out?


Saturday 20 February 2010: Tuesday and Wednesday, with the frame off the strongback and resting between two sawhorses, I eyeballed it from various perspectives and bent and twisted it a little between the sawhorses to tweak the alignment. It looks pretty fair and straight after that. In hindsight, it would have been better to have done this before I pegged the gunwales to the stem plates. But is seems possible, by gentle pressure on the frame at the right angles, to be able to adjust the way the lashings sit slightly. Or maybe the frame was just already straighter than I had been thinking? At any rate, it seems to me that a good strategy for winding and alignment might be to lash things up on the strongback as carefully as possible. But then take it out, turn it over, sight down the keelson, push it and twist it and adust it until it lies just so; and then peg the gunwales to lock it down tight.

I've been staring hard at frame 4 over the last week trying to visualize how to attach the masik and whether to cut to top of the frame away to do it.

Monday, February 15, 2010

masik

 

Monday 15 February 2010: The masik is a curved deckbeam in a traditional Greenland kayak that lies just before the cockpit. The knees slide under this beam, and one uses upward pressure of the top of the thighs, or knees against the bottom of the masik to brace when leaning or rolling. Frame 4 in the Sea Rider lies at the position where the masik would be in a traditional kayak. An advantage of a traditional masik over the 12 mm marine ply from which frame 4 is constructed is that a true masik is much wider and so provides a more comfortable surface against which to brace than would the thin plywood of frame 4.

And so I have wanted to make a real masik for this boat. I had tried steaming and laminating 2 strips of red oak about 3/8 inch thick and an inch and a half wide. They bent fine and held their shape well. But because I didn't build a full jig to clamp them, there were small gaps between the strips around the areas near where the bend was the greatest. I also didn't like the fact that at 1.5 inches wide this was still a little narrow. Looking at the way the masik is built in Chris Cunningham's and also in Mark Starr's books on building traditional Greenland kayaks, and also at this nice photo gallery by Bryan Nystrom: Steam Bent Masik, I decided to give that technique a shot.

First a blank is cut from a red oak 1 by 3 inch board:



The blank is cut on a bandsaw so that it thins to about 7/16 inch in the center, leaving the full thickness at the ends. This was steamed for about 30 minutes and then clamped:


 

After cooling and sitting, when released, there is some springback. But it looks pretty good. I round over the edges, then finish it with a belt sander and it is now ready to be fitted to the gunwales. I think I will cut out the top of frame 4 to install this. But I am still contemplating exactly how to place and attach the masik to the gunwales and whatever I leave left at the top of frame 4.


shall we move on?



Monday 15 February 2010: I grow tired of fooling around with the bow. I cut it completely apart, tweaked, adjusted, pegged the gunwales and re-lashed it over the last few days. Staring at it hard and trying to discern where anything might be off-kilter. It is nice and plumb now and looks pretty good though the gunwales and chines are starting to look a bit ragged from being hacked at too much. But, though the bow looks ok now, the keelson doesn't lie as straight as I might like. It seems to lie about a quarter inch to port of dead center at frame 4, just before the cockpit, about the longitudinal center of the boat. This curve is just discernable to the eyeball if the boat is upside down and you sight down the keelson. It is more easily noticed with the laser level sighted down the keelson. I don't think I can do a whole lot better than this without substantially cutting things apart and perhaps this is good enough? I'm still pondering that thought. I've noted before, the whole frame is flexible, a bit basket-like, and the position into which it relaxes varies somewhat and can be pushed around slightly. As the boat is skinned and eventually when it sits in the water, under the weight of a paddler, equilibrium will happen at some slightly other unpredictable line. So I am sure there is a point where it is counter-productive to worry about minor anomalies in alignment. Am I at that point yet? That is the question.

Otherwise, the gunwales, chines, keelson and stems are fully lashed. I have taken the frame down on the floor and tried sitting in it to see how it fits. It is tight. It seems that my legs are not long enough to quite use frame 3 for a foot brace. I may need something as much as 6 inches forward of frame 3 if I want to use a foot brace in this boat. I ordered some bundles of 4 and 6 mm okuome marine ply to make a footbrace, and cockpit floorboards. But UPS has been freaking out over the weather and has still not delivered that. First missing last Friday, and then again today. Perhaps tomorrow?

Thursday, February 11, 2010

fixing the bow

Thursday 11 February 2010: Another 4 hours of shoveling today. Snow from the whiteout blizzard yesterday was only maybe 8 to 10 inches. I cleaned out the street in front and then did about half the downhill neighbor's street. He is getting pretty frail and I didn't see him come out today. Some clowns left their BMW parked in front of the fire hydrant all day yesterday during the storm. Possibly it was difficult to see when they parked, but not really. I had dug it out completely and the yellow painted curb as well. But then I guess there was the whiteout thing going on. They showed up while I was shoveling, apologizing and trying to shovel out for me with a little garden spade. I just laughed, helped push them out and got rid of them so I could finish things off.

I also got the ladder and cleared most of the snow on the front porch roof since it is flat, old and leaky and had probably over 20 inches of wet, heavy snow sitting on it. No, I did not climb on the roof. Just stood on the ladder and used the snow shovel to undercut, and slide the snow off. That got most of it and was pretty easy aside from wrestling the ladder out from the backyard, wrangling it around the porch and then putting it back.

I released the clamps holding the masik pieces and they held their shapes probably well enough to do.


 

So I slathered them with titebond and clamped them back together. We'll see how well this worked out tomorrow. 

I cut the bow apart and started carefully relashing it with the laser out of the way and lining things up by line-of-sight as I lash it all back down. I'm much happier with the result. Still have some more lashing to tie and then I'll re-peg the gunwales and chines to lock everything down. Hopefully it will look a little better this time. I'm obsessing a little much over alignment and symmetry although the whole thing is a bit like a basket. You can pull and stretch deform things in various ways. Presumably, when a paddler is sitting in it paddling, the whole frame will be shifting, twisting and flexing through the water like a fish. But it can't hurt to pay as much attention to lining things up nice and straight as I run the lashings.

Wednesday, February 10, 2010

steam box -- she goes belly up


Wednesday 10 February 2010: It's Wednesday, white-out blizzard conditions outside this morning and the government is still closed. If it keeps up, it'll likely be closed tomorrow too. Good day to make some steam. Hooked a Wagner power steamer, used to remove wallpaper, to the foam steambox and put two 23 inch long strips of red oak in there to soak. After 30 minutes they were still too stiff and I was wondering if this was going to work at all. I put them back in for another half hour, and then they grudgingly bent.


I expect there will be some spring back when this is released so the curve is bent past what will be required. I'll have some idea tomorrow.

I spent the rest of the day staring at the bow plate, lashing and fiddling with it an just couldn't feel happy. It is pegged now, and I don't like the alignment. I finally decided that the laser was just in the way, and I want to be able to really see the keel line. Since everything is mostly lashed now, I detached the frame from the strongback and turned it over.



Eyeballing things with and without the laser, I decide that I'm going to cut the bow apart and try again tomorrow. I think the reason the stern came out so much better is that the stupid laser was not in the way. I could move around and eyeball the lines carefully while I lashed things down. On the bow, the laser just gets in the way.

lashing the stems



Monday-Tuesday 8-9 February 2010:  I've been lashing and unlashing and then re-lashing the stems. Actually mostly the bow plate. The stern looks good. But I think the keelson has just the slightest bit of corkscrewing in the last 12 to 16 inches approaching the bow plate. It isn't noticable until I try to line the bow plate up with the laser. I'm probably just obsessing over a pretty insignificant deviation. But I've been thinking it would be wise to put some pegs in the gunwales and chines anyway just to really lock things down. I don't want the stress from pulling the skin tight to move anything around up there. So I cut off most of the bow plate lashings, lined things up as best I can, drilled a quarter inch hole through the gunwales and pegged them to the bow plate with an oak dowel and some titebond II glue.  Pegged the gunwales at the stern similarly and will peg the chines too before re-lashing everything.

Looking at the stems, it occurs to me now that it might have been better to let the plates continue forward in line with the bottom of the keelson for a couple inches and then round up to the line up to the bow. That would have avoided having a sharp angle where the stem plates meet the keelson and also avoided that slightly weak looking triangle of plywood there. I'm almost tempted to cut the plates out and redo them. But that would waste wood and the plates as they are very much in the spirit of many other sea riders as shown on yostwerks.com. So I think I'll leave them alone and make that fix on the next boat!

Late Tuesday night I cut up panels of 1 inch silvered insulating foam and built a small steam box that is long enough to steam oak strips for laminating a masik to replace the top of frame 4.

Sunday, February 7, 2010

cutting the stem plates



sunday 7 february 2010: By last night I had finished lashing all the frame to stringer connections I can access without removing the frame from the strongback. So today I began to tackle cutting and shaping the bow and stern plates. I cut a strip 6 inches wide across the width of my sheet of 12 mm okuome and roughed out the basic outlines, cut the plates out on the bandsaw did final fitting. I drew the outlines of the chines and gunwales onto the plates and then marked and drilled holes for the lashings. The holes are all 1/4 inch.

I drilled shallow holes into the keelson and plate bottoms to accept 1/4 inch oak dowels to lock the alignment of the plates to the keelson when the lashings are pulled tight.



After rounding over all the sharp edges on the router table, I lightly sanded the plates and then sealed them in epoxy. I think next time, I'll just skip the epoxy seal of the plywood pieces and just oil them along with the rest of the frame.



It only stopped snowing around sunset Saturday after dropping about 24 inches of heavy, wet snow. So I also spent about 4 hours  today removing what must have been a couple of tons of snow from the street in front of my house along with digging out and clearing katinka, though ain't nobody going nowhere right now given the road conditions.

Sunday, January 31, 2010

on lashing....



Sunday 31 January 2010: Saturday night I start lining the frames carefully into position, checking they are plumb and perpendicular to the keelson and then lashing them to the stringers. First the gunwales and keelson and then the chines. I work from the center frames out towards the stems. I am learning how to lash as I go here and some of them come out better than others. I may cut some of the sloppier lashings out and do them over as I get better. The material I am using for lashing is known as artificial sinew. It is a made from nylon fibers that have been waxed. It lays very flat and locks into itself when it is pulled tight. It is possible to make a very strong, flexible joint using this technique since there are no screws or pegs that could weaken the joint or form stress concentrators. The frame is starting to feel taut and alive as I work my way out though only about half the frames are lashed at this time.

Drove out to Freestate Lumber in Timonium Friday to look at ash and white oak for bending a masik and cockpit coaming. All the pieces they had were flat sawn with little, to no, vertical grain and didn't look suitable. I ripped a couple of 7 foot strips 3/8 inch thick from a red oak 2x4 I found at Home Despot. Bought a heat gun and gathered materials to make a bending jig for a masik. I'm not real convinced the red oak will be suitable for this but it is worth a shot. I need to make the jig anyway and I can try the red oak to see how it does while I continue the search for more suitable bending wood.

Monday, January 18, 2010

on sanding...




Monday 18 January 2010: Happy Birthday, Martin Luther King. Being preoccupied with ancillary activities this long weekend, I manage to get very little done. However today, being a beautiful, warm January day, I indulged in some light recreational sanding. Sanding is fun. Sanding is fun. Sanding is ... wOw ... kind of like rough sculpture with wood. I am making a smell like the inside of a giant pencil factory and the sun is warm so, Vitamin D. I knock off all the planing and saw marks and round over  and smooth all the stringers.




I briefly string things together to look them over but then break it down so that I can seal the edges of the frames with epoxy that I had rounded over on the router table last weekend. These pieces are about finished. On to the stem plates, masik, floorboards and cockpit coaming.

Sunday, January 10, 2010

i make things duller



Sunday 10 January 2010: Doesn't look like much has changed. But after staring at the frame sitting on the strongback for awhile over last week it occurred to me that I need to round over all the edges of the gunwales, chines and keelson that would be in contact with the skin. And also all the frame edges that might cut into the lashings or even me. It is never a good idea to be the one who is already bleeding in those situations where it might be necessary to sacrifice one, so that the rest can survive.

Since I am planning to lash this frame, I can't just sand everything after the frame is assembled. The time to do this is now. And so the war against sharp pointy edges was engaged.

I put together a router table last night. And I took it out on the patio this afternoon in pretty bitter cold conditions for these here parts. Running the gunwales and stringers through was more tricky than I had anticipated since I could only clamp the router table to some sawhorses. And those, almost 17 foot long, ribbons of cedar are extremely sproingy. It was too wobbly, even with tightly clamped featherboards to get the stock to feed completely cleanly. So it left a few little high sports, edges that I knocked down with a block plane once I brought everything back inside. Might not have saved much time, was way noisier and more dangerous than just rounding the stringers over entirely with a block plane. Possibly with a better, more stable setup on the deck or front porch it might have worked better.

I took the frames and rounded over all open edges and interiors.

I put everything back up on the strongback and cut all the deck stringers, fore and aft. I have a paper template that I traced last night for the stern plate. But I'm still thinking about what to lash and whether to have some pegs on the bow and stern plates. I'll have to figure that out before I cut those.

Sunday, January 3, 2010

strongback stations, looking sorta kayaky



Sunday 3 January 2010: I cleaned up the epoxy squeeze-out this morning with a surform while it was still a little green. Worked on it a little later with 80 grit paper on a sanding block. I layed out the strongback station on posterboard then drilled the required holes, rough cut the outlines on the table saw, and finished it up on the bandsaw. Marked off all the station and frame locations on the strongback on blue painters tape and screwed the stations down.





Got carried away and wanted to see something kayaky looking so I started attaching the gunwales, keel and chines to the frames with bungy cords.



It was around this point that I remembered that I still needed to carve out the slots for the rear deck stringers in frames 5 and 6, and seal all the frames with epoxy. So I took this apart, looked good while it lasted, marked and cut the deck stringer slots, whipped up a couple batches of epoxy and put a seal coat on all the frames.




I may put another seal coat on the edges tomorrow evening depending on how much epoxy was soaked up by the edge grain. Then the frame should be ready to assemble and lash on the strongback.