Dawn rose...well 10:00am and rushed out to Bren's farm to check how the keel had fared overnight We loaded it onto a trailor - took it to a weighbridge which suggested that it weighted 360kg - about 95kg more than specified. But it was still in the mold and the weighbridge was only calibrated to weigh in increments of 20kg.
So we took it back to my house and unwrapped it from its mold. The mold had charred somewhat, especially the centre board slot, but nonetheless it retained its shape extremely well. The 150 plus dry wall screws did their job and no lead leaked from any part of the mold - so that was quite satisfying.
Brendan managed to source a professional scales from a friendly neighbour who runs a weighing and calibration business - thanks Kevin - and we weighed it out of the mold - 326kg in total. So by deduction it seems my bathroom scales were reasonably accurate. When we measured the keel against the FSP drawings, it seems we did add the extras lead unnecessarily so now I have the challenge of cutting off a slice off the top of the keel...shouldn't be too difficult!
Bottom line - the keel looks to be fine with a few pock marks on top where the molten lead continued to bubble, but this will probably be removed when I slice off the top of the keel.
The lesson learned were
1) refine the tap so that the lead is directed down into the mold - the pressure at the tap is quite high, presumably due to the weight of molten lead and tended to splash around, so we had to reduce to the flow to a slower rate.
2) Mark the level on the mold to where the lead needs to be poured - we poured extra since the mold didn't look full enough and I couldn't be sure if some lead had just escaped or leaked underneath. 3) The lead looked to be somewhat discoloured - as if heated higher than necessary - not sure if that made any significant difference, but may have reduced the bubbling and gurgling of the lead when it was in the mold and possible lead to increased charring of the mold.
The mold could have possible managed one more pour, but since the first was deemed a success I consigned the mold to the role of fire kindling.
Finally, I now have the task to cut the top inch or so off the keel, please feel free to comment on the best tools for the job.
The forecast this morning was for clear skies and no rain - seemed like the ideal opportunity to pour our keel. My friend Brendan is a farmer with lots of open yard spaces so we set up camp on his farm next to an old shed. Bren's son Jordan did some final welding to secure the crucible and ensure the smelter was stable.
Meanwhile Brendan was spreading pellets on his land:-
So time to finalise the smelter. So far we had taken an oxy acetylene bottle and remodeled it into a crucible This was encased by a steel drum with a smart side opening door for feeding fuel and a monstrous chimney, which was supposed to create a venturi effect and reduce the smoke in our vicinity.... and voila!
The smelter was a great success - the crucible became red hot burning only scrap wood from old freight pallets. The chimney also worked a treat - although the wooden post we used to prop it up burned through - even though it was about 3 ft away from the top of the burner. Also the aluminium pop rivets we used to hold the hinges on the door, melted away, so we had to replace with self tapping screws - suggests we were getting a decent fire going!
I weighed out 270kg of lead ingots which I had already smelted (see earlier post) and once the crucible was hot enough (reading >500 deg celcius on temperature gun) stacked them into the crucible. Less than 20 minutes later I heard a rumble from within the crucible and upon inspection, it appeared that they had melted.
Time for final preparations to the mold, ensuring it was level and scorch the inside with a gas torch. When it was time to pour, I was too busy to take some photos but I had a video camera running in the background. The tap we made was fairly leak-proof, only a tiny dribble of lead leaked. However it did not pour very accurately so we had to makeshift some barriers to direct the lead flow into the mold. Surprisingly the 270kg of lead (weighed on a bathroom scales) did not completely fill the mold so we melted a further approx 50kg of lead and topped up the mold. I am not sure if the final amount was necessary, as closer inspection of the lead keel mold plans suggests it does not need to be filled to the brim. I was pleased that the mold held up, without being encased in sand and there were no leaks. However, lots of bubbling ensued, maybe the wood in the mold was not bone dry, even though I had it stored in my garage since I made it last month.
Tomorrow, we intend taking the keel to be weighed on a calibrated scales to see if we have poured too much lead or was I using an incorrectly calibrated bathroom scales.
It was dark when we were completing the final pour - so you like I will have to wait until tomorrow before seeing the finished result!
Meanwhile, here are some updates on the planking - managed to get another pair hung:-
Still continuing with planking operations. Progress has been slow, not least because my two helpers insist I play ball with them in the garden rather than helping me in the workshop..
I have been comparing results from spiling with an articulating template and those from using the 2 batten and trellis method. I made a test plank using the spiling method and overlaid these against the profile resulting from the trellis and batten method.
Here you can see the battens underneath the test plank, which shows a slight difference in dimensions, although not so much to really show whether one is unworkable.
I also started using my staple gun with small 15mm pins which hold the battens onto the boat and molds without piercing the planks.
Using hardboard as the trellis between the battens, I attached these with a hot glue gun, but this results in a slow clean up afterwards, so I will next try relying solely on the staple gun.
One aspect of using the trellis method is to ensure that the battens are quite supple and not too strong or springy as otherwise they tend to revert to their shape and reduce the arc required in the plank. I have the process reasonably refined, as follows:-
1) Pin batten onto previous plank aligning it to the pencil line drawn on the plank at the top of the bevel. 2) Pin second batten onto the molds aligned on the marks for the lower edge of the plank.
3) Attach trellis between the batten, much like rungs of a ladder (using hot glue or staple gun)
4) Remove trellis from boat and set onto planking ply
5) Pin trellis battens onto planking ply
6) Remove trellis from battens, which act as guides for the next two steps
7) Cut planking play using circular skill saw with John Brooks jig
8) Finish edges with router armed with flush trim router, as per John Brooks directions in GLWB
One of my new home made tools has been invaluable in attempting to refine my dory gains at the transom. Gluing 80 grit paper on a thin batten, allows me to run this between the plank lands at the dory gain and mate them together.
I say attempting because it is still not a very positive process but rather test and see, test and see...and repeat, until you get fed up and resort to thickened epoxy...I'm thinking of developing this approach my gluing some 120 grit paper on the blade of my Bosch multi tool. While on the subject of multi tools, I was quite skeptical of these but on reading another Somes Sound blog by Dave in SFO, I picked up he had found these very useful, so I did some research and decided on the Bosch GOP SCE 300 Professional as a good compromise between quality and cost. So far I have found it to be far more versatile than expected and I have found quite a number of uses for it.
Here's another product which I have been using to good effect recently - it's a 10 second glue which I have found invaluable for making quick jigs and gluing up templates and patterns in hardboard. The bottle seem to be like a superglue formula while the aerosol is the catalyst. You apply glue on one side and spray the aerosol on the other, press together for 10 seconds and you have a very strong joint.
I'm on my last three plank pairs, so hope to get the planking finished within the next 5 or so days and then plan to pour my lead keel. Stay tuned!
Fitted planks no. 5 today and it's interesting to see the hull shape forming, especially close to the bow. The no 2 station has a tighter profile when compare to no. 4 which creates an interesting spoon shape in the hull. I rechecked this several times, but on re-examining the full size plans which layout the station mold shapes, it is indeed evident that the no 2 station mold is scalloped.
Moreover, the planks tend to take a narrower shape at this station, initially I was tempted to fair out this tightening twist in the planks, but I am beginning to think that it is intentionally drawn this way. I have to say it looks cool! Not sure it is so much evident from the photo.
Each plank takes about 6 shots of the West System pump, which I use to wet out the laps and then coat with a thickened mix of sapele wood flour and West proprietary thickener (can't offhand recall its correct name)
I'm using the batten and screw method outlined in John Brooks' GWLB book, which seems to create a very uniform clamping pressure.
One of the (many) downsides of working in a confined space, is that it's impossible to get a good view of the bow. I can view the stern by opening the garage doors and get some idea of the hull shape, but the bow will remain a mystery until we take her outside! I know this flies in the face of all the advice to continuously view the planks from as many angles as possible, but when your boat is one foot shorter than the workshop......
That said, when viewing the hull facing forward from underneath, I do notice that the planks are not quite level where they meet at the stem. So I am going to cut the next pair separately, such that the shorter port side will be a little wider to bring it back into line.
Please feel free to add a comment....just so I know that I'm not the only one reading this blog!!
Have to say, I was really looking forward to this... must be the pyromaniac in me!
I gathered scrap lead from a local roofer plus a bucket of wheel weights from my local tyre depot. The tyre weights were a disaster - maybe in the US, "tire" weights are still lead, but in Ireland and presumably all Europe, they all seem to be Zinc or Steel - with a very low percentage of lead. My recommendation is: don't bother with tire or tyre weights............
Anyway, I needed to prepare the scrap lead into ingots, so I bought a burner which had a 8.8KW output - which in hindsight seemed to be slightly under-powered.
My crucible was made from the bottom of an acetylene bottle with two crude handles welded on. In some ways the handles were superfluous because it's too heavy to pick up full of molten lead and pour - I resorted to a ladle.
Initially I used bakers molds made of silicon, but they only seemed to last one or two pours before tearing Baking tins are the business! They produced 12Kg ingots flawlessly. It's quite amazing the amount of dross which collects on top of the molten lead, so I am hopeful when I come to pouring the final melt for the keel, I will have clean lead.
The pot at the right of the burner contains dross I cleaned off the molten lead which was quite a staggering amount.
The aluminium sheet on the right was used as a wind shield around the burner. I think had I more insulation around the pot and burner, I would have used less fuel - as it was I used about one and a half cylinders of butane.
The soup strainer was a real cheap item which I thought would have fallen apart, but it worked perfectly as a method of cleaning off the dross on top of the molten lead, showing little signs of stress.
Having suffered too many instances of "edge setting" (I'm still not sure what that is, but I'm blaming it anyway, as most observers seem to suggest it's the main culprit for incorrect planking spiling with a compass), I opted to use a slower method, which I call the two batten and trellis method. I'm sure there is a more accurate term, but when you see the photo, you'll know what I mean:-
Yes it is a little tedious and adds more steps, but when you end up with a perfectly fitting plank, it's worth every minute of tedium.
As luck would have it my 14 year old son joined me today, as he is off school on mid term break this week. Together we turned out the perfect plank and he's probably wondering what all the fuss is about!
Simply pinned the battens to the desired upper and lower edges of the planks and hot glued the trellis between the battens to hold them in shape. I then nailed the batten to the planking stock, removed the trellis and then continued as before with the circular saw jig and router method which John Brooks describes in his book - GLWB.
I also sanded back some of the planks at the transom to see how the dory gains were had turned out:-
You can see where the cuts on the underside of the plank allowed it to bend onto the curve of the transom, but at the same time the third plank has not completely settled down onto the transom, the lighter shade shows the epoxy glue filling the void - not that it will be any less strong I imagine, but it's still a fiddle to get both boards mated and sitting snug into the curve of the transom.
Although I managed to get a reasonable result with spiling the garboards, the broad strake and next plank proved more difficult. I suspected a faulty spiling pattern (the bad carpenter always blames his tools, right?!!) so I recreated the spiling pattern using larch thicknessed to 8mm. It is articulated in three places and seems to maintain its position securely with several short self tapping screws.
However, I notice that the resulting planks turn out to have more of a curve in them than required. In other words the ends were pointing higher up towards the keel by some 2 to 3 inches than required.....
The culprit: Now I suspect this is because I did not rest the spiling pattern on the bevel of the preceding plank, but set it instead midway between the plank lines on the mold and the upper edge of the bevel.
Here the spiling pattern is laid on top of the preceding planks bevel, about 1/2" away from the top edged of the bevel...time will tell if this approach solves the problem.
Having made a couple of expensive dud planks, I started using hardboard as a test plank and refined this until it fitted and then laid this on the planking stick to mark points for fairing the baton on. This produced accurate planks, but it is a slow multi step process, and I would really like to refine my compass spiling technique such that this intermediate stage can be eradicated.
Reading various forums on spiling, I really like the approach of tacking two batens onto the build lined us exactly to the upper and lower edges of the new plank and tacking a trellis network of light timbers between them to recreate the plank. The only drawback I see is how to get a smooth surface to run the circular saw armed with John Brook's special jig and subsequently the router on the batten. Maybe one has to nail the trellised batons onto the planking stock long the battens and then remove the trellis before cutting...
I used 10 second mitre glue to tack on the small pieces of hardbard - initially I was quite suspicious of this product which Brian had recommended - it looks like superglue with an aerosol can of catalyst hardener - but it worked miraculously - gluing extremely strongly in 10 seconds...I may use this on the trellis pattern approach instead of a pneumatic staple gun.
I will try one more approach with my articulated spiling template and compass, as per John Brooks GLWB excellent book, but if the template which ensues turns out cursed as previous iterations, I will try the trellised approach and record updates in later posts.
If anyone can pinpoint why my planks are turning out more curved than they should be, please comment...it may well be that this is a known repeated error of the first time amateur wooden boat builder...!
Today, I continued on with planking, having completed my keel mold and awaiting delivery of some melting equipment - more of which later.
My dilemma is to decide which boards to cut my next planks from. In the specifications there are one set of boards scarfed at a slight angle to accommodate a more "banana" shaped plank. However, there is no reference as to which planks these boards are for, so I am going to cut them out of the same plank as I used for the garboards. My wife casually remarked that the angled planks are probably for the mid section of the boat - she obviously has a better 3D mind than me and I suspect she is right!
[EDIT Jan 2013- I since found a reference in the plans as to which strakes are made from the angled boards - answer: nos 3 and 4. Once again it proves to me that all the information is in the plans, you just have to search diligently! However, I only made this discovery when fitting the final sheer strake.....but when I re-examined how I had used the boards, to me pleasant surprise, I had applied them to nos 3 & 4!!]
So I have just spiled the patterns boards and laid them onto the planking stock. Marked out the various marks but there seems to be an ugly wobble in the lower line - I had a similar issue with the garboard around the same station - #6...I'm wondering if I have some issue with the marks at this mold.
It's dark outside, so I will go at it again in the morning and see if I can figure out what's going on.
12 Hours later.......
This morning, I eased some of the hard spots and with the assistance of Brian, who I recently discovered lives near me and also is building a wooden boat, we managed to fair out some decent lines. Unfortunately, one of my battens was too thin so when I routed the final edge the batten bent inwards leaving depressions between the nailed points. We had to re-trim the edge to take these high spots out, which meant the lap is more like 1 1/16th rather than 1 3/16ths - I can't imagine it will be too must of an issue. So tomorrow, I will make a new Douglas Fir batten out of wider stock to make sure I don't have further incidents of the batten moving while routing the plank's edges.
Also, I am going to remake my spiling pattern. It is made from ordinary 1/4" ply, which arrived from the store with a wicked warp - delivered in my absence! I used the warp as I thought to my advantage, to follow the curve of the hull, but I am not at all sure that this is working out correctly, so I am going to use some of my sapele 1/4" ply for this (once I have checked to make sure it's not all required for other parts of the boat.
36 hrs later....
Finally manged to fit the board ready for epoxying to the garboard. The Dory Gains were really troublesome, as they didn't seem to want to mate to each other. Had to do a lot of fiddlying and fudging to get anything close to a fit, and still I reckon I will be relying on the magic properties of epoxy. The angles of each Dory are the same, but I subsequently realised that I should have also calculated for the angle delta between the two planks to get the Dory gains to fit. It is not at all clear to me how to get these cut without a lot of incremental guesswork. Also I note the that the plank does not sit on the frames at stations 2 & 4 but rather kisses the frames at the lower side (sheer-side) of the plank . So I am now wondering why I bothered beveling the cheeks which were attached to the plywood frames if the planks are not going to fit snug against them.
Station 2 - the gap is obviously going to be quite large, but should I fill it in or leave it? Does the plank need to be screwed to the frame and if so where - probably at the laps.
Same issue at Station 4 where the frame and the plank is separated by a large gap. I presume the gap itself is not an issue , although the cheek on the frame looks strange.
Here is a short video which shoes the challenge I've had trying to get the Dory gains to line up.
So John Brooks came to the rescue and wrote me an email of explanation....:-
"Dory gain is same width as lap. You will also make a dory gain on the underside
of the next plank. Measure the angle between the landing for the next plank on
the transom and the dory gain on the garboard, cut this angle on the underside
of plank #2 where it meets the garboard, then make the dory gain to this angle.
On the garboard, make the lap bevel flow into the dory gain"
Thanks John for the assistance, it's beginning to makes sense now to me and by the time I get to the sheer plank, I may have a passable example..
Finally planks 3 & 4 are affixed. I spent some time rechecking the offsets and made a large dividers to check for symmetry, It transpires that the jig is perfectly aligned and level, and the molds are symmetrical.
I concluded that the difficulty I had fitting the last planks to their marks on the molds was due my spiling - relying on a warped spiling pattern. So I decided to remake the spiling board out of 9mm larch planks. So far they seem to pick up a fairer curve than the original 4mm cheap plywood. Here are the old planks which composed the spiling pattern - you can clearly see the warp in the boards.
Here is the new spiling patter in action - I am hopeful for more precise outcomes.
The bow of the boat is hard pressed up against the inner wall of my garage, so it's difficult to sight the lines from the bow - my only opportunity is to take a photo holding the camera against the wall! It will be interesting to see the boat when I take her out of the garage for the first time...
Notice where the blue F Clamp is holding the plank against the #2 mold - there is quite a large gap here - as if the mold is too narrow but checked the measurement and it seem fine. So I'm wondering if that is as it should be or if I have not trimmed the inner stem sufficiently causing it to set the plank at a wider curve...
The transom is beginning to take shape. The dorys look fine (at least to my eye).
Having run to a standstill when a supplier of fasteners told me one month after ordering the screws that his supplier's factory was demolished..(yeh likely story Dave) I decided to start building the mold for my keel.
Using JB's plans for the keel, I ordered some pine from a local supplier, somewhat thicker than specified, in the expectation that it will be strong enough to contain the lead without having to bury it the ground, as John specifies. I want to be able to move the mold when pouring the lead - using steel tubing as rollers underneath the mold.
I read lots of threads on forums about lead keel pouring - and various solutions including coating the inside of the mold with water glass - but I'm going with a wood fire in a barrel enclosing the crucible.
I had been storing some gas cylinders which I planed to use as a crucible for lead smelting, I meanwhile came across a local company who was advertising some steel barrels for free - when I arrived to collect them he also had some old oxy-acetylene bottles which were also for the taking. So when home with my new crucible, removed to valve to vent the bottle - it was marked 1970 - so it was old but still had the smell of acetone emanating from it. Five hours later we finally managed to extricate the solid mass of firebrick from within...
Next, to deciphering the plan. At first it seemed a cryptic document, but I persevered and finally made sense of the plans. No doubt a seasoned boat builder would grasp it in an instant, but to add to the complexity, you need to make a special pattern ruler which accounts for the lead shrinking.
150 screws later, I have a mold ready for pouring...time will tell how successful it is..
Having used spacers to define to mold profile, I had to cut them out as the top of teh mold is narrower that the base..
Copious use of clamps were used to bend the 1 1/2" timbers to shape. Plenty of screws where used to keep them in shape and so far it seems robust.
I used a large coach bolt at this end to keep the timbers together.
The finished mold, including vent for gasses to escape the enclosed portion of the mold, as specified by JB.
Dawn rose...well 10:00am and rushed out to Bren's farm to check how the keel had fared overnight We loaded it onto a trailor - took it to a weighbridge which suggested that it weighted 360kg - about 95kg more than specified. But it was still in the mold and the weighbridge was only calibrated to weigh in increments of 20kg.
Brendan managed to source a professional scales from a friendly neighbour who runs a weighing and calibration business - thanks Kevin - and we weighed it out of the mold - 326kg in total. So by deduction it seems my bathroom scales were reasonably accurate. When we measured the keel against the FSP drawings, it seems we did add the extras lead unnecessarily so now I have the challenge of cutting off a slice off the top of the keel...shouldn't be too difficult!
