diy boat

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.

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 the the planks at the transom to see how the dory gains were had turned out:-