Bilge keels. Hull sanding

October 01, 2022 by Lukasz Kumanowski

Last steps before epoxy encapsulation: bilge keels, sanding, CB-opening trimming.

Bilge keels first. I made them from oak - they will take the beating when the boat will be beached or run on trailer so hardwood is in place.

Starting with a pattern, to get hull’s shape.

My favorite way of patterning such shapes is CADing. Cardboard Aided Design, that is.

Shape transferred to oak. I ripped a bit wider oak planks, to have margins when shaping the keels.

Rough cutting with router, final carving with spoke shave.

Fitting onto hull and final corrections.

Now - this is a mistake from my side. It would have been much easier if I fitted bilge keels while planking. Doing that at fourth strake would allow me easy clamping and drilling holes for mounting screws. Instead, when doing it on the finished hull, I had to hold them in place with tape and lead pigs while crawling under the boat to mark drilling positions.

But it worked anyway. Each bilge keel, apart from being glued, is held in place with two 8mm thick bronze screws.

It ain’t go nowhere!

Dry fitting before taping everything around for epoxy.

For gluing oak I use WEST G-Flex (or Flex, for short). It is of honey consistency, already thickened. Good stuff.

Oak got cleaned with acetone and gluing surfaces got scrubbing with rough sandpaper, to get even stronger bond.

I left the boat to cure for 24 hours, keeping the shed at 25 degrees this whole time. Luckily we have warm week, with night temperatures around 6 degrees.

Next day Louve was ready for next steps.

Sanding!

I evacuated epoxy and kerosene stove from the shed - dust will be everywhere.

Breathing and hearing protection and off I went with orbital sander. Transom sanded with 80 grit - it will be epoxied, too.

Rest of the hull was sanded by hand. I rounded planks’ edges so that epoxy and paint will hold better.

Next thing was CB opening. John Hartmann pointed out that garboard edges inside the CB opening can be a source of trouble due to chafe. He pulled them back and fiberglassed edges before gluing the false keel.

Following his advice I routed these edges so that they are behind timber edges - false keel and keel. Being out of harms way they should not be hit by moving/vibrating centerboard so simple encapsulation with epoxy should keep them protected.

Being certain that epoxy is cured I started shaping bilge keels. According to plans they should have 25mm height along the whole length. When I asked Francois Vivier about them he replied that, if I have enough timber, it would be even better if they have 30mm in the center part and go down to 15mm at ends.

Well, I had even more thickness at hand so I left 34mm in the center part and slimmed them down at both ends. Their role is to support the boat when not in water. I suspect that they, like bilge keels on ships or some dinghies, are also helpful in stopping the boat from rolling so having some more millimeters of height will do good.

Rough shaping with scrub plane.

Streamlining with no.5 and then sanded till smooth.

The whole shed and the boat got proper vacuuming before epoxy painting tomorrow.

If the weather permits.

Trimming, shaping

September 26, 2022 by Lukasz Kumanowski

Evening work-out with hand planes.

I started with stem, shaping the false keel to match the stem profile. Plans call for narrow shape, just wide enough to mount brass protective strip.

It went pretty nice, I made a gentle curve so the brass will sit well and the shape is pleasing. Only fish will see that but, heck, they also need some beauty in life, ain’t it?

To plane false keel above the skeg (I made it a bit wider, to be trimmed after gluing) I tilted the boat. She weights a bit now!

After trimming the false keel I started fairing the skeg. Plans call for streamlined shape, reducing thickness up to thickness of the brass strip again.

If I want to be able to epoxy-coat the hull on coming weekend then there are a few jobs to be done during the week:

bilge keels
trimming CB-case opening so that plywood edges (garboards) hide behind false keel (timber) thus will be protected from chafe
sanding the hull, rounding plank edges ( a bit - we don’t want her to look like GRP-boat, don’t we?)

I plan applying at least three layers of epoxy so this will take the whole day. First two will be just WEST 207 but then I will use graphite on working part of the hull, to add additional abrasion-protection.

Ideally I would like to apply five layers. That would build a substantial epoxy thickness comparable to varnish. Much more resistant to scratches. But it will take 20 hours at 20 degrees so it will be a long day.

False keel

September 25, 2022 by Lukasz Kumanowski

Sunny and warm day. Relatively warm, of course but I was thankful for these 15 degrees. Anticipating lots of dust I wanted to work outside as much as possible.

False keel plank started as 22x70 straight piece of Siberian larch lumber. Quarter sawn, straight grain and virtually no knots.

Measurements from the hull transferred. Most critical is centerboard opening.

Small area where the keel width rapidly diminishes to match the skeg.

Flat area on garboard top power-planed and fine-tuned with hand planes.

Slot for the centerboard routed.

Lots of wood chips and dust. Good I could do it outside the shed.

All surfaces smoothed with sandpaper. I also rounded centerboard slot - this is the outside face. Sharp edges do not hold epoxy or paint well so it is worth to chamfer such areas.

I drilled countersunk holes for substantial bronze screws, placed in crucial areas of the keel. They will bend the plank into position and hold it tight during gluing. Relying only on weights is tricky on such big jobs - parts will glide as if on wet soap if not positively held in place.

Masking of all adjacent areas followed. For centerboard slot I used wide plastic tape, fastened on both sides of the slot so that epoxy drips will not enter the CB-case. After cleanup the tape will be removed.

It was a big glue-job, I needed to divide it into three batches so that the epoxy doesn’t kick off when I spread it.

And so the false stem is mounted.

False stem

September 24, 2022 by Lukasz Kumanowski

When I was steaming and gluing oak false stem things didn’t go as smooth as I would like to. Slats were gliding under clamps, glue squeeze out obstructed view - it was a mess. I should have used guiding jig to hold the whole company in place.

It turned out quite OK anyway but after rough plaining, to remove excess glue, none of side faces was perpendicular to the front or back face. I had to re-establish proper center line. I marked desired mounting holes and assumed that back face (one which will be glued) is the reference surface. Holes drilled on precision jig in a proper workshop.

I use 6mm thick, long bronze screws. Not only they will reinforce the stem but will act as a guide and clamp when gluing.

Lots of eye-balling to fit the part exactly in the center. Pre-drilled holes in false stem used as guide for drilling into the stem. I was lucky - all four holes landed exactly in the middle of the stem. Dry-fitting raw assembly for marking the centerline and parts to be cut off.

I used screw holes as a reference for the centerline.

After dry-fitting brass protective strip I could draw fore face of the false stem. All the rest will be beveled to create cutwater and match the hull shape.

I was lucky with the weather today so the work could be done outside. Scrub plane followed by spoke shave and smoothing plane as last. After shaping the whole lamination was sanded.

While waiting for the stove to heat up the workshop I ripped Siberian larch plank which will become false keel. I will mark and shape it tomorrow - it needs to have centerboard opening and some curves to nicely land on stem and skeg.

I decided to use my “standard” epoxy (WEST 207 hardener) instead of WEST Flex.

I usually use Flex when I glue oak but in this case the whole stem area is one big open grain - with plywood stem and all planks which land on it. I wanted to properly soak these surfaces with thin epoxy so standard, non-thinned glue was best suited to the task. Flex is too thick - honey consistence.
I don’t know if both epoxies are compatible - so that I can pre-wet the joint with 207 and then use Flex to glue - so I took no risks.

As always - oak got sanded with coarse paper and cleaned with acetone prior gluing. I also sanded all planks close to the stem - easier now, before false stem is mounted.

Masking tape on all adjacent surfaces and I spread the glue.

All went smooth thanks to four guiding screws. Lots of squeeze out which I had no usage for this time… I always feel bad when I waste this expensive goo.

Just as I was finishing it started to rain. I’m glad I used weather window well this morning.

Preparations for false stem and keel

September 22, 2022 by Lukasz Kumanowski

With finished planking I move to the next step: fitting false stem which I laminated from steamed oak slats.

Not very spectacular job but it took me a while fine-tuning the stem shape so that false stem fits well.

Tomorrow I’ll drill screw holes on a proper drill press at work - they need to be exactly in the centerline as the false stem will be heavily beveled to just around 18mm at the fore face.

I browsed through my wood stock and finally chose false keel plank. I decided to make it from larch. Plans specify, among others, Douglas fir as possible material. Siberian larch is much tougher and heavier so for false keel it should be well suited. The plank I chose is quarter sawn, tight-grown straight grain and almost no knots. Heavy almost as oak but much easier to glue and shape.

Before fitting the false keel I need to plain garboards to get 70mm wide flat surface, to accept the false keel. That’s gonna keep me warm on the coming evening.

Hull planking finished!

September 21, 2022 by Lukasz Kumanowski

Just about time when it starts to get cold in my area.
Temperature at night drops steadily to 4 C, a bit better during the day with 10-12 C. Warming up my shed with kerosene stove is still an option but it can be just a few weeks from now that the stove will not be able to keep 25 degrees inside.

Sheer strake on starboard mounted and curing.

Next step is plaining flat garboards’ top, to mount false keel and stem.

For false keel I originally planned using oak but I don’t have 4m long timber - it would have to be scarfed, 8:1 ratio or higher. I have such long planks of Siberian larch but this is technically not hardwood so I have doubts.

Another drawback with oak is that it requires special glue. I have it but might be not enough for the whole assembly and before I get delivery of more it may become too cold to use it this year.

Ah well, I’ll fix that!

Sheer strake, port.

September 18, 2022 by Lukasz Kumanowski

Last strake on port side. A bit challenging at first to position as there are no more landings on station molds and bulkheads end before top (bottom right now) of the strake.

I clamped it temporarily and gave my brain some time to process the thing. My kerosene stove needed service again - it was outputting almost no heat. It took me a few hours to clean it, empty fuel tank (messy job) and adjust the wick. In vain - it was not burning as it should. In the end I decided to change the wick - it was clogged with dust and I could not burn it out anymore.

The problem is that these stoves are gone from Jula. Impossible to find one in the whole kingdom. That’s certainly due to the ongoing war and energy crisis, folks are hamstring heat sources in case shit hits the fan. I was glad that I bought it years ago but I forgot to buy spare wicks. These are also mostly gone now but I found that in nearby city they still have one. Jumped in the car and rushed to get it - this stove is crucial for my boat building, without it I would have to use IR-lamps which will probably yield the whole business uneconomical with current electricity prices.

Turns out they had two these wicks! Well, now they have none…

After wick change the stove came back to life. I will have to remove it from the shed every time I produce dust.

As the boat is now very close to it I reinforced my home-made heat deflector to be more robust. I leave the stove running during nights, to cure epoxy, so I need to be sure that all stays put and fire-safe.

With 8 C outside the shed keeps 23 C in the coldest corner. Additional isolation and new wick are doing the job well.

Back to boat-building.

Before I started building my Ilur I was planning to make sheer line very dramatic, with pronounced curvature, high stem and transom, like American boats.
Since then I changed my attitude and find balanced, delicate line of Ilur’s sheer more appealing. During the build I run across so many details and solutions which show that Francois Vivier really has refined and though through this design that I decided to build her as close to original design as possible. It is just so good - why change it?

Shear line shall land 17mm above bulkheads ends.

When the plank is positioned like that the edge of station molds - all three - is exactly on the edge of the plank.

To maintain these 17mm gaps during gluing I clamped small pieces of wood, wrapped in plastic tape, on the strake. They will guide me when I place the plank on glue and will prevent the plank from gliding away from its designed position.

For easier alignment and as a support I clamped L-shaped piece of plywood onto three station molds.

Apart from gains - both on transom and stem part - there was no need for beveling the previous plank. At the transom I embedded plank edge in transom’s crown.

Landing on design line at the stem. I didn’t bevel this part before planking, leaving it to this moment. It shows that I could have done it in the first place - the plank lands nicely on its lines.

The strake dry-fitted, masking tape set - I could finally spread the glue and finish the job.

Clamping this last strake was a bit complicated, I had to be creative.

With the stove running on 3/4 power I left the shed, happy with the result.

Next will come sheer strake on starboard and planking will be finished!

No. 9, port

September 17, 2022 by Lukasz Kumanowski

With this board on it is only sheer strakes to complete planking.

I have not enough room in my shed to look from distance if the sheer is “sweet” or not so I will have to depend on marks transferred from templates.

Stove is on max heating so temperature inside reaches 25 degrees. Boatshed sealed tight.

By the evening the glue should be cured so I can start sheer strakes at night.

No. 9, starboard

September 15, 2022 by Lukasz Kumanowski

Last strake before sheer strake.

After servicing my kerosene stove I can cure the epoxy in 25 degrees. Weather is helping a bit - it does not drop below 10 C at night. Nice autumn aura.

Moderate bevel for this strake, only a bit dramatic at the transom.
All clamps in use.

Eight strake - port

September 15, 2022 by Lukasz Kumanowski

Offered and accepted by the boat.

Curing overnight, we are lucky with mild temperatures.