MV PISTERNIEMI - a wooden pleasure craft from 1938

MHo

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This model boat presents a 1938 designed pleasure craft, built for a late, local medical officer, Dr. Laukka.
The builder of the original craft is unknown.
The design of the original craft is by my model maker friend's late father, Mr. Kalari.
The boat is intended to be sailed on local scale boat contests, run under NAVIGA rulebook, Section NS, Class F2-B.
Construction is wood/fibreglass composite: Frameless pine ( Pinus Sylvestris ) planking stained and covered with thin glass cloth and clear laminating epoxy, inside and out. Final finish will be clear varnish. Light steam-bent frames may be added where visible during interior build.
Since this will be a functional model, not static, water proofing of all structures and finishes is necessary.
My build log is kept and shared in Facebook. Below is the link to my build log.
Subtitles are in Finnish and English, and you can see them by clicking the pictures.
MV PISTERNIEMI Build log
 

MHo

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The hull is almost planked.
See my building log from link below.
 

Uwek

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Would be very helpful and will make much more interesting, if you post one or two photos of the actual status also here in SOS......
 

MHo

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OK. I do not want to keep a separate log in every forum I am participating, but here are a few:
IMG_1027.JPG
Lofting with carbon rods

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Plank bending jig, dry-bending with hot-air gun

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Planks fastened with paper clamps and polyester string

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Planking almost done, three planks to the bow under work

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My shop: 1,8 m x 3,6 m wall-to-wall

See better descriptions of my work methods from my facebook log, link below.
 

MHo

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Planking finally done. Next a lot of scraping and sanding, then a little staining, and glassing the outer side with 110g glass and finishing epoxy.
( This project is put aside every now and then: I am renewing and repairing my radio controlled model airplane fleet for next season... )

54437516.jpg

The last planks on the raised bow section really tested the limits of bendability of Finnish pine, but after a few cracked attempts I got it done.
The plank is 8mm x 3mm and the bending radius is about 45 cm. The bend is three-dimensional, and some twist is also applied in both ends of that plank

55443521.jpg
 
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Moxis

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When bending the planks 3-dimensionally, are you using moisture & heat, or only heat?
 

Norway

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Moxis, nice with two compatriots in the same place. go Findland.
 

MHo

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When bending the planks 3-dimensionally, are you using moisture & heat, or only heat?
Using heat only is usually sufficient. Some of the trickiest strips I brushed with water just before bending, to generate a little steam to the point where I am bending the strip. When the aluminum bending template is heated from underside, the contact heat turns the water into steam in that contact point.
I also tried to soak the strips, but it created some visible compression damage tracks on to the wood when bending, and they will show thru the finish varnish, particularly when the wood is stained, and that is not acceptable.
The 3-D bending goes in three phases: first the major bend in edge bending jig, then the other dimension either freehand or in a board bending jig, and then the twist is added to the ends, freehand, using lock pliers to get a girm grip from the end of the strip.

May take a set of photos of this process... suomeksikin sen selittäminen on vaikeaa. :)
 

MHo

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Sanded and stained. A couple of test pieces to get the color right also shown. Next phase is to cover it with 110g glass cloth and clear finishing epoxy. Then I can disassemble the jig and do all the same to the insides of the hull.
55912460_2382223202008910_3601126891383160832_o.jpg
 

Moxis

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Using heat only is usually sufficient. Some of the trickiest strips I brushed with water just before bending, to generate a little steam to the point where I am bending the strip. When the aluminum bending template is heated from underside, the contact heat turns the water into steam in that contact point.
I also tried to soak the strips, but it created some visible compression damage tracks on to the wood when bending, and they will show thru the finish varnish, particularly when the wood is stained, and that is not acceptable.
The 3-D bending goes in three phases: first the major bend in edge bending jig, then the other dimension either freehand or in a board bending jig, and then the twist is added to the ends, freehand, using lock pliers to get a girm grip from the end of the strip.

May take a set of photos of this process... suomeksikin sen selittäminen on vaikeaa. :)
Thanks MHo, very clearly explained. Easier to understand in English than Finnish (Vaikka saattaisin ymmärtää ehkä myös suomeksi. ☺)

And very beautiful hull, stain seems to be spot-on.
 

Moxis

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Looks great. Nice to see that glassed outer surface keeps the hull in shape so that bulkheads can be removed. What is the black tool which you have used for scraping?
 

MHo

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Teardrop-shaped well sharpened scraper. It is very handy in smoothing the inside of the hull prior sanding, staining and glassing. I cut the scraper from ordinary rectangular carpenter's scraper with dremel, shaped and sharpened with bench grinder, and burred the cutting edge with TIG-electrode.
 
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