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Old 01-01-2020, 08:58 AM   #11
Bob Gardner
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These are the dowelling which hold the laminations of overlapping wood together. Wooden dowels were fitted to holes drilled through overlapping laminae. This prevented any movement or creep of the laminations during manufacture. It was only used by the British prop makers and the practice fell into disuse towards the end of the war.

With kind regards,

Bob
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Old 01-01-2020, 11:34 AM   #12
Dbahnson
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Quote:
Originally Posted by Gabriel View Post
That makes sense, the slightly raised bump is only on the front face of the prop and not on the rear (thrust) face, which suggests the dowel runs chordwise across the laminates rather than perpendicularly through them.
Another possibility is simply that the dowel occupies a full 3/4" deep hole in the rearward plank and a much thinner front piece, so the glue anchors the dowel in the back but there's not the same holding power on the thinner front piece, where shrinkage in the dowel thickness may even further reduce the holding strength. All speculation, of course.

One of the reasons that dowels are not good joinery technique is that the amount of effective grain contact is low since it's passing perpendicular to the end grain on the plank for much of its surface area. End grain makes a very poor gluing surface.

Dowels are good for pinning joints like a mortise and tenon where they prevent shearing, but they're not very good where they are used to prevent tension, such as where you might choose a lag screw, for instance. The normal expansion and contraction of wood also tends to break down the glued against the end grain.
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Old 01-31-2020, 05:56 AM   #13
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So, here is the finished prop. This is after three episodes of thorough polishing with beeswax. Note, after much research I used a beeswax sold by a small independent producer containing only pure beeswax blended with a small amount of natural turpentine to soften it and make it easy to apply.

Following Bob Gs advice I used the beeswax on both the wood and the fabric and it has brought both to a very satisfying deep lustre without being too shiny. Im very happy with the result.
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Old 01-31-2020, 02:27 PM   #14
pmdec
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Hi,
The simpler way is to made the wax yourself: Beeswax can be bought from a beekeeper (or from Amazon!) and turpentine from supermarket. You have to put the solid wax in a closed jar with some turpentine until the wax become soft enough (time=some days).
The trouble with this way is the wood remain sticky for some days. I think that there are more volatil solvant(s) than turpentine in commercial preparations.
If you add around 5% of carnauba wax, the wax coat will be more resistant, quickly less sticky and glossier. Beware: to made the mix, you have to heat until ~50C and it is VERY flamable!
Regards,
PM

Remark(!!!): I don't myself use wax on propellers, only on furniture... and on wooden floor...
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Old 02-02-2020, 10:52 AM   #15
JR44
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It looks great.
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