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Old 02-02-2017, 03:20 PM   #1
Props in War
 
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Default ? Mounted Damaged Propeller blade Brass Edged

Hello people, I am new to this forum and I hope that I can bring some interesting pieces for you all to look at !!

FIRSTLY, to start off on a difficulty Level 10 and the photos will show you why............

I only have a damaged blade, the seller told me that it is Teak and that the blades height including the mount is 65cm. The brass edging fitted comprises of a couple of pieces that have diagonal joint lines , see photos of brass covered edge of blade.
That's all I have folks, my TWO simple questions are all I can expect to be answered (ANY Other info much appreciated)

Is it WW1 ?
What country had aircraft with propeller blades such as this ?


Kind regards, Jon
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File Type: jpg prop2.jpg (93.7 KB, 15 views)
File Type: jpg prop4.jpg (97.3 KB, 15 views)
File Type: jpg prop6.jpg (93.3 KB, 12 views)
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File Type: jpg prop3a.jpg (91.5 KB, 10 views)
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Old 02-02-2017, 04:30 PM   #2
Dbahnson
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I doubt that you can get a reliable answer to either question, unfortunately. There were so many variations in propeller materials and design that you need much more than what you have so far to identify them, and even then it can be difficult.

Many, many WW1 era propellers did not have metal sheathing, and many did have canvas covering along a portion of the blade. Dark hardwoods were more common in earlier propellers, but those also extended well beyond WW1.
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Old 02-03-2017, 08:02 AM   #3
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Default Encouraging..... What about the gaps in the brass ?

Thanks for your reply, but much more than meets the eye..................

What kind/date of blade is it that used this type of brass edge, what I have is 3 parts not just one.
The first part has 3 rivets until the gap and then another 6 rivets until the next gap and then some until the damaged end. I have seen many brass edges that are one piece. Why is this made is separate sections ?

If only one propeller type had the brass is more than one piece, what was it ?

Could having gaps in the brass allow for expansion of the dense and heavy darkwood when it is spinning. Air creates friction against a moving object - so could the darkwood blade heat up ?

The dark hardwood whilst continued use later on, it is encouraging to learn that it was in common use very early on ! So I am happy to see that the material is correct for a possible ww1 aircraft usage Until I receive the damaged propeller blade I can't measure its width or thickness at various points along that width.
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Old 02-03-2017, 10:48 AM   #4
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I can't answer those questions other than by making a guess. I suspect that the technique of brass sections is not specific to any one propeller or any particular type of propeller, i.e. it's extremely unlikely that you'll identify the prop remnant from that feature. It likely has to do with movement of the metal and/or wood with either temperature changes or forces exerted on them during use, but it's hard to say whether it's the wood or the metal sheathing that is responding. (Wood doesn't change much in length, but does more so in width, mostly due to changes in moisture.)

The width and thickness, even if it could be measured, will not help with any kind of reliable ID.

Most fragments of wooden propellers, even WW1 or earlier, do not have much value unless they have well-authenticated histories associated with them. (Not just generations of hearsay, as most of them do.)
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Old 02-03-2017, 12:47 PM   #5
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Default what value would you place on this ?

what value would you place on this as a stand alone decorative item ?

Teak with brass edging , Overall height 65cm
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Old 02-03-2017, 06:49 PM   #6
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I'm not an appraiser, but I would expect something around $75 or so at an auction, though Bob Gardner might have a more accurate idea. He drops in here from time to time.

Incidentally, I think teak was not a particularly successful wood for propellers. Although the species is supposed to hold up to weather fairly well, it apparently didn't stay very well bonded with whatever glue was used. I've seen a few examples that were completely delaminated.
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Old 02-04-2017, 08:30 AM   #7
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Default Bob Gardner please appraise this item :) if you have time.....

Thank for your reply........

Very interesting about the poor bonding for Teak, I am not surprised about that as Teak is a very hard wood and looks to be less porous / is harder to absorb adhesive due to the excess of resin compared to softer woods.

Originally chosen for its strength it could be one piece, hence only a two blade propeller could be made in one piece, a three or four blade prop would need to be made from more pieces hence the need for lamination perhaps !!?

I would imagine teak to be very difficult to shape into a prop due to it being so hard.

If Bob Gardner is there please comment on the potential value of this piece

Much appreciated
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Old 02-04-2017, 08:53 AM   #8
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Quote:
Originally Posted by Props in War View Post

Originally chosen for its strength it could be one piece, hence only a two blade propeller could be made in one piece, a three or four blade prop would need to be made from more pieces hence the need for lamination perhaps !!?

Much appreciated
Actually, very few standard propellers were made without laminating the wood. There are conflicting arguments as to whether that was for stability and strength or whether it was purely a function of lumber supply considerations. (It takes less wood to make a laminated prop than a solid one, and wood is more easily dried in laminations as well.) For large production, virtually all propellers were laminated. I actually can't recall ever seeing even a two blade prop that wasn't laminated, unless it was home-made. That's not to say that a few didn't exist, but they are not common.

Teak isn't particularly "hard", but it does have calcium deposits in it, which makes it harder to mill simply because it dulls the milling tools.

One problem in the valuation of your prop is that its origin and use is completely unknown. We do know that even propeller parts that are clearly identifiable as used on WW1 fighter aircraft simply don't command much value. If you look on eBay under "wooden propeller" you'll find various trench art and propeller remnants that have sold, most of them for under $100. See this listing for example.
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Old 02-04-2017, 09:19 PM   #9
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Default That just about wraps this up then, but Thanks anyway

Thank you for your replies !!

This piece has great appeal for an interior decorator , the broken end of the blade serving as a poignant reminder of the early era of aviation !

Yes, there are lots of tidied up / blended hubs and blade tips with inset photos, but very few which retain the damage that can fire up the imagination of a crash and how it happened / who survived or who were killed !!

A Great conversation piece with the broken end and the polished brass leading edge trim that adds to its value just as any item with an age added patina has its character enhanced !

Kind regards
PS There is lots of dust in the atmosphere and together with water > erosion occurs, hence the fitting of a harder material to the leading edge.
Modern example : I have seen pitting / erosion of the paint and exposed aluminium on the leading surfaces of the F3 Tornado jet aircraft wings/pylons. If this leading edge erosion occurs due to dust in the atmosphere, how come not every propeller has protection (Some props are just varnished wood, some aluminium are rubber based paint protected. I know rpm has something to do with it)
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Old 02-04-2017, 11:44 PM   #10
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Metal sheathing was added to propellers very early one (pre-WW1) apparently with disastrous consequences as the metal separated from the wood. However, with the development of flying boats it was soon obvious that propellers were quickly destroyed by water, so sheathing was re-instituted to protect the wood.

Virtually all "modern" propellers now have metal sheathing on the leading edge, not so much for dust as for larger particulate matter like stones (and water).

And you are correct in your assumption that RPM had a lot to do with it. Early props on WW1 aircraft typically spun at RPMs in the 1700 range, which is why most of them were 8 feet or more in length. With development of higher RPM engines, propeller lengths were less, but sheathing became more common at the same time. I've never done the math for propeller tip speeds at various lengths, although some modern metal props are travelling at supersonic speeds.
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