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How to wood Prop Maint?

riobison

Well Known Member
Care and maintenance of a Wood Prop?

Care and maintenance of a Wood Prop?

I have just bought an RV4 with the O-360 180 Hp and a Aymar Demuth wood Propellers 68/82

Can anyone point me in the right direction on where I can get the information that I need to perform the maintenance in regards to cleaning and dressing the tiny nicks on the leading edge and small dents in the back side? Over all it looks in good shape.

This prop appears to be coated in a varnish with a heavy white paint on the tips and some sort of insert on the leading edge that runs from the spinner out maybe ? of the way to the tip.

Then the blade tightening sequence that we should do once or twice a year. I live in Alberta Canada so the humidity is fairly dry here.

I was told the Max Rpm for this prop is 2600. Why can?t I run 2700 rpm?

Thanks

Tim
 
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I have the sheet Mike De sends with the prop if you want a copy.

I check the bolts at annual.

I have removed mine and painted it a couple of times.

I used an enamel paint for wood.

There is a composite leading edge and the newer ones have a wrap of fiberglass over the entire propeller.

I fix dings with epoxy and filler and sand before painting.
 
Prop maintenance

Tim,

I have a maintenance sheet on my website www.PerformancePropellersUSA.com the torque values will be less for your propeller.
I use PPG automotive clearcoat DCU 2002 to finish Props, but any good clear finish can work. Just make sure you static balance during the refinish process or you will have vibration issues.
As far as your RPM. if you are sure the engine is operating properly the propeller is a cruise prop.
If you have any questions feel free to call. I am happy to help anyone thru the refinish process if you wish to do it yourself.

Frank 713-417-2519
 
I know this is an old thread, but it's worth keeping.
I have a 1980's vintage Ted Hendrickson, which has been a good performer.
It has a poured epoxy leading edge with a few raindrop hits from excess RPM.
I cut out a bit of this epoxy @ one blade tip due to some damage, and replaced it with that new West Systems Six10, which is dispensed from a tube, and is non-sagging. It's handy because you can squirt out a very small amount without using the mixing tip, manually mix it and aply it like cake frosting. After it hardens, little sanding is required if you are good at putting it on.
Any comments on this or any other leading edge hardening product?
Also, I removed the black paint from the back, the white paint from the tips and sanded down the varnish.
I sprayed PPG DP-90LF black primer on the back and the front 6" at the tip with a single generous coat that flowed out well without sags. I plan to use white or red on the tip front and revarnish the rest with Minwax Helmsman Spar Urethane.
I've patch coated with the Spar Urethane with a brush from a pot, and also with a spray rattle can in the past. It does take a few summer days before it gets strong enough to resist rain.
Comments?
 
So maybe I'm headed down a satisfactory path, but I took Dan's contribution and Googled it for:
http://www.smooth-on.com/Urethane-Plastic-a/c5_1120/index.html
Smooth-on has a wide range of products, enough to get an idea of application and durability, with the possibility of learning something and understanding other vendor's products.
PropMan uses Polymer Alloy leading edge on his product?
I'm just getting into wood props, and I find them fascinating.
I see 'Shore Hardness' specs. That could be a benefit for leading edge protection. Is there a toughness spec that is also relevant in the more flexible of the castable epoxys and urethanes?
Certainly bond strength is important to keep it from flying off the tip with all that centrifugal force.
So I guess I'm asking for specs on hardness, toughness and bonding that we would look for when shopping for a leading edge material to take some of the Voodoo out of buying & trying.
 
The single most important thing to know about wood props is that they are very sensitive to how they are torqued. If the attachment bolts are too loose, the prop will chafe against the prop hub, heat up, and eventually depart the plane. If they are too tight, the wood will be crushed, the area weakened, the torque will not hold and, again, you will loose the prop. So the most important maintenance advise is to make sure the prop bolts are properly torqued and checked often. This is especially true when the plane travels from one climate to another and when the seasons change.
The very best method for ensuring trouble free and safest torque maintenance is to use Belleville washers under your prop bolts. You must know how to do this properly for the specific number and sizing of these washers depends on the number of bolts and bolt diameter. (Of course, you'll have to use longer bolts.) The following link is for pusher props, but the information is exactly the same for tractor props.
http://www.cozybuilders.org/Prop_Bolt_Bellville_Washer/index.html
 
So maybe I'm headed down a satisfactory path, but I took Dan's contribution and Googled it for:
http://www.smooth-on.com/Urethane-Plastic-a/c5_1120/index.html
Smooth-on has a wide range of products, enough to get an idea of application and durability, with the possibility of learning something and understanding other vendor's products.
PropMan uses Polymer Alloy leading edge on his product?
I'm just getting into wood props, and I find them fascinating.
I see 'Shore Hardness' specs. That could be a benefit for leading edge protection. Is there a toughness spec that is also relevant in the more flexible of the castable epoxys and urethanes?
Certainly bond strength is important to keep it from flying off the tip with all that centrifugal force.
So I guess I'm asking for specs on hardness, toughness and bonding that we would look for when shopping for a leading edge material to take some of the Voodoo out of buying & trying.

Scott,
the hardness shore of my leading edge material is 65D. Very durable.
http://performancepropellersusa.com/Maintenance.htm Here is my maintenance sheet. Give me a call anytime and I'll be happy walk you thru the refinish process.
 
Tip crack

Has anyone had any luck repairing a crack that is on the tip? The crack is about 2" long and is right in the middle of the tip, which is squared off not round. I've read some post stating this is a common occurrence on wooden props. I just bought the plane and it needs to be repaired following a hangar collapse, so it won't be flying any time soon. The crack was not a result of the hangar. It looks like the finish has been neglected for some time.
 
I would be very afraid of flying behind a wood prop that had developed a crack in it, even if it is repaired. In fact I recently replaced my wood prop due to finding a crack in it. The prospect of losing a blade, or even just part of a blade in flight is something I want to avoid completely :eek:
 
Crack Fix

I have a A-D prop that cracked and fixed it. AD told me to fill the crack with the old runny crazy glue. If the wood fibers take the glue it is a good fix. I flew mine for 4 months after the fix with no problems. Marked the crack on both ends and it did not get any longer (prefight item before every flight) . Still have it as a spare if needed.
 
My wood prop... now a hangar decoration, is also an Aymar-Demuth.

It was a great extreme-cruise-pitched prop, performing very well at the top end. Accelerated like a steam locomotive though, and takeoff and climb performance wasn't all that hot either, but once it got wound up to top speed it was fast.

There are numerous reports of Aymar-Demuth props losing blades in flight, there exist at least 3 NTSB reports, and at least two VAF'ers have reported in-flight blade failure too.

Given that mine cracked near the blade root, and the cracks were emanating outward from where holes had been bored into the wood, and possibly some metal weights inserted into the wood for static balancing at time of manufacture, I chose to immediately and permanently ground that prop. Even if a crack in a wood prop is deemed repairable by a wood prop expert, I'd just never be comfortable continuing to fly it.
 
Sounds Repairable

Has anyone had any luck repairing a crack that is on the tip? The crack is about 2" long and is right in the middle of the tip, which is squared off not round. I've read some post stating this is a common occurrence on wooden props. I just bought the plane and it needs to be repaired following a hangar collapse, so it won't be flying any time soon. The crack was not a result of the hangar. It looks like the finish has been neglected for some time.

Give me a call or email and I'll be happy to advise you through the repair.
713.417.2519
 
Depends on the placement of the crack

I would be very afraid of flying behind a wood prop that had developed a crack in it, even if it is repaired. In fact I recently replaced my wood prop due to finding a crack in it. The prospect of losing a blade, or even just part of a blade in flight is something I want to avoid completely :eek:

Neal, wasn't yours cracked at the hub? Tips are typically repairable, but hubs are not.
 
Neal, wasn't yours cracked at the hub? Tips are typically repairable, but hubs are not.

Yeah, here's a pic of mine showing the crack next to the hole bored for a balance weight. Upon close examination, the crack is across part of one plank and then ends up along a seam between two planks. Not good at all, and I consider myself fortunate to have found it when I did.

Prop_Crack.jpg.JPG
 
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