Prop urethane leading edge

[Gaston]

Hi all

Has someone ever renewed urethane leading edge on some propeller???

is it available ??
could it be changed for something else ??
Any comments or suggestions ??
My older prop is in need for some TLC including new leading edges...

PS...a few years ago ,I repaired the leading edge with glass resin and it held for a while maybe 40 hours or so. then I had to repair it again ,this time I used epoxy,but it didn't last as long .
last summer I lost a 2 inches long part of this repair in flight,and didn't even notice it during this flight.
In fact I discovered the issue when refueling for the flight back home.
I was concerned about the vibration for the return flight, as I didn't know exactly when it did happen in the flight maybe it failed shortly after landing.
However I decided to fly it as it was with particular care for vibration right after adding full power...
To my greatest surprise, the flight proceeded uneventfully with no change in smoothness & vibration and with no significant climb or cruise performance loss.
I have to admit that prevailing rough air condition didn't help to note these changes.

Gaston

 

[lqbanotxano]

I have used 5 minute epoxy to make (2) 1-1/2" long repairs. They held no problem. My suggestion...cut off all the eurothane from the damaged area & make it all epoxy. This way the epoxy is attached to the wood.
Do one tip at a time. The tip being repaired must be pointing repair edge "UP" Sand or roughen the wood area that you are going to glue to...blow dust off & wipe with moist alcohol cloth (don't get it too wet) Cut 2 aluminum tape strips about 1" wide & about 2" longer than the repair. Glue the strips one on each side of the blade so you end up with a little tape ditch or trough...1/2" high by ???" long. You fill this with 5 min epoxy. It may help to pinch the ends so epoxy does not spill out. Peel the tape off after epoxy dries. Take your time & use a metal flat file to shape the epoxy. There is a lot more epoxy that you are grinding off than you are leaving on the prop.
Ivan

 

[Gaston]

Thank you Ivan

That's about the method I used for the previous repair...
my urethane is already all removed and the wood ready to receive new stuff.
probably,with better surface preparation,and cleaning ,the epoxy could last...

cheap and easy,worth giving it a try

must sleep on that...

Gaston

 

[Des]

Hi Gaston,
somewhere in the past, I "overhauled" the L.E. of my propeller as wel. At that time I was flying my Sonerai S II L with the 1835 VW engine, driving a Sterba swept tip 52 x 46 prop. At around 500 Hrs; the PU tips, (as suplied by Sterba) were deteriorated to such an extend that refurbishing was required. I decided to use "Haftstahl" from "Voss chemie" (Esinger Steinweg 50, D-25436 Uetersen). The french text on the box shows" Mastic acier".
I had some realy good experience with that stuff on other technical aplications.
The instructions shows that it also wil stick to wood as well. So, I decided to give it a try. This stuf, when aplied is very vicous, but it will run, so a supporting "jig" around the L.E. is required. I removed al the remaining PU, and still a bit more, to assure I had plain uncontaminated wood. Then I drilled some 2 mm. holes, about 5 mm. deep, spaced at 10 mm.,cordwise in the base. This to assure an extra fix to avoid shearing off the new L.E. stuff.
After curing, the L.E were sanded in shape.(A very nasty job, since you don't wanna touch the parent wood...) Then, I sealed everything with 2K PU DD white brilliant paint.
The first hours of operation, I was very curious, (and a bit scary as well) of how things would behave...
Well, all went fine. I only noticed, after some time,(do not know the exact run time anymore) a crack, running cordwise from the tip of the L.E. almost perpendicular to the base of the wood. Just before arriving to the base, the crack bents away a little bit inboard, so representing more or less a letter "J"
On one blade, this happens 13 cm. from the tip, on the other blade at 14 cm. from tip.
This crack shows up as a very fine black line in the white paint. I flew this prop another 300 Hrs on that engine without any further problems. No aditional cracks, nor widening of the crack...
I believe, there may be many good mastics around, but they may slightly differ in specific behaviour. At least, this one proved to do the job perfect...
Best regards,
Frans.

 

[Des]

Hi Gaston,

I managed to upload a picture of the typical crack in my prop LE after repair with "Haftstahl"

Best regards,
Frans.

 

[Gaston]

Thank you Frans

interesting comment
I'll see if I can trace this stuff around here...

Gaston

 

[pancho]

Easiest repair is simply Baking soda and "Super glue". Just make a trough with tape add baking soda and then drip in the super glue you can only do about 1/16 thick at a time and you may need to do several layers, but that is a really tough fix. I believe you can find out more on the EAA "Hints for homebuilders".
I've done it several times and have always had good results.