REFLECTOR: Reflector Digest, Vol 75, Issue 76, Leading Edge Damage

[Fred Anderka]

Bob:

Have various dents on my MT prop due to stones and cowl screws (they are now Lock Tighted).  Repairs were accomplished with J B Weld epoxy to fill the divots.  The leading edge stone divot which deformed the leading edge but did not separate from the blade was built up with J B and sanded to original profile.  Over 300 hours later all the repairs are still intact with no sign of separation, etc.  

My only concern is the pitting on the trailing face of all the blades, the forward face of the blades do not show any pitting or abrasion.  There are over 450 hours on the prop now.  I only operate off of paved strips, unfortunately I cannot vouch for the cleanliness of the runways and suspect there is a certain amount of sand etc. on all but the large airport runways with commercial traffic.

Anyone have similar pitting?  Any thoughts?

Fred Anderka
XL-RG, C-GHOL 


Today's Topics:

   1. Re:  Leading Edge Prop Damage Advice (Douglas Holub)

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That looks similar to damage one of my valve cover screws did to the edge of my Prince fixed pitch P-tip prop (maple core with carbon fiber overlaid.)  The damage was about that size and took a little bite out of the maple, too. We were traveling at the time in Amarillo, Texas. I emailed pictures of the damage to Lonnie Prince and he told me how to fix it: clean up the wound with sand paper, fill in with JB Weld, then sand it smooth in the morning. Worked great. I'm not sure if the procedure would be the same with a metal prop.

I replaced all the star washers on my valve cover screws with split ring lock washers.

Doug Holub
2009 Velocity Standard FG
  ----- Original Message -----
  From: Bob Jackson
  To: 'Velocity Aircraft Owners and Builders list' 
  Cc: Bob & Ann Jackson
  Sent: Sunday, June 19, 2011 8:40 PM
  Subject: REFLECTOR: Leading Edge Prop Damage Advice


  We 'vacuumed' up another screw (looked like a Lycoming valve cover fastener, when we 'swept' the runway afterward is what did the damage) on takeoff yesterday and this time damaged the leading edge of our MT prop -- we need your repair advice:

     The damage is about 3/8" in size, with the two most troubling aspects being the break in continuity of the leading edge, and 

  the obvious separation and bending out of the lower part of the leading edge strip on the one side.  The damage is about 

  8" from  the tip of the blade.

  I assume if I were to ask MT, they would say 'scrap that blade and build a new one from scratch'!  

     We're just curious what anyone might have to say about their experiences with this type of damage, and whether or not you guys would recommend trying to fix it ourselves.  We have a new 4 blade MT prop ordered (to improve our high altitude cruise performance),  but it won't be here for 6 to 8 weeks, so if we can safely do it, we'd like to repair this damage and continue flying it until the new prop arrives.

     What does everyone think?  We don't think we can re-bridge the missing metal, but are hoping that by injecting some epoxy and filling the gap with thickened JB Weld there would continue to be adequate rigidity and strength in the remaining leading edge stainless material to prevent vibration in flight and the lose of the outer 8" of this blade -- which obviously would be bad!

   
  Thanks,

  Bob Jackson

  Custom Turbo XL/RG

  N2XF