Cleaning hinges & retaping

[John Wells[_2_]]

Some of my flap/aileron hinges on my Mini Nimbus look very damp
and brown. I think this is mostly the old brown grease "weeping",
but I would like to check and clean up just to be sure as they look
pretty bad. The outer seals haven't been replaced for a few years
anyway.

All surfaces have both upper and lower outer and inner seals. The
outer seals seem easy to replace. The inner seals on the lower side
are straightforward, but the inner seals on the upper side appear to
be impossible to replace without removing and replacing the control
surface and borrowing about 7 hands. I plan to avoid this. Most
hinges are fully accessible from the bottom anyway.

I've started removing tape, but wanted to check the plan of action
was OK:

1. Remove all tape from underside, and outer seals from top side of
wings. This is more work than I expected -- I've had best luck with a
little blast from a low-temp heat gun, but I still need copious
amounts of degreaser to remove sticky residue afterwards. (Any
problem with degreaser residue or do I need to flush with water?)

2. clean /wipe hinges with degreaser and dry off, re-apply (much
less!) grease. (Any recommendation here?)

3. For the parts accessible only from the top (aileron attachments),
cut little access windows in the inner seals and clean as above.

4. Re-tape. one-side-sticky teflon for inner seals and patching holes,
double-sided tape, pre-curved mylar & capping tape for outer seals.


First time I've done this, does it sound reasonable?

[[email protected]]

If your ship needs buffing out, I'd do that first. That way you won't hurt the tape, because your going to replace it later, anyway. Next, I would not worry about the internal seals (I have proven to myself that properly applied Mylar seals is all that is needed). Lastly, I remove the grease and goo with Acetone, having used it for 40 years with no adverse effects to gelcoat or urethane....................flame suit on!
Have fun,
JJ

[[email protected]]

On Tuesday, February 20, 2018 at 9:25:49 AM UTC-5, wrote:
> If your ship needs buffing out, I'd do that first. That way you won't hurt the tape, because your going to replace it later, anyway. Next, I would not worry about the internal seals (I have proven to myself that properly applied Mylar seals is all that is needed). Lastly, I remove the grease and goo with Acetone, having used it for 40 years with no adverse effects to gelcoat or urethane....................flame suit on!
> Have fun,
> JJ

Exactly the way I do it also.
Using cotton swabs(not with plastic sticks) for hinge cleaning can help in reducing the amount of stuff slopped around.
Have "fun"
UH

[Charlie M. (UH & 002 owner/pilot)]

Yep, the plastic sticks can dissolve in acetone!
Don't flood things, just get it as clean as you can.

Then, go do other things so the acetone can evaporate BEFORE applying any kind of lube.

[[email protected]]

Hi John - I would seriously consider looking for the 7 hands and just take everything apart, especially if you are not certain when the last time it was done! My experience with the 303 mosquito is grease, when applied does nothing to really lubricate the center hinge pins, if not disassembled . If the pins were greased at one time and not oiled, the grease acts more as a preventative to light lubricants getting where you really need it, on the pins and inside the composite socket. Take it apart, do what JJ mentions wrt seals, you will be happy knowing that that complicated drive system and the hinges are clean and lubed properly and not providing unnecessary drag in the system.

Mark

[John Wells]

Thanks everyone. Removing all the tape residue was a real pain. Turns out the inner upper seals aren't seals but just a strip of teflon tape to prevent abrasion, so I'll replace some of that too.

What would you recommend to oil the hinges? I'm assuming lithium grease may freeze in wave, so was thinking to use a little dry PTFE lube.