Panel screws

[EricJ]

9 hours ago, kortopates said:

Although a pilot/owner is allowed to remove and replace screws under preventative maintenance as mentioned above, recognize the only approved replacement parts/hardware is listed in your IPC. Anything else is considered a alteration or modification. A minor modification can be approved by an A&P but not under preventative maintenance. Thus its best to seek the guidance of your IA performing your annuals before making modifications to avoid surprises later.
 

^^This.

I'd also second the warnings about stainless head galling and wear especially when using a non-standard head.    The torx may wind up being worse than the philips.   

I'll also second that just keeping them reasonably lubed and not over-torqued goes a long way.   They're unlikely to come out if snug, and they're unlikely to seize if lubed once in a while and not over-torqued.

[StevenL757]

1 hour ago, carusoam said:

Buy lots of extra screws...

 

31 minutes ago, Hank said:

This works well for me. 

Ditto

[Nukemzzz]

Galvanic corrosion

[MB65E]

Tightening a screw first usually frees it up so removal is easier. Sounds backwards but works better than any easy out I’ve ever used. 
-Matt

[Guest]

20 hours ago, Ross Taylor said:

I have no idea if this is the case here...but in my most recent career, in wind turbine tech work, we found that stainless fasteners and nuts were more susceptible to galling (seizing) when driven in/on with motorized drivers.  When spun on by hand, stainless nuts would go on normally...but when an electric driver or impact was used we'd get a high frequency of seized fasteners.  The same happened with stainless bolts and screws.  Anti-seize compound helped, but was not a 100% cure.  We developed guidance for the installers that discouraged the use of drivers.  But...like I said...I have no idea if that translates to a potential problem using a screwgun on the panel screws.

PP thoughts only...not a professional torquerator (a tribute to -a-)

I wonder how many maintainers are using power drivers to install inspection panel screws?  I’d guess that most do.  I’ve banned them in my shop, we use a ratcheting screw driver and a 1/4” speed handle.

Clarence

[N201MKTurbo]

I will start all the screws in an inspection plate by hand, run them in with the electric with the clutch set low (4 on mine), then finish them with the Snap On screw driver.

If you set the clutch on the electric high enough to run them all in, it will overtorque them, strip out the + on the screws and the bits.

[StevenL757]

5 minutes ago, N201MKTurbo said:

I will start all the screws in an inspection plate by hand, run them in with the electric with the clutch set low (4 on mine), then finish them with the Snap On screw driver.

If you set the clutch on the electric high enough to run them all in, it will overtorque them, strip out the + on the screws and the bits.

Exactly what I do on mine.  To check the torque, I loosen a couple by hand by ensure the clutch is appropriate (#4 on my SnapOn electric), then run all the others in the same.  Always works...never buggered one up.

[N201MKTurbo]

One other thing to consider, when running them in with an electric driver, you can end up with a lot of friction between the screw countersink and the dimple in the wing. This can wear out the metal on the wing, which is very difficult to replace!

lubing the screws before installation reduces this friction significantly. 

The threaded parts of the nut plates are steel. They were originally cad plated. After screws were run in and out a few hundred times, it removes the plating from the threads. This allows the threads to rust, seizing the screws. Lubing the screws before installation puts some oil on the bare steel threads reducing the potential for rust. 

[N201MKTurbo]

One of my customers in my day job puts cover plates on aircraft. Before installing the screws, they put a drop of primer paint on the threads and counter sinks. A hangar neighbor of mine just retired from American Airlines as a mechanic, he said Boeing recommends the same thing when installing rivets. It seals out moisture and protects the fastener. They use primer paint. 

I’ve never tried it on Mooney screws. I don’t know how hard it would be to remove them later, or how much mess it would make. 

I did do it on some rivets I replaced  Recently, it was easy to clean the skin afterwards.

[StevenL757]

1 hour ago, N201MKTurbo said:

One of my customers in my day job puts cover plates on aircraft. Before installing the screws, they put a drop of primer paint on the threads and counter sinks. A hangar neighbor of mine just retired from American Airlines as a mechanic, he said Boeing recommends the same thing when installing rivets. It seals out moisture and protects the fastener. They use primer paint. 

I’ve never tried it on Mooney screws. I don’t know how hard it would be to remove them later, or how much mess it would make. 

I did do it on some rivets I replaced  Recently, it was easy to clean the skin afterwards.

I may do some testing using this technique; and depending on results, work that into my “routine”.  Definitely sounds more time consuming, but interested in end results.  Thanks for this...

Steve

[Skates97]

7 hours ago, N201MKTurbo said:

I will start all the screws in an inspection plate by hand, run them in with the electric with the clutch set low (4 on mine), then finish them with the Snap On screw driver.

If you set the clutch on the electric high enough to run them all in, it will overtorque them, strip out the + on the screws and the bits.

 

7 hours ago, StevenL757 said:

Exactly what I do on mine.  To check the torque, I loosen a couple by hand by ensure the clutch is appropriate (#4 on my SnapOn electric), then run all the others in the same.  Always works...never buggered one up.

I do the same thing with the Milwaukee drill I have, but I have it set to #3. I had to drill out some when I did my first annual, I have no idea of what process was used to put them in before I bought the plane, but three annuals later I haven't had any problems with any that I have put in. I keep a healthy supply of screws on hand and if the head looks worn at all just toss it and replace. 

[StevenL757]

22 minutes ago, Skates97 said:

I keep a healthy supply of screws on hand and if the head looks worn at all just toss it and replace. 

Good call.  They’re so inexpensive, there’s no reason not to.  

[Bartman]

I replaced every screw on my inspection panels with this annual with the proper screw but used Stainless from Spruce. Put them in a cup with a couple of squirts of the Corrosion X and they all went in easily with my cheapo handheld nearly worn out lithium battery powered Black and Decker rechargeable handheld screwdriver. 

[Jeph357]

I use this 

[Jeph357]

https://www.suncoating.com/wp-content/uploads/01-Sandstrom-28A.pdf

[Guest]

You bring your hand crafted ultra rare $500,000 airplane in for maintenance and the first tool the maintainer digs out of his box is an electric impact driver.  

Not in my shop, and I doubt in any high end automobile shop either, but I may be wrong.  I teach my guys that these machines are lovingly crafted and are someone’s pride and joy, treat them that way.

Clarence

 

 

[Ross Taylor]

What we used, specified for the wind turbines out in the elements (some in pretty corrosive coastal environments), was Tef-Gel - it's specifically designed to prevent corrosion, galling and friction welding of fasteners.  Good stuff.

 

[jamesm]

Some told me  and it  seems to work pretty well for screw removal. Where the screw head(s) that have seen  their better days... put a little valve lapping compound bit.

side note:  Use ACR bits are much  better than cheap one thrown in screw sets.

[0TreeLemur]

On 6/28/2020 at 5:22 PM, jamesm said:

Some told me  and it  seems to work pretty well for screw removal. Where the screw head(s) that have seen  their better days... put a little valve lapping compound bit.

side note:  Use ACR bits are much  better than cheap one thrown in screw sets.

What is ACR?  Thanks.

[MooneyMitch]

My method....... still......... for over 33 years.......I use SS screws, no lube..... no nuttin’.  

Start them with low torque setting battery powered driver, then snug with hand held cross head screw driver.

I don’t have corroded screws, period.  

Mooneys have always been hangared.

So far, so good. 

[carusoam]

ACR the brand name of a high quality tool manufacturer...

an example of the ACR bit below... not sure about the sizes desired... just a pic.

https://www.browntool.com/Listview/tabid/344/ProductID/1630/Default.aspx

Best regards,

-a-

[Hank]

1 minute ago, carusoam said:

an example of the ACR bit below... not sure about the sizes desired... just a pic.

Almost every Phillips head screw on my Mooney uses a #2 Phillips bit. Some little bitty ones use a #1, but not many.

[jamesm]

2 hours ago, 0TreeLemur said:

What is ACR?  Thanks.

ACR= Anti-Cam Round out   places like The yard store sells them  and many other aircraft suppliers has them.

https://www.yardstore.com/phillips-2-acr-b-4x4-bit

It kind hard to see in picture but has "teeth" to help grab the screw.

 

[Gordy]

If you do this your mechanic will hate you forever.

[N201MKTurbo]

44 minutes ago, Gordy said:

If you do this your mechanic will hate you forever.

If you do what?