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Pesky cowling screws keep stripping

JDA_BTR

Well Known Member
Now that I’m an expert using an easy out to remove cowling screws for the lower cowling I’m wondering if anyone has adopted a Torx or hex solution? Looking for a better screw here.

I’ve had enough training and education on this aspect of experimentation....
 
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Now that I?m an expert using an easy out to remove cowling screws for the lower cowling I?m wondering if anyone has adopted a Torx or hex solution? Looking for a better screw here.

I?ve had enough training and education on this aspect of experimentation....

Since you mentioned torx or hex I assume that what is striping is the head where the screwdriver interfaces?

There is a couple of potential causes for this (may be a combination of both).

- Worn screw driver tips. We tend to never throw screw drivers away, but they don't last forever. My preference now a days is buy screw drivers that use replaceable tips. If one strips on a couple of screws, I toss it and install a new one.

Over torqued - The majority of people over torque screws. Do some research on what the proper torque value is. It is much lower than most people think.
 
Good thoughts. I've got new tips. I usually put the screwdriver on "1" and let it stop at that. They will come off pretty easy that day or a few days later but two months later the problem arises.
 
Screwed

Dud: Not sure what your setup looks like, but the quality of the screwdriver tip makes all the difference. Buy the best ones you can find and replace them when they show any wear. Also you can run a tap into nutplates a little ways to clean them out but be careful to not remove much of the self locking feature. Boelube or similar anti seize will help when its removal time.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
- Worn screw driver tips. We tend to never throw screw drivers away, but they don't last forever. My preference now a days is buy screw drivers that use replaceable tips. If one strips on a couple of screws, I toss it and install a new one.

Over torqued - The majority of people over torque screws. Do some research on what the proper torque value is. It is much lower than most people think.
+1
Some screwdrivers are just better than others. I had a Craftsman #2 Phillips that would reliably remove damaged screws when others would not. It?s now retired due to wear, but if they still made them I?d buy 10.
For nutplates, I like to rub a little of the wax-like Boelube on the threads prior to insertion. May be my imagination but they seem to come out easier.
 
I usually put the screwdriver on "1" and let it stop at that.

I get that, but a setting of one is a big variable depending on what tool you are using to drive the screws. 1 on a small screw driver will be much different than 1 on a 20 V Dewalt Drill/Driver.

The speed that it is turning when the screw torques up will have an influence on how tight it gets with any given torque setting as well.

BTW, I think the plans specify AN525 screws on the cowl (though people tend to ignore that because they are not pretty)
The reason is that they are a structural screw so they have a smooth shank. This is much better for long term durability of the cowl. When threads of a screw are baring on fiberglass, coupled with vibration, it tends to work as a saw over time and enlarges the hole.
The AN525's are cad plated steel which doesn't strip out as easily as the softer stainless screws.
 
Good info...
Plus I never use a drill to put ON aircraft screws. I do pre-loosen by hand then use a driver to remove.
I have found a good ?big ball? ratchet screwdriver to be best applying a ?two finger? torque.
I toss screws at the slightest imperfection.

R
 
I think I remember a thread here where the best ever screwdrivers were discussed! Will go look for it.
 
Improving the bite of a screwdriver on a Phillips screw

One common mechanics tip that I haven't seen mentioned is this. Dip the tip of your screwdriver into some valve grinding paste prior to removing each screw which doesn't want to come out. This will vastly improve the grip of the screwdriver into the screw head. That said, the use of structural Torx head screws would definitely be the way to go.

Charlie
 
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