This just came to mind last night as I was going through my field box.....

How often do you guys replace nylon wing bolts?? The ones I had were pretty old...I through them away, as I had forgotten how many times I've used them in the past.

That's a good question.

Mine are on there second flying season.
I use them for my landing gear also.

Bob

Without the proper education for assessing wear and damage over time, it might be a good idea to toss them occasionally.

We used to boil our nylon props for twenty minutes in order to rehydrate the nylon and restore some strength. Did it work? I don't know, but the props usually looked better afterwards. This might work for the nylon bolts too. Or it might not.


Ed Cregger

yeah what he said (NM2K )

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Without the proper education for assessing wear and damage over time, it might be a good idea to toss them occasionally.

We used to boil our nylon props for twenty minutes in order to rehydrate the nylon and restore some strength. Did it work? I don't know, but the props usually looked better afterwards. This might work for the nylon bolts too. Or it might not.


Ed Cregger
[/quote]

I don't think there's any visual cues, other than the obvious, such as flattened threads or cracks.

Short of subjecting them to a stress test of some kind, or putting them under a microscope...I don't think there's a way anyone would ever know if a bolt is fatigued. Maybe I'm worried over nothing....but I guess they're cheap enough I don't really mind throwing them out occasionally.

Simple math. Nylon bolts 10 to 15 cents each -airplane 100 bucks & up. Better safe than sorry !!!!!!!!!

IF you think their too worn or too old toss em

That is interesting. I do know that nylon straps used in construction are checked for condition and have a red stripe embedded in the woven material. When the wear gets to the red stripe the straps are removed from service and cut in half to prevent them from being used elsewhere. But there is no time limit on the life of the nylon straps, just a wear limit. There is not weight check required either, just the wear limits.

So if your nylon bolts are in good condition keep on using them.

Question, do you change out the wooden blocks that the screws go into? Do you recycle the glue joints that hold the piece of wood that has the blind nuts or even the wood threads in some applications? If you cycle out the bolts maybe you should check those out too. Shouldn't you remove the mounting piece and install a new one? Do your replace all the control horns and clevis made of nylon too? Do you replace the nylon fibre glass filled motor mounts?

Think about it.

Cheers,

Chip

OOPs a repeat, sorry.

That is interesting. I do know that nylon straps used in construction are checked for condition and have a red stripe embedded in the woven material. When the wear gets to the red stripe the straps are removed from service and cut in half to prevent them from being used elsewhere. But there is no time limit on the life of the nylon straps, just a wear limit. There is not weight check required either, just the wear limits.

So if your nylon bolts are in good condition keep on using them.

Question, do you change out the wooden blocks that the screws go into? Do you recycle the glue joints that hold the piece of wood that has the blind nuts or even the wood threads in some applications? If you cycle out the bolts maybe you should check those out too. Shouldn't you remove the mounting piece and install a new one? Do your replace all the control horns and clevis made of nylon too? Do you replace the nylon fibre glass filled motor mounts?

Think about it.

Cheers,

Chip

I do not change the wooden blocks, or motor mounts, nor do I recycle glue joints. Those are far more substantial than a 1/4" nylon bolt would be. Any wing bolts would certainly "cycle," the question being for how long, thus the thread to see the opinions of others.

And yah...I occasionally change out clevises and control horns...you can't expect the 1/32 " nylon clevis pin to last forever. Preventative maintenance....

I usually crash before they wear out!!!
Just kidding, but I check every clevis, control horn, engine mount, wing attachment every time I fly. I CA the threads in wooden blocks. One of my rituals before I fly and after flying.
I can say that I've never had a plane crash from a broken clevis, or control horn or any attachment device.
If a part seems questionable I replace it. It's not the cost of the part but the risk of injury to myself or other flyers/spectators which concerns me.
I tighten my prop and do a range check prior to flying, but not prior to every flight, just prior to the day's flying but that's just me.



Tom

When the head of the bolt or screw breaks off when I'm tightening them down. If they can take that last chinch then they must be OK.

Boiling nylon relieves manufacturing stresses, and makes the nylon stronger and able to recover from shape changing stress. I've got 1/4 nylon for most of my LG bolts, and wing bolts. I've never had one snap that wasn't boiled beforehand. 20 minutes in rolling boiling water is all you need. Add celery and potatoes to taste.