Safety-wire type body panel fastening

[Deuce Rails]

Could someone explain how the safety-wire-loooking body panel fastening system works in this picture?


http://www.motorsnippets.com/cars/boulogne/graphics/bugatti_type_35a_side.jpg

Thanks,

Matt

[Ted H]

Maybe some kind of Dzuz type fastners that are safety wired to keep them from vibrating loose at speed?
Ted

[tommy]

I always thought that the bolts hold the panels on and the safety wire was there just to keep the fasteners from backing out.

I seem to remember a system where a series of studs stuck out from the upper and lower panels. Wire was laced over the upper stud then down under the next lower stud and back up over the next upper stut etc. etc. When you get to the front return using the same system. When finished the wire forms a diamond pattern when viewed from the side. Clip the wire and off it comes. It would be a quick process to lace it up for pit repairs before Dzus fasteners came along.

[stealthcruiser]

hard to tell from the pic,but they appear to be castellated nuts.
my guess would be snug them down a little past finger tight,and lace the wire thru,with the "exit" wire pulling the wire in a tightening direction.
if doing a series,finalize the safety by doing a wrap around safety on the final(end run)fastener.
standard safety wire practices preach"safety no more than 3 fasteners in one run",but that shit don't matter here.
later

[Fat Hack]

We used to do something similar with header bolts back in the 80s. You could buy special bolts with small heads that had the holes in 'em, or you could carefully drill out the ones that came with your headers.

You'd pass safety wire through the holes on two bolts after tightening them to keep them from backing out or vibrating loose.

[Roothawg]

90% of aircraft bolts are safety wired. The object is for the fasteners to pull against one another always tightening.

I am not sure what that guy did, but it looks wrong. Looks like he wired through the cassellated nuts. Generally, the heads are safetied in series, no more than 3 ata time. What the guy did in the pic is called single strand and it is usually only used when you have a large number of fasteners in close relation to each other...like 25 fasteners in a circle with a spacing of say...1/2 apart.

The other way is called doublestrand and it is the most standard of the 2. Usually, you twist the wire with safetywire pliers and it comes out to about 7-10 twists per inch. If you are interested in this you can go to the local airport or bookstore and pick up a "Standard Aircraft Handbook" it has a lot of valueable information on fasteners,rivets and materials.

Hope this helps.

Root

[Kevin Lee]

Root - Thanks for that info. Two questions. How do those nifty little pliers work? And are they pricey? I was planning on doing something similar for my belly pan and that's the exact picture I had in mind. The method you mention for wiring sounds way more clean.

[ QUOTE ]
I'm thinking of ways to fasten an aluminum belly pan. So far I've come up with this. Tabs welded along the bottom of the body just behind the bead. Drill and tap the tabs or drill and spot weld a nut to the back. Pan will slide between the very bottom of the body and the tab. Fasten from the front with the hex bolts backed with copper washers and safety wire the whole thing. I saw some panels on a Bugati (maybe?) done the same way. (all stainless or chrome hardware) Hood sides could be done this way as well.


[/ QUOTE ]

[Paul]

nevermind http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif

[sodbuster]

Kevin,
Here is what they look like. Also will you be home on Thurs. this week?

http://i19.ebayimg.com/03/i/00/91/60/08_1.JPG


http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45340

[Roothawg]

Basically, they just clamp on and you push the silver tab back on the inside of the pliers. Then twist...It's pretty easy and once you have done a couple thousand it becomes second nature. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif

Email me if ya want to get a set of good ones and I can turn you on to a tool dealer that specializes in aviation stuff.

[justinm]

http://www.whizwheels.com/Tips/safetywiring.html

general FYI site that's pretty complete.

[Kevin Lee]

Nice, thanks. Sod - I'll be around Thurs. after 4:00 or so. I've got your book(s) at home now too.

[Roothawg]

This quote is off of that website. It is total crap.....the rest looks ok though.

Quote:
For this reason, wire between nuts should be twisted with the hands. The use of pliers may damage the wire. Pliers should be used only for final end twist before cutting excess wire.


Yeah right.....try twisting 150 strands a day by hand....

[stealthcruiser]

grimlok,
sent you a pm

[Deuce Rails]

Thanks, guys, but I don't think that it's safety wiring.

Here's another example. This car seems to run the wire only in the areas where the body panel joins together. There's no further safety wiring to anywhere where you'd really expect it, like on the pitman arm, or on the bolts that hold the spring shackle.

[Deuce Rails]

Here's a closeup of a completely different Bugatti. As Roothawg says, it looks like it's done wrong if it's supposed to be safety wired.

I hope that this closeup helps.

[Deuce Rails]

Anyone?

What are the ears on the last pics? Are these screws or bolts?

[SamIyam]

[ QUOTE ]
This quote is off of that website. It is total crap.....the rest looks ok though.

Quote:
For this reason, wire between nuts should be twisted with the hands. The use of pliers may damage the wire. Pliers should be used only for final end twist before cutting excess wire.


Yeah right.....try twisting 150 strands a day by hand....


[/ QUOTE ]

I semi-agree with this.

When I was an aircraft mechanic, doing all aspects of small aircraft maintenance, I didn't really like to always use the clamping feature of the safety wire pliers... only because it did put a small nick in the wire... the other problem I ran into was that when you clamped the wire and began twisting, if you didn't judge the lenght correctly, you would end up with a twisted double strand that wasn't consistant. Then again, I worked for the most anal retentive, type A guy on the planet... and he kinda rubbed off on me. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

In addition, there were some instances, when the strand was short, that you would do it by hand, or at least not use the rotating feature of the SW pliers...
FWIW, I always kept a pair of duck billed pliers handy and would often times use them to do my safety wire work... that and a pair of dykes...(depending on the length of the strand.)
Sam!

[Roothawg]

The only time I have ever twisted wire by hand was in A/P school. I have worked in every aspect of aviation from FBO's to small commuter airlines and now the FAA. None of these places have ever twisted wire by hand. If you spend the money and buy a set of Snap on pliers, they come with a rubber insert to catch the wire you cut loose and also helps to prevent nicking the wire.

As far as consistancy, you just learn that through experience. It is a safety backup ....that's all....thus the name Safety wire.

One other thing is that the pigtail is supposed to go the opposite direction of your wire, so if this were true....there would be no reason for wire pliers because they rotate clockwise.

[Deuce Rails]

I just found this old post, and thought I'd bring it back up for any new thoughts.

--Matt

[Tim]

with pics ;) here ya go

http://project33.com/article.cfm?ID=60

[Ayers Garage]

If you want safety wire pliers, in my opinion, Milbar is the brand to have.

My dad gave me his Milbar S/W pliers when I was in A&P school in 1994. They are over 40 years old now and still as good as ever.