Master the Figure 8 Fencing Knot: The Ultimate Knot Strength Test

the figure eight fencing knot is a simple easy fencing knot that you need to know today I'm going to show you how to tie it then we're going to show you how it strains up then I'm going to put it on the fence state test bench I'm going to find out how strong it is make sure you're wearing your safety glasses let's get started [Music] the figure eight knot is perfect for joining two wires that are not under tension like when you're starting a new roll mid run there are better knots for straining and tensioning wires check out my channel for more information on them to make this not easier to follow I've given each wire a separate color first put a simple pigtail in one of the wires it really doesn't matter which one and make sure that it touches where it crosses over now tying this knot is quite easy if you remember Under and Over because we brought this wire over the top this wire now has to come underneath and the two main sections of wire here stay parallel to each other while we're tying the knot we repeat this pigtail at the other end remembering the opposite rule Under and Over because we just went over the top of this wire we now have to go underneath this wire when we tighten our second pigtail now because we just went underneath this wire we have to go over it on our next twist and because we went over it here we have to go underneath this wire so all you have to do is repeat the pattern of over under over under then the two wires pull together and you've got a figure eight knot making a pigtail this wire is over the top so this one has to come from underneath keep the two main wires parallel because this one went over the top this one has to go underneath bend your pigtail put it underneath because it went underneath put it over the top of this one and under that one there's a figure eight that'll tie up nicely we'll put a board up to make it easier to see last but not least finish your knot off now you can either tie these two dags to the wire some people love to do that I think it's a bit of a waste of time because it doesn't add strength to the knot I just simply trim them off with a pair of side cutters leaving a nice little neat knot behind that you'd never know is there okay my favorite part it's time to do science so we've got the fence stay torture rack all set up how does this work there's a bottle jack at this end that actuates a lever that pulls and stretches the wire apart the wires supported at either end by a spiral fast which is the only Joiner strong enough to allow a bench like this to work and that focuses all of the energy onto our subject not at the center and we find out how many kilos of strain tension we get to before this knot breaks to do that I'm going to be setting a camera up just above the crane scale and I'm going to be running this camera and that camera at the same time now of course it's all very well to know what strain tension this knot will break at but every wire has a different strain tension right and a braking strength so what we're going to do after this test is set this wire up without a knot in it and find out what its braking strength is so we can calculate a percentage radio let's science the heck out of this I like science I'm gonna go nice and slow so that we can get a good measure of the strain tension in case you're asking this machine does come with a guard just not using it nice and slowly there we go so just in case you're wondering the figure eight knot always breaks where the wire is Twisted the compression force is actually being pushed onto the bends and that's the Achilles heel of this knot so now what we're going to do is we're going to strain a length of wire from the same roll it's two and a half mil High tensile wire and we'll see what the breaking strain of this particular roll of wire is and then we can find out the percentage breaking strength of the figure eight I can feel it lengthening any time [Applause] anytime [Applause] I think we just broke our camera I don't know if you can see this but it's really cool when the wire breaks the galvanizing actually pulls away from the inner core which shrinks at the brake site kind of cool okay so take two I've put the camera on a tripod this time so hopefully the shock doesn't shut it off and make it lose its memory which is what happened last time so I've got another bit of wire from the same roll two and a half High tensile secured with the same spiral fast as each end scales are zeroed let's break some wire that tripod feels like me when I go and visit the accountant all right let's go so we're up to 182 and a half already starting to feel a bit tight so it's already well beyond recommended strain tension 365. now we're into the stretch Zone you've got your recommended strain tension then you've got the same again and then after that the wider stretches thank you okay Don't Panic it's maths time we've got 331 kilos brake tension for the figure eight divided by 478 kilos brake tension for the wire Times by 100 we end up with 69 so if you like breaking stuff don't forget hit the Subscribe button give it a like and I've done plenty of other videos with knots in the past including one using a test bench like this to compare all of the modern common wire joiners and some of the results were surprising I've put a link to that in the description and there's a little link up there guys I'll see you next week when we get to break some more stuff I didn't script it

Channel: Farm Learning with Tim Thompson

Views: 97,827

Keywords: Tim Thompson, how to, farm, adventure, farming, agriculture, reviews, gear, fencing knots, farm fencing, wire, knot, budget fencing, homestead, farm fence, electric fence, tim thompson, cattle fence, fence, high tensile, fence line solutions, figure 8 knot, speed knot, rural, knots, building a farm fence, fence installation, homesteading, tex brown knot

Id: dw5i8Jju6UQ

Length: 7min 8sec (428 seconds)

Published: Fri Jul 07 2023