High Tensile do's and don'ts
Hi-Tensile Fencing Tips - Some do's & dont's
Over the years, fencing is something that has intrigued me from many different perspectives. The main agricultural purpose of the fence is to hold livestock in an area that you want them in. But, there are many other factors and aspects that come into play in the building of the fence. Of all of the various types of agricultural fencing I feel very strongly that 12.5 gauge hi-tensile fencing is the best choice you can make. It is 3 to 4 times stronger, will last 3 to 4 times longer, is easy to put up and cost less to put up than any other traditional type of fencing. However, in the course of traveling around the country it is obvious that many mistakes and errors are made in its construction. Here are a few tips that I am hopeful will help you with your hi-tensile fencing endeavors. These comments are based upon permanent fencing. Portable fencing is another topic of it own.
- Don't attach wires tight to line posts: The wires must float past each line post. This is needed to maintain the elasticity effect - allowing the hi-tensile wire to react as it is intended to. It allows the wire to be springy and bouncy. 12.5 gauge hi-tensile wire will stretch about 2% of its length - then it will return to initial tension. We must allow this to happen! Now 2% doesn't sound like much, but it amounts to 27 feet in a quarter mile. It becomes "super beneficial" under circumstances such as: trees or limbs falling on fence, wildlife, feral animals running livestock thru fences, etc. We must allow the wire to pass thru all line post connections.
- Different gauges of fence wire: It really is best to use the same gauge of wire thru-out your system. There is this thing called resistance. The electric pulse travels down your fence wires and every place there is a joint or connection, a little resistance is created. Also if the wire is rusty, the rust itself creates resistance. 17 gauge wire has much more resistance than does 12.5 gauge. Its kind of like water in a pipe, in that you wouldn't run a mile of 1/2" pipe then switch to 1" pipe then back to 1/2" pipe would you? I know, I know, you have this roll of old telephone wire that you bought at a sale years ago and you want to use it. It's a little rusty, it may be 20 years old, but you want to use it. You will be much better off to just spend 2 cents a foot and buy new 12.5 hi-tensile wire.
- Over-tensioning hi-tensile wire: Hi-tensile wire needs only between 150 to 200 pounds of tension. If you are used to putting up barbed wire, then you would normally put about 300 to 350 pounds of tension on it. So, don't over tension hi-tensile wire. This is normally the last step in putting up your fence. As you tension the wire, just watch the sag between line posts.you don't need to take all the sag out of it. In a 40 foot line post spacing it is OK to have 1 to 2" of sag between posts. The exception here is with a goat or sheep fence where you have a wire only 6" off the ground. In this case you may need the 200 pounds to keep the wire clear of the ground with uneven terrain.
- Poor quality line post insulators: This is probably the largest area of failure (and frustration) for electric fencing. You can buy quality insulators for $7 / bag of 25, or you can buy cheap ones for $3 a bag. Darker colors last longer. Stay clear of yellow insulators. Good ones usually have a 10 year warranty and cheap ones do not have a warranty. One failed insulator on a steel post will cause your whole system to lose effectiveness. Why take the chance?
- Inadequate energizer: I am an advocate of trying to have from 8 to 10 KV on my fence. That means that you will have good voltage year around. It's not hard to have 10,000 volts in early spring when the grass/vegetation load is low, but you need to be able to maintain good voltage in May & June when the vegetation load is heavy and wet. If you go from 10KV to 8KV – you are still in good shape. But if you go from 6KV down to 3KV in May, then you may have problems. Although a $500 to $800 energizer sounds like a lot of money (and it is) in most cases when you look at the total length of fence is will likely figure in at less than a penny a foot.
- Inadequate grounding: Yes, you do need to install adequate grounding for your energizer, no matter how large or small the energizer. A good rule of thumb is to have a minimum of 3 feet or ground rod for each output joule of the charger. Example: a 10 output joule charger will need a minimum of 30 feet of ground rods, or 5 each 6 foot rods. You can get by with ground off to t- posts or such things when it is wet out – but when it gets dry it will fail to be enough. You need that 6 foot depth to get into good moisture. The rods should be spaced a minimum of 10 feet apart in an area of permanent moisture.
- Building new fences beside old fences: Old fences normally have broken wires and tangles of repairs that can get into a new electric fence built too close to the old fence. If it is out of question to remove the old fence, then at least walk it many times over looking for loose and potential problems. I have done this many times with customers and invariably we will find an old piece of wire neatly hidden that is shorting out the new fence. Amazing how invisible old rusty barbed wire can be in a bed of leaves, forage and vines. And a short does not always emit a loud pop or spark. The old long duration chargers did, but the newer more powerful ones with short pulse duration do not.
- Line post selection: When choosing the type of line post that you will use – try to think of it over a 20 year period rather than the cost per each post on that day of purchase! And although you may have used steel t-post all your life, just remember that "steel is the enemy" with electric fencing. If you do decide to use steel t-post, just remember to use the best quality insulator that you can get, with a 10 year warranty. Sunguard treated Fiberglass is an option.Sucker rod composite posts are and option. Powerflex composite posts are an option. All of these are all composites that are insulated and require no insulators, only cotter pin attachment. Each of these has some flexibility, allowing the wire some latitude. The sunguard treated fiberglass posts have warranties saying they will not turn yellow of sliver, however most of us know that you will still want to wear leather gloves when handling them. The sucker rods are for sure going to have slivers unless you paint them, which is time consuming. The Powerflex Posts are easy to handle and are lighter in weight. They are also more flexible and do seem to hold in the ground better with less lift out problems. Fiberglass and sucker rods would need to be pre-drilled as it is very difficult to drill them in the field. Powerflex Posts can easily be field drilled and wire spacing located where you want them. Considering that a good portion of your fence budget is consumed in line posts, it is a good idea to consider the options and weigh out the longevity of each.
- Train your livestock to electric fences: Training animals to electric fence is a very easy thing to do and in most cases takes less than a day in a smaller enclosure before turning them out into the paddocks system. If you are going to be bringing new animals into your system that have never been around electric fence then you should prepare a smaller area where they can get used to it without getting out; with cattle usually one good shock is all it takes, with goats maybe a few more. The shock registers in the brain of the animal and once educated they will remember for a long, long time. This training area should have good power on the fence to ensure that they leave with a lasting memory.
- Don't just assume everything is working: Yes, electric fences do need to be checked periodically. Normally, every time you check on your livestock you are going to want to check your voltage on your fences as well. You can not do this without a voltmeter. It's a must have with electric fencing – you need to know what the voltage is. Some voltmeters also will show current which will additionally help you find shorts or faults that arise. As you grow with your system, you will begin learning what to look for with your voltage and should problems arise, you will be able to quickly resolve it.
- Nicked, kinked or dented wire: If you do get nicks or kinks in your wire during installation – you need to remedy it then. If the wire gets a kink in it during payout, then you should go ahead and cut it and install a crimp. Otherwise it may break at the most opportune time, when you don't have time to repair it.
Same thing on dented wire, For example, you get sloppy installing a crimp sleeve and your crimp tool puts a dent or craze in the coating – you may as well fix it on the spot as it again may break later. If the class III coating gets damaged – it is a weak point so fix it. Hi-tensile wire has a very high breaking point of 1000 to 1500 pounds – but it needs to be installed cleanly and correctly.
- Product installed incorrectly: Yes believe it or not this happens all the time. One pet peeve of mine is with end strain insulators. There is a right way and a wrong way and I have seen my share of the wrong way. The wire needs to pull thru the mass of the insulator – not thru the little hole in the end. If you are in doubt – then ask someone. The only dumb question is the one you didn't ask.
- Electrical connections: I think this area is one that needs to be discussed more. I see a lot of people just wrapping a jumper wire around the fence wire. I also see a lot of these that will arc and give a pretty poor electrical connection. There are a lot of good quality crimps, split bolts, taps, etc that do a good job for very little money. As the pulse flows down and around the fence wire there is resistance created with wire wraps. This is not a problem at the ends where you may want to hand knot your wire to an insulator...but on the fence wire that you are transmitting an electronic pulse you need a good connection on your jumpers. I've noticed that you many times read 1 to 4 amps (leakage) at each wrapped connection. That's not much, but when you add them all up, then it does make your voltage drop, simply due to resistance.
I hope these general comments help you with working with hi-tensile wire. I strongly feel it is the best fence you can put up for any type of livestock. As you progress with it, you will be amazed that only a single strand will keep cattle where you want 'em.