Thursday, March 13, 2014

Did he really say that...out loud?



  Does your supplier pee on your leg, then tell you its warm rain? Or, to put it more delicately, are you getting everything you're paying for when you buy fence materials? Chances are, unless you know your supplier and check each delivery, what you get is what you get.
  The easiest way for anyone to get your business is to offer you a “better price”. I won't go into that loaded term here, but let's just assume for now that means a lower price per unit. There are a couple of ways for a supplier to do that. One, is to buy in such large quantities that they can save money on the unit cost, as most manufacturers and distributors offer quantity discounts. This is unattractive to all but the very largest of companies because of the high cost of storing and paying for inventory. Most companies trying to drive down unit price do so by seeking out a supplier that offers a lower price per unit for the parts they need.
To do that, the supplier must remove something from the product.
  It takes a measurable amount of material costs and labor costs to manufacture anything, along with transportation cost to get it to the end user. To reduce the unit price, one must reduce either the cost of labor, i.e. “outsource”, or the cost of materials, or the cost of transportation. In the age of spiralling fuel costs, cheaper transportation is very scarce, and the cost of transportation is largely out of the control of the supplier. Labor can be found elsewhere, much cheaper than in the U.S., but that usually means additional transportation costs. Recent increases in the relative wages in common outsource supply countries has led to a closing gap in the cost of goods sourced in Asia when compared to American made goods.
  This leaves only material costs as a means of controlling unit price. Many manufacturers are succumbing to the pressure to drive down unit price by reducing the amount and the quality of the raw materials they use. The alternative is to continue making top quality products at reasonable prices to compete with the poor quality, lower priced alternatives being dumped on the market.
  Unfortunately, for most contractors, the alternatives are to buy poor quality, and hope the check clears before the product fails, or try to figure out how to win a bid against someone selling lower priced, (inferior) products. The key is to help the customer see that by buying lower price, he is getting lower quality, and will not be satisfied for long. It can be a difficult sell, but Bill Gates didn't get rich clipping coupons. The key is to teach the customer that though a component looks like the one you are selling, it will not perform the same.
  No one likes to spend too much money for what they buy, and saving fifty dollars today and finding out that you'll pay hundreds to repair the problems caused by the poor quality component that you saved money on is absolutely painful. Insist on getting what you pay for, and be ready to pay a fair price for quality, or prepare to pay for a lot of broken promises.


Wednesday, November 13, 2013

Hey Look Ma, No Wheels!

In the last post I pointed out that the wheel under a gate could be eliminated if the gate were built rigid enough to support itself. 'So what', you say? There are probably millions of gates out there with a wheel under the swing end. In this post we'll look at some of the reasons that may not be the best way to build a gate.
Rather than looking at gates with wheels and why they are built that way, let's look at sound gates and how they are made so they don't need wheels. No matter what material is used to build a gate, there are certain principles of physics that apply to all gates and will affect how they should be designed.
There is a lot of opinion about bracing on gates, and most of it is based on anecdotal evidence. You will often hear a gate builder say something like, “The man who taught me this business has forgotten more about fence than most other guys know, and he said do it this way.”
   That's great, as long as he forgot all that fence stuff after he taught you! All kidding aside, it is a truth in life that the worst reason to do something in a particular way is that it has always been done that way. There should be sound reasons behind what we do, not just tradition backed by emotion. Henry Ford's dad taught him to hitch a horse to a wagon to move stuff on the farm. Fortunately, Henry didn't let that stop him from building something far better.
  In order for a gate to be strong and long lasting, it needs to be rigid.  Flex in the system will tend to loosen the connections between components of the gate, and as this looseness grows, the gate gets weaker and starts to sag and flex and even lay over. Often it is at this point that a wheel is added to keep the leading corner from dragging. This is not a solution. If I break my leg, the doctor can give me a crutch, and I can get around. If he doesn't set the bone and cast it so it can heal, (be rigid again), I'll use that crutch the rest of my life, and the longer I do, the more I wear out my shoulder, and the other joints in my body because I'm compensating for the weak leg.

In the next post we will look at the geometry of a gate and how proper bracing makes a gate stronger, and improper bracing just makes it heavier.

Tuesday, November 5, 2013

Some is Good, More is Better? (part 2)

The question is, “How do I hang a heavy gate”? The answer starts long before that in the design phase of the job. Simply put, the farther apart you can place your two hinges, the stronger the overall system will be. This means designing a gate with hinge points as close to the top and bottom of the gate as possible.
  Whether you are building the gate from scratch, or you already have the gate, once you know the distance between the hinges, the next factor in the equation is the width of the gate. How big is the opening? With these two numbers, and the overall weight of the gate, it is possible to compute how much rotational force, or “moment” the gate produces. This is the force that destroys hinge systems. Choosing a hinge designed to carry a given “moment” is crucial to making a strong gate system.
  The wider the opening, the longer the gate, and the greater the leverage exerted by the gate on the hinge, and the gate post. Spreading that leverage over a larger hinge distance lessens it's overall impact on the system.
I only know of one manufacturer that rates hinges using these calculations. You can find their “Proportional Load Charts” by registering at their website, www.mftfence.com, and downloading their 2013 Catalog.

  I started this installment with the statement that the farther apart your hinges are, the stronger the gate system will be. There are several ways to optimize this distance. For ornamental gates, gusseted corners can help support that weight. Never place a hinge in an unsupported area of the upright, as it will flex under load. For wood gates, consider placing hinges where top and bottom rails of the gate meet the upright. Chain link can offer some interesting variations. In industrial and commercial applications, one way to gain strength for gates on very wide openings is to build an “extension”. Extend your gate post above the fence line to the distance you want to gain between hinges, then extend the gate upright to the same height, bracing it to the top rail with a brace at no more than 45 degrees, for rigidity). 



If you look closely at this gate, you can see that it is almost as described.  The gate builder has added an extension to the top of the gate to gain strength.  Unfortunately, he is not taking advantage of this height.  He has kept the top hinge just below the top horizontal rail of his gate.  It would be a much stronger system if the top hinge were at the top of the extension.  The other flaw in this design is that the angle brace comes down at an angle greater than 45 degrees, which prevents taking advantage of it's strength to keep the gate rigid.  Notice the addition of a wheel at the bottom of the gate.  It could be eliminated, and the gate would be much stronger, if the top angle brace were attached to the top horizontal rail of the gate at the point where the lower angle braces meet in the center of the gate.  But that's a topic for the next post!

Some is Good, More is Better? or, Why Three Hinges on a Gate Isn't a Good Idea

In the past month I've talked to several fence contractors who shared the same misconception. In each case they thought that adding a third hinge to a gate would allow a heavier gate to be hung safely. There are several reasons why this is not so.
The first is that, no matter how hard you try, you will never be able to get all three hinges aligned in a straight line. There will always be a straight line between any two of the hinges, but to get all three in perfect alignment would be a tough job with a laser in perfect lab conditions, much less in the field. Why does that matter? Because the “odd man out” hinge will tend to push or pull on the gate frame, twisting it and leading to damage to both the gate and the hinge affected. To make matters worse, the hinge that is odd man out can change, depending on how far open or closed the gate is in its arc of travel.
Several of the contractors I talked to pointed out that the doors on their house have three hinges. That's often the case, and as someone who worked as a carpenter for nearly twenty years, I can say that the chief reason for that is wood doors are not stable without a third hinge. The center hinge on a door is there to make the door more rigid, not to support the weight of the door. See the following article for deeper understanding of this. http://bit.ly/1hgisiZ

A second reason is that the weight of a gate is primarily borne by one hinge, not two, or even three. Unless you spend a lot of time perfectly balancing the hang weight of the gate from the hinges, one hinge will likely carry the bulk of the weight, most of the time. Think of an old wrought iron gate installation. The ring and pin hinges used for hundreds of years work well as an example. The bottom pin carries the weight, the top pin serves as a pivot to guide the gate through its arc and keeps it from tipping over.

“So how do I hang this heavy gate”, you ask? That's the subject of the next installment.

Monday, June 17, 2013

Thursday, June 13, 2013

It's Not Easy, Bein' Green...Or Is It?


Modern Fence Technologies Working Toward a Sustainable Environment

Kermit the Frog said 'It's not easy bein' green', but Modern Fence Technologies is proving him wrong.

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The "Love Boat"?
Cargo ships burn low-grade "bunker fuel".
“We can afford to use better quality materials because we're not paying to ship materials and finished goods halfway around the world.” Mark Knudson
East Troy, WI (PRWEB) June 13, 2013
Recently the media has paid a lot of attention to the state of the environment and the potential for health risks and even global warming. Modern Fence Technologies is announcing its commitment to combating the destruction of the environment. “Part of our commitment to making our product here is that the people who work here want to be good stewards of the resources that we have been blessed with,” said Marge Knudson, a principal of the company.
Modern Fence Technologies practices green manufacturing to reduce the amount of waste and saves money doing it, while making gate hinges and other hardware for the fence industry. By shifting to a four day/ten hour schedule, the cost of lighting and environmental control in their manufacturing facility has been reduced significantly. In addition, all scrap materials are collected and recycled. By watching the market, scrap metals can return enough money to make a big difference on the bottom line. Even paint has been addressed, by using powder coating technology, the volatile organic compounds (VOCs) associated with traditional “wet paint” are eliminated.
All of this adds up to savings for Modern Fence Technologies. “We can afford to use better quality materials because we're not paying to ship materials and finished goods halfway around the world,” Knudson's husband Mark, another principal of the company pointed out. "Using better materials means replacing them less often, which also helps the environment," he added.
Another key component of the equation is the environmental cost of international shipping. According to portoflosangeles.org, the Los Angeles/Long Beach complex receives roughly 60% of the goods imported to the United States. The California Air Resources Board has studied the effects of pollution originating in the Port, including rail and truck traffic and pointed out:
“Air Pollution from international trade and goods movement is a major public health concern at the statewide, regional and community level. Adverse health impacts from the pollutants associated with goods movement include but are not limited to premature death, cancer risk, respiratory illnesses, and increased risk of heart disease.” (Environmental Health Perspectives, 2006 April; 114(4) A-204-A205)
Modern Fence Technologies avoids these hazards by making their products in the U.S. of domestic materials, avoiding both the financial and the environmental costs associated with overseas manufacturing. “We're saving money by manufacturing here, and we're doing our part to preserve the world we've been given.” Mr. Knudson finished.