Monthly Archives: March 2015

Sewer Systems

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One of the less favorable jobs I’ve had at work over the years is fixing sewer backups. I want to apologize in advanced for anyone who is grossed out by this topic. My reason for writing about it anyway is that sewer systems are in fact essential infrastructure in our lives. They allow for convenience and improved sanitation. Before the advent of the modern sewer system, disease was spread through contaminated drinking and bathing water. Sadly, certain underdeveloped countries still lack adequate systems. I plan to discuss what makes up such a system,and how it works.

Not many people know what actually happens when you flush a toilet. Fortunately (or unfortunately) I have spent a little time working on the systems that manage our waste and want to share how it works. I don’t have experience with the urban setups like they have here at Penn State, so I will just talk about rural/suburban infrastructure.

When you flush a toilet or use a sink, or take a shower, the effluent flows down, through a “trap” and then through a network of downward sloping pipes. The trap is basically a u shaped piece of pipe that is designed to “trap” some of the water flowing through it. The point of this is to block the passage of sewer gasses from backtracking into your bathroom and making it smell bad. The pipes are sloped (as a rule of thumb 1/4 inch drop per foot) so that gravity does all of the work moving the effluent along. Old pipes were made of cast iron and new pipes are PVC. The drain pipes from each toilet shower bath and sink link together and flow downwards until they reach outside of the house. At this point, the main sewer line goes into what is called a septic tank. The septic tank is a large buried concrete box designed separate solids from liquids and allow for bacteria to consume the waste. Over time healthy bacteria will consume much of the solids and dissolve it into liquid form. On the opposite end of the sewer main entrance there is a outlet pipe. All of the liquid from the septic tank flows out of outlet pipe and into the distribution box. The so called “d-box” is pretty much just a fitting that allows for multiple drainpipes in the drain field. The liquid flows from the d box into perforated drain pipe ( pipe with holes). These drain pipes are under ground like the rest of the system and are run in long lengths away from the septic tank. The purpose of these is to allow for the liquid to drain into the ground. Although this may seem odd, bacteria and fungi in the soil work to digest the liquid and any chemicals in it and return it to pure water. One has to pay careful attention to the type of soil the drain field is made from because sandy ones drain too quickly and therefore do not give the bacteria time to clean up the water.

 

Flat Tires

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For today’s passion blog, I would like to talk about fixing flat tires. Although I mastered this skill while on the job at Highland orchards, my first opportunity to fix a flat tire came in my younger years when I popped a bike tire. Consequently, my dad showed me how to go about patching it.

The first thing to mention is that there are two major types of pneumatic (air filled) tires you will run into. The first is the tubeless tire. This is the standard for cars and all down the road vehicles. This just means that the only parts are the tire and the steel/aluminum wheel. The next type is tube tires. These have a tire, inflatable inner tube, and a steel or aluminum wheel. These are found on tractors and bicycles for the most part.

Each type must be fixed differently. Since I learned tube tires first, I’ll talk about them first. The first step to fixing a flat tube tire is to find if there is a nail or screw or something in the tire. If there is, remove it. Next, remove the rubber tire from the rim. This is accomplished with a large flathead screwdriver or a specially made tire iron. Once it is removed, then take off the thin rubber inner tube. If the hole is not obvious, inflate the inner tube and spray it with soapy water. The air leaking will create bubbles at the leak site. If the hole is larger half an inch then the tube should just be replaced. Otherwise, clean the area around the hole, wipe with alcohol, and then apply rubber cement. After that, press on a rubber patch. Then use a roller press down and remove all air from the between the patch and tube. Now the tire is ready to re assemble.

For a tubeless tire, you can jump right to finding the leak. Look for nails/screws sticking out of the tire, and spray on soapy water if it is still not obvious. Once you have found the problem area, remove the nail or screw if applicable. If the hole is anywhere on the sidewall of the tire it should not be fixed but rather replaced. If the hole is on the tread, start by driving the reaming tool in and out of the hole to make it the correct diameter. It may seem counterintuitive to make the hole larger, but it is necessary to fit the plug. Once the hole is reamed, apply glue to the plug (it reminds me of a slim jim) and push it into the hole with the special tool, which works much like a large sewing needle.  Then simply pull the tool out and the plug is set. Trim the excess plug material and then inflate the tire. Once you are sure the leak is stopped, you are good to go!

Patching tires can save a lot of money. I bought a patch kit for $5 or less at Harbor freight (great store for cheap tools/materials) and patched my truck tire, which would have cost $100 or more to replace.

Civic Issues: reflection on another group’s deliberation

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For this week’s civic issue blog, I would like to reflect on my experience at another class’s deliberation. The topic of the deliberation was the legalization of marijuana.

The group presenting the issue first started by giving an overview of the topic, and asked the audience general questions about the stance. This was a good way for the audience to begin thinking about the issue. Since attendance was so large, the audience was split into three groups and the leaders for each approach cycled through each group. I really appreciated this structure because it allowed much more intimate discussion and better organization. Additionally, there were still around 12 people in each group so there were still a large number of opinions to be had.

When the first approach leaders came to our group, they went over the basis of their approach and proceeded to ask questions. I thought that this method was very mechanical based off of how they framed the approach. Instead of creating a general concept for the approach, they prescribed specific characteristics for it. I thought that this really seemed to hinder discussion because it almost seemed as though the presenter’s minds were made up. Of course what they had to say was accurate and valuable, it just felt as though there was little room for negotiation, or more critically, deliberation. Despite of this, the group did have lots of worthwhile deliberation. However, it usually happened when we departed from what the presenters framed. I felt as though our deliberation achieved constructive dialogue because we had a more open framing that allowed the audience to input their own opinions and perspectives more easily.

One benefit of the presenter’s method was that they were truly prepared and knowledgeable about their topic. Besides knowing many specific facts, they were able to provide the audience with almost all of the relevant information to understand the approach.  Also, they spoke well and had many question lined up so there was little awkward silence. The only divergence from this was when a moderator asked a question with an obvious answer, or a question that didn’t really ask for any opinion and had little room for interpretation.

 

There was a man around the age of 50 who participated in discussion in the same group as I. He was an obvious supporter of marijuana because of the opinions he shared. I thought he was particularly interesting because he kind of listened to what the questions were, and then answered something completely different, whatever he wanted to talk about. This presented the leaders a challenge of harnessing his contributions without making him a nuisance to the deliberation. On a personal note, I didn’t like his contributions because he spoke like he was an expert, but he was inaccurate on several important facts.

When it came to the conclusion, the leaders conversed briefly, and then presented their reflections and final thoughts on the discussion. One thing they did was present what they said was the general consensus of the group, and asked if anyone still disagreed. My hand went up, along with one other individual in the room. I found this to be very interesting. I did not find any of the previous dialogue to be persuading by any sense, so I came to think of why so many people agreed in the end. My proposal is that if people were asked the same question in the beginning of the event, the same number of hands would have gone up. I attribute this to the fact that most college aged students are socially liberal, as are many people involved with education. Additionally, many of the people who showed up to the deliberation were probably advocated for the legalization of marijuana. I did not feel slighted because I had a unique opinion among the group, but rather I felt slighted because they almost completely ignored any aspect of a conservative opinion. I think they could have had a much better discussion if they had done this, instead of just agreeing with themselves the entire time.

Fiberglass

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Fiberglass is a fairly common material in everyday life. It is used to make boats, ladders, tanks, and insulation just to name a few examples. Although it has been replaced by plastic in some applications, it remains relevant because of its strength and ease of patching/forming. Fiberglass is basically a mix of two things: fibers and resin.

The fibers are about the width of floss, and come in the form of a cloth like mesh. In this state, the cloth is very flexible and can be shaped in any way. The beauty of fiberglass is that first you shape the cloth, and then using the resin, it will harden and stay in that shape. The resin can be imagined as glue that dries very hard.

The first time I used fiberglass was actually for one of my own projects. I bought an old sailboat and it happed to have a hole in the hull. Of course, boat don’t work very well if they start to sink, as I figured out when I was testing it for the first time. Since the boat was made of fiberglass, it was fairly simple to patch it with fiberglass. The hole was about the size of a quarter.

The first thing to do when patching with fiberglass is to roughly sand around the perimeter of the hole. This is to get rid of the “gel coat”, which is a glorified paint on top of the fiberglass. It is essential to sand this off so that that the new fiberglass will bond to the old fibers, and it will make the final patch smooth.

Once the area around the hole was prepared, the next step is to cut out a piece of cloth to patch the hole. It should be larger than the hole on all sides so it has material to grab on to when it solidifies. After the cloth is ready, you need to mix the resin. Like many adhesives, it comes in two parts. In this case, there is resin, which reminds me of syrup, and then hardener. It is important to wear rubber gloves and be very careful with the chemicals because they will stick to your hands for days and permanently stain clothes. After you mix the two together you then saturate the cloth with the mixture, and then press it onto the sanded area, covering the hole. To make sure it sticks properly, you must press all of the air pockets out with a stick or a roller.

Fiberglass usually takes a couple of hours to dry completely, depending on the ratio of hardener and resin. Once it is dry, you just sand it down and apply another layer using the same procedure as last time. This process of adding layers makes the patch very strong. Once you are satisfied with the patch, it is very easy to sand it down and paint/gelcoat it to blend with the rest of the object.

I find fiberglass to be a very useful material because it allows you to add thin shells in any shape you want, without needing complex tools. It is waterproof, will not rot, and is reasonably strong.