Model Rockets

Who doesn't love pyrotechnics? Ever since I was little I've looked forward to every 4th of July with great anticipation. I dreamed of creating my own beautiful, powerful, and ever so temporary art in the sky just as the pro's did.

Then one day my dad bought me my first model rocket kit from the hobby store. My dream was finally realized. Sort of. Putting together the kits only satisfied me for a short time. Soon I began looking for a similar but more involved project. Then I found this guys page:

http://www.jamesyawn.net/

He does some really cool stuff, but one of the coolest things he's done is laid out instructions for building rockets from scratch. That's right. Even the engines. With a minimal amount of materials too.

Making the rocket itself is quite easy really. It’s basic paper craft. Making the engines is a little more tricky because involves getting the water content in the fuel just right. That’s really the hardest part. If you dry it out to much it’s unworkable and is quite a pain in the ass to rehydrate evenly. If you leave to much moisture in it though it’ll inhibit the burn too much. Plus it’s hydroscopic, which means whenever it’s exposed to open air, it’s absorbing moisture. Since you have to heat it up to make it pliable enough to load into engines, it’ll dry out a little every time you heat it up. This means you basically have to practice until you’re really comfortable with the process. He covers this all in greater depth on his site.

Another problem I often encountered was having my nozzles blow out. This can be caused by a combination of factors involving the fuel grain itself, but I found that lining the inside of the end of the engine with glue before pressing the bentonite into a nozzle helps hold it in place.

Here are a few I made back in high school.

File Knives

I've always loved knives. There is something primally satisfying about holding a knife in your hand. It's a feeling likely rooted in the early parts of our brain that developed for survival long ago, when holding a knife in your hand could mean the difference between eating and being eaten. Therefore it only makes sense that having the ability to make your own knife would be even more satisfying.

I embarked on my quest for a homemade knife last summer. I had seen knives made out of files online and thought they were pretty dope looking. Plus the idea of sourcing a readily available resource for the blank felt pretty survivalist. So I went out and bought a Nicholson Blackhawk handy file, bastard file, and a mini bastard file.

I annealed the files in my mini bbq by burying them under the coals and putting a hair dryer to the coals to stoke them. I got it to where it was barely starting to glow red and then I buried it in vermiculite to insulate it and slow the cooling. I realize now eyeballing the temperature is risky business but at the time I was doing the best I could. After all it worked and made the steal softer and easier to work with, which is the goal of this step.

I cut the files to size and shape with my Dremel. The blades that came with it burned out or shattered pretty quickly. I went through all twelve of them on one file before buying some reinforced blades. Once I had the general shape down it was time to grind them to shape. I didn't have access to a good grinder so I ended up dangerously half assing it with a handheld belt sander turned upside down. This means I had to hold the trigger with one hand while holding the file with the other... this resulted in a loss of precision. But I wasn't expecting much for my first knife anyway.

I drew where I wanted my bevel to end with a sharpie. With 40 grit sand paper the metal grinds away pretty fast, but the sand paper wore away pretty quickly also. I think this is because I just used whatever type of 3M paper they had at the hardware store. I don't think it specified what materials it was for but I'm fairly certain it was for wood. Using belts made for this kind of work would probably make a difference.

Once I had the knives in the shape I wanted, I tried to harden them with my home made forge. There is alot to read about hardening steal and it is very complex. But basically my goal for these files was to heat it to around 1475 F and then quench it in vegetable oil. I simply couldn't get the files hot enough in my BBQ so I ended up building this forge.

Sadly it's design is blatantly flawed and it doesn't fit the file properly, so I stuck it in at and angle for about a minute and this happened.

I ended up making it into a shorter knife, no big deal. You need to make mistakes to learn after all.
So after reading a bit about DIY forges I built this bad boy. Filled with perlite around the air pipe and packed and lined with furnace cement.

Basically without a well controlled heat source and a sensitive way to measure that heat, you can't really harden a steal that accurately. Each type of steel hardens at a different temperature, and getting that temperature wrong means underhardening the blade -which makes it softer so it won't hold an edge- or overhardening the blade -which makes it brittle and prone to cracking-. Basically I tried to use the Curie point (1414 F - the temperature at which steel loses it's magnetivity) to estimate the temperature I quenched at. I tested my blade regularly with a magnet as it was heating and once the magnet stopped sticking, I held it in the forge for about 10 more seconds before quenching it in oil. This is a highly unreliable method. It turns out that without a pyrometer the best way to accurately judge when a steel is ready to quench to attain maximum hardness is to visually assess the surface of the steel for decalescense. This is a phenomenon that occurs with all steels at their relative critical temperatures for hardening. It's seen as a shadow of black that moves in from the edges of orange glowing steel before disappearing as the steel reaches the temperature. This is caused by an endothermic change in the arrangement of the molecules in the steel. More can be found on this topic elsewhere online.

After I quenched them I immediately tempered them at 400 degrees twice for on hour, cooling in between. This reduces the hardness a little, making the knives tougher and reducing any stress built up in the knife during hardening.

As you can see I tried to fit a handguard on there too. Would have looked real nice but I messed with it too much and screwed it up beyond repair.

I also bought some Holstex and tried my hand at making sheaths. They're pretty sloppy, but not terrible!

DIY Hard Cider

Alcohol is so expensive! Most people don't realize how easy it is to make their own. One of the simplest things you can brew is hard cider. You basically mix some things together and wait for it to ferment. Making something that actually tastes pleasant is truly an art, but making something that gets you drunk and doesn't taste terrible is really simple!

Equipment:

Fermenter- I use a five gallon bucket. Alot of people like to use glass carboys but as long as the bucket is made of food safe plastic it shouldn't matter. This was my fermenter for my first batch:

Airlock- I bought one for a buck fifty at the brew store. My first one however was jerryrigged out of a piece of 1/8 inch ID hose and a souvenir mini syrup bottle.

Hose- I use 1/8 inch ID poly tubing from the hardware store. You use it to syphon the cider out of the fermenter when racking.

A secondary vessel of some kind like another bucket is needed for racking.

And the ingredients:

-Apple Cider

True hard cider should be brewed with real apple cider. The cloudy, flavorful stuff. The better quality you're starting material, the better you're finished cider will be. You put shit in, you generally get shit out. Optimally you'd want some unpasteurized cider fresh from an orchard (pasteurization ruins some of the flavor). However pasteurized cider from the grocery store will work too. To tell the truth, I still haven't taken this step toward quality. I used grocery store apple juice. Many real brewers would look down on this method, but it's simply what was most available to me. You have to make sure it doesn't have any preservatives in it though. Any preservatives like present like potassium sorbate will prevent the yeast from going to work. The only acceptable additives should be ascorbic acid and malic acid.

-Sugar

The amount of sugar naturally present in apple juice won't get the alcohol concentration very high.
Therefore you must add sugar if you wish for the alcohol content to be higher and you would like the cider to finish sweet. I added 2.5 pounds of sugar to my first 5 gal batch and it finished around 9% alcohol by volume. I added 5 pounds of sugar to my more recent batch, and it should finish around 14% ABV if I'm lucky. The alcohol concentration can be calculated using the starting specific gravity and the ending specific gravity. Therefore you must measure the specific gravity after you add sugar,  before you start fermentation. Then can you subtract the ending specific gravity from the starting specific gravity and multiply that by 131 to approximate the alcohol concentration by volume. You can measure the specific gravity with a measuring device sold at brewshops and online that float at a certain level due to the density of the liquid and are graduated with numbers specifying the density for a given depth. I actually didn't bother buying one because I have small graduated cylinders and a milligram scale, so I measured 10 ml out in a cylinder I had torn on the scale, then weigh the 10 ml and divide it by 10 to determine the density.

(Starting specific gravity - Ending specific Gravity)*131

-Yeast

For my first batch I used champagne yeast. It worked quite fast and after two and a half weeks the specific gravity had not changed in 3 days so I racked it and gave it a sip. It tasted just like cheap white wine. With a hint of apple. Not a strong one though. It wasn't disappointing, since it got me quite drunk. But it wasn't quite what I was expecting. So I looked around in some forums and found alot of people using pale ale yeast, since it apparently leaves much more apple flavor in tact than champagne yeast. Well I've been sampling the unfinished product and it worked! It's got much more apple flavor to it than the last batch, despite using cheaper apple juice. The problem is pale ale yeast die out around 9% alcohol, and I wanted something as strong as I could make it. So after the pale ale yeast reached 9% ABV, I racked it and added champagne yeast, putting it back in the fermenter. 

One problem I did not expect was that within the first couple days of fermentation with the pale ale yeast, the was a strong odor of sulfur emanating from the fermenter. I opened it and did not observe any noticeable contamination but did see bubbling like I have seen from yeast before. I looked into the issue online and it turns out that insufficient nutrients can cause certain yeasts like pale ale yeasts to produce sulfur during fermentation. Apparently this can be prevented by adding yeast nutrient, something available at brew stores and online that I had neglected to give further notice before. However now that fermentation was well along and it the smell was already there, I searched for a solution to the problem and found that a miniscule amount of copper compounds can be added to neutralize the sulfur smell. However, copper compounds can be very toxic and are only need in miniscule amounts for this purpose. But it turns out the easy DIY solution to the problem is to soak some copper in the cider until the smell is gone. The surface of the copper reacts with acids in the cider and diffuses safe, minute amounts of copper into the cider. I suspended stripped speaker wire into a bottle of cider and shook it every now and then throughout the day. By the end of the day the sulfur smell was gone and it was quite pleasant!

-Potassium metabisulphite

This is a preservative I bought at the brew store in the form of tablets. It keeps bacteria and other nasties from growing in your brew while it's aging. It's not necessary if you're going to drink it quickly after brewing, or if you brew your cider up to the maximum concentration of 14%, at which point there is enough alcohol to keep it safe. It should be added after racking, before bottling. One tablet per gallon is recommended.


Once you dissolve the sugar in the apple juice (which is best done by heating the apple juice gently on the stove and stirring the sugar in bit by bit) and let the juice cool to room temperature you may add the yeast. It is then best to keep it below 70 degrees Fahrenheit, but mine room wanders slightly above. Once the alcohol concentration reaches your desired concentration, you may syphon the cider off into another bucket, leaving the bottom half inch of cider on the bottom with the yeast cake. This can be discarded or used to start another batch. The cider is then chilled and left in that bucket to settle more yeast out. The cider can then be racked once or twice more but I haven't found it makes much of a difference unless you let it sit for a long time. I haven't aged my cider yet, I drank the last batch fresh. But from what I read aging it really brings out the flavors and makes it less harsh and more enjoyable.

That's all I've got for now. Good luck and happy drinking!