Shopping bags are nice because they are free. But ironing out the wrinkles is a chore, and for just a few dollars, you can buy the paper used to make the bags. It’s called 60 pound kraft. or 60 pound postal wrapping paper, and you can buy it at an office supply store. As of the year. 2000. a 125 square foot roll costs about S3, and that’s enough to make 3 dozen of the tubes just described.
For S20. a nearby paper dealer sold me a 1650 square foot roll, and that’s enough to make 600 tubes at a cost of less than 4 cents per tube. Of course the glue is expensive when you buy it in small bottles. But like the other supplies, the price drops dramatically when you buy more. As of 2003. a gallon of white glue costs SI 1.
Sixty pound kraft paper works fine for short tubes with walls up to 1/8″ thick, but not for anything larger. Sixty pound kraft is only .006″ thick. In tubes made from paper this thin, the normal variations in paper thickness, plus the variations in the thickness of the glue, make up a significant percentage of the wall thickness. As you increase the number of wraps, the variations accumulate, and the tube’s outside diameter becomes irregular. The tube in the previous example took 18 wraps to make. At 18 wraps, the variations are acceptable. At anything over 20. they become troublesome.
When working with paper this thin, you will also find it hard to roll a sheet more than 8″ wide without making it wrinkle. This limits the tubes made from 60 pound kraft to a maximum length of 8″. Larger and longer tubes need thicker paper. The best paper for making large tubes is kraft liner board, but before you start looking for it. you need to understand how the paper industry works.
The paper industry is split into three levels. At the top are the paper mills. Paper mills are gigantic factories that buy scrap paper and wood chips by the trainload. convert them into pulp, and then into rolls of paper weighing up to 6 tons each. They make paper only when someone orders it. They do not keep paper in stock. They do not sell paper in small quantities, and their minimum order is usually 20.000 pounds (10 tons). Paper mills produce prime quality paper and B-grade paper. Prime quality paper is made exactly to the customer’s specifications. Prime quality kraft liner board is the best paper for making hand-rolled rocket casings, but it’s almost impossible to buy in small quantities. The mills make it onlx for the customers who order it. They rarely have any left over, and even when they do. they don’t sell it to the public.
B-grade paper, also called odd lot or job lot paper, is paper that’s “a little out of spec”: what another industry might call a “factory second”. It might be from the beginning of a mill run before the machine was properly adjusted. The color or the texture might be wrong, or the thickness might vary. And rather than throw it away, the mill sells it to a “paper converter”.
Paper converters form the middle tier of the industry. Paper converters buy a few prime quality papers, but only the most popular types, which they repackage and sell to retailers like the store where I bought the 60 lb. kraft. They deal mostly in large rolls of B-grade paper, which they buy from the mills, and sell at a discount to nearby industries that don’t care about color, texture, or thickness. With rare exceptions, paper converters take orders by phone, load them onto trucks, ship them to commercial destinations, and sell only to customers with established accounts. They do not normally deal with the public, and though they may have exactly what you want, they will probably ask you to buy it through a retailer.
At the bottom of the industry are the retailers, also called paper dealers, and the paper dealers are the only members of the industry who maintain stores where you can walk in and buy something. In most parts of the country you’ll find a PAPER DEALERS column in The Yellow Pages. The problem is that kraft linerboard is an industrial material used primarily to make cardboard boxes. It is not used by the public, so most dealers don’t sell it. and even the ones who do don’t keep it in stock. This doesn’t mean that they can’t get it for you. It means that it’s a special order item, and will be subject to the minimum dollar amount imposed by the converter where they buy it.
Because paper dealers don’t normally sell kraft linerboard. they will not have samples to show you. and they won’t be able to help you select what you need. The paper converters have the samples and the paper, but they usually won’t sell it to the public, so here’s how to proceed.
Paper converters tend to locate in large cities near the industries that buy from them. Check The Yellow Pages of nearby cities under the PAPER CONVERTERS or PAPER CONVERTING headings. When you find a list of converters, pick up the phone, and start calling them. In the example ahead, we’ll pretend that you need some .015″ thick linerboard for making 1-65 casings. 1-65 motors are 15″ to 16″ long, and we’ll assume that you plan to experiment with longer motors too. so you’ll need some paper that is 24″ wide.
1. First ask each converter if they sell kraft linerboard. If they say yes. ask them if they have any that’s approx. .015″ thick. If they say yes again, ask them what their minimum purchase is (i.e. the dollar amount), and make a note of what they say.
2. When you’ve spoken with all of them, call back the ones whose minimum order is affordable, who sound like they have what you want, and tell them that you want to see some samples. They should be happy to show them to you. They’ll probably want you to make an appointment, and they might want some more information about you. At that point you can explain that you’re a private party, that you know they don’t sell to the public, and that if they have what you want, you’ll order it through a dealer. Also note that paper converters often deal with customers over long distances. If a personal visit is difficult, they might be able to send you a sample by mail.
Important note. When making the tubes for these rocket motors, you need the strongest paper you can find. Kraft linerboard varies tremendously in strength, depending on what kind of fiber it is made from. It is not something you can order sight-unseen, and before you buy it. you absolutely must look at a sample. Linerboard made from 1009c newly processed wood fiber is called virgin kraft linerboard. Because the fibers are long and unbroken, it is very strong and very hard to tear. Virgin kraft linerboard is the best paper for making rocket casings.
Linerboard made from 1009c recycled fiber is called 100% recycled kraft linerboard. Because the fibers have been chopped up and broken in the recycling process, it is weak, and it tears very easily. 100% recycled kraft linerboard is the worst paper for making rocket casings. Virgin kraft linerboard is hard to find. Recycled kraft linerboard is easy to find, and most linerboards are a made from a mixture of virgin and recycled fibers.
Important note. These tubes are made by rolling the paper around a metal bar. When you go to look at the samples, take the bar with you. and bring along a micrometer or a vernier caliper, so you can verify the paper’s thickness.
Important note. Paper that is too thick or too rigid will kink when rolled around the bar. and paper that is too thin will amplify the problems of wrinkling, telescoping, and uneven wall thickness. As a general rule. I like a paper whose thickness equals 1% of the i.d. of the motor casing. Given a choice. I’d make an 0.75″ i.d. casing from paper that’s .0075″ thick, and I’d make a 1.5″ i.d. casing from paper that’s 0.015″ thick. If my choices were limited. I might vary from these figures by plus or minus 25 percent.
3. When you arrive at a converter’s office, ask to see samples of kraft linerboard approximately .015″ thick. Tell them that you need a roll at least 24″ wide, and tell them that you need a very strong paper. When they bring out the samples, roll each one around the bar. and pick the toughest paper they have that wraps around the bar without kinking.
At this point don’t be surprised if the paper they show you is not the thickness you specified. As I said before, paper converters sell mostly to industries that don’t care about texture and thickness. During my own odyssey. I quickly learned that, when I asked for paper that was 0.015″ thick, my request was interpreted to mean anything from 0.010″ to 0.020″.
Also, the paper industry uses several standards for measuring thickness. When you say 0.015″. they might think you mean “15 mil”, and 15 mil paper can actually be thinner. When the samples they showed me were not the thickness I wanted. I asked if I could walk through the warehouse and pick something out. Taking the micrometer with me. and measuring the paper as I went. I found and bought some paper that was suitable. But they didn’t have a sample, because they were very busy at the time. They hadn’t kept their samples up to date, and what they displayed in the office represented less than half of what they actually had for sale.
4. When you’ve seen the best they have to offer, take a sample with you. Write down the details (like the name, the thickness, the width, the stock number, etc.). and go to the next converter. When you’ve seen the samples of several converters, pick the one that is best, and ask the converter if he’ll sell it to you. If he says yes. you’re done. If he says no. ask him if he knows a dealer who can order it for you. If he does, your search is over. If he doesn’t, start calling paper dealers. When they answer the phone, say approximately the following. “Hi. My name is So-and-So. I need to bux some paper from United Paper Converting over in Gotham City. I know exactly what I want, but they don’t sell to the public, and they’ve asked me to order it through a dealer. Can you order it for me?”
5. When you’ve found a dealer who can help you. give them the details, show them the sample, and call the converter yourself to verify that all the specifications are correct: i.e. no mistakes. Because it’s a special order, they’ll usually want payment in advance, and delivery will take about a week.
6. If you are serious about making homemade casings, when you’ve found the paper you want, you should buy as much as you can for the following reason. The paper you’ve chosen is probably a B-grade paper. The converter may have only a few rolls, and when they are gone, he will not be able to order more. He might get something like it again, but you can’t count on it. And even if he does, there’s no way to predict when.
If you can’t find kraft linerboard. look for tagboard. Tagboard is used for making price tags and file folders. Many years ago it was also used for making dress patterns in the garment industry. Most tagboard is as strong as good linerboard. and though it’s more expensive, it is often easier to buy. It comes in several colors (manila and white are the most common), and you can buy it in 24″ x 36″ sheets from distributors and retailers who sell paper to the printing industry. Look in The Yellow Pages, or search the Internet for sites selling “tagboard” or “tag board”.
Tagboard comes in standard weights and thicknesses that vary a little depending on the manufacturer. Of the companies I spoke with, the approximate figures were: 100 pound tag = .007″ thick. 125 pound tag = .009″ thick. 150 pound tag = .011″ thick. 175 pound tag = .013″ thick, and 200 pound tag = .015″ thick. They also said that they could special order it in 24″ wide rolls. But the smallest rolls were 40″ in diameter, and they weighed 1.000 lbs. I
A Caveat and a Suggestion
The preceding information is based on my own experience shopping for paper in Southern California. There are dozens of dealers and converters within a 100 mile radius of where I live. Even so. I found it very difficult to buy linerboard in small quantities. Of all the converters I spoke with, all but two had S200 to S300 minimums. After many phone calls.
1 located and bought just two 42 lb. “counter rolls”. But a month later, when I tried to buy more, they were no longer available. I also found that, here in Southern California, many of the independent dealers, who used to sell small quantities of tagboard at reasonable prices, have recently been bought out by big companies that also have S300 minimums. By calling a tagboard manufacturer. I was able to get the name of a nearby retailer, who sold me 100 sheets for S40. But at 40 cents per sheet, the cost of a homemade tube was about equal to the retail price of a commercial tube.
The problem is not that people in the paper industry are inherently greedy, but that the paper industry is a high volume. low profit business. Converters buy the paper in rolls weighing up to 6 tons each, and the average converter has to sell S200 worth to make S20. If a customer wants one or two small rolls, the converter has to get a large roll from the warehouse, load it onto a machine, set up the machine, cut and roll the paper, and return the large roll to storage. This can occupy a fork lift driver and a machine operator for half-an-hour. By the time the converter has paid their wages and his other expenses, he’s lucky if he’s made S5. Most of the converters I spoke with said they’d be happy to sell me small rolls if I’d order them 20 to 50 at a time. This leads me to think that someone who lives near a converter might make a business out of buying small rolls of linerboard or tagboard in large quantities, and reselling them to the people who need them. To anyone thinking of doing this. I suggest the following. Start with paper that’s .012″ thick. Rocket builders can make casings up through 1″ i.d. from 60 lb. kraft. but they need thicker paper for anything larger. The .012″ liner board is ideal for casings from 1-1/8″ through 1-1/2″ i.d.. so the market for the .012″ paper should be the greatest.
Sell the paper in 65 lb. rolls. When shipping by United Parcel, as the weight of a package increases, there’s a rapid decrease in the cost-per-pound for anything up to 70 lbs. Beyond 70 lbs., the cost-per-pound rises. A 69 lb. roll is the most economical to ship, but paper can increase in weight by several percent in damp weather. Making the rolls weigh 65 lbs. allows for a weather-related weight increase, and keeps them safely under the 70 lb. limit. Advertise in American Fireworks News and on the Internet. AFN is distributed to rocket and fireworks makers throughout the country, and there are several chat groups on the Internet that talk about rocketry and pyrotechnics.
Red Rosin Paper
If you can’t find linerboard or tagboard. a less desirable alternative is something called red rosin paper, and most roofing suppliers sell it. Red rosin paper is about 0.012″ thick, and comes in 3 ft. wide x 500 square foot rolls. The problem is that red rosin paper is made from 100% recycled fiber, and only the best grade will work for rocket casings. The best grade in Southern California is called 4 pound red rosin paper, and that means that it weighs 4 lbs. per 100 square feet. A 500 square foot roll should weigh at least 20 lbs. If it doesn’t, don’t buy it!
When you shop for red rosin paper, take along a bathroom scale. When you find the paper in question, weigh yourself alone. Then weigh yourself holding the roll of paper. If the difference in weight isn’t at least 20 lbs., don’t buy the paperl Before I knew better. I bought something called “standard grade” red rosin paper. The roll weighed less than 15 lbs., and the tubes that I made from it were too light and pithy to be of any use.
Here in Southern California I found some 4-pound paper in the paint department at Home Depot. Painters use it as a cheap, disposable drop cloth. As of this writing, it is called Ratan Red Rosin-Sized Sheathing, and I’ve successfully used it for tubes up to 1-1/8″ i.d. by 18″ long with wall thicknesses up to 3/16″. At the time of this writing, it is made by
Salinas Valley Wax Paper Inc. of Salinas. CA. and distributed through Home Depot in the Western half of the U.S. Salinas does not sell to the public, and the paper is not sold in the eastern part of the U.S. at this time, but similar products might be available. As of the year. 2003. you can expect to pay S10 to S15 per roll. Red rosin paper is usually made from kraft chipboard, and “chipboard” is usually made from all the scraps that the paper mills want to get rid of! It is very soft. It tears easily, and though the tubes made from the 4 pound paper are not very good, they are at least usable.