Vacuum Forming for the Hobbyist PDF eBook digital download12.95
Learn how to use heat and vacuum to mold flat plastic sheets into complex
shapes. Build your own low cost equipment using hardware store items and
your kitchen oven as a heat source.
This popular book takes a common manufacturing process and boils it down
to its simplest form, so it can be done right in the home. Its a mystery
to me why vacuum forming is so largely ignored in the hobby and craft fields.
Its a fast and easy way to mold high quality plastic parts. Best of all,
it requires no special skills and very little equipment.
This book goes beyond vacuum cleaners as a source of suction and shows
you how to get 5 times more forming power. Chapter 2 tells why heat lamps
and heat guns won’t work well, and shows how to use your kitchen
oven and alternate heat sources
Chapter 1 - The Basics
Vacuum Forming (also called Thermoforming), is a simple process that
uses heat to soften a plastic sheet, and then vacuum to suck it down
tightly against a pattern or mold. The plastic quickly cools and retains
You can start with flat plastic sheets up to 1/4 inch thick and heat
them in your kitchen oven. The mold or pattern can be made from wood,
plaster, epoxy resin, aluminum, plastic and many other materials or built
up from a combination of materials. Many times, you can form over an
This process makes "Shell" type parts that can have many
uses. Some examples are:
Candy Molds, Toys, Model car bodies, Model airplane parts, Boat hulls,
Signs, Holiday decorations, Soap and Candy molds, Containers and packaging.
Chapter 2 - Heat Sources
Most plastics require between 250 and 400 degrees F. to get soft enough.
We are not trying to melt the plastic, just make it soft like a sheet
of rubber. Your kitchen oven was designed to heat food at these temperatures,
so its a safe and convenient way to heat plastic as well. This chapter
shows the differences between gas and electric ovens and how to use them
Find out why heat guns and heat lamps should be avoided. Other heat
sources are discussed, such as, electric frying pans and griddles, toaster
ovens, hot plates etc.., with advice on using each one.
Chapter 3 - Vacuum Sources
A simple explanation of what vacuum is and how its measured, with charts
and conversion tables. Vacuum is commonly rated in "Inches of Mercury" (IN.
HG.) Most commercial vacuum forming is done with 25 -27 IN.HG.
with a maximum of about 30 inches possible.
Note:Vacuum cleaners only pull 4 to 6 IN.HG. out of a possible
30 IN.HG. Don’t be fooled by the commercials that show them picking
up bowling balls. It doesn’t matter how many horsepower, or how loud
it is, or how much it dims the lights. Even the best "Shop
Vacs" don’t pull very hard, they just flow a lot of air!
This is barely enough to form thin plastic sheets with marginal definition.
Learn how to increase that 50% by coupling two vacuum cleaners together.
Seven other low cost sources of higher vacuum are discussed, such as.
intake manifold vacuum (from your car), Modified bicycle pumps, air powered
and electric pumps. Learn how to modify a bicycle pump to pull 27 IN.HG.
and use stored vacuum form tanks.
Learn how to get 5 times more forming power by combining a vacuum
cleaner with another higher vacuum source to create a "two Stage" system.
You won’t find this information available anywhere else!
Chapter 4 - Forming Equipment
Learn how to make a simple holding frame out of aluminum angle from
the hardware store, and use this frame with inexpensive spring clips
to hold a plastic sheet for heating. See ideas for simple vacuum boxes
made from cake pans, and more sophisticated two stage vacuum boxes.
learn how to modify a sump pump check valve from the hardware store
to combine a vacuum cleaner with a second higher vacuum source. This
method uses the speed of a vacuum cleaner, but finishes off with a more
powerful vacuum source. The valve is easy to make and works automatically.
Chapter 5 - Plastics
There are a million types of plastic sheets, but only a half dozen that
you are likely to come across. This chapter discusses the common types
and gives you practical advice on choosing a plastic for your application.
Properties such as impact resistance, forming characteristics, pre-drying,
and cost are considered. Useful tips on where to buy plastic sheets and
how to deal with plastic distributors.
Chapter 6 - Molds
The theme of this book is "low budget", so this chapter focuses
mainly on wood and plaster molds. Learn six
"common sense" rules of moldmaking, such as avoiding undercuts,
surface preparation and the use of release agents. Read important information
on using hollow molds and forming over existing objects. An example shows
how to cast a plaster mold to reproduce an existing model car body.
Chapter 7 - Forming
Once you have the equipment built, this chapter gives you practical
advice on the actual forming process. Learn how to tell when the plastic
is ready to form and learn about common problems and how to solve them.
Photographs show sample parts made with different plastics.
A detailed example is given that shows how to form a radio controlled
model car body over the plaster pattern created in the last chapter.
Chapter 8 - Finishing
Learn three ways to trim out the finished part depending on thickness.
Read about glues and paints for different plastics.
Note:The back of the book contains a supplement
with more forming tips and solutions to common problems, as well as information
on plans that are available for building your own machines with built
in ovens. Please visit the book index on this website for other
books and plans on vacuum forming equipment..