for Working with Acrylic
"If you don't buy the tools you need, you will eventually
pay for it, but not have your tool."
What Henry is trying to say is that it pays to have the tools you need. Not only are you paying for materials which may go to waste but you are also investing time. Most importantly you are gambling with your self confidence; completing a project successfully will give you a stepping stone to your next project. Before starting any project try to determine what tools you are going to need and how sophisticated you want your project-to-be. Because acrylic is clear, it is very unforgiving of mistakes. Your goal should be to build things which look like you bought them, otherwise perhaps buying them is a better option.
Probably one of the most important tools you will use for achieving professional
quality results. Routers may run between $100 and $300 depending on quality.
A router, which is capable of accepting both ¼ inch and ½ inch shank bits,
will be beneficial. You also want a router that can be fitted with guide
collars. Another thing to keep in mind when purchasing a router, many
of the methods I will be describing are based on mounting your router
under your work table with the cutter protruding from the surface. Look
for a router, which you feel, will be easy to mount in this manner.
Although acrylic is softer than tool steel, it will dull regular tool steel cutters rather quickly. When buying router bits look for the highest quality carbide tipped cutters you can find. They will be more expensive (around $20) but will make smoother cuts and last longer than lower-quality bits.
Solvent Cement and Applicator: The adhesive used to cement acrylic actually melts the plastic chemically, allowing the molecules from both parts to combine, forming strong, watertight, clear joints. The method most commonly used in acrylic fabrication is referred to as capillary cementing. The parts to be joined are held in the desired position, and a water-like solvent cement is allowed to flow into the joint, bonding the parts together. The product most commonly available, and I would recommend, is Weld-On #3. Thicker solvent cements (Weld-On #16) are also available, although I do not recommend using these as they often result in unsightly, unprofessional looking joints.
Scrapers: Every glue joint needs to be as perfectly fitted as possible. The smallest gaps will result in bubbles in the joint which are unsightly and weaken the joint. This includes the texture made by sawing and machining. Scrapers can be made from any piece of steel (preferably tool steel) which is flat and has a sharp corner. The flat side of a hack saw blade works well, although I prefer using a cut-off cutter bit used on metal lathes because it is stiffer. Most plastic suppliers will also carry scrapers appropriate for acrylic. Tool marks should be carefully scraped away until the edges of the material are smooth and square. This also creates better surfaces for flame polishing.
Scoring tool: Scoring a piece of plastic sheet actually places a heavy scratch on the surface, creating a weakened area. Bend the piece of plastic, supporting the material just behind the score mark and Crack! You now have 2 pieces. This method of cutting plastic takes a little practice but is very easy to master. It works extremely well for 1/8 inch and ¼ inch material although the larger the piece is the greater the pressure you need to apply. I would not recommend it for large sheets or anything over ¼ inch thick as the break will tend to drift away from your score mark. Scoring tools are usually sold by your local friendly plastic store and will only cost a few dollars, it is an investment which will pay for itself in a very short time.
Blow Torch: Just a plane old propane blowtorch can be used to flame polish edges, giving them that clear bright finish. Professionals use a hydrogen/oxygen torch, they do work better but I've never met a hobbyist with one. I've never had any problems flame polishing with a propane torch although colored plastics tend be more difficult. Flame polishing requires a lot of practice to do well, buy some scrap and practice until you are completely comfortable with holding a blowtorch on your newly completed project without creating a big mess.
Squares: Check everything for squareness then check it again. Pay the money for a good carpenters square and combination square, they will save you twice as much in headaches resulting from parts which fit poorly or jigs which hold parts incorrectly.
Clamps: You can never have too many clamps!
Some other tools you may find useful:
Drill bits need to be purchased specifically for cutting into acrylic. The cutting surfaces are ground at different angles and work surprisingly well. Expect to pay between $5 and $15 per bit based on diameter. I would not even bother trying to drill a hole in acrylic with a standard drill bit unless you're completely desperate and have a drill press.
Saber saw blades also must be purchased at your acrylic supplier. The teeth are specially shaped to cut acrylic, and they outperform standard blades well enough that they will be worth every penny.
Hole saws work very well in acrylic but, as with router bits, you need to buy very high quality hole saws or you will find yourself cracking and melting plastic instead of cutting it. Expect to pay $10 and up. I prefer the Starrett brand.
Strip heaters are used to locally heat up plastic to create nice bends. You can purchase strip heaters from various suppliers or you can make your own. Hopefully I will publish an article on making strip heaters in the near future.
A table saw is not a tool which is absolutely needed for working with acrylic. Most plastic suppliers will cut sheets to size for you, and simply charge you by the square foot. If you do happen to have one however, I have found that the carbide tipped blades available at the hardware store perform well and don't feel there is any real need to purchase one of the special circular saw blades available (they run about $100).
Bandsaws are very convenient to have but keep in mind that acrylic tends to dull steel quickly. If you are melting through plastic instead of cutting, it's time for a new blade.
Good luck on your projects, more to come soon.
Some sites you may want to check out:
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Copyright © 2002 by Kenneth K. Uy. All rights reserved.