It’s very common for the home project enthusiast to not know what to ask for when it comes to clear plastic for a project. Often we’ll get “I need polycarbonate or acrylic for a project” and we on the distribution side, at the sponsor of this blog, Redwood Plastics and Rubber, are left with making a decision on materials. You know that? That’s OK! We love to help but instead of picking something for you, we would instead work with you to figure out the details of your application because there are good reasons for doing so.

Firstly polycarbonate and acrylic are *not* similar materials beyond the fact that they’re hard and clear. The first difference you should probably be aware of is price. Polycarbonate is about 25% more than acrylic meaning if all things are equal you could be potentially paying too much for a plastic that isn’t optimal for your application. So when is each plastic optimal? Lets start with what each plastic does well and where it is poor.

Polycarbonate is incredibly strong which is why it’s often used as safety glass. Any application where you’re going to face impact you want polycarbonate. Additionally polycarbonate has a bluish tinge that some people find more attractive than just a pure “clear” (like acrylic has). Polycarbonate is the only version of the “twin” or “multi” wall greenhouse plastic so if you’re needed that corrugated product than you need to know it will be polycarbonate. Where polycarbonate has trouble is outdoor weathering (UV-resistance) and very poor scratch resistant. Polycarbonate will eventually scratch and it will degrade in the sun over a couple of years. There are anti-scratch and anti-UV versions of the product but this is done by a film being applied (not a chemical added) which means eventually the film will degrade and the plastic will be vulnerable.

Acrylic on the other hand has excellent scratch resistance and good resistance to UV and weathering. However, acrylic is more brittle and is not available in less expensive economy forms like twin-wall polycarbonate. Colored acrylic actually has poor availability due to so many colors, levels of transparency, etc. It is also important to know that acrylic comes in two major grades: extruded and cast. Extruded is less expensive whereas cast is stronger, clearer, and yes, more expensive. How do you know which is which? Well, if you drawing or plans you’ve looked up happen to call for 49″ x 97″ acrylic sheet than that is cast – because it’s 1″ wider and longer than the standard sheet size of 48″ x 96″. Otherwise, you probably wouldn’t notice a difference.

Hopefully that helps narrow things down a bit?

Good luck with your projects and here’s to a great 2018!

 

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Know Your “Phenolic”

Posted: May 28, 2018 in Uncategorized
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Phenolics, more correctly known as “industrial laminates“, are one of the most misunderstood industrial plastics available. There is so much confusion among the general public that many in the DIY community don’t even know what to ask for. This isn’t a good thing, as these plastics are on the more expensive side and a failure to figure out what’s best for your application could lead to failure or wasted money. The first thing you need to figure out is what your application requires and why a phenolic is necessary. Phenolic plastics are used in two primarily applications: where a super “hard” and mechanically strong plastic is needed and also in electrical applications, such as circuit boards. For applications where mechanical strength is key, then CE grade laminate is the most available and least expensive option. If the application is electrical and/or fire-retardant properties are important then a fiberglass epoxy product called FR-4 is likely the best.

An important note here is that the FR-4 product, which is very popular and widely used, isn’t a phenolic at all! Phenolic is an old plastic resin, one of the first ever used, and it became associated with industrial laminates which are essentially compressed layers of fabric, cloth, paper with a plastic resin binder. Typically the brown colored mechanical grade products like the CE grade laminates are the true phenolic. However, many industrial laminates exist which use different binding agents.

One other area people get tripped up with is the branch of “melamine” laminates. Melamine laminates are commonly used as kitchen cupboards; however, this is different from the engineering grade melamine laminates available from industrial distributors such as Redwood Plastics and Rubber. Watch out for that, as the products are not interchangeable.

At the end of the day, do not feel anxious or embarrassed to simply ask a plastics expert for help. They will work with you to understand the priorities of your application and deliver the best solution. That’s their job!

Why You Should Be Using More Acetal

Posted: April 30, 2018 in Acetal
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Let’s start with a question: Do you know what acetal plastic is? If you don’t, and you’re a member of the DIY community interested in using plastics you’re probably missing out on this readily available plastic with excellent properties. Acetal shot to fame in the 1990s in the paintball gun (called “marker”) aftermarket modification community. Acetal offers a plastic with the closest properties to metal: when you hold an acetal part it *feels* different than most plastics. Admittedly, most plastics feel and look the same…Soft and waxy. However, acetal is heavy and dense, it has a weight to it that makes it feel more like metal and that is where this material really shines: replacing metal.

In paintball markers acetal was a no-brainer. Like metals, and better than all other plastics, acetal is beautiful to machine and excels in replacing metals for small, precision parts. As a plastic, it does not suffer the same corrosion issues metals do and yet is still lighter. This allowed the markers to shoot better and faster. Outside of paintball, acetal works great as a bushing replacing nylon. It handles the same PSI in application (4000) but does not suffer the moisture absorption issues nylon does. As such, acetal is often used as a direct replacement for cast nylon in “wet” applications.

Acetal comes in two forms, the homopolymer (white) and copolymer (black). There used to be quality issues with the white but those have been remedied. Though the materials have some small differences, they probably would not affect any DIY application, so pick whichever is more available from your local distributor. Besides being available in rod acetal is also available in plate with 24″ x 48″ plate being the most common. For more information on Redco acetal please click here.

 

Building backyard playgrounds and “forts” for kids is a common job for the hobbyist. Usually lumber is employed in this application; however, sometimes you want to go the extra mile. You may be surprised to learn that the same colorful playground plastic used in public and commercial playgrounds is available to the public. The product is called “Densetec Play” and is plastic sheeting for this express purpose. Densetec play is available in all the bright colors you’d expect but has additional hidden advantages as well. Designed for outdoor use, Densetec Play is fully UV-stable and will not be affected by rot, rust, or mold which will attack traditional materials used in this application.

Densetec Play is easily fabricated using household power tools. It can be cut, drilled, sawed or routered with easy into endless complex shapes. The special “orange peel” surface texture helps the product be resistant to liquids, dirt, and grime allowing for easy cleanup. Densetec Play is available in 1/4″, 3/8″ and 1/2″ thicknesses. The average cost per 4′ x 8′ sheet would be $200-$350 USD depending on quantity. For more information on Densetec Play, contact the distributor Redwood Plastics and Rubber.

In your searches for plastics to fulfill your dream of various projects you may encounter the term “elastomers”. What are elastomers? Defined generally that is a material that “rebounds” when impacted or compressed. The rule of thumb is the material has to return to 90% of its original size 10 minutes after compression occurs. The two elastomers you’re most likely to encounter are polyurethane and rubber. Again, as a rule of thumb, polyurethane is a more expensive – but premium – replacement for rubber and outlasts rubber in most applications. Where rubber should be substituted for polyurethane is in applications with lots of vibration. That’s why you see rubber used as bushings on vehicle suspensions for example.

Rubbers and polyurethane are also defined by a wide range of hardnesses, unlike other plastic materials. Commercially sold rubber usually ranges from 40A durometer (quite soft) to 80A which is fairly rigid. Polyurethane ranges from about 52A-75D and that change in letters following the number is important. At 75D the polyurethane feels “rock” hard and it is primarily used in applications like sprockets and bushings. One major advantage to elastomers over some other plastics is that they are readily moldable. Not just injection molding, but simpler and less expensive open cast molding.

If you have questions about whether polyurethane or rubber is right for your application please contact us today.

 

Sick of cracked, rotten, and unstable wooden jack pads for your RV? Want to do a little project that will make you feel accomplished and provide a long-lasting solution? The good news is making your own plastic jack pads is an incredibly easy project that virtually any member of the “DIY” community can do! Fabrication of a couple pads for your RV should take 15 minutes or less.

What you will need to start:

-(1) 12″ x 24″ x 0.75″ (thick) piece of UHMW black-reprocessed plastic.

-(2) pieces of rope 1/2″ in diameter 12″ long.

-Table saw

-Power drill with 3/4″ bit. The bit should be at least 1.25″ long.

Instructions:

  1. Measure with a colored marker or tape the halfway point on the UHMW plastic. You want to simply cut it in half to obtain two 12″ x 12″ pieces. One of the pieces may be undersized but that is not important for this application.
  2. Cut the UHMW in half.
  3. Find the midpoint on each pad again. Mark it.
  4. On either side of your mid-mark, 1″ in, make two points 2.5″ on either side of that line.
  5. Drill thru-holes with your 3/4″ bit in those two marks.
  6. stick a piece of rope through the holes. Tie knights on each end wide enough that the rope cannot get pulled back through the drilled holes.
  7. *Optionally you can then cut the corners off the pads.

There you go, you have two jack pads that should last as long as you have your RV! Estimated cost per pad would be $35.00 including materials but they would likely retail around $70.00+ for an equivalent pad were you to buy them.

Matting For Your Workshop

Posted: February 14, 2018 in Uncategorized
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This posting is going to be a little different than the others. We’re not talking about plastic for a specific project but instead about the comfort of your own “DIY” workstation or workshop.  If you’re like us, you’ll be spending long hours standing as you machine and fabricate your various projects. Do your feet ever get sore? Do you get lower back or joint pain? How about even Plantar’s Fasciitis on your feet?

The reality is for a long day’s work in the shop you need to take care of yourself. Investing is specially designed rubber “ortho” matting such as Redwood Plastics and Rubber’s line of Redco™ Protivity™ Specialty Floor Matting would be a good choice. The first two options of matting “Checkout Comfort” and the premium “Anti-Fatigue”. These function by reducing strain and pain for people having to stand for long periods. They also are finely textured, which will reduce slip and fall risks.

Another interesting member of the matting series is the “ShockGuard” mat. This mat serves to prevent people from receiving high voltage shocks and is compliant with ASTM D-178-81. A certificate can be included with the order. There are other mats available that could serve a purpose for the “DIY” community, for example if you’re building a home gym, there is a “Sport Floor” option that is highly impact resistant.

For more information on these products contact Redwood Plastics and Rubber.