Why Hobbyists Should Consider Acetal

Posted: March 11, 2021 in Acetal

In the DIY community, many of you enjoy machining components for your own projects. There are so many types of plastic available – how do you choose one for your project? While there are many factors that need to be considered when choosing a material acetal is a great choice for many home projects. What is acetal? Its real name is Polyoxymethylene but what should matter to you is that it’s an excellent engineering grade thermoplastic. Above all other plastics, it has excellent machining qualities and can be machined to more precise tolerances than most other plastics (+/- 0.005″ is achievable).

Acetal has a “heavy” metallic feel to it and indeed it is excellent at replacing small metal parts. One example application is using acetal to machine replacement parts for paintball markers as acetal performs best in those applications (particularly as bolts). Other applications include bushings, small gears, homemade guitar picks, and countless others. The plastic is moderately priced and is a superior replacement to nylon in applications that involve water submersion. It is available in both white and black color with blue as a rarer option. If you enjoy machining and want a sturdy plastic that will be fun to machine…Acetal may be an excellent choice!

If you want to know if acetal is right for your home hobby application please contact Redwood Plastics and Rubber.

Sometimes the world of plastics and rubber can be confusing to those of us in the DIY community. There is a lot of slang and jargon when it comes to these materials and misnaming materials or using brand names incorrectly is common. One of these materials is commonly called “phenolic” which officially refers to one of five resin systems used in what are called “industrial laminates” but instead can refer to a couple different parts of the family.

The most common reference phenolic is applied to is actually C/CE grade industrial laminate. This is actually accurate as C/CE grade laminates are a true phenolic based product and is a “true brown” in color. It is a widely available, very strong, product for mechanical applications. Be aware as well this product is also referred to by one of the primary brand names “Micarta”.

The other use for phenolic is actually referring to any industrial laminate in the family. This is obviously more difficult for a plastics and rubber representative to narrow down for you. Bringing in a sample of the material you would like is the best way to get a match as with so many laminates they look similar so unfortunately a picture doesn’t work.

The good news is most DIY applications would work well with the C/CE grade production mentioned above. Exceptions would be bearing applications but your local distributor can help you with those. The key takeaway point here is that “phenolic” doesn’t always mean what you think it does and its best to get specific about it! If you have questions, please contact Redwood Plastics and Rubber.

Greasing and Lubricating Plastics

Posted: January 12, 2021 in Uncategorized

It’s a simple fact that in most applications low friction is a desirable property and this is especially true in tight fitting parts or DIY bearings. Hobbyists know that metal components require greasing and they assume the same is for plastics, is this true?

In general, we lean to “no”. Many common plastics used for bearing applications are naturally average to low friction without grease or lubrication being added. In fact, they are self-lubricating, meaning the relatively soft plastic wears a very thin layer of itself onto the mated component – such as a shaft – causing a low friction surface.

However, bearings that need little to no greasing can be commonly procured. Materials exist that are light duty (UHMW, PTFE) that are naturally very slick and high capacity bearing materials, such as Nylon, Tuffkast, and PEEK, are available in lubrication-filled bearing grades.

If you do want to grease that’s OK – white lithium grease usually works best with plastics; however, you are taking a risk. That risk is of grit or contamination getting into the bearing and damaging the relatively delicate surface finish of the bearing as the grit is carried by the grease. Plastics are softer than metal, no way around it.

The simplest option is to select the right material that doesn’t require grease and maintenance in the first place and an expert distributor such as Redwood Plastics and Rubber would be happy to assist you!

Best For Wear

Posted: December 14, 2020 in Uncategorized

A little bit of a different article here as we want to highlight materials with specific properties vs. focusing on a specific material type itself. In this case, wear materials, and we’ve seen them used in everything from saw guides, to skid plates, to non-mechanical drawer slides in DIY applications. The fact is many plastics make excellent wear materials and when wear properties are key, there are a few standouts.

Redco MD

Molybdenum disulfide (“moly”) filled nylon is a classic workhorse in the plastics industry. The addition of moly to the nylon creates an excellent material for high wear, low RPM applications. If a lower coefficient of friction is desired, oil can be added to the recipe.

UHMW

The entire UHMW line (and there are many grades) are excellent wear materials. However, a little tip is that the reprocessed grade, which is the least expensive grade, actually has better wear properties than the virgin grade. The reason is the material partially cross links when it is “recooked”. In a DIY application where wear and low coefficient of friction are the two main properties you care about, it’s difficult to find a better intersection of properties and economy than UHMW.

Tuffkast

All Tuffkast grades are a premium, high wearing material though the Tuffkast 010 is the best in applications involving extreme wear. If you have a budget that demands the best paired with an aggressive application, Tuffkast is a material to ask about. Tuffkast has virtually no drawbacks except premium pricing.

Polyurethane

Many polyurethane grades have outstanding wear properties especially as you get into the range of the harder durometers (90A+). As an elastomer, polyurethane offers other benefits such being able to be molded as well as impact resistance.

To figure out the absolute best match of materials to your wear application, contact Redwood Plastics and Rubber today.

Product Spotlight: SBR 70

Posted: November 17, 2020 in Uncategorized

Today we want to highlight another product, this time SBR 70 rubber. SBR stands for Styrene-butadiene rubber and is essentially a synthetic alternative to natural rubber. It is made of up approximately 75% Styrene and 25% Butadiene. Styrene is a very inexpensive material and its large percentage in the product creates an inexpensive rubber. The product is popular for its low-cost and high availability.

It’s commonly used in tire type applications though they tend to be lower-duty types (for example aircraft tires are natural rubber, not SBR). SBR has similar properties to natural rubber but has limitations in some areas including heat-resistance (which often isn’t an issue in DIY) applications.

So, where do you use it?

If you need a light-duty, IE. typical of DIY, roller or tire application you won’t beat the price of SBR. In addition, it works very well as general purpose skirting or homemade gaskets. It is quite abrasion resistant and has decent flexibility at low temperatures, which is important to remember. It is also water-resistant which may be useful if you’re lining a trough or pond. Note that the product is not bio-compatible rated but may work well in a decorative pool.

For more information on rubber products download the Redwood Plastics and Rubber line card here.

Halloween Decorations From Recycled Materials

Posted: October 23, 2020 in Uncategorized

Something a little seasonal today…There’s a chill in the air.

We found a blog that lists a bunch of Halloween DIY decorations, many of them made from plastic, and all of them look either fun to create or look just plain good!

We’ll post a couple pictures below but you can read the entire article here.

Redco Acrylic is an attractive and versatile plastic used in a wide variety of functional and decorative applications by the DIY community. That said, it’s one of the less forgiving plastics to work with and mistakes can lead to a poor surface finish or even the sheet cracking. While it’s impossible to ensure nothing ever goes wrong, we’re offering some best practices to minimize damage and maximize the chances of a successful project!

One issue people run into with acrylic is cracking the plastic when drilling holes. While this is a risk, it can be mitigated by placing the holes at least 1″ in from either side of the sheet. More is better, if you can work with a design that can place holes 2″+ in on either side of the sheet, that is best. Another issue is cutting the plastic with a saw. Many people look up beautiful acrylic applications and objects on the internet that can only be described as “art”. However, in order to fabricate these pieces – sorry to say – takes professional skills and equipment you will likely not have. If you keep expectations in check; however, there are many DIY guides on YouTube for techniques such as flame-polishing, which is necessary to give the cut edges of acrylic a nice “glass-like” look.

Bonding acrylic is easier, though also unforgiving. There is not actually an acrylic “glue” but instead you solvent bond acrylic. What’s the difference? Solvent bonding actually chemically melts part of the acrylic which then re-hardens when the new piece is joined to it. This creates a very solid permanent bond; however, where the solvent touches will also create a permanent “stain” or “etch”. Similar to if you accidentally spread super glue on a surface where you don’t intend to. Acrylic bonding agents are widely available for purchase online.

So far this sounds like a bunch of warnings against acrylic fabrication but that’s not our point! Acrylic is a sturdy, beautiful, naturally UV-stable plastic that is versatile in so many applications. However, where people get disappointed with acrylic is 1.) unrealistic expectations based of projects they’ve seen online and 2.) making fabrication errors we’ve hopefully covered solutions for today.

If you have acrylic related questions feel free to contact us.

 

 

We have a saying at Redwood Plastics and Rubber that many customers know the rubber they use as “flat, black and stored out back”. To many people rubber is rubber and it’s all essentially the same. However, outside of the most rudimentary applications, that’s a dangerous assumption that could lead to premature failure in your application. in fact, many rubbers are “black” in color but have different properties – everything from chemical resistance, to operating temperature range, weather resistance, and, of course, price. The key is to match up with what you need. Not all rubber is covered in this short primer but the rubber most likely to be used by the DIY community is.

Natural Rubber:

This rubber type is typified by abrasion-resistance and in non-DIY applications is commonly paired with abrasives, especially in the aggregate or construction industries. The limitation of the rubber is that it typically does not have good weathering properties including resistance to UV.

EPDM:

Excellent resistance to bursting and pressure, EPDM works well as a gasket and premium grades can handle temperatures up to +250 degrees F. However, it is weak to hydrocarbons and oxidizing agents.

SBR:

Decent abrasion and impact resistance but is primarily known as the most economical grade of rubber. Good in applications without demanding requirements.

Silicone:

Excellent properties over a wide temperature range up from -76 F to +440 F. Is available in food-grade white or blue. Excellent release for materials paired with it.

Neoprene:

The “jack of all trades, master of none” rubber. Neoprene offers balanced properties in many applications but does not necessarily excel. The commodity grades can have poor resistance to some chemicals and the premium grade has reduced properties in temperatures below -15 degrees C.

As we mentioned there are other types of rubber available; however, the types listed above constitute the majority used in DIY applications. For assistance with the selection of your rubber please contact Redwood Plastics and Rubber. For a a PDF copy of Redwood’s excellent rubber line card, click here.

One of the easiest DIY applications for performance plastics is food grade surfaces, especially for outdoor kitchens. Several plastics are available that are compliant for direct food contact, with the ones you’re most likely to encounter being HDPE, UHMW(PE), and natural nylon. Specialty “cutting board” grades of HDPE in particular exist; however, for a DIY application you shouldn’t need to go that route. The question is – what to use when?

Unless you require a very hard plastic natural nylon is the most expensive of the three options and as a cutting surface is probably “overkill”. As a note, where nylon would be best is if you’re making a food grade part. Nylon will hold better tolerances and its hardness would benefit as say some sort of paddle or roller. In regards to choosing UHMW or HDPE for your cutting surface? Well, it depends really what that surface will be used mostly for.

For horizontal abrasion, such as using steel wool frequently to descale fish or perhaps skinning game, then UHMW would be superior. However, UHMW is so wear resistant it will eventually dull knife blades over time. If all you’re doing with your board is cutting or chopping, then HDPE would be superior as it will not dull blades. There is a trade off; however, in that HDPE is much less wear resistant than UHMW!

For assistance with your application or if you have questions on plastics available for outdoor kitchens, please contact us Redwood Plastics and Rubber today.

 

We found a pretty neat video on the YouTube channel of “Atomic Shrimp“. He previously made some homemade HDPE plate (though “plate” may be a stretch) from old milk jugs and other household HDPE items. In this video you see him cut out a pulley blank from the plate then machining it to specifications. Not too many tools are required and the ones that are needed should be owned by most home hobbyists. We like the simplicity of this project and how the techniques would be relevant to making pulleys from UHMW or other plastics.

What we would caution is that HDPE and other polyethylene plastics are quite soft and Atomic Shrimp’s keyway in the center of his pulley would not hold up to a lot of torque. However, for his Lego application it’s probably fine. Nylon plastic or nylon with a metal hub (in heavy duty situations) would be the way to go when the shaft going through the center is keyed and the pulley is driven.