Posts Tagged ‘plastic fabrication’

Admittedly plastic welding is a fabrication technique that is going to be attempted by few “Do-it-yourselfers”. Plastic welding will require the purchase of special tools and filaments which are not always easy to come by.¬† In addition, since most plastic welding is done by specialists, it is difficult to get fabrication tips from plastics distributors or manufacturers. You’re likely going to have to search the internet for ideas and while we cannot vouch for the tips, YouTube seems to have several good videos to get you started off right.

In particular the company “Techspan” which manufacturers plastic welding equipment has, what looks to us, as a good 4-1/2 minute video on the basics of plastic welding. In particular we like that it talks about preparing the plastic for fabrication/welding (something often overlooked in these types of videos) and it goes into topics such as “tacking” which is welding two pieces on a 45 degree angle to each other. We’d prefer to let the video speak for itself and we’ve linked it below:

 

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We found a great little video on YouTube by user “Make:” which in just three minutes (before credits) gives all sorts of great tips for the DIYer using acrylic in their applications. It starts off with a good point that not everyone knows: acrylic comes in both cast and extruded forms. Yes, they have differences that are important in an application. Yes, there is a difference in cost. Other important tips include how to thermoform, glue, and most importantly – drill, the plastic. Drilling is especially important as the plastic can crack easily, so using lubrication and a soft touch is essential to prevent a wasted part. It will help you answer some questions you didn’t even know to ask prior to diving in: do you have all the materials you need? How are you planning to smooth the edges of the acrylic?

We’ll let the video do the rest of the talking:

Perhaps no industrial plastic is more requested by the “do-it-yourselfer” community than acrylic. Prized for its beauty and well-known because it is used in many applications where the public would encounter the material (displays, aquariums, giftware). In short, acrylic has gained an impressive reputation. But when you work with the material, especially if you’re inexperienced, you really need to do your due diligence in learning the strengths and weaknesses of acrylic and learn how to fabricate it properly.

One of the first tips – especially if you’re just starting out – is to temper your expectations. People imagine they can create polished, flawless projects at home similar to what they have seen in existing products or on the internet. But acrylic is “fussy” to fabricate, it can crack easily if fabrication is done near the edges of the material, it can scratch and the nice, polished finish you see is done by a technique called “flame-polishing” which is a skill that needs to be developed and requires special equipment.

We will provide a couple key tips on this blog but also want to direct you to another blog that seems to be an excellent resource for general acrylic fabrication, which can be found here.

Some tips we can offer:

-ALWAYS leave the masking cover on the acrylic (this provides protection from cracking).

-Avoid fabrication such as drilling near the edges of the acrylic (best to leave a couple inches) as the material can be prone to cracking.

-Acrylic has good UV-resistance, use it outdoors in confidence.

-Cure time for glued acrylic is around 48 hours – be sure you have a way of stabilizing your project while the glue bonds.

Lastly, for some quick tips on gluing acrylic check out this Youtube video:

 

Plastic fabrication questions come up often with “Do it yourselfers”. The public is less familiar with working with industrial plastic compared to wood or metal and wonder what changes need to be made. The answer? Not much.

Drilling & Bits:

For plastics solid carbide, carbide tipped and high-speed steel are most commonly used. Of the the three, carbide tipped¬†(note the difference from solid carbide!) would be the closest thing to an “all-around” bit as it offers an excellent finish with the strength of the steel core. Jarring motions and general inconsistencies working by hand means that solid carbide bits should be avoided.

Bits come in both “O-flutes” and “V-flutes”. The V-flute is better for harder plastics such as Micarta, industrial laminates, acrylic (cast). The O-flute would be better for your polyolefins (UHMW and HDPE in particular), extruded acrylic and polycarbonate. In general, the more cutting edges you have, the better as this can make your inconsistent and amateur (no offense intended) feed rates more forgiving. Higher speed drills or routers will create a better finish and a smoother action.

Sawing & Hardware:

Similar to drilling or routing, carbide tipped blades and high RPMs are best for sawing plastics. Otherwise, they cut similar to wood. Like wood, you may need to do some light sanding on the edges after cutting to deburr the plastic. Customers seem to be especially intrigued by the smooth, glass-like surface finishes in many finished acrylic products they see for sale. However, you need to know that acrylic does not finish like this with regular fabrication at home. You will need to obtain a torch and teach yourself how to flame-polish the acrylic, or use a chemically-based flame-polishing alternative. Both options have short tutorials readily available on YouTube by the “DIY” crowd (note: of course Redwood Plastics does not recommend or endorse any particular video).

We also get asked a lot about particular hardware for plastics. Unless it’s M-Clips or bolts for FRP grating then there really isn’t any special hardware for most industrial plastics applications you would be working on. It’s important with plastics you’re using outdoors to oversize the holes by 1/8″ to allow for thermal expansion and contracting using washers is key to not place too much stress on the plastic, which could cause warping.

do-it-yourself