Plastic Polishing Questions

Can you mill square slots in PMMA of width to 0.025mm (0.001″) to depth 0.025mm (0.001″)? If so what precision can you hold on the width and depth respectively? Can you polish milled square or ball nose slots in PMMA to an optically clear finish? If so, down to what width slot can you polish?  I can provide drawings to describe the above requirements.

Difficult plastic parts with small features and high tolerances are one of our areas of expertise. We have secondary operations which allow us to supply a polished component on all features with negligible impact on dimensions.


We’d like to know if you can make the part in the attached drawing.  Material is clear polycarbonate with an optical quality finish and tolerances of 0.0002″.  While the part’s length is given as 25cm or about 10 inches, we will accept longer. We are under a tight timeline and need these parts in three weeks. We can accept a lower quality finish, coarser tolerances, and/or shorter lengths if we have to. Please respond ASAP to this request.

First it is always best to define further what  “optical quality” finish you require. Optical could simply mean clear but for true “optics”  special machining and polishing techniques may need to be utilized.  Depending on the feature, tolerances of 0.0002” can be achieved. We can work with design engineers to optimize your specifications and maximize manufacturability and cost. Three weeks lead time is usually not a problem with our rapid delivery machining services.


We’d like to receive a quotation to produce the polycarbonate die as per the attached drawing.  Since the device needs to be optically clear, we would like to utilize your vapor polishing services, followed by annealing.  The cylindrical cavity within the die is the most important part, both dimensionally as well as optically. Is this a part that your company can machine for us?

To prevent stress cracking or crazing of plastics in developing a component, it just may need to be annealed before, during and after machining and vapor polishing, depending on material and part configuration. We can also select the best machining technique to achieve the highest quality surface finish in your critical areas. This ensures the best optical clarity after vapor polishing.


I direct a University lab and am looking for polishing options for an SLA part made of WaterShed XC 11122. This part is a custom cross-sectional tube that is roughly 4cm across and 10 inches long. It needs to be polished for optics so we are looking for a finish of SPI A-1 or A-2. Please let me know what your capabilities are in this area.

There are various polishing methods that we utilize for plastic machine parts. We would need to see a print or the actual part to determine the best polishing methods and to determine what finish we can expect to achieve. Can you provide us with a sample or a drawing?


I am looking for a vendor to polish a Cyclic Olefin Copolymer. The exact material grade is called Zeonor 1420R. Is this a material that you can polish?

Connecticut Plastics has experience in both machining and polishing of Cyclic Olefin Copolymer. Please submit an RFQ with a drawing or list dimensions and quantity, and we will be glad to quote.


The attached drawing shows the top piece of a tube holder assembly to be used in research labs. It needs to be polished and optically clear so that the content of the inserted tubes is visible. I imagine Acrylic would be best, however the part could be exposed to ethanol and 10% bleach. Some users might also place it in a fridge at 4ºC. All that being said, I am interested to know if you think another material might be better suited.

Connecticut Plastics can offer our years of experience in recommending plastics for both chemical and thermal compatibility with your process. Acrylic is a good choice for your application, and there are other polymers that may work as well. We will be glad to provide you with a quote for machining your part utilizing the various materials that will be best suited to your application. Please see our website for more information on acrylic polishing.


I need a quote on buffing two instrument lenses. They have very minor scratches on the surface and I need the lenses to have better clarity.

There are multiple methods for plastic polishing that may be utilized. The most popular are flame, vapor and mechanical buffing or polishing methods. Connecticut Plastics has the experience to utilize each and select the one best suited to achieve your desired results.


I purchased an SLS (selective laser sintering) part and it is pretty rough (16 micron RA).  Do you have a method for polishing Nylon 11 or nylon 12?  Can the part be vapor polished?

Laser sintered parts cannot be polished. Nylon cannot be vapor polished. Consider machining from scratch.


I have two polycarbonate parts for a project I am working on. They are 3.5″ diameter X 4″ rod. I just found out about vapor polishing and would really like them clear now that I have machined them. Could you provide me with a quote for vapor polishing these two parts?

We can, however the clarity of your parts will be dependent on the quality of the machined finish not on the vapor polishing process.


I see that your company provides plastic polishing services. I would like have polished a cylindrical polycarbonate component (90 x 80 mm) What would be the optimum surface roughness (ra) that your company could achieve?

Polishing success is highly dependent on machine finish. Typically we are able to produce a 10 to 20 ra finish with parts that we machine and polish. Parts machined by our customers generally cannot meet that standard of ra finish.


We are looking to have a polycarbonate housing manufactured. It has fairly complicated geometry and requires vapor polishing. We will need a signed Non Disclosure Agreement before I can send a drawing.

Please send a Non Disclosure. It is common practice for us to sign before receiving prints.


Is it possible to chemical or flame polish PET-P? The part resembles a ring 300mm ID 25mm wide and 25mm high. Just one surface needs to be polished.

PET-P cannot be chemical or flame polished, there are alternatives like buffing available. Additionally, direct machine polishing is a possibility.


I need to deposit AR and conductive coatings on a Polycarbonate (Makrolon) molded optical waveguide. I have attached a drawing.  My question: What kind of finish polishing is preferable for my component – vapor polishing or with diamond powder?

Vapor polishing is the process of choice for polycarbonate. We are able to polish both internal and external features with a high degree of clarity.


I have 4 Blue Lexan sheets .250″ x 24″ x 96″ in dimension.  I need to know if you have the capability to polish these sheets.  The sheets are going to be thermoformed and the surface finish is critical.  This is very time sensitive project, so a quick turn around is needed. Please get back to me at your earliest convenience.

Sorry the sheets are too large for our current capacity.


I am looking for a vendor to do some vapor polishing on smooth machined surfaces. The material is Ultem. Medical Grade. This component will be implanted. Would you be interested in doing this work?

We are very interested in any work involving vapor polishing of Ultem.


What kind of dimensional stability does vapor polishing provide? I have some parts that need to be optically clear, but have tight tolerance O ring grooves. Also could I get a quote for a 50 piece order to be polished? The parts measure 2.000 x 1.185, with a through bore. Attached is a picture of the part.

Vapor polishing when prepped and run properly will not affect dimensional stability.


I need at least 1 condenser lens and 2 projector lenses. Both lenses need to be optically clear. I have attached the drawings. Is this work that your company can perform?

Yes, we plastic polish lenses regularly.


We urgently need a PETG windshield to be polished to a flawless finish. There is small wave deformation that is limiting vision through the windshield as well. The windshield itself is 4ft long by 2 feet wide and is shaped like a bubble canopy for aircraft. Is this something your company can help with?

Sorry, this job is too large for us.


We want to surface treat extruded PVDF tubing, does Connecticut Plastics have the capability to chemically or flame polish the surface?

PVDF does not chemical or flame polish.


Can I get a quote on polishing two parts? If possible, I would also like to know what kind of polishing method is required in order to accomplish a smooth clear finish, as well as how much material would be removed when the acrylic is polished.

Plastic buffing and flame polishing work well on acrylic, please send us a drawing and we’ll be happy to send you a quote.


Can I get a quote on polishing two parts? If possible, I would also like to know what kind of polishing method is required in order to accomplish a smooth clear finish, as well as how much material would be removed when the acrylic is polished.

Plastic buffing and flame polishing work well on acrylic, please send us a drawing and we’ll be happy to send you a quote.


We were advised to look into having our machined components vapor polished. Can this process eliminate the machine radius marks? The CNC cutter is cutting at very high speed. The radius size is R0.05 mm only. Can you tell us if vapor polishing method would be feasible for our parts?

Vapor polishing of plastics will make cutter marks clear but it will not remove them.


We have some polycarbonate parts that need polishing. Can you provide price for Vapor polishing only, then and also for machining and vapor polishing?

Yes we can quote polycarbonate vapor polishing only, as well as complete plastic fabrication.


I would like a quote for machining the acrylic prism described in the attached drawing.  Additionally, if instead, we were to send you the machined part, and just need the large, sloped face to be given an optical finish, would that be possible?

Our machine plastic optical finish is not a true optical finish. We can produce a functional see through component but not one where a light path is controlled. Typically our surfaces have too much scattering.


I am interested in getting 2 blow mold cavity halves polished for transparency. They are to be made from polycarbonate. Is this something your company would be interested in doing?

We are happy to vapor polish for our customers. Parts must be sent to us as clean as possible. We will anneal after polishing as well.


We require 30 black ABS molded samples to be polished or buffed. Our previous buffers left scratches that are unacceptable to our customer.  The customer expects these parts to have a surface finish which is completely free of any defects. As these parts have been returned by a customer, and they are expecting the parts back soon it is important that this is turned around quickly. Can you please provide an estimated quote how much this would cost on a per part level for the 30 samples.

Buffing may not be the best choice. There are many solutions for plastic polishing that can provide better and more consistent surface finishes than buffing.


I need vapor polishing information. 

Please call me concerning plastic vapor polishing information. We can advise on the best material choices as well as finish requirements and expectations. Vapor polishing is best left to the experts for the best result. Poor quality polishing, stress cracking and chemical exposure to employees can occur without proper handling.


I have some ultrasonically welded ABS parts that I’d like to cross-section and then polish.  We need the ability to view the penetration of the energy directors. The parts are small and are used in a retail environment for loss prevention.  Is this something you are capable fabricating?

We can cross section and polish using a variety of methods, buffing, vapor polishing and direct machine polishing.


I have a transfer mold for pulp & paper that requires a smooth finish to prevent sticking. The material is white UHMW. Is this material suitable for polishing? If not, can you recommend another material?

UHMW can be polished through buffing. Depending on the plastic part configuration, we can achieve a high finish.


How effective is vapor polishing for hiding parting lines on Polysulfone parts or would mechanical polishing be better suited for this? Aesthetics are critical on this part.

Parting lines on molded parts are typically a fairly significant feature. I would recommend a buffing wheel to remove. In some cases we have machined them first.


My question is about plastic polishing. I have a polycarbonate part that requires polishing. When we receive the parts from our current machine shop, a significant amount polishing is required to meet our requirements.  Your sample photos of polycarbonate parts are very impressive. We would like to eliminate any polishing on our end. Can our parts be polished like the ones you show? Could you get a better finish after machining than our current vendor?

Generally speaking, the better the machined finish, the better the polished results. We machine polycarbonate every day and can achieve some of the best surface finishes in the industry.


We have 5.00″ wide x .016 thick HPDE sheet that is translucent. Can this be vapor polished on both sides or would you recommend another type of polishing.

HDPE cannot be vapor polished but we have other plastic polishing methods that would be affective.


I am interested in your vapor polishing process for polycarbonate. I am wondering what type of surface finish is required on the parts in order for the vapor polishing to work correctly.

We can vapor polish any surface but typically the better the prior finish the better the result.


Do you vapor polish Isoplast 301?

Isoplast cannot be polished with a conventional approach. We have other plastic polishing methods that work well depending on the application. Please send your prints.


I have three machined cast acrylic parts to be used for a NASA space experiment.  I would like to get a better finish on the surfaces shown in the attached drawing.  Supplied parts have slight haze and visible scratches. Is this something that you can do?

They look to be mechanically polished. At this point in the process it is difficult to improve. We find our best results come when we perform both the machining and polishing.


I have three machined cast acrylic parts that will be used in a NASA space experiment.  I would like to get a better finish on the surfaces shown in the attached drawing.  The parts currently being supplied to us have a slight haze and visible scratches on their surface. Is this something that you can do?

Yes we can polish the components via vapor polishing and buffing or flame polishing.


I am looking to have fabricated a 3mm x 3mm square plastic component, 3mm, 5mm, and 10mm thick with a 45 degree angle cut on each end and a flame polish edging after grinding.  Is this something you can do?

Yes we can.  Please contact me so that we can discuss the various methods of plastic polishing further.  Vapor polishing or machine polishing may be a better choice for your plastic component.


I am looking for a new advanced way to polish Polycarbonate Ophthalmic Lenses. Currently using an aluminum oxide with a velveteen polishing pad.

I would recommend vapor polishing of your polycarbonate parts. It is a labor intensive process best done by experienced personnel. We can accomplish that for you, if you are interested.


Need polished plastic part that is compatible with styrene & won’t be etched by styrene vapor. What would you recommend?

Please consider polycarbonate or acrylic they work best when your application calls for a polished plastic part.



I need to have a mechanical polish on the concave surface of two parts shown in the attached drawing.  The material is ABS with a thin electroplated Nickel coating.  It is to be over-coated (after polishing) with vapor-deposited aluminum.  Can you do this?

Yes we can, we buff plastic on a regular basis.


I need to have a component fabricated. There is a flatness spec involved- my question is how flat you are capable of polishing Ultem- 1000?  Some confusion also remains on what the precise spec is, but let’s say it is around 1/8 lambda at 500 nm. Is that something you can do?

We don’t produce true optical quality work. Most of our polished components are for visual inspection type applications.


I have a question regarding the polishing of a laser sintered PEEK part. I would like to learn the types of polishing you think would work for this material. I am most interested in the vapor polishing for internal surfaces that are hard to reach.

Peek will not vapor polish. Consider some type of buffing operation or finish machining approach.


I am looking to get the best surface finish on ESD Acetal.  Currently our model shop can only get a 16 micron finish.  After looking at your website, it appears that vapor or flame polishing will provide a smoother finish?  Can you tell me the very best finish that would be achievable on a flat rectangular part without affecting tolerance?  Or can tolerances be built into this process? 

Vapor polishing or flame polishing are not effective for acetal. We have achieved surface finishes to 8 micron however considering the ESD acetal, 16 would be more typical.


I am a product engineer of Foxsemicon Integrated Technology Inc. in Taiwan. I look for the process of “Vapor Polish” on internet. And it shows me that your company has owned this process of vapor polish on your company website. Would you supply the information of vapor polish for me, or tell me where I can find the information including the equipment and technique. I will be glad for your reply.

Plastic vapor polishing is a proprietary process. I am sorry but we cannot divulge our methodology. I do not believe that anyone sells equipment for the process


I am restoring a vintage boat and am looking for someone to polish the 45 year old windshield. Is this a service that you might offer or do you have any recommendations?

Sorry, that is not something we do. You are best off trying to buff it yourself with a rotary or vibratory buffer and a good compound. If it is not too bad you could do it by hand. Test in a small corner before proceeding to the entire windshield. Supplies are available at www.mcmaster.com


I have an oring seal in Acrylic and Polycarbonate which is not sealing well. How can I repair the groove?

Considering the three standard plastic polishing methods of vapor polishing, buffing and flame polishing there is really only one choice. Flame polishing will not get down in the groove and inexperienced operators frequently melt their parts. Vapor polishing works well on polycarbonate but not as well on acrylic. In addition, the vapor polishing will smooth the surface but does not remove tool marks. The best choice is buffing. A light buffing compound with either a dremel tool or cotton cloth if the part can rotate will achieve the best finish. Buffing can have a fairly aggressive blending and smoothing action to remove heavy tool marks.


I want to design a light pipe in polycarbonate. What is the best finish you can achieve on the mating surface?

Plastic finish quality relates to part configuration. Very low numbers can be achieved through a combination of machining and polishing on flat surfaces. Bores are somewhat more difficult because of the type of tool used and access issues. From a general sense, a typical plastic machined finish can approach 20 microinches with plastic polishing improving it 5 to 10 microinches better. Bores and internal features vary from there and are largely part/configuration specific.


I was wondering if your company offers a plastic (polycarbonate) polishing service. If so, would you polish plastic parts that we would send to you, or do you only perform this service on parts that you manufacture?

We would be happy to polish parts that your send us. Please be aware the polishing quality is directly related to machining finish and cleanliness. The best job is typically done when we produce the parts ourselves as we have the proper coolant and handling techniques.


Please let me know what you feel the achievable surface roughness after vapor polishing may be for this particular shape. 15 microinches is a little too high for my application, but our discussion left me with the impression that you may be able to improve the spec for a simple shape like this one.

Plastic surface finish is related to part configuration. A simple shape such as yours (long hexagon), can typically be produced to less than 15 microinches when combined with vapor polishing.


We are interested in learning about the possibility of polishing optical polycarbonate components. How well can your vapor polish process bring up the surface finish on a machined PC part? Does it distort the surface? How fine must the surface finish be before vapor polishing? What is your turnaround time?

The surface will improve 5 – 10 micro inches. It does not distort or change the size dimensionally. The machined finished is very critical as vapor polishing does not remove the tool marks it only makes them clear. Also important is that the part needs to be very clean, no oils or grease. Our turnaround time is about one week.


We have an acrylic dome for a scanning lidar system that was machined in-house but we do not have the ability to get an optical finish on it. I do not have an image of the part right now, but can supply one. It is a slightly tapered cylinder, from just over 3″ to just under 3″ diameter and 3″ long, with one end closed and the other open with an external mounting flange. The walls are 1/4″ thick and lathe finished to a semi-transparent but still frosted finish. Only the walls of the cylinder need to be optical, the end cap and flange do not. Would it be possible for you to do the finishing on this piece, and if so can you give me a ballpark cost? Thanks!

Sorry on single piece items, we typically do not get involved. We focus on production only. If you want to do it yourself, try www.mcmaster.com for buffing wheels, cloth and rouge.


We’re doing a custom paint job on an Army Humvee, for the Army. Our situation is, the tail lights. We can’t find a place to readily replace them and they’re in fairly bad shape, with dulling by the sun etc. I’m wondering if they can be polished. If so, would you share the best way to polish them, i.e., what compounds, high or low speeds with a polishing wheel etc.

A good question, a simple cotton buffing wheel and some various grit compounds will work fine. Test in a small area to be certain you are not damaging it. Work from rough to fine. Low speeds on the wheel so that you do not burn the plastic.


Which plastic polishes the best?

That depends, polycarbonate is very clear with vapor polishing. Acrylics work best with flame polishing. Keep in mind, vapor polishing can cover internals and threads while flame polishing is good for large flat areas.