Masking Part II: Perfect Masking Lines

Learn how to get perfect masking lines, also several different masking materials explained.

      In the last masking article, I covered the very basic masking supplies needed for powder coating and also the reasons you would need to mask. In this article, I will show you some not so common ways to mask off parts when powder coating and also show you how to get nice, clean looking masking lines.
powder coat masking

Why Masking is Necessary For Powder Coating and Which Masking Supplies To Use

Masking is a tedious but required part of powder coating.  Masking powder coat is done for either appearance or for function and both of these topics will be explained more in-depth in this article. I will also discuss some of the more basic, but important, powder coating masking materials and supplies.

Don't forget to check out Masking Part II and the Wall-Mounted High Temp Tape Dispenser.

When powder coating, it is important to mask off certain areas of certain things.  Powder coating is a thicker coating than most paints and if you don't mask certain areas, things might not go back together when you're done.  You can also use masking techniques to make designs, logos, and words on the things you are powder coating for a different look.  Masking techniques and supplies are not all standardized, sometimes you have to get creative to mask off certain items.  Again, this will be one of several articles on masking, so I will cover the basics of masking here.

powder coat tape masking
This alternator case is masked with Polyester Powder Coating Tape.  This tape can withstand 400 degrees without degrading.


Cleaning and Degreasing before Powder Coating

cleaning parts powder coatingLets talk about the first step of the powder coating process. The very first thing to do is thoroughly clean and degrease your item. Even if it is brand new, it should be cleaned.After cleaning your part, check out this article for the following steps: "How to Prep for Powder Coating". The first thing you need to do is figure out what its made out of. Steel, aluminum, etc. Some metals like aluminum are very sensitive to certain cleaners and it can cause can corrosion and damage on a microscopic level. I will explain the steps I use to clean below.

Alternatives to Sand Blasting

removing rust before powder coatingWhen powder coating, media blasting (sand blasting) is one of the best preparation methods possible.  It cleans, de-rusts, and it leaves behind a texture that makes powder coating stick like nothing else. Read this Media Blasting article to realize the full benefits. But for the stubborn people out there (I was one of them) who don't own a big air compressor or sandblaster and don't want to invest in them, I will go over some alternatives to sandblasting. Note: The alternatives are slower and do not achieve the same durability in the powder coating finish as media blasting.

Stripping Powder Coat

stripping removing powder coatLets talk about how to remove powder coat. Why would you want to strip powder coat from a part? As you start powder coating, you are going to make some errors. It doesn't always come out like you expected. If that happens, it is nice to be able to remove the powder coating so you can try again. There are several ways to remove powder coat. You an remove powder coating with a chemical stripper, media blasting, or a burn-off oven.

Powder Coating: Perfect for Car Restorations

I am going to take a break on explaining the types of tools needed for powder coating and discuss powder coating from a car restoration standpoint.  I am in the middle of a car restoration myself. My car is a Mitsubishi 3000GT VR-4. I learned to powder coat for this car and powder coating will play a major role in making this car look new and keep it that way for many years.  Because powder coating comes in so many colors, shades and textures, it can match basically any finish possible.  Even if you have a 60's era muscle car and would like a completely concourse restoration, powder coating can be used to match those original finishes.

powder coated alternator power steering pump and starter motor

Black Mitubishi 3000GT VR-4

Media Blasting Part II - Setting up a Sandblast Cabinet

This article will talk about setting up a media blasting cabinet to be as efficient as possible so that you can easily prepare your parts for powder coating. I explained the different types of media blasting methods such as pressure pot, siphon blasting, sandblasting cabinets, blasting outdoors, and dedicated media blasting rooms in the previous article: Media Blasting.

For most powder coaters, a media blasting cabinet will be the most ideal way to prepare your parts for powder coating.  They are available in a range of sizes that will suit small DIY projects up to very large projects.  Media blasting cabinets keep all of your blasting media contained in a sealed environment and which allows you to get the most use out of your media and also keep your area clean. Here is an example of a cheap media blasting cabinet for a small DIY powder coating setup:

powder coating in garage

Why Sandblasting is the Best Method to Prepare for Powder Coating

sandblasted alternator coverMedia blasting also known as sandblasting is a great preparation method for powder coating.

When powder coating, it is very important that the item you are coating is completely clean of oils, dirt, paint, rust, corrosion, and damaged plating (zinc, nickel, chrome, etc). All of these things can interfere with the powder coating process causing imperfections in the finish or causing it to fail completely. After cleaning your item of all oils and dirt, a media blaster does the job of removing rust and corrosion very easily and thoroughly when compared to other methods.

How to Properly Ground Your Parts

Improve the attraction of powder to your parts while powder coating.

If you are powder coating a metal part, it should be grounded. The grounding is what attracts the powder to the part. The better the ground, the less problems you have, especially when doing multiple coats. Often a powder coating gun or the guns control box will come with a little 18 gauge ground wire and a mini alligator clip that you can connect to your part to ground it. I will call this the "stock" ground. The stock ground continues through the control box, through the wire it uses to plug into a wall outlet and after that is a mystery to me. This is not a good example of a ground. No matter how good of gun you have, you should have a DEDICATED GROUNDING ROD.
Powder Coat grounding rod

Monitor Temperatures using an Infrared Thermometer

Having consistent and accurate oven temperatures is very important when powder coating.  Knowing what temperature your part is at when it is in the oven is essential.  I will be talking about how to do this using an infrared thermometer.

powder coating part metal temp ir thermometerAn infrared thermometer, also called IR thermometer, also called  IR Temp Gun can measure the temperature of an object without actually touching it.  They display the temperature on an lcd screen.  They also usually have a laser pointer to help you accurately read temperatures. I'm sure you can see how a tool like this would be helpful when powder coating.  In case you don't see the importance, take a look at this scenario to see how great these tools can be:  You just finished spraying your powder on your part, and you stick it in the oven. Lets use an example cure schedule of 400 degrees F for 10 minutes(your powder will specify your cure schedule). So you have the part in the oven, you shut the door and you set the temperature for 400 degrees. You DO NOT start the 10 minute timer when you shut the oven door. The 10 minute timer starts when the entire part itself has reached 400 degrees. The easiest way to tell when your part has hit 400 degrees is with an infrared thermometer.