COIN FAQs: Stippling vs. Sandblasting & Other Options

Sandblasted Chief Master Sergeant Air Force Coin
Sandblasted Chief Master Sergeant Air Force Coin

Sandblasted challenge coins have a unique and high-end look!  Sandblasting is an available treatment for challenge coins made of any metal – brass, zinc alloy or iron.  Sandblasted challenge coins have a  matte surface wherever there is an area of unpainted electroplated metal.  To understand why you might choose sandblasting as an option for your challenge coin, you must first understand the manufacturing process.

What is sandblasting?  Sandblasting is technically the forcible propelling of a stream of abrasive materials against a surface; this is done under high pressure to smooth a rough surface or roughen a smooth surface. 

Sandblasting the surface of a challenge coin will result in mattifying the finish – so a shiny silver plated coin will have a matte finish silver look to any area that has been sandblasted. 

With challenge coin manufacturing, sandblasting is a multi-step process.  First, the coins are electroplated in the finish you desire: shiny nickel, shiny silver, shiny gold are usually the best finishes to get maximum visual results with sandblasting. 

After the coins are plated, we create a laser etched mask that covers all of the areas that will NOT be sandblasting – leaving the areas to be blasted exposed.

These masked coins are then put in an air-tight sealed chamber.  The coin sandblasting is accomplished by using highly pressurized compressed air to “blast” fine particles of tiny glass or sand through a very fine nozzle.    This step is done by hand – individually blasting each coin.  The process takes approximately 30 seconds per coin per side.  Once this step is completed, the masking is removed and the coins are hand polished.  They then move to the paint department.

The cost of sandblasted challenge coins is higher than most coin upgrade options due to the labor-intensive nature of the blast.  The result, however, is a high-quality impressive coin.  A very small percentage of coins are sandblasted.

A less expensive treatment for challenge coins is called “stippling”.  Stippling is raising a fine texture of metal in any area on a coin that is 2-dimensional (does not have relief).  Stippling comes in several patterns and these patterns do not raise the cost of the coins.  Stippling does not offer the same very fine pattern that sandblasting does.  Stippling also does not mattify the coins – so the stippled pattern will be the same finish as the other areas of the coins.

AIRMAN-TO-AIRMAN-COIN

Soft enamel paint can be poured over stippling to create a unique look on your coins.   We recommend using a rougher pattern for the stippling so that it can easily be seen behind the enamel paint.  Note: stippling is not recommended for coins with hard enamel (cloisonne) paint.  The polishing process for the paint will remove the stippled pattern.

Sandblasting and stippling are recommended for use in larger areas of your coins where you do not want paint.  If you expect your challenge coin to be carried in a pocket daily – stippling areas that are not covered in paint will reduce the effects of normal wear and tear – such as small scratches or dents. 

Stippling and sandblasting also add more contrast to areas of raised metal on any coin.

Consider adding sandblasting or stippling to your next coin!  And watch our video below to see photos of challenge coins with sandblasting, stippling and even some coins with paint poured over the stippled areas – to get more ideas and more information:

502d OSS Coin Painted with Stippling
502d OSS Coin Painted with Stippling

VIDEO TRANSCRIPT

Hello and welcome to another edition of “Coin FAQs” where we answer your frequently asked
questions about challenge coins. Today our topic is “Sandblasting”. Now, first of all, what is sandblasting? Sandblasting is where we use a hand held device and we actually remove part of the electroplated finish and roughen up the metal beneath it.Why would you do that? Well, if you look at a challenge coin that has been sandblasted you’ll see that it getsan elegant finish to certain areas of the challenge coin. Sandblasting is expensive because it requires us to do multiple treatments to a coin once it’s electroplated; including masking off the coin and then applying the sandblasting by hand.

We have another option for you if you like that look and it’s called “stippling”. Stippling is a little bit less expensive than sandblasting because it requires no extra
work after the coin is plated.With a stippled challenge coin we actually raise a texture, a small ridge of bumps, into an area and that’s done directly in the die. So every challenge coin that is die struck comes out with that stippling pattern. The difference between stippling and sandblasting is that stippling will have the same finish in those areas as the rest of the challenge coin.
With sandblasting, we are actually removing that shiny finish and you are seeing a small, very fine pattern of bumps and a matte finish to the coin. So that’s the difference between stippling and sandblasting. But again, stippling gives you an option of having an upgraded feature or look to your coin without the additional expense.
If you want to magnify the shininess of a challenge coin, then we recommend stippling an area behind any raised parts of metal and then, to make it really shiny, we can add
an epoxy dome. The epoxy dome will take light coming from around the room and will reflect it out to wherever we have raised areas on the stippling. So it gives you a really shiny, amazing looking finish to the challenge coin.

Finally, we another option for you using stippling. And that is taking areas that are recessed, creating that stippled pattern and then covering
them with enamel paint. This gives you yet another look to your coin – an upgrade look to the challenge coin. So that’s the difference between sandblasting and stippling and we have more information about options for challenge coins on our website.
You can see our gallery of challenge coins and watch other videos about coin designs at CelebrateExcellence.com. Join us again next week for another edition of “Coin FAQs”.
And – remember to Celebrate Excellence everyday.