Masking Issues

Chemical Agent Resistant Coating (CARC) is the organic topcoat used on the majority of the armed service’ combat vehicles, aircraft, ordinance and tactical equipment. Its unique formulation allows coated vehicles to be decontaminated in the event of exposure to chemical or biological warfare agents. It also has properties that make coated equipment less prone to infrared detection.

Applied as a wet spray, the process cures in relatively low temperature oven. Given that this coating i...

Below is an excerpt from a featured article written for pfonline.com. Read the entire editorial HERE.

What differentiates CFS as a masking products supplier is the extent to which work with finishers on finding solutions to process problems. Masks generally fail due to inappropriate application, poor sizing or excessive wear. For these cases the solution is often simply finding a better standard product for the job. But there are other cases where solving a root masking problem requires developing a custom solution.  In either case it...

Chromic acid anodization (CAA) is the one of the oldest and most widely used processes in the aerospace and metal finishing industries. Type I Chromic Acid Anodizing is an electrochemical process that creates a thin aluminum oxide film by rapidly controlling the oxidation of an aluminum surface. The resulting aluminum oxide film is electrically non-conductive. CAA produces a thinner film than Type II and Type III Anodizing (hard coat) and produces enhanced drawing and forming characteristics and is often is used for flight-critical aluminum components that are subjected to high stresses.

It is common that some areas of the product need to be masked to prevent anodizing. Tape is the easiest type of masking to apply. However, pressure sensitive adhesive tapes previously were ineffective masking selections for CAA. Most of the tapes either fell off or showed very high acid leakage of the CAA material under the edges of the tape.

Liquid masking has been the most effective existing solution for masking a part in a CAA process. While liquid maskants show satisfactory performance, the application process is lengthy (requiring...

Masking caps and plugs need to fit properly in order to work as anticipated. Part III dives into what happens if those aren't quite right.

A new vehicle cab rolls down an e-coat line with 65 threaded holes which needed to be masked. A call is placed by a purchasing agent to a supplier that sells masking plugs. The size of the holes is relayed to the supplier who sends a variety of masking solutions for the holes in each part. Sounds simple right?

Not so fast… CFS was invited to evaluate why the current supplier’s plugs had failed - causing extensive tapping of all threaded holes after being coated. We quickly determined that the masking did not fit properly. Some were too sma...

In Part I we discussed how masking can fail as the part surpasses it's life cycle. In Part II we will discuss what happens when the mask is not the correct one for the process being used. 

Often when our team members are on-site with large customers, we are presented with opportunities in new departments or on different production lines. We hear “it’s what we had on hand and it worked…kinda”. Sometimes having masking experts take a look can be a game changer.

For a recent customer, we saw a very cumbersome, mechanical masking solution being utilized. It required a bit of finessing to insert, the use of an impact wrench to apply and a tremendous amount of torque for it to expand and fill the void. Unfortunately, this pressure quickly overcame the structural integrity of the rubber mask, greatly reducing its life cycle. This reduced life cycle required each mask to be replaced each month at a cost of $75 per piece. Perhaps that would have been acceptable – but there was still a 30% failure rate! Certainly, there had to be a better solution?

Enter CFS and our custom masking capabilities. We were able to use our Patent Pending vent plug which acts as a one-way valve – easy to apply and non-leaking. The CFS solution reduced application time 75%, saved 50% on the masking costs, extended the life expectancy of the mask and virtually eliminated rework.

Product Finishing thought so highly of this innovation that their Editor In Chief wrote a featured article in their magazine and online! CLICK HERE to read the full story of how this new product came to be!

We encourage companies to contact us with the tough problems. The solution may be eliminating hand trimming of tape by using die cuts, swapping out the style of masking or even creating a completely custom solution. CFS can help your productivity and bottom line.

Want to see it in action? Check it out:

&nbs...

A Guide to the Cost of Failed Masking in Finishing Processes

A rack of discards sits in the middle of the room. Shelves of streaked parts, awaiting their disposal. “What happened”, we ask? “Oh, the plugs must have leaked as they were coated”, was the reply. We discuss whether rework is an option, but in the end, it is cheaper to just scrap them rather than strip and start over. “That is why we called you”, they sighed.

Masking can fail for several reasons:

1. The mask is not correct for the process being used
2. The mask is not sized properly
3. The mask has reached its end of life

For this article we will focus on the third mode of failure – the plug or cap has outlived its usefulness.

Walking through manufacturing plants and coating operations, we often see the same sight. Buckets, bins and shelves with full of used silicone and EPDM caps and plugs covered in coating, torn and deformed from overuse. While it is true that these plugs and caps are designed for reusability, they do have an end-of-life. When they are used past this point, issues can quickly mount.

Although most coatings don’t adhere to silicone, over time repeated bake cycles will cause both silicone rubber and EPDM rubber to dry out. As this happens, caps and plugs become less pliable, crack, craze and build up coating with each new use. Once this happens, plugs will not seal properly, and caps will begin to tear and leak.

Some coatings, such as plating, involve the use of chemicals. Some of these chemicals can be caustic and will greatly reduce the life span of any rubber materials used for masking. In some case the caps or plu...