Surface Preparation of Unpainted Aluminum

How to Remove Oxidation on Aluminum 

Many years ago, some of the tankers and trailers had unpainted aluminum skins.  Direct application of pressure-sensitive vinyl graphics to these surfaces often resulted in adhesion failures.

The cause of adhesion problems on aluminum is usually oxidation on the surface of the metal. Whether you are applying an emblem to a vehicle surface or a label to an aluminum part or bonding aluminum extrusions together using very high bond (VHB) tape, you must remove this contaminant.

Unpainted aluminum begins to oxidize almost immediately.  A telltale sign of oxidation is to rub the surface with a clean cotton rag. Any black residue on the rag indicates that oxidation has begun. 

Exposed to the elements, aluminum begins to oxidize immediately. Unless you remove this oxidation, pressure-sensitive films and tapes will not adhere properly.

The first step in cleaning oxidized aluminum surfaces is to degrease the aluminum, wiping it down with a wax and grease remover.  Saturate the surface with the solvent.  Before the solvent has a chance to evaporate, dry the surface with a clean rag. Then clean the surface again with isopropyl alcohol (IPA).

While you can remove oxidation with a commercial acid brightener, the more common procedure is to abrade the surface with either a red or grey Scotch-Brite™  pad or steel wool.  After scouring the aluminum with the Scotch-Brite™ pad, wipe the surface clean with  IPA. After cleaning, rub the aluminum with a clean rag to check for any remaining oxidation. The surface should now be clean for application of vinyl graphics or high bonding tape.

Vinyl Application Videos

Squeegee Technique. Nothing is more basic in vinyl application than the squeegee. But some squeegees work better than others. And there are right ways and wrong ways to use this simple tool. This video clip reviews squeegee selection, squeegee care and squeegee technique. Click to Link

Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link

Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link

Transferring Frosted Window Graphics Films.  Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link

3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link

Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free.  Click to Link

Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link

Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link

About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.

Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer.  Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.

Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for  publications, such as  Signs Canada, SignCraft,  Signs of the Times, Screen Printing, Sign and Digital Graphics and  Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published.  Vinyl Sign Techniques is available at sign supply distributors and at Amazon. 

Slides of Jim's Artwork

© 2016 Jim Hingst