Tag Archives: surface prep

a roll of paper towels

Clean White Paper Towels

Q. What should I wipe the surface with before applying WEST SYSTEM Epoxy?

A. Use water and paper towels.

If using a solvent, like acetone, make sure to use clean, white, non-printed paper towels—not a rag. Using printed paper towels with acetone or other solvents can make the ink rub off, contaminating the newly sanded surface. Continue reading

Epoxy's adhesion to metal is affected by surface treatment

Effects of Surface Treatment

On Epoxy Adhesion to Metals

by Brian Knight—GBI Technical Advisor

Above: Surface treatment can make all the difference in epoxy adhesion to metal. Photo by Manny Becerra on Unsplash 

We have performed tens of thousands of adhesion tests over the years and many of these tests were done on metal surfaces. Below is a summary of tests done on a variety of metal surfaces and done with a variety of surface preparations. As you look at the chart, notice the surface preparation that gives the highest number.

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Bonding surfaces should be as dry as possible.

Avoiding Surface Contamination

For Good Adhesion

by Brian Knight—GBI Technical Advisor

Above: Sanding the bonding surface is important to good adhesion with epoxy.

“Cleanliness is next to Godliness,” the old expression goes. This is certainly true when preparing a surface for an epoxy application. The surface has to be clean to begin with or there may be adhesion problems. But often, our good intentions with respect to cleaning a surface result in contaminates deposited on the surface. Below are some potential surface contaminates, ways to avoid them, and an almost foolproof method to determine if a surface is clean or contaminated. Continue reading

Comparing Surface Prep Techniques

For Paints and Primers

by Joe Parker

Above: Surface prep testing using ASTM D3359. This calls for a single-edged razor blade to score a pattern through the coating. Applying a strip of masking tape diagonally across the pattern, then pulling it slowly back over itself will reveal the relative degree of adhesion to the substrate or primer.

Before you begin a project, it is a good idea to consider all of your options. Information about products or methods you may want to use is often available on product labels, from manufacturers, or your own experience. However, many times the information you need to make good choices is just not available. Then your best option is to test. In our most recent sailboat renovation, we had to figure out what to test for and how to do it. Continue reading