How can I remove fine scratches from Spectar PETG?

There are 2 easy ways to remove fine scratches from sheet made of Eastman Spectar™ copolyester. Scratches can be removed by using either heat or solvent methods. Both methods work well—choose the one that is most practical for your application.

The most popular way to remove scratches from Spectar sheet is by applying heat to the sheet surface using a low-temperature flame. This works well on heavy-gauge sheet. An alternate way to remove scratches is by using a simple solvent mix, which may be preferable for thinner-gauge sheet.

Scratch repair: Low-temperature flame

  1. Make sure the masking is removed from both sides of the sheet. (Heating one side of the sheet may make masking on the reverse side more difficult to remove.)

  2. Remove dirt or dust from the sheet prior to heating.

  3. A common handheld heat gun can be used to eliminate scratches. A typical butane or oxygen/hydrogen torch works well.

  4. Always start on the lower heat setting to prevent bubbling or part warpage; watch distance and speed.

  5. Allow sheet to cool before handling.

Deep scratches or gouges may not be suitable for repair by this method.

Spectar Scratch repair

Scratch repair: Simple solvent mix

  1. Mix 1 part water with 1 part acetone.

  2. Submerge the part in the solution for about 60 seconds.

  3. The mix will soften the plastic surface, allowing scratches to “heal.” Do not leave the part inside the solution for more than 2 minutes.

  4. Remove the part. Rinse with water.

  5. Let dry.

  6. Allow sheet surface to reharden for 1 hour or more before handling. Try not to touch the surface with fingers to avoid any risk of indentation.

  7. If the dip method is not practical, you may also apply the solvent using a squeeze bottle. Flood coat the surface of the sheet with the acetone/water mix, making sure all areas are covered continuously for at least 60 seconds. Rinse with water. Allow to dry.

The following picture shows a sheet of Spectar that was scratched over its entire surface using fine sandpaper. The right side of the sheet was repaired using the solvent dip method.

Spectar Scratch repair

Notice the dramatic improvement!

 

For information on fabrication, see how-to videos and fabrication guide.