It is not uncommon for technicians to find that sections of a damaged area may absorb moisture from the environment which will prevent resins and adhesives to bond. Composite materials must be completely dry prior to beginning a composite repair.

Drying may be accomplished with a heat blanket and a vacuum bag. The heat from the heat blanket converts the moisture into vapor and the vacuum extracts the voids. When performing this technique, bring the part up to temperature slowly and in a controlled process. Heating the area too fast may break down the bonds in the laminates and cause more damage. Using lower temperatures over a longer period of time produces the best results.

There are various approaches to inspect the dryness of the damaged area. One in particular is using a moisture meter. HEATCON’s HCS2049 Moisture Meter for radomes indicates moisture levels in aircraft radomes. It has a direct reading scale for instantaneous reading of Good, Fair, Poor and Unacceptable radome moisture levels.

To learn more about products to help dry absorbed moisture in composites, email us at info@heatcon.com or visit www.heatcon.com.