Can Coated Coils Be Brazed or Repaired Afterwards?
Key facts
| Step | What to do |
|---|---|
| 1. Prepare | Remove coating mechanically for a short distance around the joint |
| 2. Braze | Braze as normal; protect nearby coated fins from heat |
| 3. Clean | Remove flux residue and oxide; let the area cool and dry |
| 4. Touch up | Apply an air-dry coating over the repaired area and cleaned margin |
| 5. Check | Leak test, then inspect the touch-up after cure |
Why the coating must come off
Brazing heats the joint far beyond what any coil coating is designed for. Coating left on the joint burns, and its residue can stop the filler metal from wetting the surface, leading to a weak or leaking joint.
Protecting the rest of the coil
Keep the heat local and shield nearby fins and coating with heat-resistant material. Discoloured coating next to the joint should be removed and recoated.
Flux
Flux residue left on the joint is corrosive. Remove it thoroughly before touching up.
What this means for your project
Include a field repair kit with the order if brazing on site is likely, and give installers the touch-up instructions.
Technically reviewed byPelagard Technical TeamCoating selection, application and quality controlLast reviewed:
