A 12.7mm thick section of Devcon Epoxy will harden at 21ºC in 4 hours. The material will be fully cured in 16 hours. The actual cure time of epoxy is determined by the mass used and the temperature at the time of repair.
Proper surface preparation is essential to a successful application. The following procedures should be considered:
All surfaces must be dry, clean and rough.
If surface is oily or greasy use Devcon Fast Cleaner 2000 Spray/Cleaner Blend 300 to degrease the surface.
Remove all paint, rust and grime from the surface by abrasive blasting or other mechanical techniques.
Aluminium repairs: Oxidation of aluminium surfaces will reduce the adhesion of an epoxy to a surface. This film must be removed before repairing the surface, by mechanical means such as grit-blasting or chemical means.
Provide a “profile” on the metal surface by roughening the surface. This should be done ideally by grit blasting (8-40 mesh grit), or by grinding with a coarse wheel or abrasive disc pad. An abrasive disc may be used provided white metal is revealed. Do not ’feather edge’ epoxy materials. Epoxy material must be ’locked in’ by defined edges and a good 3 - 5 mil profile.
Metal that has been handling sea water or other salt solutions should be grit blasted and high pressure water blasted and left overnight to allow any salts in the metal to ’sweat’ to the surface. Repeat blasting may be required to ’sweat out’ all the soluble salts. A test for chloride contamination should be performed prior to any epoxy application. The maximum soluble salts left on the substrate should be no more than 40 p.p.m. (parts per million).
Chemical cleaning with Devcon Fast Cleaner 2000 Spray/ Cleaner Blend 300 should follow all abrasive preparation. This will help to remove all traces of sandblasting, grit, oil, grease, dust or other foreign substances.
Under cold working conditions, heating the repair area to 38ºC - 43º C immediately beforeapplying any of Devcon’s Metal-filled Epoxies is recommended. This procedure dries off anymoisture, contamination or solvents and assists the epoxy in achieving maximum adhesionto the substrate.
Always try to make the repair as soon as possible after cleaning the substrate to avoid oxidation or flash rusting. If this is not practical, a general application of FL-10 Primer will keep metal surfaces from flash rusting.
Spread epoxy over prepared surface with a putty knife or similar tool. Press material firmly into all cracks and voids to ensure maximum surface contact and avoid trapping air. Apply a minimum of 1.6mm thickness. Do not feather edge. Use butt joints.