Gelcoat Tint and Repair

Gelcoat Tint and Repair

#- Sand area around the repair with 320 grit to remove staining UV discolouration

# - Choose a smooth undamaged area near the repair to do colour matching. Sand the area with 320 grit, followed by 600,1200 then finally polishing compound to achieve full gloss and original gelcoat colour

#- Using a toothprik add very small amounts of pigment to the white gelcoat and mix thoroughly, Use only small amount of gelcoat at a time, in a separate mixing cup. Test the colour on the glossy prepped area, avoiding direct sunlight as this can ‘trick’ the eye and make matching more difficult. If the pigmented gelcoat becomes too dark, use this gelcoat to tint a new batch of white, as it is easier to control the pigment amount when premixed with gelcoat

#The colour you make will remain unchanged when cured, however, too much hardener can ‘burn’ or discolour the gelcoat. Carefully add no more than 10 drops per ounce of gelcoat, do not over catalyze. Working time is 15-20 minutes, much less in direct sunlight.

*N.B,-The hardener MEKP is poisonous and corrosive. Use caution when handling this material

#-Use the spreader to apply catalyzed gelcoat smoothly and evenly to the repair area, leaving the new gelcoat slightly higher than the substrate. You may find it useful to tape around the repair with 1 or 2 layers of masking tape, to keep the gelcoat confined to the repair area, and add a little thickness to the new gelcoat as it will shrink a little during the curing process. You could also keep some of the match unanalyzed in case it is necessary to refill.

#-Once cured (at least 2 hours at 20C/70F) wipe with Acetone, and sand the repair using the sanding block and 320 grit. Leave masking tape on until you have smoothed the repair down to the tape. This will prevent over sanding of the original gelcoat. Remove the masking tape and start sanding with 600 grit to blend and level the repair area, finish with1200 grit.

The gelcoat should be hard and make fine dust as you sand.

If it starts to ‘crumble’, wait another hour or 2, Finally , polish with the compound, overnight cure is best for achieving high gloss.

Tinting From a White Base Color From a Neutral Base

Ivory-add gold oxide Start with pigment closest to the predominant color

Grey/White- add black Add other pigments for shading

Smoke Whites-add gold and black

Beige-add brown

Do Not apply gelcoat over epoxy.

Do Not use gelcoat as a filler for screw holes or larger voids in fiberglass.

Wet Sanding

Wrap sand paper over the block, dip in clean water, Sand until paper starts to clog, rinse in the water. move to fresh paper after 3 or 4 washes.