Possible Causes – Remedies:

Insufficient coverage – Apply a total of 18-23 thou. Wet film in 3 passes.

Slow Gel or Cure

– Increase Catalyst to maximum 2%.

Low temperature

– Gelcoat and mould must be min. 15°C.

Trapped Styrene

– Hold Gun at least 50cm away from mould. Adequately ventilate, or tilt mould to expel styrene vapor.

Styrene evaporation

– Do not use over 30°C.

Uneven Gelcoat

– Apply at uniform distance from mould.

Wet P.V.A. Release agent – Dry thoroughly.

Water/Oil in air lines – Flush out and drain traps.

Laminate applied too soon – Do not laminate for at least 2 hours.

Uneven Catalysation – Service and calibrate equipment.

Surge in catalyst delivery – Ditto.

Pre-Release – Refer Pre-Release.

Laminate too slow – Increase catalyst in laminate if temperature low.

Possible Causes – Remedies:

Insufficient cure

– Correct catalyst level in gelcoat and/or laminate.

Wait longer before demoulding.

Transferred from mould –

Resurface the mould.

Woven roving / Too close to the gel coat –

Should have 3 layers of 1.5 oz. mat or equivalent chop between gelcoat and woven roving.

Gelcoat too thin

– Use .018 – .023 wet film thickness.

High exotherm of laminate – Cure laminate slower. Laminate in layers.

Use lower exotherm laminating resin.

Possible Causes – Remedies:

Wax build up on mould

– Polish mould.

Polystyrene build up on mould –

Scrub with stiff brush or stainless steel wool and strong solvent, rebuff and re-polish.

Dust on mould –

Keep mould covered when not in use.

Rough or wet P.V.A. – Apply smoothly and allow to dry.

Releasing part too soon – Allow more time before releasing part from mould, particularly at low temperature.

Raw Catalyst – Start catalyst flow away from mould.

Possible Causes – Remedies:

Allowing gelcoat to cure too long –

Gelcoat must be laminated same day.

Use of waxed gelcoat –

Do not use waxed gelcoats on mould.

Excessive or soft wax on mould – Polish mould before use.

Excessive styrene added –

Add maximum *2% styrene.

Over-catalysation at high temp.

– Reduce catalyst to 1% minimum.

Uneven cure due to uneven thickness –

Apply gelcoat to uniform 18-23 thou wet film thickness. Avoid heating or fan blowing before gelation.

Uneven cure due to styrene vapor in low spots –

Ventilate mould properly.

Gelcoat applied too thick – Apply gelcoat at 18-23 thou wet film thickness.

Trapped solvant or water – Check for contamination.

Moving or Bumping mould – Take care until laminate applied.

Possible Causes – Remedies:

Silicone in wax or polishing cloth – Eliminates silicones in contact with mould.

Contaminating on mould –

Keep mould covered when not in use.

Excessive thinning of gelcoat – Thin maximum *2% styrene.

Thin gelcoat –

Rotate stock, Contact supplier.

Gun pressure too low – Increase pressure to obtain good fan.

Possible Causes – Remedies:

Too much catalyst in hot weather –

Drop catalyst to minimum 1%.

Applied too thick –

18-23 Thou. Wet thickness.

Bad handling when demoulding – Demould carefully.

Applied unevenly – Keep consistent distance from mould when spraying.

Thinning with acetone or other solvent –

Thin only with styrene monomer.

Possible Causes – Remedies:

Air trapped between gelcoat and laminate – Remove with roller.

Over catalysation – Use maximum 2% catalyst.

Catalyst Drops

– Service and calibrate equipment.

Poor catalyst dispersion in gelcoat or laminate –

Mix thoroughly.

Possible Causes – Remedies:

Removal of finished article from mould –

Sand back, buff and polish.

Possible Causes – Remedies:

Poorly cured gelcoat

– Refer to remedies.

“Soft dull Gelcoat”

Under cure

– Allow longer to cure.

Ensure correct catalyst –

Create air flow to remove access styrene from deep areas.

Water exposure (before full cure)

– Do not allow water contact untill gelcoat is cured.

Inappropriate use of shrink wrap

– Use only white pollyethylene film.

Exposure to harsh chemicals – Clean only with mild detergent solution. Do not use solvents strong alkalies or acidic cleaners

Refer to supplier.

Possible Causes – Remedies:

Impact damage – Take care hammering moulded parts.

Stress due to flexing – Take care demoulding parts.

Allow product to cure.

Gelcoat too thick – Use a wet film gauge.

Mould mark –

Resurface mould.

Laminate too thin –

Increase thickness.

Possible Causes – Remedies:

Polystyrene / wax build up transferred to part during lay-up – Clean mould regularly.

Poor cure of gelcoat –

Apply gelcoat at correct thickness, catalyst level, and temp.

Inhibition of cure by styrene vapour.

Thick or uneven gelcoat – Apply at .018 – .023 wet.

Strong Alkaline Cleaners –

Avoid cleaners with Ammonia or high pH levels.

Possible Causes – Remedies:

Faulty adhesion between gelcoat and lay-up –

Avoid use of soft mould waxes, which can penetrate gelcoat and adversely affect adhesion.

Gelcoat left too long before laminate applied.

Pre-Release –

Refer to Pre-Release section

Innappropriate use of shrink wrap

– Use only white polyethylene film.

Contamination –

Ensure no solvent, moisture, catalyst, dust, or overspray is deposited on gelcoat before laminating.

Possible Causes – Remedies:

Resin Drainage from laminate –

Avoid resin rich areas.

Uneven laminate cure –

Avoid abrubt changes in laminate thickness

Under cure – Use Correct cat level. Create airflow over mould to remove styrene from deep areas.

Gelcoat too thick – Apply at .023-.025 in 3 passes wet on wet.

Incorrect insertion of cores and stringers – Use compressing material between the item and laminate.