DURATEC Optimum Mould Repairs Why Recoat a Mould ? ®

DURATEC
®
Optimum Mould Repairs
www.duratec1.com
Why Recoat a Mould ?
A mould can be recoated more
quickly, and at less cost, than
producing an entirely new mould.
The Duratec Vinyl Ester Primer and High Gloss Top Coat
range provide a hard mould surface with great adhesion to
the original polyester, vinyl ester or epoxy based tooling gelcoats. They can be used to modify, repair and resurface
existing composite moulds to recover shine and provide
greater gloss retention, provide superior impact resistance
and improved heat distortion temperature, eliminate subsurface porosity for improved vacuum integrity, to create a
“better than original” tooling surface.
Preparing the Mould
A SUCCESSFUL mould resurfacing
starts with PREPARATION
Use Technifill XP to fill in any pits or porosity. Use a putty
knife to force the Technifill XP into the gaps and cavities.
Leave a slight mound to allow the filler to be sanded flat.
If the tooling surface cracks due to excessive flexing of
the mould, it will likely crack again in the same place after
resurfacing. It is necessary to improve the bracing to
prevent the flex before resurfacing. Grind out the crack to
the laminate, and use Technfill XP to fill in the gap.
* Do not apply Duratec Vinyl Ester
products over any putties that
contain phenolic microballoons.
Sand the entire surface to a matt
finish with a coarse sandpaper
(80-grit) removing all of the gloss.
Wipe the sanded surface clean
with a fast solvent and a clean
white cloth. Do not use a tack rag.
The goal is to remove a consistent
depth of gelcoat to minimise the
dimensional change to the mould.
Sand mould
Sand mould with minimal
dimensional change
The best proven method for removal of mould release is:
1. Strip the mould surface clean
of release agent with a
suitable mould cleaner such
as Chemlease 501. Wipe on
with a white cloth.
2. Buff/polish using Aqua-Buff
2000 or Glossmaster polish.
Resurfacing with
Duratec White Vinyl Ester Primer
3. Wash using clean water and
a white cloth.
Thoroughly stir Duratec 1794-006 White Vinyl Ester Primer
in the can prior to catalysing. Due
to the rapid gel time of the primer,
mix only the amount that can be
applied within 16-18 minutes at
25°C. (Higher temperatures yield a
shorter pot life and gel time, while
lower temperatures yield a longer
pot life and gel time).
4. Wipe with Chemlease 501
and a white cloth.
Chemically strip mould prior to sanding
Suggested Duratec & Aqua-Buff
products:
500 C - Duratec Thinner
748A - Duratec Catalyst
1794-006 - Duratec VE Primer - White
1910-045 - Duratec VE Top Coat - Red
Aqua-Buff 1000 Fast Cut Buffing Compound
Aqua-Buff 2000 Ultra Fine Polish
Catalyse at 2% with 748A Catalyst
full strength (20 cc per quart). Thin
by 10 to 20% if necessary, to a
desired spray viscosity with Duratec
500C Thinner or MEK solvent after
catalysation.
Apply a “tack coat” to the entire surface and allow it to flash
for 2 minutes. Follow with wet passes, slowly building to the
desired thickness (15-20 mils / 350-500 microns). Heavier
thickness can be achieved by repeating the process
immediately after gel has occurred. The primer will be dry to
the touch in 1-4 hours, depending on thickness and
temperature, and ready to sand within 2-4 hours.
Dry sand the entire surface with 180 grit sandpaper and
allow for an overnight cure.
* Spray pressures should be 35-50 psi. If a
pressure pot is used, provide 10-15 psi pot pressure.
When cured, dry sand
the surface to remove
entrapped dirt and dust
beginning with 320-400grit sandpaper. Finish
with 800-or higher-grit
wet/dry sandpaper. Wait
a minimum of 8 hours at
25°C for the solvent to
release prior to
compounding and polishing with Aqua-Buff 1000 and 2000
buff and polishing compounds.
Duratec Vinyl Ester Hi-Gloss
Topcoat Application
Thoroughly stir Duratec 1910-045 Vinyl Ester Hi-Gloss
Topcoat in the can prior to catalysing. Due to the rapid gel
time of the topcoat, mix only the amount that can be applied
within 18 minutes at 25°C. Catalyse at 2% with 748A full
strength (20 cc per quart). For improved flow and
levelling properties, thin 5 to10 percent with Duratec 500C
Thinner or MEK solvent.
* The ambient temperature must be at least 20ºC when
applying Duratec Vinyl Ester Topcoat.
Equipment Note: Use air aspirated or pressure pot spray
equipment. The recommended line air pressure is 35-50 psi
and pot pressure is 10-15 psi. Airless, air-assisted airless
and air-aspirated gelcoat plural-component spray systems
can also be used. Spray the entire surface with a fine mist
coat and wait 2 minutes for the solvents to flash off. Follow
with wet coats building to a thickness of 15-20 mils / 375500 microns.
* Do not inhibit cure by adding wax surfacing agents.
The topcoat will cure to a hard, glossy finish in approximately
8 hours.
DURATEC®Sunshield Clear
Enhanced UV Resistance for the
Ultimate Clear Finish
Sunshield Clear 904-061 is a unique polyester
topcoat that is compatible with epoxy, vinyl ester
and polyester resins and can be applied to epoxy
laminates as an in-mould or post mould coating.
Sunshield cures to a
durable surface with
excellent gloss levels
and great scratch
resistance.
904-061 also provides
excellent UV resistance with 50% more
resistance to yellowing than a commercial ISO
NPG UV.
Duratec Sunshield is
available in US 1 gallon
cans and is backed with
excellent instructions to
ensure an exceptional
finish every time.
www.atlcomposites.com
For further information on
Duratec Mould Resurfacing Products,
please contact Mick Bunker 0411 704 023
or Mac Dalton 0411 649 586 from
the Technical Team at ATL Composites
[email protected]
ATL composites