Corrothane XT Filler

Product reference: 3/44

Product title: Corrothane XT Filler

Valid from: 25th October 2007

Last reviewed: 31 May 2019


A three-pack cold cured vinyl ester – urethane copolymer filler. 

Suggested use

As a heavy-duty filler, where good chemical and high
temperature resistance are required, either for immersed or
non-immersed service


This product is very moisture sensitive and may foam if mixed
or applied in moisture condensing conditions, or at relative
humidities above 75%. Tins are nitrogen filled, do not open
before use. It is recommended that wherepossible
de-humidification equipment is used during the application of
this product.

Health & safety

Before handling or using this product the material safety data
sheet should be read and all precautions observed. Particular
attention is drawn to Hardener B which contains Isocyanate.

Surface preparation

Use over the top of a pre-primed surface. For further
information, refer to Corrocoat Technical Services.

Application equipment

Brush or trowel or scraper.


Using a suitable implement, work the product into the preprimed area. Ensure the area is thoroughly wetted out.
Apply further coats to the required film thickness.
Corrothane XT Filler may be applied to pits and small areas
up to 6mm dft in one coat. It is not recommended that
large areas are applied in excess of 3mm in one coat.

Mixing ratios

88.02 partsBase
01.30 parts Hardener A (organic peroxide)
10.68parts Hardener B(Isocyanate)
(All ratios by weight)

Mixing instructions

Product should be at ambient temperature before
mixing. Mix the base with a good mechanical stirrer until it
is uniformlymixed. Add Hardener A(organic peroxide) to the
Base and mix thoroughly. Allow mix to stand for a minimum
period of 10 minutes. (NB. The Base peroxide blend is
relatively stable and will not react significantly until
Hardener B is added). Add Hardener B (Isocyanate) and
mix thoroughly immediately before applying.

Pot life

Generally 50 – 70 minutes at 68°F (20°C). Pot life will vary
substantiallywithtemperature. RefertoCorrocoat technical
services forinstructions regarding application in hot climatic


The performance of Corrothane XT Filler can be
adversely affected by the addition of solvent thinners and
their useis prohibited.


1 and 5 gallon kits. Due to hydroscopic nature of this
product the use of part tins is not recommended, suitable
kit sizes should be purchased to meet usage requirements.


It is recommended that over coating takes place within 12
hours. Although longer over coating times may be
acceptable this will depend upon climatic conditions and the
level of ultraviolet light which significantly accelerates speed
of cure.

Storage life

6 Months stored and away from heat sources and direct
sunlight and below 68°F (20°C). Frequent temperature
cycling will shorten storage life and affect pot life.
Beyond 6 months this product becomes increasingly
susceptible to moisture uptake and foaming and out of
shelf-life material must not be used. (Discoloration
of Hardener B will occur with time. This has no
detrimental effect on the product). All components must
be used within their designated shelf life.

Color availability

Off white only.

Recommended DFT

Between 20 mils (500 microns) and 6mm
dependent upon requirements.

Theoretical spreading rate

32 sf per gal at 40 mils (1.21 kg/m²/litre at 1mm) dft.

Volume solids

This material contains volatile liquid convertible to solids.
Volume solids obtained will vary dependent upon
polymerization conditions. Nominally 99% of the contents
are convertible to solid.


 0.03lbs/cubic inch (1.072 g/cm3 )

Flash point

88°F (31°C).

Temperature limits

302°F (150ºC) Immersed. No known
lower limit. 500°F (260ºC) Non-Immersed
(provisional figures)
dependent upon environment.

Curing Time

Full cure is 4 days at 68°F (20°C). For optimum results
a short post cure of 4 to 6 hours at circa 176°F (80˚C) is
recommended. However, post cure is not necessary for
many environments.

Cleaning fluid

Methyl Ethyl Ketone, Methyl Iso Butyl Ketone – before