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I decided to go and post it anyway, as I'd most likely forget, due to your requests.
1 Coat all interior surfaces with 5 or 6 coats of rolled epoxy
The inside of the tank should be treated similar to the outside of a
hull. We recommend a minimum of 20-mil coverage, which is five or six
rolled coats of epoxy, for all interior surfaces of tanks. This is
similar to the coverage recommended as a "barrier coat" for the
exterior of a hull. After it is rolled on, brush the epoxy out to
minimize any entrapped air. Install surge baffles to minimize free
surface effect, using generous fillets and giving them the same 5-6
coats of epoxy as the rest of the tank interior.
Any tank openings, such as fill, vent, inspection or clean out, should
be oversized and also receive 5-6 coats of epoxy. We recommend that
fasteners be epoxy bonded in place to secure any hardware to the tank or
in the construction of the tank (See details of hardware bonding in the
WEST SYSTEM User Manual & Product Guide.)
2 Use a slightly resin-rich/ hardener-lean epoxy mixture
Carefully metered resin/hardener ratio is critical to any epoxy's
performance. In all projects, with one exception, we recommend
dispensing and mixing epoxy at the target ratio within our acceptable
range. Tank building is the exception to the rule. When mixing epoxy for
tank coatings, we recommend a resin-rich/ hardener-lean mixture at the
outer limits of the acceptable range as shown in Table 1.
This is because excess resin in epoxy is less likely to adversely
affect the physical properties of cured epoxy than excess hardener. When
excess hardener is in the epoxy matrix, it cannot fully react with the
resin and will become suspended in the mixture. Because amines (in the
hardeners) are water soluble, they can potentially leach out and cause
odd tastes, contaminates in the liquid, and porosity in the epoxy film,
among other performance defects. The maximum resin-rich ratios noted in
Table 1 are at the end of acceptable ranges for WEST SYSTEM epoxy. These
ratios should not be taken any farther from the target. These maximum
resin-rich ratios meet specification to obtain a properly cured epoxy
film and to minimize extracts leaching out of the epoxy. When using 300
Mini Pumps, one way to obtain the resin-rich/hardener-lean ratio within
the acceptable range is to dispense the following:
Epoxy Combination Pumps Resin Pumps Hardener
105 Resin +205 or 206 Hardener 6 5
105 Resin +207 or 209 Hardener 7 6
3 Mix thoroughly, using a double-pot method
We recommend using a double-pot mixing method when building or coating
tanks. Completely thorough mixing of epoxy is difficult to achieve when
resin and hardener are pumped and mixed in one container. A film of
resin or hardener will cling to the bottom or side of the container
leaving areas of unmixed or undermixed components. This can be readily
seen when tinted epoxy is mixed together.
To ensure thorough mixing, first dispense and mix resin and hardener in
one container, carefully scraping the sides and bottom. Scraping is key
because it incorporates the majority of the single components into the
mixture. Second, transfer this mixed epoxy into another clean mixing
container. Use a new stir stick to mix a second time. This transfer will
eliminate any clinging unmixed material and additional mixing will
assure thorough crosslinking of both components.
4 Post cure at an elevated temperature
Post cure at a minimum of 120 F for 4 to 8 hours (after the epoxy has
cured at room temperature and can no longer be dented with your
thumbnail). You can use a temporary oven or radiant heater to apply an
elevated temperature post-cure. A high-wattage incandescent or halogen
light bulb can raise the temperature in a tank high enough to do the
job. This is often the only way to do an integral tank. However, watch
the fire hazard as some light bulbs can get hot enough to cause the
epoxy to char or possibly ignite. Alternatively, allow the coating to
cure for 2 weeks at room temperature.
5 Scrub cured epoxy thoroughly with water
Scrubbing with water and a scouring/abrasive pad, such as 3M's Scotch
Brite* pad, removes any surface contamination, specifically any
potential amine blush that may form on the surface. Amine blush is
water-soluble and can be removed with tap water. The scrubbing action
agitates the surface to help removal. Solvents don't normally remove
the amine blush because of its water solubility. So leave the lacquer
thinner, acetone, vinegar, alcohol, and other solvents in the storage
bin, and use water. After scrubbing, rinse again with water and dry with
paper towels.
If you have any questions, please feel free to call.
Regards,
Bruce Niederer
Tech Advisor
Gougeon Brothers, Inc.
100 Patterson Ave., PO Box 908
Bay City, MI 48707-0908 U.S.A.
fax: 989-684-1287
West System toll free phone:
866-937-8797
Proset toll free phone:
866-377-6738
URL: http://www.gougeon.com or http://www.westsystem.com
1 Coat all interior surfaces with 5 or 6 coats of rolled epoxy
The inside of the tank should be treated similar to the outside of a
hull. We recommend a minimum of 20-mil coverage, which is five or six
rolled coats of epoxy, for all interior surfaces of tanks. This is
similar to the coverage recommended as a "barrier coat" for the
exterior of a hull. After it is rolled on, brush the epoxy out to
minimize any entrapped air. Install surge baffles to minimize free
surface effect, using generous fillets and giving them the same 5-6
coats of epoxy as the rest of the tank interior.
Any tank openings, such as fill, vent, inspection or clean out, should
be oversized and also receive 5-6 coats of epoxy. We recommend that
fasteners be epoxy bonded in place to secure any hardware to the tank or
in the construction of the tank (See details of hardware bonding in the
WEST SYSTEM User Manual & Product Guide.)
2 Use a slightly resin-rich/ hardener-lean epoxy mixture
Carefully metered resin/hardener ratio is critical to any epoxy's
performance. In all projects, with one exception, we recommend
dispensing and mixing epoxy at the target ratio within our acceptable
range. Tank building is the exception to the rule. When mixing epoxy for
tank coatings, we recommend a resin-rich/ hardener-lean mixture at the
outer limits of the acceptable range as shown in Table 1.
This is because excess resin in epoxy is less likely to adversely
affect the physical properties of cured epoxy than excess hardener. When
excess hardener is in the epoxy matrix, it cannot fully react with the
resin and will become suspended in the mixture. Because amines (in the
hardeners) are water soluble, they can potentially leach out and cause
odd tastes, contaminates in the liquid, and porosity in the epoxy film,
among other performance defects. The maximum resin-rich ratios noted in
Table 1 are at the end of acceptable ranges for WEST SYSTEM epoxy. These
ratios should not be taken any farther from the target. These maximum
resin-rich ratios meet specification to obtain a properly cured epoxy
film and to minimize extracts leaching out of the epoxy. When using 300
Mini Pumps, one way to obtain the resin-rich/hardener-lean ratio within
the acceptable range is to dispense the following:
Epoxy Combination Pumps Resin Pumps Hardener
105 Resin +205 or 206 Hardener 6 5
105 Resin +207 or 209 Hardener 7 6
3 Mix thoroughly, using a double-pot method
We recommend using a double-pot mixing method when building or coating
tanks. Completely thorough mixing of epoxy is difficult to achieve when
resin and hardener are pumped and mixed in one container. A film of
resin or hardener will cling to the bottom or side of the container
leaving areas of unmixed or undermixed components. This can be readily
seen when tinted epoxy is mixed together.
To ensure thorough mixing, first dispense and mix resin and hardener in
one container, carefully scraping the sides and bottom. Scraping is key
because it incorporates the majority of the single components into the
mixture. Second, transfer this mixed epoxy into another clean mixing
container. Use a new stir stick to mix a second time. This transfer will
eliminate any clinging unmixed material and additional mixing will
assure thorough crosslinking of both components.
4 Post cure at an elevated temperature
Post cure at a minimum of 120 F for 4 to 8 hours (after the epoxy has
cured at room temperature and can no longer be dented with your
thumbnail). You can use a temporary oven or radiant heater to apply an
elevated temperature post-cure. A high-wattage incandescent or halogen
light bulb can raise the temperature in a tank high enough to do the
job. This is often the only way to do an integral tank. However, watch
the fire hazard as some light bulbs can get hot enough to cause the
epoxy to char or possibly ignite. Alternatively, allow the coating to
cure for 2 weeks at room temperature.
5 Scrub cured epoxy thoroughly with water
Scrubbing with water and a scouring/abrasive pad, such as 3M's Scotch
Brite* pad, removes any surface contamination, specifically any
potential amine blush that may form on the surface. Amine blush is
water-soluble and can be removed with tap water. The scrubbing action
agitates the surface to help removal. Solvents don't normally remove
the amine blush because of its water solubility. So leave the lacquer
thinner, acetone, vinegar, alcohol, and other solvents in the storage
bin, and use water. After scrubbing, rinse again with water and dry with
paper towels.
If you have any questions, please feel free to call.
Regards,
Bruce Niederer
Tech Advisor
Gougeon Brothers, Inc.
100 Patterson Ave., PO Box 908
Bay City, MI 48707-0908 U.S.A.
fax: 989-684-1287
West System toll free phone:
866-937-8797
Proset toll free phone:
866-377-6738
URL: http://www.gougeon.com or http://www.westsystem.com
