West System 205-A Fast Hardener

Description

Bonding & Filleting
WEST SYSTEM Epoxy
is excellent for structural bonding and fillets. It can be easily thickened with a number of fillers to modify consistency and strength.
There are two types of structural bonding that can be done with epoxy.
TWO-STEP BONDING
is the preferred method for most situations because it promotes maximum epoxy penetration into the bonding surface and prevents epoxy-starved joints.
SINGLE-STEP BONDING
is appropriate when joints will have minimal loads and excess epoxy absorption into porous surfaces is not a problem. In both cases, epoxy bonds best when it is worked into the surface with a roller or brush.
Coating, Laminating & Clear Finishing
COATING AND LAMINATING
are popular uses of WEST SYSTEM Epoxy. Epoxy wets out fiberglass cloth, protecting the substrate while letting its beauty shine through. We recommend WEST SYSTEM 105 Resin with blush-free, water-clear 207 Special Clear Hardener for bright finishes and clear coats.
COATING
involves rolling the epoxy onto a surface with a foam roller, applying it with a brush, or spreading the epoxy over the surfaces with a plastic spreader. .
There are two methods for laminating with fiberglass and epoxy.
THE DRY METHOD
refers to placing the cloth over a dry surface, wetting the cloth with epoxy and spreading the epoxy over the cloth, smoothing it as you go.
THE WET METHOD
involves applying the cloth to an epoxy-coated surface after the wet-out coat becomes tacky, which helps it cling to vertical or overhead surfaces. This method makes it more difficult to position the cloth, so the dry method is the preferred, especially when using with thinner cloth.
Clear Casting & Pouring
CASTING AND POURING
are best done with WEST SYSTEM 105 Resin and 207 Special Clear Hardener.
AVOIDING UNCONTROLLED EXOTHERM
is important, as this heat reaction can quickly spoil the casting.
Epoxy cures by exothermic (heat) reaction. That heat must be kept under control when when creating a thick casting (greater than ¼”). For thick castings, add epoxy in multiple layers . When the first pour is tacky like the back of masking tape, a second pour can be made. When the epoxy cures enough to become tacky, it means the previous layer has begun to cool down and will not contribute heat to the next layer. Adding another layer at this stage allows you to skip any surface prep.
If the poured epoxy casting cures past the tacky stage, allow the epoxy to finish curing then sand ot dull and clean the surface before applying the next epoxy layer. This will ensure good adhesion between layers.
Safety Information
DANGER CAUSES BURNS TO EYES AND SKIN. HARMFUL IF SWALLOWED. HARMFUL IF ABSORBED THROUGH THE SKIN. May be harmful if inhaled. May cause allergic reaction. Avoid skin and eye contact. Avoid inhalation of vapors. Do not ingest. Use with adequate ventilation. Use with liquid-proof gloves, eye protection and protective clothing. FIRST AID: SKIN CONTACT – Immediately wash with soap and water. EYE CONTACT – Immediately flush with water for at least 15 minutes. Consult a physician. INHALATION – Remove to fresh air. Consult a physician if breathing discomfort or irritation develops. INGESTION – Do not induce vomiting. If conscious, give 2 glasses of water. Get immediate medical attention. KEEP OUT OF REACH OF CHILDREN