Epoxy filler is a general term used to describe filler used to fill in cracks, dents and surface imperfections on metal and non- metal surface. This product should be strong, durable, weather and heat resistant. It should apply easily and come in a single component instead of mixing a resin and hardener or catalyst. There are many uses for this type of filler and in many industries as well.
The foundry industry was first to identify a metal filler for castings and imperfections in castings.
They needed metal filler that was one part or single component, easy to apply, dries fast and looks like the metallic look of the casting. Metal fabricators, welders, auto body shops, ornamental metal workers, hobbyists and do it yourselfers were soon introduced to this unique and ready-to-use metal repair and patching compound.
In the past, these metal parts were liquid coated with a latex, alkyd, solvent based or industrial liquid paint and coating to protect metal surfaces against rust, corrosion, chemical attack, weathering or immersion. Liquid coating was the only way to paint and protect these surfaces and the paint was usually solvent based applied through an airless or hvlp paint system. When there was a need to apply a filler to repair these dents, voids, rough welds and surface imperfections, two part epoxies made with a resin and a hardener with pigments, metal or plastic fillers could be used to mask and hide these voids and simply liquid painted over.
New Type of Coating
While liquid painting was common, regulations forced paint manufacturers to re formulate paint and coatings to contain less solvent which would also lead to the development or powder coating. This is a type of coating which is applied as a dry powder. The powder does not need solvent to keep the filler and binder parts in a liquid form. This type of paint is applied with an electrostatic gun and is then baked/cured under heat usually in an industrial oven which helps it flow and form a skin. This new development is mainly used for coating of metals, appliances, extrusions made from aluminum, auto and bike parts.
Features for Epoxy Fillers
Demand for coating using this powder started to increase because of the reduced solvent emitting into the atmosphere. This type of coating emits zero volatile organic compounds unlike solvent based paints. Coating applicators started to grow as liquid coating applicators were forced to either switch from liquid coating to coating with powder or install a production line to be able to apply both liquid and powder based coating on the needs of their customers. As mentioned before, this application requires heat or an industrial oven to cure. If there is now a surface imperfection, dent, void, crack, rough weld that needs to be patched, smoothed over filled in, two part epoxies could not be used because epoxies will start to shrink, pop out, outgas, bubble, blister when exposed to the required baking temperatures needed to flow and cure. Epoxy fillers, metal patching compounds have to be single component, epoxy free, heat resistant, easy to apply and will accept the powder process.
Applications and Uses
There are many uses and applications for a one part epoxy filler which also provides advantages to the metalworking industry worldwide. Reducing rejects in foundry production, repair gouges, worn metal surfaces, patch rough spots and dents. This one part filler can also be thinned out to be brushed and sprayed onto the surface. Sealing, protecting, filling metal and non-metal items has been done for many years and will continue to be done as long as quality during the manufacturing process is strict and thorough.