The ability to control the curing speeds of fibreglass resin is incredibly valuable to anyone working on a fibreglass moulding, laminating or repair project. By manipulating how fast or how slow the curing time is, you'll be able to elevate efficiency, eliminate errors and improve the overall quality of your work fairly dramatically. You'll also be able to prevent expensive mistakes from occurring and recurring time and again.
The fibreglass resin curing duration is determined by key factors like temperature and humidity, but knowing which additives to use is the secret to uncovering the pathway towards a truly successful fibreglass project...
Speeding up the curing time is ideal for cold environments such as winter or when a quick project turnaround is essential. Conversely, slowing down the curing process gives you more time to work on your project - an asset for larger jobs, detailed design work and warmer conditions. If you don't know which accelerators, retarders or key catalysts to use, it's time to get your latest fibreglass project into gear!
In this guide, we'll lay out all the essential fibreglass additives and important information you need to modulate curing times. Whether you're a professional or a DIY-er, you'll find out how to safely and efficiently speed up and slow down fibreglass curing times for a strong, premium-grade finish. We'll also provide you with some key safety considerations to keep at the front of your mind when adjusting fibreglass curing speeds.
To cut down drying times and supercharge work efficiency, please consider the following options to speed up fibreglass curing:
Use A Cobalt or DMA Accelerator
You can use a Cobalt or DMA accelerator, available now at Fibreglass Supplies. Ideal for colder climates, use 0.5% - 2% to resins to accelerate gel times. Scott Bader's Cobalt Accelerator G is frequently used when temperatures are low and resins and gelcoats or topcoats need a "kick" to help speed up the curing process.
Crystic Accelerator D is a solution of dimethylaniline (DMA) in styrene for use as an accelerator to get a rapid room temperature cure. These types of additives work by elevating the reaction between the resin and catalyst (MEKP - Methyl Ethyl Ketone Peroxide) so the material can cure faster, especially in cooler conditions.
Increase The MEKP Catalyst Ratio
By upping the MEKP (Methyl Ethyl Ketone Peroxide) catalyst ratio in the corresponding resins, it increases the concentration which causes a quicker reaction, cutting down the working time and speeding up the curing process. However, be careful to only work within the safe limits and do not use too much catalyst as it can lead to a brittle or weak end-product.
Work In A Warmer Environment
Your fibreglass resins will cure faster in warm workspace temperatures between 18-27°C and a relatively low humidity of around 40%. The warmer temperatures will support faster chemical reactions and the low humidity will help you to not only avoid a slowing of the curing process but also prevent a hazy or cloudy finish on your final project.
If you want to slow down the curing process for large, complex projects, or you want to control curing for more detailed work that requires a long work time, make sure you do the following:
Use Additives To Slow The Curing Process
Use a peroxide or wax additive to delay the curing reaction - or employ something like Summer Catalyst Hardener. Summer Catalyst is designed to maintain or even prolong the curing time of the resin and topcoat in warmer conditions above 20°C, allowing you to work effectively in high temperatures. This is the perfect product for hot summer days, and flat roof work that is exposed to direct sunlight, giving you more time to work compared to when you're using a standard hardener.
This catalyst is also ideal for a range of other projects where a longer working time is required, including mould making, boat building and casting.
Reduce The MEKP Catalyst Ratio
Slowing down curing can be achieved by lowering the MEKP to approximately 1%. Anything lower than 0.75% and the resin may not fully cure. By lowering the MEKP to slow the curing process, you'll be able to benefit from all the adaptability you need that comes with improved flexibility and a longer cure time.
Work In A Cooler Environment
Work in temperatures below 18°C and you'll be able to draw out curing times by slowing the chemical reaction process. A longer cure time can be achieved by using fans or working in conditions or environments that are shielded from hot weather to control the cure speed. You can also choose to work on colder days of the year that are more conducive to a slower curing time.
To guarantee a premium-grade fibreglass finish, adhere to these key tips:
Safety is paramount whenever you're looking to change fibreglass curing speeds, make sure you do the following:
