I made MDF coasters and decorated them using epoxy resin with attractive colors and pearl powder.
It took 25-30 hours to completely dry out. In the meantime, few dust particles settled on it and I lost its glow.
How to dry it out faster?
Or better, how should I avoid this the next time?
To cure them more quickly you can either:
If you do either of these, you must maintain the heat constantly until fully cured.
Don't be tempted to add more hardener as it can stop the resin curing and remain sticky indefinitely.
There are additives that promote curing (called accelerator) however they are typically yellow in colour so will add a slight yellow hue to the resin. Also, the faster the resin cures, the greater the chance of it yellowing as a combination of the heat by-product of resin curing and heat applied to cure the resin faster.
There are reduced accelerator resins around which are slower curing but cure clearer.
To prevent dust from settling on the resin while curing, you can cover them with a cloche or bowl.
For more info on what I have said, you can read what ArtResin say at https://www.artresin.com/blogs/artresin/44707073-how-to-make-resin-cure-faster
Make sure that you mixed the resin components in proper proportions and for long enough to achieve a homogeneous blend. If the components are not mixed thoroughly, some of the resin will cure slowly or not at all.
Not including enough hardener will definitely increase the curing time. Check the instructions to see if the proportions are by weight or by volume. 50/50 by weight can be dramatically different than 50/50 by volume.
Unrelated to your question but worth noting... working with resin in warm environments creates additional challenges, specifically related to heat. Almost all resins will crack and deform while curing if their heat rises above the limits of the material. To avoid such issues, you need to apply the resin in thin layers and allow each to mostly cure before adding the next. I started a river table resin pour on a cold night and was able to safely apply four layers, each 1/2 inch thick. The next day, during a hot high noon, I added a fifth 1/2 inch layer and cracks appeared everywhere, penetrating down through the previous nights layers. The project was ruined and now hangs on my shop wall as a reminder to watch resin temperatures and apply resin thinly.
