The general rule of thumb for letting epoxy sit before pouring is that you should leave freshly poured epoxy to settle for approximately 3 hours in between each new pour.
However, this rule may differ depending on the various types and brands you try using for epoxy pouring projects.
Likewise, your intents and purposes for pouring epoxy may affect the proper amount of time to let your epoxy sit before pouring more.
For example, the amount of time that your epoxy should sit in between pours when using thin layers of table top epoxy for encasing ½ inch epoxies and pouring a 3 inch deep river table may differ by hours.
That’s why it is important to always check the epoxy product’s packaging and label, as well as read instructions for pouring it, before actually pouring epoxy.
How Do You Prepare Epoxy for Pouring?
Preparing the surfaces you will pour epoxy onto/into is simple; sand them and sanitize them.
Whether you’re pouring epoxy into the gap of a river table, or you are pouring epoxy into wooden molds, it’s crucial that you first clean the surface of dust and debris as well as check it for smoothness.
If there are rough patches, splinters, blistering, chalking, or flakes visible, use sandpaper to remove them and smooth them out and re-clean the entire area to be epoxied.
Once you’re positive that your surface area is nice and neat, with nothing to cause blemishes on the finished epoxy once it is poured and cured, you’re good to start your first pour.
Can You Pour Fresh Epoxy Over Tacky Resin?
Epoxy resin, once poured, requires a bit of time to harden in between each additional pour.
Typically, two or three hours is plenty of time.
But, sometimes, even after a few hours, spots on the top of your poured epoxy could still be tacky.
If you have mixed your epoxy product carefully, an additional layer of fresh epoxy should resolve the issue.
How Do You Know When Epoxy is Ready for Pouring?
Freshly epoxy is generally ready to pour just a few short minutes after you mix it.
It is crucial, however, to read the label/instructions of the epoxy product you’re using before mixing or pouring.
That way, if the epoxy needs a longer amount of time between mixing and pouring, you’ll be aware and can take proper action.
As far as knowing when epoxy is ready for pouring on top of recently poured epoxy, check the surface of the poured epoxy for wetness or soft spots, it should already be dried and semi-hardened first.
Can You Pour New Epoxy on Wet Resin?
So long as the resin has been set for two or three hours, in most cases, you can pour new epoxy on top of it with no problems.
That said if the temperature is high, and there is a lot of humidity, pouring new epoxy on freshly poured epoxy isn’t suggested.
High temps and humidity tend to lower the drying, hardening, and curing process of fresh epoxy.
Cold temps, on the other hand, usually increase the drying and curing of the epoxy.