What is the fastest way to cure epoxy resin? – Speed up resin curing

What is the fastest way to cure epoxy resin

How can I cure epoxy resin faster?

Sometimes you may find yourself in a situation where you need to speed up the cure time for your epoxy resin. Cure times for epoxy resin vary. Here are some suggestions on the fastest way to cure epoxy.

Before we get into that though, let me take a bit to explain a little resin chemistry so you know what we are dealing with. An epoxy resin kit contains a bottle of the epoxy resin plus a bottle of the hardener. They are sold together in a kit and designed to go with one another — like a lock and key. Once hardener is added to resin, a chemical reaction occurs causing the mixture to heat and eventually solidify. Without the heat production, the mixture would never get hard. Likewise, if the surrounding temperature of your resin casting area isn’t warm enough, the mixture won’t cure because it can’t maintain the temperature of the reaction.

So we can speed up resin curing by attacking one or both of those variables: the warmth of the reaction and/or the warmth of the casting area temperature.

Warmth of resin reaction

1. Warm up your resin and hardener bottles in a hot water bath for about five to ten minutes. By warming the bottles, you can jump start the reaction with additional heat. This will help the resin to cure faster.  If you want to learn more about this, be sure to check out the article what temperature should I mix resin.

2. Once you have cast the resin, apply extra heat. You can do this with a heat gun or propane torch.  Watch your resin carefully.  There can be ‘too much of a good thing’ and applying too much heat in one area can make that spot cure quickly and possibly crack or cure with lots of bubbles.

Casting area temperature

Resin ideally likes a temperature of the low 70’s F or low 20’s C. So what are some ways we can raise the temperature?

1. Create a resin ‘hot box’. By increasing the resin working area’s temperature you can speed up resin curing.  A heat source such as a lamp with an incandescent bulb over the resin can be enough to keep it extra warm.  Here are some articles showing how to create a resin hot box:

Cold weather casting
Cold weather resin tips

2. You can cast your resin outside if that temperature is above the recommended 70 to 75 F temperature range.
3. Cure your resin in a warm oven. A 150F oven is great for helping resin to cure faster. *Once you have used an oven for resin curing, do not use it for food purposes again.*

What should you not do?

-Don’t add more hardener than recommended. This can reduce the pot time of your resin, and it may start to cure before you can get it all poured.
-Don’t use a different hardener than the one that came with your kit. It is likely incompatible and your resin won’t cure at all.
-Don’t mix more than the maximum of each component that the manufacturer recommends. Your resin and hardener will heat up too quickly and will cure before you can ever pour it.
-Don’t add anything extra to the mix to get it to cure faster unless the manufacturer recommends it.

Like this post? You may be interested in  10 reasons why your resin casting is a disaster and how to avoid them

Unpublished Blog Posts of Resin Obsession, LLC © 2019 Resin Obsession, LLC

6 Comments

Tera

I apply heat to my cast resin by setting up a small halogen goose-neck desk lamp 6-10 inches over the cast resin. The halogen light bulb gets very warm and cures my resin faster. (This would not work with an LED lamp-LED doesn’t get hot.)

Reply
Katherine Swift

That’s good to know Tera. I didn’t know halogen bulbs could get as warm as incandescent bulbs for this purpose.

Reply
Michael Storer

I would be more specific about adding extra hardener.

A little too much and the resin will not cure at all but just stay as a slushy mess.

It’s one of the two typical curing problems “my epoxy didn’t cure”

The other main problem for a failed cure is measuring correctly but not carefully scraping the sides bottoms and corners of the mixing container.

Improper mixing also means that resin to hardener ratios are a bit out in places.

For consistently good work measure ratios accurately.

Reply
Tony

Heating the components is a good idea of course.

The other things you speak to are more appropriate techniques for post cure heating to get the highest level of crosslinking in the resin system.

A typical epoxy system will reach 90% cure in 10,000 minutes at ambient temperatures. It will never fully cure or crosslink not matter what. But a post cure heat schedule will get the system to greater than 97%.

In your post, I think that you are actually speaking to either polyester or vinylester thermoset systems.

You admonish against using more curative to increase the heat. In general that is good advice, however it is easy to alter the thermodynamics of both the resin and the curative if you are speaking about polyester or vinylesters.

Of course the biggest real issue is not the heat of the cure alone, it is a function of the mass of epoxy being mixed. Not much MEKP, diethylene triamine, dimethylaniline, and cobalt napthenate and cobalt octoate, usually supplied as a 6% solution, will change the cure temperature a lot. Almost all suppliers can get you these products. Easy to use.

However, if you were to cure say 5 gallons of adhesive, using the same level of hardener, promoters and catalysist used in curing 5 ounces of resin, one might find themselves with a very nasty fire on their hands. The flames are pretty but the smoke is horrible. Avoid this!

Lots of other factors are in play depending upon the base resins used, desired outcomes, and many chemistry issues.

Post cure heats are the best way to get real cures. There is lots in the literature about post cure heat schedules. Well worth knowning about

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