When bonding objects, resin, and epoxy are the two most commonly used items. Epoxy is a solid or liquid glue while the resin is a polymer-made hardening material.
But before buying and using them, people usually ask, “which is stronger resin or epoxy?”
Usually, the resin is a sealant that’s used as an adhesive or on wooden surfaces to fill holes and cracks.
However, epoxy is considered stronger due to its resistance to damage by water and heat.
Table of Contents
The Difference between Resin and Epoxy
As already stated, the resin is a multipurpose adhesive that’s common in construction and woodworking jobs.
It’s a viscous liquid with adhesive properties that can make plastic, glass, foam, stone, metal, and wood bond together.
Another application of resin is as a filler in coatings, paints, and other furniture finishing products. It’s available in dry powder and liquid forms.
Epoxy resin, on the other hand, is a popular material that packs excellent performance characteristics like a high strength-to-weight ratio.
In addition, it also depicts a low shrinkage rate when it’s being cured which helps achieve tight tolerances during the stages of production.
The Strength of a Resin Epoxy
As already stated, epoxy is a stronger type of adhesive. However, that’s not the strongest one. Polyurethane varnish and polyester resin are even stronger.
And the strength makes the latter used commonly in applications that need strong and durable adhesives.
Popular applications of the light yet strong adhesive polyester resin include making bicycles, snowboards, skis, and surfboards.
Sticking concrete bars for building bridges and gluing metal parts in industries are other applications of polyester resin.
Polyester varnish, on the other hand, packs properties similar to that of regular varnish. But the harder polyester varnish offers extra protection.
The Hardest Resin
In terms of hardness, resin ranks higher than epoxy. Moreover, the former is also more flexible.
So, if you need an adhesive that’s more flexible and stronger, you should pick resin over epoxy.
Which is Stronger Resin or Epoxy?
Here’s the answer to “which is stronger resin or epoxy?” When the epoxy is compared to a polyester resin, the former is stronger.
Epoxy gets its durability and hardness from the slower rate of curing than polyester. Contrarily, the weaker polyester resin is less flexible and cheaper.
However, both epoxy and polyester resin are susceptible to damage from ultraviolet light. So, for projects subject to direct sunlight, adding a clear paint or varnish coat adds protection.
How to Add Hardness to Resin?
If you want to make resin harder for a project, these steps will help:
- Use the heat as some resins need heat to make the curing process faster
- In some cases, a catalyst that’s generally an acid the epoxy reacts with quickly hardens the resin
- Every epoxy resin can have a different chemical composition with which, the choice of hardener varies. Using the right hardener ensures proper curing and imparts the strength that watertight boats need.
Are There any Disadvantages to Using Epoxy?
Yes. There are a few disadvantages associated with using epoxy resin. No resistance to UV radiation is a major one due to which it can break down quickly on exposure.
Another drawback is that it isn’t safe for use in food applications.
When rubbed or scratched against countertops, concrete, or other hard surfaces, epoxy can get easily peeled or chipped.
Moreover, epoxy is not crystalline and is amorphous instead.
The lack of natural flexible strength makes it a bad choice for projects like a rubber band that need flexibility.
Lastly, epoxy isn’t resistant to heat as much as vinyl or polyester resin offers resistance.
While using additives adds heat resistance to it, epoxy still can’t withstand exposure to temperatures over 93-degree Celsius/200-degree Fahrenheit.
Scratch Resistance of Epoxy Resin
Comparing epoxy resin and polyester resin, the former is more prone to scratching.
Due to lower molecular weight and higher viscosity, epoxy resin tends to break over time. That’s what makes it easily scratch-able.
Even contact with a hard object or a fingernail can cause the surface to scratch.
In terms of UV exposure, polyester resin offers better resistance than epoxy due to high-quality additives. These additives ensure protection against the degradation that sunlight can cause.
Wrap Up – Which is Stronger Resin or Epoxy?
When comparing strength, epoxy scores better than resin. Moreover, the former is also more durable than the latter which bonds to selected substrates only.
Epoxy is available as a 2-part material that makes it easy to use as you need to mix it before applying.
On the other hand, the resin needs a mixing hardener and should be used in small amounts only.
It’s clear that epoxy is the answer to the question, “which is stronger resin or epoxy?” The other one is more flexible.
Thus, the resin is considered a better choice for buttons, jewelry, and flexible items. In addition, epoxy also doesn’t work well with metal and glass, which resin bonds well with.
So, you should go for epoxy if you need an adhesive that requires less maintenance and lasts longer while needing extra effort to mix before use.
Is epoxy resin the same as resin?
Both are types of adhesives but what makes them different is the drying time. Since both need mixing before use, resin takes more time to harden.
And in terms of cost, epoxy is more expensive than resin glue because of its bonding capability that’s better than other adhesives.
Is epoxy or polyester resin stronger?
Yes, epoxy resin is stronger than polyester resin. This makes it an ideal adhesive for repairing fiberglass.
How strong is resin epoxy?
The typical strength of epoxy resin falls between 5000 psi and 6000 psi.
Does epoxy resin break easily?
When the epoxy resin is used, the product won’t break easily but might bend or dent.
How long will epoxy last?
The typical life of an epoxy floor is 10-20 years but the actual numbers may vary with the maintenance, use, and thickness.
In heavy traffic conditions, an epoxy flooring may last 2-3 years.
How long does resin last for?
When prevented from contamination and stored in closed containers at room temperature, epoxy can last many years.
However, polyester resin comes with a 6-month shelf life only.
Does epoxy melt in sun?
The chemical compound in resin prevents it from melting in the sun.
Do resin rings break easily?
Resin doesn’t break when fully cured but if something goes wrong first, it can break spontaneously.