different types of resin

Which resin is right for my jewelry making project?




When it comes to resin, there are so many options!  I'm going to go through the possibilities here with a list of their pros and cons.

All resins are a two part system, consisting of the base resin and the hardener (or catalyst).  By themselves, they are inert compounds, but when mixed, a chemical reaction occurs where they cure.

A few terms you need to be familiar with when it comes to working with resin:
Pot time:  amount of time you have to work with the resin before it starts to cure.
Demolding time: is the amount of time after which you can remove the cured resin from its mold.  The demolding time is important if you want to pop the resin jewelry out of its mold in order to reuse the mold again without waiting for the piece to completely cure.
Cure time:  amount of time it takes the resin to completely cure.  If your resin is still goopy or sticky after the cure time, it's not going to get any better.

There are four types of resin commonly encountered in jewelry making:

1.  Polyester. May also be referred to as fiberglass resin.

Pot time:  minutes
Cure time:  minutes to hours
Cost:  low to mid range  (especially cheaper if you use a polyester resin marketed for a commercial industry such as boats and vessels)
Safety:  can be dangerous.  very noxious smell.  must wear a respirator and work with a hood or in a well ventilated area.

Pros:  Cures to a very hard finish which can be sanded and buffed to achieve a shiny, clear surface. If the surface becomes scratched, that same surface can be polished once again. Pieces made from polyester can be bonded with more polyester resin to create larger pieces.
Cons:  Not UV light resistant.  Will eventually yellow with time.  Because it does cure very hard, polyester resin projects may break if dropped on a hard surface.

2.  Epoxy

Pot time:  minutes
Cure time:  hours to days  Demolding time may be shorter.
Cost:  mid to upper range.  Epoxies get more expensive the clearer you want your finished casting.
Safety:  safe. wear gloves, improve ventilation.  respirator not needed

Pros:  Widely available.  Best all purpose resin
Cons:  Cannot be buffed.  Must be finsihed with an additional layer of resin or a resin sealer spray to get a glossy finish.

3.  Polyurethanes

Pot time:  minutes
Cure time:  minutes to hours
Cost:  mid to upper range.  Polyurethanes also get more expensive with an increase in clarity and for water clear versions.
Safety:  may be dangerous.  Some polyurethanes must be used with a respirator and ventilation hood.

Pros:  Some come with a very quick cure time (under 1 hour)
Cons:  Very moisture sensitive.  May not cure well in humid climates.  Some color addtives do not also work well if they are not specifically designed for polyurethane resin (may attract moisture).

4. Silicone

Pot time: minutes
Cure time: hours
Cost: mid to upper range, especially for water clear silicone
Safety: safe. wear gloves

Pros: The perfect material for making molds for casting the other three resins above
Cons: 'Rubbery' finish. Not suitable for jewelry

So here's my breakdown of how I use resin: I use epoxy for everything unless I am trying to cast something larger that I want to have a shiny gloss finish. In that case, I use polyester because I can polish it on my buffing wheel instead of using the gloss sealer spray or coating with another layer of resin. If I lived in a less humid environment (like the desert), I would definitely do more with polyurethane resin as I suspect I could work with it without needing a dehumidifier. The silicone is strictly for mold making.  (You can see our silicone molds for resin in the resin molds category.)  So now that you know a little more about the resins you can use for making jewelry and other resin crafts, don't forget to read our article on how to make resin jewelry. You can also find all of our jewelry quality resin in our resin category.