Can polyester resin eventually cure if it was too cold at first?

  • Thread starter mess
  • Start date
  • #1
59
8
Summary:
I mixed polyester resin in around 5°C and overnight it went to -10, and for the next few days it was too cold to cure.
I finally brought in a heater and kept it at about 30C for 3 hours. It still smells like uncured offgassing. Will it ever cure or did the freezing/prolonged cold ruin it and i have to remove it?
 

Answers and Replies

  • #5
59
8
I also left the catalyst and resin outside in below freezing temperature, is there a chance i damaged it?
 
  • #6
Baluncore
Science Advisor
2021 Award
10,368
4,697
I also left the catalyst and resin outside in below freezing temperature, is there a chance i damaged it?
No. You preserved it.
The problem with cold resin is mixing the catalyst into the thick cold resin. Poor mixing requires longer for the catalyst to diffuse or migrate through the mix. Diffusion is very poor at low temperatures. The heat generated by the reaction will accelerate the reaction, unless that heat is rapidly lost to a cold environment, in which case you must wait for the environment to warm.
I once waited for a week during a cold snap for polyester resin to set. It took another week before I could remove it from the mold.
 
  • Informative
  • Like
Likes hutchphd and jedishrfu
  • #7
59
8
No. You preserved it.
The problem with cold resin is mixing the catalyst into the thick cold resin. Poor mixing requires longer for the catalyst to diffuse or migrate through the mix. Diffusion is very poor at low temperatures. The heat generated by the reaction will accelerate the reaction, unless that heat is rapidly lost to a cold environment, in which case you must wait for the environment to warm.
I once waited for a week during a cold snap for polyester resin to set. It took another week before I could remove it from the mold.

Its been about 3 weeks now and it still stinks :/ ive since put a IR heat lamp on it for about 12 hours total, with no change in smell. it smells like freshly mixed resin, not as strong, but it still smells when i go up close to it.
 
  • #8
Baluncore
Science Advisor
2021 Award
10,368
4,697
Has it gelled yet, or does it still flow? Is it like rubber?

It will continue to smell for quite a while. If it smells different to plain resin, then it is reacting, and you did remember to put the catalyst in. The smell will permeate grains, flour and similar products.

What is the size and shape of the item? If it is a thin laminate it will reflect or radiate as much heat as you can provide. Maybe you need to make a polythene tunnel or tent, supported by hoops or wires. Use a fan heater and circulate air continuously throughout the chamber. Maintain a stable 20°C for 6 hours.

Just an idea. You have tried IR, but you might benefit from “UV grow lights”. Catalyst reacts very rapidly in direct sunlight due to the UV.
 

Related Threads on Can polyester resin eventually cure if it was too cold at first?

  • Last Post
Replies
6
Views
25K
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
1
Views
8K
  • Last Post
Replies
1
Views
1K
Replies
2
Views
1K
Replies
5
Views
4K
Replies
1
Views
992
Replies
5
Views
5K
Top