Idea I had about fiber glass resin

[android272]

so you all know how resin works. you take the resin and add the catalyst and heat is what makes it harden. the hotter is the less catalyst you add. when I make the resin I always make a lot then put all of it on the model. but someone on a video suggested that you apply a little bit on your model then let it dry then come back later. well its pritty hot and the resin mite harden too much that I can't use it any more.

so I was thinking what you happen if you where to put foil over your resin and put it in the refrigerator while you wait for the resin that you just applied on your model to harden. there are two things that I can see that mite go bad with this idea. And they are the resin may go bad in the refrigerator for I don't know how it reacts to cold, and or it mite make the frig smell awful.

what do you guys think of this Idea.

 

[ventrue]

The better solution would be to mix only the amount you need, and mix another batch when you come back.

Don't store chemicals near food, especially not in an open container. Don't put hot stuff in the fridge.

 

[android272]

I still use the stupid container that the resin came with. so getting the hardened resin is a pain. does any one have a suggestion for something that is better to use for mixing the resin.

I would not put it in our primary frig but the one in the garage which we do not use that much.

Just wodered what people thought.

 

[ventrue]

I use PP plastic cups, works like a charm. Reusability is not an issue with a ten cent cup.

Make sure that your cups are sufficiently heat resistant though.

 

[Roadkiller]

I still use the stupid container that the resin came with. so getting the hardened resin is a pain. ...

If you still want to use that container, just line it with tin-foil. If you still have unused resin that hardens in the container, just take the foil out and throw it away.

A roll of tin foil will cost about the same as a bunch of cheap cups, so personal preference comes into play

 

[ClayChickens]

the resin cures based on a chemical reaction, not heat...
the heat is coming from said chemical reaction, and the refrigerator probably wont keep it from hardening

 

[guybrush]

hi,

apart from having polyester resin lying around next to food, I like the idea. It is correct that the resin hardens based on a chemical reaction, which means that its temperature (before hardening) relates to the reaction speed: A decrease of ten degrees celsius cuts reaction time in half, so in principle, you can stop it from reacting by cooling it. The heat is actually coming from a physical reaction, due to the hardening (like those crystallizing hand warmers): Anything which becomes solid becomes relatively warm, even freezing water. THAT you cannot stop by cooling. I'd be curious how it works out.

 

[ventrue]

The heat is actually coming from a physical reaction, due to the hardening (like those crystallizing hand warmers): Anything which becomes solid becomes relatively warm, even freezing water. THAT you cannot stop by cooling. I'd be curious how it works out.

What you're forgetting is that frozen water is a lot colder than liquid water. You're right that energy is involved when materials change their state, but from liquid to solid, you get energy back, not the other way around. Ever wonder why the back of your freezer is warm? That's the energy it pulls out of the stuff you put in it.
This is also how those hand warmers you mentioned work: The substance in the bag is "tricked" into staying liquid below its melting point (where it should actually be solid) and pressing the metal plate finally makes it solidify - giving off the energy that was needed to liquify it earlier.

 

[marshon]

Put simply, it won't really work. One of the other properties of resin is viscosity, or how 'runny' it is. The effect of cooling it to say 2 degrees will increase the viscosity to a state where it won't pour.
When you take it out of the fridge / freezer, the time needed for it to warm back up to a usable viscosity would negate the lengthening cure time. In essence it would go off before you could use it.

I always mix up only what I can effectively apply and use within the few minutes of pot life for my given resin. That is generally about 3/4 of a plastic cup maximum. I have also used the foil liner technique, but ended up just using disposable cups and coffee stirrers as mixing sticks.

But keep experimenting, it's the only way to develop new techniques