What's the smallest practical amount of phenolic resin for binding a pumped star

[mabuse00]

In this case, Emarald green/Ruby red?

 

Any practical experience how much is needed to get a reasonable resistance against hard breaks?

Edited December 13, 2021 by mabuse00

[MadMat]

Since I have only a little experience with phenolic resin, I'm not sure about the specific answer to your question, but I just wanted to make sure you know that phenolic resin adds significant fuel value to your composition and you will have to adjust your formula (reduce other fuel/s) to maintain your fuel to oxidizer balance

Edited December 13, 2021 by MadMat

[Carbon796]

I've modified my formulas of both colors to use 6% PR as a fuel component. Though for cut stars, I still prefer to use SGRS as the actual binder. For larger pressed comets I will bind them with the PR and heat cure them. Which necessitates the inclusion of hexamine also, for crosslinking.

 

.83 PR to 1 RG is the recommended conversion. Though some do use it 1 to 1.

 

When PR first came into more mainstream use by hobbyist. Bill O. Was recommending a minimum of 6% PR. For proper binding, whether heat cured or not iirc. So I've always made sure to include at least 6% PR when converting or reformulating my star comps.

Edited December 13, 2021 by Carbon796