AzoMittle Posted March 4, 2016 Share Posted March 4, 2016 (edited) In Giovanni Forli's chlorate blue star he uses dextrin as a binder and shellac as a fuel (noted as can be subbed for red gum). Will the shellac/RG still act as a fuel if I were to drop the dextrin and bind with alcohol? Will the formula behave the same? 60....KClO320....CuO (Black or Red)10....PVC (Fine powder)06....Shellac (Red Gum can be used also)04....Dextrine If I drop the dextrin should I adjust the other amounts at all? For example, -4% dextrin = +1% to each of 4 others?: 61....KClO321....CuO (Black or Red)11....PVC (Fine powder)07....Shellac (Red Gum can be used also) edit: I would have figured this had been asked before but I don't see anything in search. Edited March 4, 2016 by AzoMittle Link to comment Share on other sites More sharing options...
Maserface Posted March 4, 2016 Share Posted March 4, 2016 The easiest way is to simply adjust the shellac for the omitted dextrin. Shellac has a fuel value approximately .52:1 to dextrin, and red gum is .55:1. Adding half as much shellac/red gum as dextrin omitted would be a good start. Link to comment Share on other sites More sharing options...
Seymour Posted March 5, 2016 Share Posted March 5, 2016 It should be noted though that if a formula is 4 or 5% dextrin, using 2 or 3% Red Gum or Shellac will not be enough to act as an effective binder if no other binder is used. Even 5% Red gum is not enough for strong stars in my opinion. Link to comment Share on other sites More sharing options...
AzoMittle Posted March 5, 2016 Author Share Posted March 5, 2016 Ya it was one of the moments where I kind of went, "wait a minute I don't think I'm doing this correctly, wait, why have I never thought this through, better go ask the experts." Brain fart if you will. Shellac seems to bind pretty good for me as long as its mixed in well (I've only bothered to use it as a binder in BaClO3 stars though, so take that with a grain of salt). If a formula calls for 4-5% dextrin I usually swap it for 3-4% SGRS. I think what Maser was saying is that if a formula calls for 10% RG and 4% dextrin he recommends taking half the amount of dextrin (2%) and adding it to the RG total (now 12%), I believe. Link to comment Share on other sites More sharing options...
Maserface Posted March 6, 2016 Share Posted March 6, 2016 What Seymour is saying is correct, it's important to consider every role that an ingredient has when making substitutions. My response was only acknowledging your question regarding the fuel values. Good luck Link to comment Share on other sites More sharing options...
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