Is this possible?

[asdfd]

Hello all, I have been wanting to try out some form of crackle/dragon eggs for a while now and I've had my eye on bismuth trioxide comps. I have seen a formula using red gum instead of nc lacquer as the binder and I was wondering, would it be possible to replace the red gum with dextrin or add say 5% dextrin to a different crackle formula and have it still work? I plan to use them in matrix stars. I don't care if they are very loud or not I just want them to be audible in matrix stars up in the air.

 

Thank you.

[Richtee]

I have used phenolic resin and NC. NC seems to perform beter. I don’t think dex will work... you need the fuel value of the binder... I THINK.

 

In all honesty, I really don’t know SQUAT about how those things work. Heard a couple possible explanations, but I don’t think anyone’s got the whole picture.

 

And you need a heavy duty solid prime coat, BTW.

Edited November 28, 2022 by Richtee

[cmjlab]

I've only made NC bound DE / crackle and I find those are finicky enough that I didn't bother with the red gum or phenolic bound DEs / crackle. But if you have the stuff, it'd be worth a small test before ruling it out as a possibility - truth be told, even if we told you that NO it won't work, it could just be our methods and processes that don't work.... Good luck! Let us know if you do test it, I'd be interested.

 

Charles

[asdfd]

Thank you for the replies, I think i will try it out sometime soon and report my findings. If it doesn't work I'll try out either the red gum bound comp, or just deal with nc lacquer.

[a_bab]

Crackle stars would notoriously NOT work when bound with dextrine unfortunately. They are traditionally bound with NC.

But other non-water binders work too. PVB is especially recommended and you can easily get it from a broken windshield. Use isopropylic alcohol to dissolve it.

 

As others have said you may crack this nut with dextrine. I never tried it.

 

The reason dextrine doesn't work IMO is a reaction in the wet medium and the binder interfering with the strange reaction that causes them to pop.

Finally, crackle stars will eventually go bad; after a few years of storage they no longer pop like in the first day because magnalium slowly degrades.

Edited November 29, 2022 by a_bab

[rellim]

I make crackle cores rolled on mustard seeds. Three percent dextrin is all that is needed because copper and bismuth oxides are very dense. The greater strength of NC bound crackle likely works better when pressed into comets.