Binding problems?!

[VikingPyrotechnics]

Hi guys,

 

I rolled yesterday ruby red stars.

However, I did not have enough dextrin. So I added little gum arabic. When I wanted to look at the stars today,

I noticed that they looked almost white. And shatter even between the fingers with light pressure.

I'm not the best at chemistry. Why is that?

 

Thanks and greets.

VP

[TYRONEEZEKIEL]

Give it more time. You have not given enough time for the stars to dry. I have had similar problems from time to time. I think that it has to do with the components of the comp holding moisture longer more than it has to do with the binder not working.

 

There have been times that I have made stars like normal with 5% DX and have had the comp crush between my fingers even after 2 days. It wasnt until about a week that they stiffened up. They did turn out rock hard. Just give it some time. I know that Gum Arabic is usually used in smaller amounts per mass than DX is IIRC. Just be patient. I'm pretty confident they will be alright

[Arthur]

Lots of trad comps only harden in the final stages of drying. A week in a warm place wouldn't be surprising.

 

Modern comps using curing resins or acetone based setting systems will dry in a few hours, but you pay money for this.

[mabuse00]

Remember you've got strontium nitrate in there, which is not so eager to dry by itself...

[taiwanluthiers]

Yes, it might not be a bad idea to acetone bind strontium nitrate based comps... they don't dry too fast and sometimes can take weeks to fully dry when water bound!

[VikingPyrotechnics]

I have often made ​​this mix. And otherwise, it's always quite fast

become hard.

 

But now the stars are slowly but surely hard.

I'm just surprised that it has taken sooo long time,

to become hard.

[NeuroticNurse]

If you can get your hands on one of them, one of those food driers, with silica cat litter below the layer that you've got your stars on, over a few days might help you. Its hastened the drying process a buggerload for me, and its a hell of an improvement over the days when I would just pour the silica on top of it and leave it in a warm spot for a fortnight or so.

For forty five bucks on ebay they're not unreasonably dear.

[taiwanluthiers]

You might consider parlon binding ruby red from now on... and cut it instead of roll it. Acetone obviously dries a lot faster and cut stars ignite easier.