What's a good gum arabic black match recipe?

[Baybird]

I know it's probably super simple, but I really just can't find it anywhere on this forum so I'm asking here. Do you know of any good recipes for this or any resources already out there that define this clearly?

[DavidF]

According to Ronald Lancaster, 1 part of gum arabic dissolved in 4 parts of water is used with 8 parts of sulfurless black powder. According to Kentish, the easiest way to dissolve gum arabic is to put it into cold water and let it dissolve naturally over time. According to Shimizu, 3 parts of gum arabic and 40 parts of hot water are used- but, he suggests using the solution in a heated bath to which the black powder is added. The increased solubility of potassium nitrate in hot water is probably why so little binder is used by Shimizu. This seems about as clear as mud to me. I have not used gum arabic.

 

If it was up to me, I'd start with a strong solution of gum arabic that adds up to 3% by weight of gum arabic and 97% black powder. I'd then add water to bring it up to working consistency. I'd also use 1% of the black powder weight of CMC in the original solution- not necessarily to bind, but to keep the solids suspended in the slurry so they don't settle out. A good starting point would be 60% black powder and 40% binding solution, at room temperature. This way you won't overshoot on the solution, and you can always add more water to thin it if necessary. That's where I'd start, having never used gum arabic.

EDITED to add:

Grandmaster

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Posted 07 June 2018 - 05:50 PM

Gum arabic is not soluble in alcohol.

 

To add to what Stix already described, gum arabic is most often used as a solution. There's a few instances where it's used as a powder, but it's not as common. I'm not sure I'd describe it as more flexible though. My impression has been that it makes good blackmatch because it's less suceptible to humidity. It definitely makes very hard stars and comets.

 

Typically, it's prepared as a 4% solution. I typically heat the water to facilitate dissolving it. It should make a light yellow to brown solution depending on the quality/grade of gum arabic used. On it's own, the solution will eventually go sour. I'm not sure how the binding strength is affected, but I can't stand the smell. Adding in a little bit of a preservative like a benzoate or salicylate will make it last nearly indefinitely. I prefer potassium benzoate as to not tempt any sodium from affecting my colors.

• stix and NeighborJ like this

Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

The sky is my canvas, and I have 2,113 pounds of powdered paint in the workshop.

I found this old post by using my search engine and entering 'gum arabic in black match', which re-directed me back to APC

Edited October 30, 2023 by DavidF

[Zumber]

Its just 10 days before I have used 8 kg black powder to prepare lots of black match using gum arabic and result was excellent match turns out stiff and rock hard easy to handle(easily insearted into paper tube).

I weighted 3.5 kg black powder and placed it into pot then I weighted 125 gm by weight of gum arabic powder( i sieved it using 40 mesh screen and used fine powder only) then I took 1 liter of warm water and added gum arabic in it and made its solution then I poured this solution in bp and added again hot water in it until i received right consistency. Only problem I was facing is after 5 to 10 minutes gum arabic solutions sitting at bottom of bp slurry so i was stirring slurry continuously and i was adding hot water if it is turning thick. As Shimizu wrote use non sparking non flame based heater underneath pot But i avoided it and insted I made stock of hot water near me.

So for 7 kg black powder I used 250 gm gum arabic.my match speed isnt affected and match turns out stiff and hard. Hope this method will help you.

-swap

[cmjlab]

For "7kg you used 250 grams gum Arabic".

 

Was that all extra added to the b.p., or was some of it added into the hot water /dissolves, and some in the b.p. as a dry ingredient?

[Zumber]

No, all gum arabic is dissolved in hot water and hot water solution is added in bp, not dry gum arabic powder.

[cmjlab]

Got it, thanks.

[Zumber]

You are welcome.!

[Richtee]

Guess I never used this “gum” stuff. I bake corn starch to dextrin. Cheap and effective. Maybe the gum stuff adds fuel value tho?

[Zumber]

I do have commercial pyro grade dextrin which i used to make stars and black match etc but black match is not stiff and flexible as compared with gum arabic. Dextrin is good for stars but gum arabic is superior than dextrin for black match.

[cmjlab]

The humidity's effect on black match is why I was curious. My black match always gets ED and goes limp when it's high humidity out, and bad enough sometimes to recrystallize after drying again - which makes it burn like shit.

 

I tried black match with 1.5% gum Arabic and it did not turn out very sturdy (dissolved gum Arabic in water, then made paste/slurry). So I figured I'd try again with more gum Arabic since I've read a couple places now that it does better in humid environments once fully dried.

 

I've not had a chance to try it yet with the amounts identified in posts above, but that's why I was curious about it.

[Mumbles]

For what it's worth, I tend to use gum arabic solution in combination with another binder. DavidF posted what I do to prepare the solution. I use it most often in pressed comets. Gum arabic solution on it's own, at least at the concentration I use, doesn't have a lot of binding strength. Essentially I use dextrin or SGRS or something like that to provide wet strength and some dry binding power, and the gum arabic solution to supplement the dry binding to something rock hard.

 

You can dissolve gum arabic fairly concentrated if you want. I've seen references to being able to make a 33% solution without a problem. The more concentrated you get it, the more viscous it gets. It's also available in all sorts of grades giving solutions somewhere between clear to pale yellow all the way to something that resembles black tea. I tend to go with the higher quality material available for book binding, paints, or other pigment applications. The darker stuff I've gotten in the past also tends to have more insoluble material. The higher quality stuff tends to cost more, but a little goes a long way. A pound makes about 3 gallons at 4wt%, which is probably a few years supply for me. It's been a long time since I've made any, but I feel like I didn't even need to heat the water to get the 4wt% solution to form, which might have been why I stuck with it. It's probably also a hold over from something I read from Mike Swisher at some point.

[cmjlab]

Thanks, I hadn't seen the use of two binders anywhere, I'll give that a shot. It gets humid as shit in July here in Virginia. For the past several years it hasn't been too bad till the week of 4 July then it becomes swelteringly humid for some reason! (Or thats when I'm outside the most and begin to notice)