Email digest for the Global Conservation Forum (ConsDistList) egroup. ------------------------------------------------------------------------------------------------------------
1. RE: Firecrackers on paper object 2. RE: Firecrackers on paper object ------------------------------------------------------------------------------------------------------------ 1.From: Monona Rossol Posted: Saturday September 20, 2025 9:33 AM Subject: RE: Firecrackers on paper object Message: Hi Susan, Regarding conservation of a small pack of fire crackers: D. Thor Minnick is right about the potassium compounds. Early flash powders were more likely to be made from potassium chlorate instead of potassium perchlorate. Fine alumimum powder could be the fuel. Over time, some of these flash powder mixtures can become unstable. My experience is primarily with the chemistry because I was a technical editor for Kosanke's Encyclopedia of Pyrotechnic Chemicals for years. So I started this inquiry for you with a very experienced pyrotechnician: First a definition: An explosive ordnance disposal (EOD) unit exists in the fire department in any major city. These people have the facilities to do this kind of thing and sometimes they get interested in wee projects like this. My contact pyro suggested the EOD people might even use these for training purposes. Of course, you run two risks: 1) they are not conservators and might muck up your objective; and 2) the fire department might just confiscate the fire crackers. It seems there are laws that may be violated by altering these firecrackers. He also said: "My limited insights into this come from military museums and collections of military explosive devices, etc. used for EOD training, where of course preserving the device is important so they can't just make solid, prop dummies of them like we generally do, yet of course they can't have the hazard. In general, what they seem to do is of course identify the hazards as best they can, then have trained, experience people safely remove the explosives, with a view toward doing as little damage to the device as practicable, have whoever did it certify that it's free of explosive, and then they maintain a record traceable to the individual object (possibly including photographs, video, etc.) of what was done, who did it and that they did it sufficiently. Using this process, huge collections of formerly very dangerous things have been successfully and safely maintained. The only problems I'm aware of come when the procedure isn't followed." Looking at the picture of the little fire crackers, he also pointed out: "Granted, it's a small quantity, but there's almost certainly flash powder in there (if they are real and not just some sort of decorative item.) There's also of course the fuse itself, which if it's real, will have some kind of priority composition in it. Both the powdered charge and the fuse have the potential to cause injuries and/or start fires." The fact that the fuse is also a hazard means a conservator would have to remove all of the charge in the cylinder and also replace the fuses. You might as well replace the cylinders, too. I also talked to conservators, and it is not uncommon to make replicas of items like this, and there is nothing unique about these that needs preservation, in my opinion, other than the chemicals you are removing. My opinion, take the originals to the Fire Department for proper disposal and make replicas. ------------------------------------------- Original Message: Sent: 9/18/2025 1:16:00 PM From: D. Thor Minnick Subject: RE: Firecrackers on paper object Hi Susan, Firecrackers of this size generally use KNO3, KClO4, or KClO3 as the oxidizers. Fuels may be Al, S, and charcoal. Interesting problem. I do not think you will be able to undo the crimped paper ends to "drain" out the mixture. Good luck. ------------------------------ D. Thor Minnick Conservator Minnick Associates Honolulu United States ------------------------------ ------------------------------------------- Original Message: Sent: 09-12-2025 17:10 From: Susan Russick Subject: Firecrackers on paper object We have a c. 1973 Yoshio Nakajima pamphlet that has a small bunch of firecrackers adhered to the cover. I'm planning to remove as much powder as I can from the cylinders, but am wondering about other steps that might make it safer to store in a library collection. Any thoughts? Thanks, Susan ------------------------------ Susan Russick Chief Conservator Northwestern University Libraries ------------------------------ 2.From: Erik Farrell Posted: Saturday September 20, 2025 2:56 PM Subject: RE: Firecrackers on paper object Message: I agree with Thor on both composition and assessment of uncrimping the ends. I have worked on larger flares of similar construction, and for those I had EOD slit the paper tube vertically to remove the incendiary charge, then mended the cylinders using Japanese tissue and wheat starch paste applied to the interior. If you are trying to inert and retain the original firecrackers, I would go down that route. I haven't published that one yet (although bits of it were in an AIC talk I gave in 2024), but feel free to contact me and I can share images showing tools/methods. After scaling it down to firecracker size I think the same process would work, but it'd be a bunch of very fiddly tweezer work under a microscope. As others have pointed out, the fusing is also reactive. The fuse is generally in a configuration which is non-explosive (e.g. a small central core of a self-oxidizing incendiary or an inhibited low explosive with a relatively slow burn rate, surrounded by a waxed fiber or similar). I don't know how you could remove the fuse without damaging the work. I also don't think there's enough hazardous material in it to be worth removing, and at least for BATF classifications I don't think you would be required to store that as an explosive. The firecrackers themselves are also not really an alarming quantity of explosive material, but are technically explosives nonetheless. Unfortunately most of the commercially available BATF-compliant magazines are wood-lined, and the VOCs involved aren't great for long-term museum preservation. Although geared towards flammables rather than explosives, I think the note Michelle linked on storage of matches would actually be quite reasonable for this. If this is the only explosive material in the collection I don't think you would be wrong to consider retaining it in safe storage, although you should consult your local fire marshal first. Per Chris - the oxidisers typical in this type of firework are very water soluble. However, they do need to be extracted if you're relying on that as a deactivation measure; simply wetting and drying will not reliably deactivate the material, although it will change the distribution of oxidiser within the explosive mixture. This can deactivate the compound, and things like black powder are notoriously unreliable after wetting/drying. But unreliable and inert are very different states; you can end up with a heterogeneous mixture where some areas are oxidiser-poor and will not detonate, some areas are oxidiser-rich and may detonate, and some areas are still stoichiometrically ideal and absolutely will detonate. Thoroughly saturating with water and then extracting that water before it has a chance to dry will, theoretically, remove the oxidiser and inert the compound. It is incredibly difficult to verify that this has been successful without destructive sampling. In general, if trying to inert an explosive device, I would tend towards removing the energetic compound (...or contacting my friendly neighborhood EOD team to remove it, depending on the configuration) rather than trying to deactivate it in place. Be aware, not all EOD are created equal. Most civilian and military branches have standing orders not to attempt non-destructive deactivation, so will seize and destroy the object as the first resort. US Marine Corps is, as of my last dealings with them, still allowed nondestructive methods. There are also a few retired EOD scattered around who will also do that work unofficially. For something this small (and civilian in origin), I'm not sure USMC would get involved. For contacting civilian EOD (generally via a local fire department) specify that you are dealing with old firecrackers, that they appear to be stable, and that they are part of an artwork you don't want destroyed. Before you contact them, make sure that type of firecracker is legal to own in your jurisdiction, and/or have a plan prepared to remove the firecrackers from the artwork if needed. I don't think anyone is going to be overzealous enough to seize and destroy the entire artwork for the sake of a pack of firecrackers, but I would also have some contingencies in place in case things do start going in that direction. ------------------------------ Erik Farrell Senior Objects Conservator The Mariners' Museum and Park Newport News, VA ------------------------------ ------------------------------------------- Original Message: Sent: 09-19-2025 20:52 From: Chris Stavroudis Subject: Firecrackers on paper object Hi Susan, I'll stick my neck out here. If I'm not mistaken, once the explosive in this sort of firecracker gets wet it can no longer explode. I believe it dissolves the oxidizers Thor mentions and even when dry, the explosive system is disabled. On that theory, perhaps you could use a thin-needled syringe to inject water and then draw the water back out. Treat the exterior first with cyclomethicone to prevent the water from migrating into and out of the paper. Honestly, I think the larger concern is the fuse material. If I'm not mistaken, that is usually made from a higher grade explosive so that it doesn't blow out easily. It also should be somewhat waterproof given its intended function. ------------------------------ Chris Stavroudis Paintings Conservator Freelance/Private Practice/Self-employed/Independent W Hollywood United States ------------------------------ Original Message: Sent: 09-18-2025 13:15 From: D. Thor Minnick Subject: Firecrackers on paper object Hi Susan, Firecrackers of this size generally use KNO3, KClO4, or KClO3 as the oxidizers. Fuels may be Al, S, and charcoal. Interesting problem. I do not think you will be able to undo the crimped paper ends to "drain" out the mixture. Good luck. ------------------------------ D. Thor Minnick Conservator Minnick Associates Honolulu United States Original Message: Sent: 09-12-2025 17:10 From: Susan Russick Subject: Firecrackers on paper object We have a c. 1973 Yoshio Nakajima pamphlet that has a small bunch of firecrackers adhered to the cover. I'm planning to remove as much powder as I can from the cylinders, but am wondering about other steps that might make it safer to store in a library collection. Any thoughts? Thanks, Susan ------------------------------ Susan Russick Chief Conservator Northwestern University Libraries ------------------------------ You are subscribed to "Global Conservation Forum (ConsDistList)" as [email protected]. To change your subscriptions, go to http://community.culturalheritage.org/preferences?section=Subscriptions. 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