More on Phenolic Resin and cut charcoal stars

[OldMarine]

I don't know squat about it but am only going by the info I've read in Mr. Widman's posts and critiques by other knowledgeable folk on these forums. I'll be damned if I'd dare criticize proven methods before I'd even tried them.

 

Edit; Didn't mean to sound like a biatch but I'm reading hard on this subject and hope to be proficient with the resin soon.

Edited November 2, 2016 by OldMarine

[Carbon796]

Per, Mike Swisher

 

.84 gramme of dex

.47 gramme of RG

 

Is consumed per 1.0 gramme of oxygen

Edited November 2, 2016 by Carbon796

[braddsn]

Mike...with color stars, it's pretty easy.... since the formulas call for redgum anyways, I simply replace the redgum (1:1) with phenolic, then roll with the isopropyl instead of water... and of course omit the dex completely. With charcoal stars, so far I have had good luck simply replacing the dex with the same amount of phenolic. BUT with that being said, I can see this is going to get somewhat tricky.. because by adding the phenolic to charcoal comps, they are burning faster. It's a double edged sword because you need to have enough phenolic in the comp to ensure proper binding, but this amount also makes the star burn faster. I need to do some more reading on the subject... all of my research so far has been hand's on, trial and error.

[Seymour]

I personally use an empirical formula that I got off a thread on this forum. Indeed it was in the title of the thread. From memory the original poster got the formula from a Chinese source, either on the MSDS on fireworks or from purchasing the resin. While until it is verified by other sources I cannot trust it completely, and of course phenolic resins sold as resinox have no guarantee of having the same ratio of feedstock chemicals between batches, I use it for calculations because right now it is all I've got.

It is : C48 H42 O7

Then of course if comparing to red gum, What is an empirical formula for Red gum? This seems much harder to get a figure for than phenolic resins and I've never seen one, though I have seen info stating the chemical names of some major components.

 

Ignoring theory and going to pure practical experience, I too have replaced Red Gum with Resinox 1:1 and have never had it do anything but improve compositions. As for Dextrin, it really depends on the formula, but many coloured star compositions are quite over fuelled and especially in the case of greens, it can be a bit of tightrope walking to get all the necessary bits in (Parlon, MgAl, some organic fuel) in sufficient quantities and then have enough Barium nitrate to burn them all cleanly. I know Adding KClO4 helps with this, and also that compositions solely oxidised by Barium nitrate can burn cleanly and vividly, but simply dropping the dextrin does not hurt most coloured compositions. Indeed I've yet to see one that is negatively affected by the omission of the dextrin.

 

Edit: With Blue compositions, as one of the better examples, temperature and oxygen balance can be much more fine tuned, so I don't advise casually dropping the dextrin and disregarding the fuel value in every situation.

Edited November 3, 2016 by Seymour

[dynomike1]

Thanks Brad I didn't know if you were adding Phenolic for the lack of Dextrin or not. As soon as my chemicals get here i am going to make pink, and it calls for Red gum and Dextrin, that's the reason i asked. I pumped some 3/4" crossetts and used Phenolic and they did seem to burn faster, but i cant tell till i find one of my old ones and do a burn test.

[braddsn]

Yep Mike, I just rolled a 2kg batch of pink and they came out great! I just dropped the dex, and replaced rg with phenolic. Rolled with 91% isopropyl.

[OldMarine]

Just pressed my first phenolic/hex bound comets (actually first comets ever) and so far they look good. My dehydrator I use for a drying box heats up to 170F so i I think they'll cross-link nicely.

[dynomike1]

Om you are using phenolic and hex? We are using just phenolic and having good results. I know what they are saying across the woods, but we are making it without the Hex.. Brad what comp are you using? I am going with Buell Pink.

[OldMarine]

I used Widman's BP/Ti formula pressed into 1½"comets. Set up so hard in 3 hours of heat I can't shatter one against the counter edge. I'm amazed!

They say phenolic alone is great for smaller stars but the hex is needed for larger stuff that will be broken hard.

I'm going to try Hardt Sulfur blue by just subbing 1:1 for the dextrin tomorrow.

Edited November 5, 2016 by OldMarine

[braddsn]

I agree with Mumbles that pyro is a hobby built around patience. My experimenting with phenolic only happened because there is charcoal formula that I was using to make 3/4" cut stars, and I wasted 6kg of comp (3 batches of 2kg comp) trying to make these stars, and they would NEVER dry. It wasn't that I wasn't patient. I tried everything... I let them air dry for a week, then put in dehydrator, and they swelled and cracked. Then I tried the next batch with way less water (barely enough to be able to cut them), and just let them air dry for 3 weeks. No good. Then the last batch, I cut them, and brought them into my house (I rarely do this for safety reasons) and let them dry on my kitchen table for a week. It's very humid where I live, so I thought the A/C might do the trick. They still were soft. The mystery to me is, at the same time I was making this particular comp, I had also cut some 3/4" TT comp, and some 1/2" slow gold comp, both charcoal comps, and those stars dried hard as a rock! It was this one specific charcoal comp that was giving me problems, and that's when I decided to give the phenolic a shot.. and it worked! It is a glitter comp, and they still look perfect in the sky. So in this stubborn case, the phenolic was the solution for me. And for all of my color stars, the stars roll just as easy as with dex, but they dry 10x as fast, and phenolic is 1/2 the price.. and it lowers the ignition temp of the star, which is icing on the cake.

 

OldMarine, I was just like you the first time I dried phenolic stars in my dehydrator. 3 hours later and it took a hammer to break em. It is impressive!

[braddsn]

Mike, here is the Pink I use, it is the Spanish Fuscia in the Jopetes PDF: KCLO4 - 27, Strontium Nitrate - 27, Copper Oxide - 9, Redgum - 10, Parlon - 13, MgAl 230 - 10, Dex - 4

 

I suggest trying it if you haven't. It is a very impressive pink.

[dynomike1]

I used Widman's BP/Ti formula pressed into 1½"comets. Set up so hard in 3 hours of heat I can't shatter one against the counter edge. I'm amazed!

They say phenolic alone is great for smaller stars but the hex is needed for larger stuff that will be broken hard.

I'm going to try Hardt Sulfur blue by just subbing 1:1 for the dextrin tomorrow.

I am fixin to pump some 1" comets without Hex, will see what happens with thoses.

[dynomike1]

Brad i looked at that comp last night, but wasn't sure Fuscia meant Pink yet. This was the one i was looking at. Kclo4 40, Kno3 10, Parlon 12, Mgal 200m 10, Redgum 6, Strontium Carbonate 11, Copper oxide 6, Dextrin 4. I think i will make a small batch of each and see how much difference there is.

[NeighborJ]

Braddsn, I've just finished making a batch of the jopetes fascia with Phenolic and all I can say is wow. I'll need to make more.

Has anyone tried making crackling matrix comets with Phenolic? I'm concerned the solvent will bleed and kill the DE. I guess the better question here is will NC dissolve in Denatured Alcohol? If not, then good, I can make the DE with MEK and the comet with alcohol and they shouldn't bleed into each other.

[Mumbles]

Brad i looked at that comp last night, but wasn't sure Fuscia meant Pink yet. This was the one i was looking at. Kclo4 40, Kno3 10, Parlon 12, Mgal 200m 10, Redgum 6, Strontium Carbonate 11, Copper oxide 6, Dextrin 4. I think i will make a small batch of each and see how much difference there is.

 

 

That's a good pink, though I trust the spanish one is pretty good too. You wont be disappointed either way.

[dynomike1]

Yesterday i pumped some 3/4" crossetts and 1x1" Tigertail + Grapenuts Ti. I checked them today and they are rock hard and no cracks. This was Phenolic resin with no Hex. I am going to make some pink tomorrow when my chems. come in. Neighbor what was the burn time on the fuscia? You know Pink comps are hard to come by. Dag i guess since Phenolic won't work with strobe, i guess it wont work with glitter either.

Edited November 7, 2016 by dynomike1

[NeighborJ]

Dynomike, the fuscia was 3/8" cube and burned for 3 seconds on the ground. I'm not entirely sure if it was completely dry either.

The Phenolic may change a glitter but it will still drop the sparks. I tried the pyroscience blue in a shell last night with 5% Ti and it worked great with a long hanging tail. I'm sure it should drop the AL bits as well.

[OldMarine]

From all I've read, glitters will work with phenolic but they perform differently. D1 is said to give pinkish spritzels mixed with the normal ones and burn time is slightly increased. I'll know as soon as it rains here.....

[Zmuro]

Do you have any PVB so you could compare this binder to the phenolic resin?

[dynomike1]

Do you have any PVB so you could compare this binder to the phenolic resin?

No. J looked kinda purplish on my screen. OM i think we are going to miss the rain. I would like to see a video of the glitter, even though i think i have a lb. or 2 already made up with Dex.

Edited November 7, 2016 by dynomike1

[NeighborJ]

OM, I too have noticed the pink spritzers in certain white stars most notably was the Gary Smith white parlon star. My theory for this phenomenon was the fact that strontium is added to many aluminum alloys for strength and what we are seeing is the remnants of the contaminated scrap metal. I believe Austar just made a post about this in MGAL milling.

Dynomike, I guess on camera that fuscia has a purple hue but in person it is unmistakably pink. Maybe I'll post a video of a shell, it may look better in the air and farther away.

[Mumbles]

Strontium is effective in such a low amount (less that 0.05% generally) in standard alloys that it would not be a factor in producing colored sparks. Master alloys used to add strontium containing 10-90% Sr do exist, but they're not what we use. That's not to say I wouldn't love getting my hands on some though. The commercially available aluminum we use is actually quite pure. There are a lot of things that get added to aluminum in the alloying industry, but those additional properties from additives really aren't useful for making flake or atomized powders. The feedstock for both tends to be highish grade aluminum without many additives. The other elements are primarily from impurities present from ores or feedstocks to begin with.

 

With the incandescent carbon tail from parlon, I'd doubt you'll be able to effectively see any Sr actually present.

[dynomike1]

I wished i could get caught up so i could make a shell. The white strobe that i put Phenolic in, i would like to see how white it is compared to bright white. I feel like it is going to be brighter.

[austar]

Where i work we add strontium to add structural integrity and strength mainly to cast aluminum bullbar parts. As this is the only thing that we polish at work (i am the metal polisher lol) i use the powder from the 400 grit linishing belts as my main source of alloy powder. The strontium cant be anymore than 8%-10%. I have yet to detect any red hints from it when burning. I have on occasions used the strontium rods that we add to our furnuces and they have a definite red glow, despite the fact that they are not pure strontium either.