11 replies to this topic

[JL96]

Hi

This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9.

https://youtube.com/...U?feature=share

66 Potassium Perchlorate
15 Parlon
14 Copper Oxide (Black)
5 PVB

Enjoy

Edited by JL96, 18 May 2022 - 12:42 PM.

[MadMat]

What is PVB?

[davidh]

https://ctpyro.com/c...utyral-pvb-1lbs

[Carbon796]

It can be used as a binder and fuel. Somewhat similar to Phenolic resin. It also has a similar slowing effect as PR. When used with BP type comps, iirc. When used in combination with PR and heat cured. It can add some toughness to the finished comet. So that it's less brittle than PR alone. Jim W (CTPyro) uses it as such, for his world record shells.

It's been noted that it can have a whitening effect on blues. Specifically with blk copper oxide, as the color imparter. You'll often see it used in much lower percentages with blues, because of this.

Edited by Carbon796, 20 May 2022 - 11:46 PM.

[JL96]

Yes I have tried a few blues with PVB but this is the deepest one so far, I prefer it as a binder as it is easy to work with especially when rolling stars, and dried fast and very solid stars. I'm 100% sure on this but it also makes stars more resistant to water?

[Carbon796]

Doubtful, in theory it sounds plausible ( with various plastic/rubber type binders ). But the bound star matrix is usually still porous.

I'm not sure about rolling, but with pressing you can probably get the pvb. Down to about 2%, make up the fuel value difference with sulfur. That would in theory, improve color depth. It looks like it's kinda fuel starved anyway.

It is a good looking blue, better than I would have expected.

[JL96]

Yeah I also had ideas about dropping the PVB down to 2% as it does burn very slow, but nit sure how much sulfur to substitute. I was also surprised with the colour considering the formula and other blues I have tried with perchlorate and PVB

[Carbon796]

I'd just sub it 1:1 to start. To see if it's worth pursuing. I don't think I've seen an accurate representation. Of what pvb's fuel value might actually be.

With parlon as the chlorine donor and primary fuel source. It's not surprising that you find it to be slow. Parlon is a sluggish "fuel" that works best in metallic fueled comps.

[Crazy Swede]

It can be used as a binder and fuel. Somewhat similar to Phenolic resin....

I would say it is pretty far from being similar to phenolic resins!

 

PVB is a lot less reactive when it comes to burning speed compared to phenolic resin (or red gum) but it is a much more effective binder and does not disturb the flame colour if used in small amounts.

 

Using it as a primary fuel will probably seldom be effective but should instead be seen as a very good binder, especially if combined with NC lacquer!

[Carbon796]

Swede, the only similarities I was implying. Was that they both can be used as binders and both have fuel value.

If anyone has access to FW'ing. Swede ( if I'm remembering correctly, who you are, pretty sure I am ) has some of the best information/comparisons/test results of various additives in strobe star formulations. And highly complete, comparisons of chlorine donors in colored strobe, and colored star formulas, and others. Truly invaluable information, if your a builder. And primarily focus on colored effects, with an intent to tune/modify them.imho.

Edited by Carbon796, 22 May 2022 - 11:56 AM.

[Fliyud]

Hi

This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9.

https://youtube.com/...U?feature=share

66 Potassium Perchlorate
15 Parlon
14 Copper Oxide (Black)
5 PVB

Enjoy

 

I am writing through an automatic translator. So he can distort the meaning of my question.

Why is PVB needed in this composition if Parlon is an excellent binder. And then it includes 15%. Stars will be like a stone.

 

[Crazy Swede]

 

Hi

This composition is based of Pihkos KP Blue but with both the red gum and dextrin replaced with 5% PVB as a binder. The stars were rolled with pure alcohol and dried for a day. The silver glitter is winokur 9.

https://youtube.com/...U?feature=share

66 Potassium Perchlorate
15 Parlon
14 Copper Oxide (Black)
5 PVB

Enjoy

 

I am writing through an automatic translator. So he can distort the meaning of my question.

Why is PVB needed in this composition if Parlon is an excellent binder. And then it includes 15%. Stars will be like a stone.

 

With PVB you can use alcohol as a solvent, which often is preferred over acetone or MEK that you would need to dissolve Parlon. That helps a lot if you would want to roll stars and the moist composition will never be as tacky as when using Parlon as a binder.