22 replies to this topic

[pyrotechnist]

OK this may sound weird or stupid but is it possible to use a very small amount of PVA glue as a replacement for water to bind stars that are sensitive to a lot of moisture like glitter for instance? As I see it the glue will dry quickly and leave the star with a nice solid plastic sheen that should also make it a little more resistant to weathering.

[crystal palace fireworks]

I don`t see why not!,...as long as you water the PVA down a bit.

Im wondering if an alcohol based spray glue might be another option for you? (i.e it disapates/drys quicker), but is it safe to mix with star compositions?

ok guys, are there chemists out there who could advise!

[Arthur Brown]

Every formulation will have it's own peculiarities! Remember that water goes away unless it reacts before it evaporates, BUT PVA will add a binder and furl to the mix and may need to be reconsidered in the formulation. There is a possibility that you will have to subtract the dry mass of the glue from the fuel needed in the formula and even then the result may not be what you expect. Recorcinol resin is a practical waterproof fuel/binder that can be used in some products once you master the method.

[wjames]

funny you should mention that....i considered it today.........for a sparkling based star/powder.


KN03 dissolved in IPA...mixed 1:1 with iron filings worked well.....ran short on time, so didnt get round to trying my AL flake.....didnt want to rush anything....I'll look into it 2morrow.

[pyrotechnist]

I have been thinking about this for a while now when I thought about using it as an alternative fuse. The idea behind it being that it:

1) will waterproof the grain a bit more.
2) dry time will be reduced.
3) no smelly or toxic alcohol will be used.
4) it will also act as a sort of fuel like Arthur mentioned, maybe releasing chlorine in colour formulas?
5) help reduce the break down of fuel within glitter stars due to using water.

Author: I assume you may just have to subtract the amount of fuel used within the formula for the amount of PVA binder used and do a few tests. New and weird effects may be achievable using this .

[Arthur Brown]

You have a scale? Take a blob of glue -say 1 gramme, then let it dry and weigh it again. I guess you will get a residual weight of 0.3g so for every g of glue you use subtract the glue's residual weight from the fuel.


Well that's my approximation

[pyrotechnist]

I may try this with some D1 glitter, I think I will use pure PVA glue and just mix until dampened and pump the stars. I also assume they can be rolled easily enough due to the glues strengths. Failing this an alcohol + PVA mixture could be used in a 1:3 or 2:3 ratio of Alcohol:PVA like CPF mentioned above.

[digger]

OK this may sound weird or stupid but is it possible to use a very small amount of PVA glue as a replacement for water to bind stars that are sensitive to a lot of moisture like glitter for instance? As I see it the glue will dry quickly and leave the star with a nice solid plastic sheen that should also make it a little more resistant to weathering.

Back to the beginning for a moment, Just remember that PVA has a large water content and I assume that you will have to water it down somewhat to mix it in properly.

It is an interesting idea, but just remember when making glitter stars etc to weigh the water (7% - 10% max) into the composition and work it in well with gloved hands. It may look still pretty dry, but so long as the mix is no longer dusty you will be able to pump it and it will dry rock hard with excellent glitter results.

Water binding systems have a great many merits, easy, cheap no nasty vapours, quickly dried in a warm place and it is easy to clean down your tools afterwards too. I used to use solvent based systems, but I now only use them where absolutely necessary to stop unwanted reactions in certain comps and with certain hygroscopic chemicals.

Edited by digger, 16 October 2008 - 09:36 PM.

[pyromaniac303]

I think as the PVA glue is air-drying, this will cause problems with driven in moisture.

As a good example, pour a droplet of PVA onto an unwanted flat surface, then come back to it after a few minutes and you will find it has formed a film over the surface. Another hour or so and it will appear solid, but cut into it with a sharp blade and you will still find liquid PVA in the centre, sealed off from the air and unable to dry. Unless using very low concentrations in your comp, it may cause similar problems.

It may be a useful technique when rolling stars that you can dry in various layers though.

Will be interesting to see how it affects the burn rate and drying times.

[dr thrust]

wouldn't pva glue trap moisture in the star when it skins over? also as it burns it will form a residue affecting the stars performance

[digger]

Yep I agree with the above two comments as well.

[wjames]

although taking into account water percentage is a good idea......shouldnt there be a consideration of pH level for PVA....which im unsure of.

does pvc not react with boric acid ?????

[dr thrust]

yeah in fact if i cast my mind back.. many moons ago before i found this fine forum and pre INTERNET as-well i tried to make stars with various glues ect and couldn't get a thing to burn glues ect aren't ideal the flame cant pass though readily, where a binder like dextrin, red gum is a fuel aswell which readily burns and aids the stars performace

[pyroduck7]

it would act as a fuel and slow burn rate down, might work in colerd stars as a chlorine doner? thay would also burn slow, and might leave a stickeymatch like smell?/ and might need primer unless the glue is wateery

[digger]

it would act as a fuel and slow burn rate down, might work in colerd stars as a chlorine doner? thay would also burn slow, and might leave a stickeymatch like smell?/ and might need primer unless the glue is wateery

Unfortunately PVA has no chlorine in it.