Chinese time fuse not igniting standar 7:3 flash!

[ollie1016]

As the topic title says! I've been trying some 2" reports and all 5 failed. Each shell was filled with 10g of 7:3 flash powder and with .2g of ferro titanium 40#. All chemicals are high quality and diapered for 10 minutes. Al is 250# bright flake.

Really confused! Made my first 25 shot cake and used visco for time fuse and the salute finale worked amazingly! I was thinking prime the fuse inside with something? But what?! I'm fairly new, been doing it for 2-3 years. Any input would be highly appreciated. Ollie

[sparky]

you will need to crossmatch inside or prime the inside heavily

[stug161]

Is the 250 bright the same you used for the finale that did work? I am not sure, but with that big of metal I would say you will need more heat/fire to start the reaction. Maybe a few stars with some BP coated rice hulls would ignite easier:)

[psyco_1322]

Some time fuse has issues throwing enough fire out the end to provide good ignition. It would be best to cross match or use some kind of prime on the end if you cut it square.

[ollie1016]

Is the 250 bright the same you used for the finale that did work? I am not sure, but with that big of metal I would say you will need more heat/fire to start the reaction. Maybe a few stars with some BP coated rice hulls would ignite easier:)

 

It is quite hard to ignite with a match and ok with a blow torch. I have to live with my 250# as I can't really spend much more money on chems this year. I will have a try with these primes.

1) NC + BP + MgAl

2) cross match

3) put some BP coated rice hulls in

 

Thanks

[AdmiralDonSnider]

I assume the bright type Al will be a bit harder to ignite due to its decreased reactivity (compared to dark pyro Al) as well as its grease/stearine coating.

 

When I use chinese timefuse for shell timing, I crossmatch the outer end and cut the inner end diagonally (accounting for the cutoff section in timing). Then I prime this inner end with NC based BP slurry and dip it into something like 5FA or 7FA while still liquid. This worked every single time.

 

Btw. I had failures when relying on just slurry priming on the outer end, but in this case it is to spread fire.

Edited July 17, 2013 by AdmiralDonSnider

[TYRONEEZEKIEL]

If you are using the time fuse with all white strings going around it, you will have a hard time. It is notorious for misfiring and not taking nor spitting fire very well. I have some that I got free from pyro direct. I wont use it again. I lost almost a third of my display on the 4th because of it. Try this instead. I promise you that you will see a huge difference. http://www.thepyropro.com/

[808goboom]

If your flash powder burns on the ground when u test it then its obviously not the flash powder thas the problem...it could be your time fuse.i too have Chinese time fuse(tan color) and its hard to ignite if you don't prime it properly. Chinese time fuse has some kind of asphalt or rubber type goo inside that melts and extinguishes the flame when the lift powder goes off.therefore, the time fuse dies out. I highly suggest using visco fuse as time fuse for now until u buy better quality time fuse...I wouldn't use that generic tan Chinese time fuse unless u prime it properly..cross matching or slant cutting are some ways to prime it. Also, covering the ends of the time fuse with green mix or some other hot burning powder will help ensure ignition. But again, I highly suggest using visco just like how u used it in your cake for your inserts. It's more reliable then Chinese time fuse.

[Carbon796]

The tan CTF is perfectly serviceable if used properly. But it must be crossed matched on both ends. Almost all time fuses have an asphalt / tar layer surrounding the powder core. That's part of what helps suppress the burning core from igniting the device prematurely. Using visco for time fuse on a 2" mortar fired salute is just an accident waiting to happen.

[ollie1016]

It's got to be the fuse I then. I worked with another 2" salute I tested yesterday with a slow flash. Kno3 - 5

Al - 4

Sulphur-1

 

And it worked great, ill have a try with the NC and cross matching inside and outside.

[Carbon796]

If your flash powder burns on the ground when u test it then its obviously not the flash powder thas the problem...it could be your time fuse.i too have Chinese time fuse(tan color) and its hard to ignite if you don't prime it properly. Chinese time fuse has some kind of asphalt or rubber type goo inside that melts and extinguishes the flame when the lift powder goes off.therefore, the time fuse dies out. I highly suggest using visco fuse as time fuse for now until u buy better quality time fuse...I wouldn't use that generic tan Chinese time fuse unless u prime it properly..cross matching or slant cutting are some ways to prime it. Also, covering the ends of the time fuse with green mix or some other hot burning powder will help ensure ignition. But again, I highly suggest using visco just like how u used it in your cake for your inserts. It's more reliable then Chinese time fuse.

 

It's obviously not his FP, because he has to use a blow torch to set it off, is using the wrong aluminum, and the wrong ratios. And thanks for asking how to make reliable time fuse out of Visco. 3 minutes after suggesting it was more reliable in this thread.

 

- Rich

[psyco_1322]

^ Burn! Lol

 

That tan fuse is junk. The powder core is small and really dusty. It also doesnt help that the string windings just fall apart also, making it a mess when you are trying to crossmatch it.

 

It purely just bad ignition, if you start putting some bp prime on the inside of the fuse, the flash is going to light, even if its made with bright Al.

 

Also, not all time fuse is Jap, most the stuff is from China, the tan stuff stands alone for being bad quality.

Edited July 18, 2013 by psyco_1322

[ollie1016]

 

 

It's obviously not his FP, because he has to use a blow torch to set it off, is using the wrong aluminum, and the wrong ratios. And thanks for asking how to make reliable time fuse out of Visco. 3 minutes after suggesting it was more reliable in this thread.

 

- Rich

 

Just slightly curious, why is it not FP? 7:3 ratio, like 95% of people use and its with perc and Al....

[ollie1016]

I tried it with some NC prime and it didn't work. I then got a piece of my nice high quality 3mm visco. Primed on lift side with meal + 2% MgAl and on the inside I left an inch of fuse for added ignition. Once the powder goes its fine, just needs a massive kick to get going!

[Carbon796]

That's because the 7:3 ratio is suppose to be used with DARK flake aluminum. 809,10890,5413 or IBA. There are some that spec the use of bright flake, but that's usually -325 And its not the standard 7:3 formula. Your trying to make a substandard formula, work with a substandard ignition source. Which is why your having so many issues, and its increasing your chances of having an accident. I can't think of anything easier to make correctly, than 70/30, but here we are ? Edited July 19, 2013 by Carbon796

[psyco_1322]

There is no reason one needs to adjust the formula for bright flake. We all know it's less reactive, but no addition of oxidizer is going to make it better. It's just going to be an under-performing mix. If anything is going to fix the situation, it would be sulfur, or the more expensive alternative, Antimony Trisulfide. You can just add 10% to the mix.

 

When we state a NC prime, it's not dipping the fuse into NC....it's NC lacquer bound BP. If you cut the fuse with a razor blade, you can prime the surface. Of course, some good cross matching would be the best method. The tan fuse is serviceable, but it's not reliable.

Edited July 19, 2013 by psyco_1322

[Carbon796]

There is no reason one needs to adjust the formula for bright flake. We all know it's less reactive, but no addition of oxidizer is join to make it better. It's just going to be an under-performing mix. If anything is going to fix the situation, it would be sulfur, or the more expensive alternative, Antimony Trisulfide. You can just add 10% to the mix.

 

When we state a NC prime, it's not dipping the fuse into NC....it's NC lacquer bound BP. If you cut the fuse with a razor blade, you can prime the surface. Of course, some good cross matching would be the best method. The tan fuse is serviceable, but it's not reliable.

 

If there is no reason to adjust the formula. why are you suggesting it be adjusted with the addition of sulfur or antimony trisulfide? Neither one of those is included in the standard 70/30 formula. Which is the posted formula he is having issues with. Also, no one suggested that there was a need for more oxidizer. Yes, it is less reactive. His, to the point of not igniting reliably using the standard 70:30 formula, because he is not using the correct aluminum. It's a safety issue. If your going to make salutes, make them correctly, with the correct materials. Can bright flake be made to work ? Absolutely. But I'm not aware of a single published formula, by a known author that specs -250 bright, solely for use with perc.

[AdmiralDonSnider]

I consider this discussion unnecessary. Bright flake will work in the 7/3 formula, even with 250 mesh. This material contains much finer particles anyway, due to the way that it is produces, probably as small as 2my according to Lancaster. The problem is the lack of inner priming that spits fire correctly. A burning out timefuse just does a quick poof and will probably fail with the less reactive aluminum. But that´s purely the techniques fault.

[Mumbles]

I think what Psyco was saying isn't that using bright flake requires different formulas. I got the impression it was more that the addition of other things like sulfur or antimony trisulfide will help to make up for the slower reaction rate and lower flame sensitivity that using bright flake entails. As you both alluded to, this would have alleviated some of the issues with technique. I agree with you Carbon796. If you're going to make salutes or flash, you should know what you're doing and do it correctly. It's not very forgiving.

[psyco_1322]

I don't see how using the bright Al is a safety issue. From the standpoint of burn rates/dangerous quantities and overall reactiveness to impact or friction, it's probably safer. The unsafe part is when people don't properly fuse the device, and it ends up laying out in the field somewhere, unlit. That scenario could have happened with any device, salute or shell. I have personally had good time fuse not ignite dark Al based flash in this kind of situation.

 

70:30 is not the one and only formula out there. People often add 10% sulfur to flash to bulk the mix up, since it's cheap and doesn't hurt the performance. It actually ends of lowering the ignition temperatures and increasing the sensitivity of the mix. This would help with making sure your bright flake mix ignites a bit easier. Antimony trisulfide will do the same thing, except it's more expensive, and sort of unhealthy for the body.

[Carbon796]

Agreed. Psyco, we are sort of saying the same thing, just differently. I don't think the use of bright AL is a safety issue. It's the reliability of his devices continually not functioning properly, that's a safety issue. In my "opinion" a more appropriate AL would increase his reliability. Could he add a sensitizer, sure. 8:3:1 is also quite common. Edited July 20, 2013 by Carbon796

[leedrill]

i second that his mix is probably safer than that of standard 7/3, and i have had the issue when experimenting with blue al for some timed reports.

 

being that the blue al i have is very finicky { even though it has been graded to between 2 to 6 um] to get less than 0.5 grams to confine is very difficult i can do it with 0.2 grams, but need to prime the inside and have tried different ways with no repeatable results but with dark, no experimenting needed {i dont know why i tried this other than i wanted to see what blue al was like in smaller reports}. and as has been concluded by other people bright flake and even really good quality blue al is not very well utilised in small devices and even in bigger salutes.

but as both psyco and carbon have stated NOT RELIABLE and is why dark al is used by most pyros for this application and with chinese time fuse cross matched on both ends will be just as reliable, if done properly than most time fuse { but still some people seem to have issues with this time fuse }. in my opinion is because people get use to getting away with less work with superior quality TF

i know most of this is covered in this post now thats just my 2 cents

[FlaMtnBkr]

The only vids I have seen of blue Al are from the 'inventor' and I believe he says blue al needs help with ignition for reliability. And that about the smallest it can be used is 10 grams.

 

How did you determine the size? And did you seperate out the smaller particles? If so, then you may have made the rest of the aluminum even less reactive and harder to light.

 

I don't think anything else needs to be added to the OP flash, though sulfur probably would help. Conventional and propper fusing/priming of the time fuse is all that is needed, IMO.

[leedrill]

the blue al i have is bought that way from a hungarian supplier

was listed as that particle size during sale is easily as fine as my dark there is a lot of inferior blue al sold in the states but there is some superior product out there

[ollie1016]

The only vids I have seen of blue Al are from the 'inventor' and I believe he says blue al needs help with ignition for reliability. And that about the smallest it can be used is 10 grams.

 

How did you determine the size? And did you seperate out the smaller particles? If so, then you may have made the rest of the aluminum even less reactive and harder to light.

 

I don't think anything else needs to be added to the OP flash, though sulfur probably would help. Conventional and propper fusing/priming of the time fuse is all that is needed, IMO.

 

It's just straight 250# Bright Al and fine perc. It will make a very loud report with 0.2g in a firecracker.