Pyrogeezer Posted January 30 Posted January 30 For those members who ask what type of powder is used in Visco Safety fuse and commercial blasting fuse I have attached a couple of pictures of a sample of powder Goex sent me several years ago to use in our American Visco Fuse. They sent it in a 1 pound can and labeled it 140 Fuse Powder. The 140 stands for the burn rate of 140 seconds per meter or about 42.5 seconds per foot. This product has a very consistent and reliable burn rate. The grain size is right between a 6F and 7F sporting powder. A good high quality product. They did make several different burn rates.
Zumber Posted January 30 Posted January 30 Thats great. Thank you for sharing pictures. One question is there any binder in commercial 6F and 7F powder grains or it just pressed hard and then corned without binder?
Pyrogeezer Posted January 30 Author Posted January 30 Hi zumber; no there is no binder used in high-grade commercial fuse powders. As you said it is compressed and then corned. The sizes are separated by siving the grains coming Directly from the corning Mill.
Zumber Posted January 30 Posted January 30 2 hours ago, Pyrogeezer said: Hi zumber; no there is no binder used in high-grade commercial fuse powders. As you said it is compressed and then corned. The sizes are separated by siving the grains coming Directly from the corning Mill. Thank you pyrogeezer...! Just now opened some commercial visco fuse and unwound it to check its powder. And it has blend of fine bp and grains Thank you again Here is attatchment
Pyrogeezer Posted January 30 Author Posted January 30 Thanks for sharing your picture zumber. Do you know where your fuse was manufactured?
Zumber Posted January 30 Posted January 30 (edited) I am living In India. Fuse is manufactured in our state. Edited January 30 by Zumber
Pyrogeezer Posted January 30 Author Posted January 30 That's very interesting zumber, thanks for the information. I was friends with Mr. Chelladurai, one of the directors of Standard Fireworks in India.
Zumber Posted January 30 Posted January 30 Yeah Standard fireworks is biggest fireworks factory probably ranked 1 st In India. 1
Pyrogeezer Posted January 30 Author Posted January 30 Yes they make excellent firework products. Mr. Chelladurai sent me a beautiful bronze statue as a gift! When I have a chance I will send you a picture of it. 1
Zumber Posted January 31 Posted January 31 Thats great...!! Whenever you have plan again to India we will meet together. 1
pyrokid Posted January 31 Posted January 31 @Pyrogeezercould you please share your knowledge on the effects of particle size on fuse performance? Here we have quite a contrast: uniform relatively coarse particle versus mixture of grains and powder. I have personal experience with Chinese visco of 3 mm size which I consider first rate and the composition appears to be entirely fine powder without discernable grains.
Pyrogeezer Posted January 31 Author Posted January 31 Hi pyrokid; Good questions. Particle size plays a big role in the performance and also the manufacture of Visco type fuse. First we need to pick the type and size of Visco we are going to make. Let’s talk about our standard 1/8” Visco BP fuse. Through experience we have found that using standard 7F size BP along with Meal D produces a even burning pyro fuse. We use these two powders because of the powder nozzle aperture size used to produce this fuse. When making 1/8” Visco, there are 3 draw strings that carry the powder through the feed tube. Too large a grain will cause clogging of the nozzle and in turn an erratic burn rate. In some cases, there is sometimes no powder at all in the cotton weave. In order to fill in the gaps between the 7F grains we use Meal D. This prevents a possible jumping effect or rapid burning due to the air gaps between the grains. In larger fuse, say ¼” we can use a larger grain powder, again filled in with Meal D. You can make a good burning fuse with Meal D alone or finer grade power. right down to corning mill dust but it produces a lot of waist powder flying around during the processing. In ¼” fuse and larger you can use 5F or 6F along with your meal powder. You can use straight Meal powder for Visco (which burns at approximately the same rate as 5-6 or 7F), but it’s getting very costly. Now we usually make our own at a fraction of the cost of commercial powders.
Recommended Posts