Spolettes

[jwitt]

Well, I think I've used cheap chinese (white) time fuse for the first and last time. Long story short, I don't trust the stuff, and I don't feel like running two time fuses- I want one reliable timing and ignition device.

 

So, after getting back from the farm, I tinkered around with my 1/4" ID x 1.5" tubes and a quantity of my hottest batch of Alder BP. I cut off a section of oak dowel and started ramming increments. Testing went well- I used a small pile of granulated "crap" Alder BP to ignite the end of the spolette and within a few tries got my timing down. I can reliably crank out spolettes accurate to within .1 seconds (I think...hehehe). One spolette takes aprox. 3 1/8 teaspoons of powder.

 

I marked my dowel for:

 

1) first increment- ensuring I get a nice, rock-hard 1/4" at the bottom of the spolette and 2) I then remove the dowel from the top of the spolette tube and ram 3-4 more increments to get to the desired part of my 3) stair-step segmented timing line. The first increment is rammed with 10 strokes of a nice big lixie dead blow hammer, the following increments get 7 hits each.

 

The tip of my rammer is rounded, supposedly this spits fire a bit better. Blackmatch and paper nosing finishes the tube. Upon completion of a shell, bottom of BP grain is roughed up a bit (carve an X into it) and blackmatch is tied and secured with glue in a U shape, touching the end of the grain. 10 test spolettes all performed identically!

 

 

For consistency, I set aside a nice little tub of my current best BP, since I know I'll have to re-do timing when I switch to another batch.

 

Any advice? I noticed there was a shortage of spolette information here. I guess people figure it's too time consuming, but I found it to be reasonable compared to cutting, splitting, cross matching a piece of time fuse and then popping it into a passfire tube...especially if I get consistent results!!!

Edited May 10, 2010 by jwitt

[AdmiralDonSnider]

Spolettes are great and consistent timing devices. Timed report shells show what´s possible using this technique.

 

Some people add a bit of metal powder to create a tracer-like effect; others even ram or press whistle mix, but this can be dangerous.

 

Fulcanelli contains some valuable info about spolettes and devices made with them. Have a look.

[Cookieman]

Well, I think I've used cheap chinese (white) time fuse for the first and last time. Long story short, I don't trust the stuff, and I don't feel like running two time fuses- I want one reliable timing and ignition device.

 

So, after getting back from the farm, I tinkered around with my 1/4" ID x 1.5" tubes and a quantity of my hottest batch of Alder BP. I cut off a section of oak dowel and started ramming increments. Testing went well- I used a small pile of granulated "crap" Alder BP to ignite the end of the spolette and within a few tries got my timing down. I can reliably crank out spolettes accurate to within .1 seconds (I think...hehehe). One spolette takes aprox. 3 1/8 teaspoons of powder.

 

I marked my dowel for:

 

1) first increment- ensuring I get a nice, rock-hard 1/4" at the bottom of the spolette and 2) I then remove the dowel from the top of the spolette tube and ram 3-4 more increments to get to the desired part of my 3) stair-step segmented timing line. The first increment is rammed with 10 strokes of a nice big lixie dead blow hammer, the following increments get 7 hits each.

 

The tip of my rammer is rounded, supposedly this spits fire a bit better. Blackmatch and paper nosing finishes the tube. Upon completion of a shell, bottom of BP grain is roughed up a bit (carve an X into it) and blackmatch is tied and secured with glue in a U shape, touching the end of the grain. 10 test spolettes all performed identically!

 

 

For consistency, I set aside a nice little tub of my current best BP, since I know I'll have to re-do timing when I switch to another batch.

 

Any advice? I noticed there was a shortage of spolette information here. I guess people figure it's too time consuming, but I found it to be reasonable compared to cutting, splitting, cross matching a piece of time fuse and then popping it into a passfire tube...especially if I get consistent results!!!

 

 

I thought I was the only one that thought chinese time fuse was inconsistant. I noticed that when I crossmatched my shells some of the powder would fall out on me. I had one 6 inch shell that shot out of the mortar and didn't even open.The time fuse were all cut the same lengths, possibly the blackmatch was damaged when the lift charge was added. I recently started using spolettes and have had no problems with timing or ignition.

[jwitt]

Of course I've only built one shell, but in testing, I'm just not satisfied with the white-string chinese stuff. That led me to skip over using my red-string chinese time fuse right up to spolettes. If a spolette fails, I know who to blame.

[Ventsi]

I really don't know whats wrong with you guys' method. I've shot over a dozen shells with the fuse you're describing and they all worked fine. Sure it burns a bit slow but thats fine, you use less. I know its not the best out there but it works just fine for me.

[jwitt]

I had problems in tests, so instead of working my way through them, I'm just taking route. Of course, that means I won't get to the heart of the problems, but through dissection of failed burned samples, it seems like there's something blocking the powder train or a gap in it. In one case, fire didn't pass through...the end was hollow. Strange, might have been "rough" handling, which is a bit hard to believe because I was pretty careful.

 

It's also a weak little fire compared to the big ballsy spolette

[dagabu]

More time fuse for me

 

I have built a lot of shells and have seen every type of fusing fail at some point.

 

-Spoletts need to be counter drilled especially in big shells due to the lift breaking/blowing out the rammed powder.

-Time fuse needs to be properly primed... properly.

-black match, visco, paper fuse and the sort all have their foibles as well, nothing is 100%, nothing.

 

In my timed reports that use a six strand black match for prime, not a one has failed to light. With a slurry or cross matching, there can be a 20% failure. With almost 1000 cap plugs blown to smithereens and another 2000 coming this summer, I dont expect to see a single cap plug sitting on the ground.

 

Come to PGI, take my class on the cheapy white time fuse used in cap plugs, shoot your our rocket or pound it out of a mortar, you will see for yourself.

 

D

[jwitt]

I guess I figured time fuse was the "easy solution" and was proved wrong. I'll admit that instantly ditching one method for another isn't the best way to make true progress...the spolette hooked me once I made a few though. Heh...just got out the caliper and did some measuring, my "3 seconds" set by testing turns out to be exactly 1 inch.

 

I guess I'll find out about blowing spolettes pretty soon...or on the 4th when I shoot a whole mess of shells. Good excuse to get a drill press though.

[jwitt]

Well, my spolettes worked great through this July's shells! No failures on about 50 shells.

 

I'm going to meticulously assemble a couple 6" shells next year though (striving for perfection in those shells). I bet I have to start worrying about making proper spolettes. Time to break out Fulcanelli and read a bit. I might have a question or two after that.

 

 

.9 inches of powder worked great for me- 2.75 seconds. An entire inch was a bit long.

 

 

Edit-

 

So I'd heard some talk of back-drilling spolettes for larger shells (in fact, mentioned by dagabu above) Fulcanelli only spoke of scratching the powder grain to ensure ignition.

 

1) What's the deal with drilling to prevent blow-through?

 

2) I wonder- for a 6" hemi with two fuse holes, since the fuses are angled, lift pressure wouldn't be hitting the spolette end-on. I guess blow-through is more of a function of total pressure in the mortar. So...what about question #1?

Edited August 9, 2010 by jwitt

[Peret]

I know the white fuse discussion was over a couple of months ago, but I missed it. I got some to try because it was so cheap, but it gave me very poor results. I had one shell fail even though the fuse burned right through - the spit failed to ignite the burst. I recovered the shell and was able to push a piece of visco right up through the burned out fuse casing and try again, and the second time it worked. Taking a closer look, I notice the powder core on the white fuse is a lot smaller than on the regular time fuse, and in burn tests it gives a very feeble spit. You get what you pay for, which currently I see is practically free! I can't be the only one with bad experiences.

[Cookieman]

I know the white fuse discussion was over a couple of months ago, but I missed it. I got some to try because it was so cheap, but it gave me very poor results. I had one shell fail even though the fuse burned right through - the spit failed to ignite the burst. I recovered the shell and was able to push a piece of visco right up through the burned out fuse casing and try again, and the second time it worked. Taking a closer look, I notice the powder core on the white fuse is a lot smaller than on the regular time fuse, and in burn tests it gives a very feeble spit. You get what you pay for, which currently I see is practically free! I can't be the only one with bad experiences.

 

 

Your not the only one, I had a few shell failures with the same fuse.Though nothing is 100%, I use splolette's now and so far, no shell failures.

[dagabu]

I know the white fuse discussion was over a couple of months ago, but I missed it. I got some to try because it was so cheap, but it gave me very poor results. I had one shell fail even though the fuse burned right through - the spit failed to ignite the burst. I recovered the shell and was able to push a piece of visco right up through the burned out fuse casing and try again, and the second time it worked. Taking a closer look, I notice the powder core on the white fuse is a lot smaller than on the regular time fuse, and in burn tests it gives a very feeble spit. You get what you pay for, which currently I see is practically free! I can't be the only one with bad experiences.

 

WHOA!!!!

 

Time fuse and spoletts are not meant to light any shell from the powder core. ALL timefuse should be punched and cross matched or slit and cross matched. Even if you prime the end of the time fuse (with the exception of very few items) the device may fail to light.

 

The blunt end of the spolette is the end with black match covering the end and that takes fire from the leader, the spolette burns down to the black match that is bucketed inside the end of the spolette.

 

Back drilling is used when less then 2" of BP is needed in the spolette for timing. The back drilling is usually done make the timing more precise and if a more modern method is used, the drill bit is 1/2 the diameter of the spolette inside diameter and only the core is drilled back so that the entire 2" collumn of BP can still be gripping the walls of the tube so when the shell is bottom fused, the lift will not push the BP out of the spolette.

 

Why anyone would use raw timefuse or spolettes to ignite burst is not reading any of the books that have been written over the past 100 years. The ONLY job of either is to carry the flame to the cross match/bucket.

 

The cheap white timefuse works splendidly, I have 840 pieces of it going up in the air tomorrow night in front of whomever is on the B-line tomorrow night.

[Peret]

Why anyone would use raw timefuse or spolettes to ignite burst is not reading any of the books that have been written over the past 100 years. The ONLY job of either is to carry the flame to the cross match/bucket.

Yeah, I know that now (blush). I had in fact read almost all the books written in the past 100 years, but there's no substitute for experience disappointment. I put a tube with black match on all my fuses now.

 

Where on earth did you find time to make 840 pieces?

[jwitt]

Where on earth did you find time to make 840 pieces?

 

That feller has a system. A fancy system- an incredibly cool fancy system of awesomeness that involves dozens of precisely timed inserts.

 

 

 

Now I get the back-drilling, thanks for the explanation.

 

 

 

As far as cheap time fuse- I started making timing/ignition assemblies (time fuse glued into passfire tube with blackmatch nosed into the end) and every one worked nice when taped to the BBQ grill- the BM shot out of the end somethin' fierce. But up in the sky, the first one failed, so I became skeptical. The core was burned through, but it did not light the BM pieces that were shoved into the end of the passfire tube. (I did not cross match on the inside of the shell)

 

That's why I went to spolettes, because I didn't want to take the time to learn how to work with the fuse properly. Turns out I don't mind the time / effort involved in making spolettes, even for a decent batch of shells. I also trust my spolettes to do the job in the air, even though I don't have the experience and statistics to back that claim up. The one failure I had since beginning shell building was "clearly" related to the BM spolette primer being blown off the shell on lift because I didn't secure it with a twine clove hitch. The recovered shell showed where the glue melted, and it didn't look like the BM burned the spolette tube at all.

Edited August 10, 2010 by jwitt

[mfstraydog1]

well this is a little off the post. i am going to be using spolettes on my can shells. so i am wondering what Dia. of spolette tube every one is using. the first few i would like to roll by hand just to say i can do it. but i would also like to find a good source online for them.

[Cookieman]

well this is a little off the post. i am going to be using spolettes on my can shells. so i am wondering what Dia. of spolette tube every one is using. the first few i would like to roll by hand just to say i can do it. but i would also like to find a good source online for them.

 

These are the ones I use and they work well for me.

[Algenco]

I get mine HERE , better price

[jwitt]

And I get mine here which is an even better price

[Algenco]

And I get mine here which is an even better price

 

 

You win!!

This is what I like, everyone helping to find the best price.

 

Compare total costs, shipping charges vary

[jwitt]

You win!!

This is what I like, everyone helping to find the best price.

 

Compare total costs, shipping charges vary

 

I found them to be the best place to grab paper products and mortars by putting together the same cart at 4-5 different shops. Since I've figured out how to shop for all these things efficiently, I do an oxidizer order, a fuel order, etc, and get everything I need as efficiently as possible by doing that sort of comparison shopping. (Really got stung by shipping on first few orders of goodies)

 

Edit: Totally related to spolettes and paper products, as well as being the winner ...

Edited August 11, 2010 by jwitt

[mfstraydog1]

lol thanks for the info looks like jwitt wins

[jwitt]

Aww shucks

[Algenco]

http://i468.photobucket.com/albums/rr47/Algenco/cartoons3/3.gif

[jwitt]

The only thing I wasn't winning at was designing/making the ramming dowel correctly. If not done exactly right, it's an exercise in frustration. I went through several, getting 'em stuck and breaking off while trying to extract. My good one is in the bag of tubes- when I inventory my pyro stuff soon, I'll have to spec it out.

[Mumbles]

I get my tubes here. While not as cheap, the quality is top notch.

 

http://www.hobbyhorse.com/pyro_tubes.shtml

 

You don't even need supports to ram them. A word of caution. Don't use them in 3" multibreak shells that have 2.5" long casings. I used to use those same kind of tubes. I drilled a wooden support, and they worked just fine. I recently got a steel tube to fit the tubes pretty well. I haven't set it up yet, but I have a feeling it will work well. I've spent countless hours trying to get a good accurately marked rammer for these things, but I had an epiphany; use a caliper. I cut my rammers to be exactly 3" long, so it makes for easy math.

 

I usually just scratch back my spolettes as timing usually isn't too critical. When you need really exact timings, then you'll have to drill back, even with the most accurate of pressing. It is also necessary for very short timings. I think Dagabu got it mistaken though. Spolettes less than 2" are quite solid. I think it maybe should have been less than 1/2". I go down to 3/8" or so, but I think it depends a lot on the tubes you're using. 1.5x the ID of the tube is around where I would consider it to be solid.