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Cross-Matching and Passfires


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#1 Ventsi

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Posted 06 February 2010 - 02:27 PM

Here's what I do to every one of my shells, works everytime:

Pass-fire
First for the pass-fire , I start off with a 1/4" ID x 2" tube, this is then trimmed down to the necessary length, this is for a 3" ball so it gets 1.5".
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Now the time fuse, cut yours to the needed length +3/8" for crossmatching with the part going inside cut at an angle, this will make sure fire gets to the inside of the shell:
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Some wood glue is smeared on the TF and its inserted so that 1/2" is sticking out:
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Next cut some black match, 6 pieces work fine for me:
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These go into the open end of the tube, make sure they go all the way down and are in contact with the slanted part of the TF:
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Next wrap 2 turns of masking tape having about 3/8" hanging over the lip:
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Next finish off with a clove-hitch knot and tadaa! Ready to go. This will act like quickmatch lighting your shell from the center and giving you better breaks.
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These go into a 3/8" hole inside if your shell, I just put a blob oh hot glue and paste over them with paper.
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_____________________________________________________________________________
Cross-Matching

First I start with a piece of time fuse, this is then cut down the center,3/8" in using a pair of anvil cutters
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Next I take a small piece of fast grey fuse, inside there are three perfect thin pieces of Black Match:
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These get a quick dip in thin BP slurry[NON WATER BASED!] and get pushed down into the slit we just made. This makes sure that the BM adheres to the powder core of the time fuse.
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Next tie off the top with a clove-hitch knot, some folks use dental floss and it works well, I personally use hemp twine.
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Any questions, tips and critiques are highly welcome.
Stay Green!

Edited by Ventsi, 06 February 2010 - 04:05 PM.

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#2 dagabu

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Posted 06 February 2010 - 03:48 PM

Two things I see that bother me:

1. We all try real hard to not introduce water to the inside of time fuse and I see you adding a slurry right before tying it up.
2. Masking tape is just asking for trouble, when the tape sits, the glue changes, some get sticky and it penetrates paper others get brittle and it falls away.

My suggestions are to use straight black match for cross match, no slurry and to use kraft with a dab of PVA for the buckets. I like the hemp, the wood glue and the rigid tubes.

D
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#3 Ventsi

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Posted 06 February 2010 - 04:03 PM

Thanks D, though the slurry I use is Alc/Red Gum based, you can also use NC/BP.

I suppose you are right about the tape, I use to use kraft/PVA but hated having to wait for it to dry.

Edited by Ventsi, 06 February 2010 - 04:04 PM.

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#4 dagabu

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Posted 06 February 2010 - 04:24 PM

Thanks D, though the slurry I use is Alc/Red Gum based, you can also use NC/BP.

I suppose you are right about the tape, I use to use kraft/PVA but hated having to wait for it to dry.


Oh, sorry! Didn't see the Alc part! If you shoot the shells within the month there is no problem with masking tape but wintering over will ruin shells.

D
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#5 Ventsi

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Posted 06 February 2010 - 04:52 PM

Huh, what? I don't know of such thing as winter. :P But the CA rainy "winters" get really annoying.
Any who, yeah kraft paper would definitely be a better and preferred alternative.
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#6 Mumbles

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Posted 07 February 2010 - 11:17 PM

You might consider using gummed paper tape, or even just using the masking tape to adhere some dry paper. I was shown a way that you pack the end of the tube full of BM, and slide bamboo skewers in there, breaking them off to lock the BM in there even if the nosing comes off. They also pierce the nosing supposedly to prevent the fire from being sucked out of the tube. This is for spolettes, so it's obviously not an issue for time fuse.
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#7 ExplosiveCoek

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Posted 07 July 2010 - 07:11 AM

1. We all try real hard to not introduce water to the inside of time fuse *snip*


Hm, can you explain why?

#8 dagabu

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Posted 07 July 2010 - 08:06 AM

Hm, can you explain why?


Time fuse and spolettes have black powder inside of them and they are prone to failure if they are even damp. Spolettes depend on a very thick tube to keep water away and time fuse uses tar to keep the water away.

The issue is not directly related to using a water based prime for priming a split time fuse but rather the capillary action of water migrating down the core and dampening the powder. Once the prime is dried, the water is actually trapped inside the time fuse and the time fuse may never dry.
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#9 Arthur

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Posted 07 July 2010 - 08:35 AM

Small shells I glue the time fuse to the hemi then use a piece of 1/4" paper tube glued to the time fuse inside as a flash bag (gummed paper over the open end.

Big shells I glue the 1/4" card tube into the hemi with a QM tail to the centre of the sphere. The Time fuse I glue into the tube when it's all dry and probably fully pasted. that way I don't damage the crossmatching with gummed paper tape.

Always there is a string and glue fillet round the time fuse to prevent the fire by-passing the timer or pushing the time fuse into the shell.

For crossmatching I cut the end of the time fuse and push a piece of BM into the slit then tie together again with thin string.

#10 dagabu

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Posted 07 July 2010 - 10:05 AM

Small shells I glue the time fuse to the hemi then use a piece of 1/4" paper tube glued to the time fuse inside as a flash bag (gummed paper over the open end.

Big shells I glue the 1/4" card tube into the hemi with a QM tail to the centre of the sphere. The Time fuse I glue into the tube when it's all dry and probably fully pasted. that way I don't damage the crossmatching with gummed paper tape.

Always there is a string and glue fillet round the time fuse to prevent the fire by-passing the timer or pushing the time fuse into the shell.

For crossmatching I cut the end of the time fuse and push a piece of BM into the slit then tie together again with thin string.


Pretty traditional methods there. No one can argue against the methods you site but I like to punch my time fuse just because I can no longer tie all of those knots.
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#11 Arthur

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Posted 07 July 2010 - 01:44 PM

With the bigger shells the crossmatches time fuse is a component that can be made and dried in advance. So I can make the time fuses crossmatched with BM and the BM held into the cut in the time with a dextrinated BP paste, they are fully dry in a few days and then can be built into the shell and lift cup.

The cheat method is to slit the time fuse for 5mm and wedge it open with a single large grain of BP. No glue no problem so far.

#12 dagabu

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Posted 07 July 2010 - 03:15 PM

With the bigger shells the crossmatches time fuse is a component that can be made and dried in advance. So I can make the time fuses crossmatched with BM and the BM held into the cut in the time with a dextrinated BP paste, they are fully dry in a few days and then can be built into the shell and lift cup.

The cheat method is to slit the time fuse for 5mm and wedge it open with a single large grain of BP. No glue no problem so far.


I understand, the Chinese wet dip almost all of their shells and expect them to dry in shipment to the states. I have opened plenty of duds and have found that there are two things that happen that keep the shell from breaking. Taking fire or giving fire.

Taking fire: 3" ball shells seem the be the biggest culprits. Some have all of the prime burnt off the time fuse and the tar is melted over the core, some have all of the prime in place, some have an exposed core, all the prime burndt off and no fire in the core. When I open the core up, the color of the core is darker and chunky indicating wetness.

Giving Fire: The core burns to the prime and stops. Removing the prime I see that there is a coating, shiny, taste test shows it to be sulfur. Water in the BP, sulfur is spit out blocking the fire from the prime.
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#13 Weirdo

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Posted 01 September 2010 - 05:36 AM

That is a really handy siccor that you have there, dooes it have a special name or something? Where did you buy it?

#14 dagabu

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Posted 01 September 2010 - 07:05 AM

That is a really handy siccor that you have there, dooes it have a special name or something? Where did you buy it?


Those are made for SEARS and K-Mart and are called "Handi-Cut" shears. Gerber also has a good version that is a little cheaper called "Superknife".

I have several pairs of shears but these are my favorites and can easliy be transformed into precision time fuse cutters.
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#15 Bonny

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Posted 01 September 2010 - 08:56 PM

I slit my timefuse with a razor blade and then insert the BM. I've never tied any, but instead use a BP/NC slurry to glue/seal the end together. I've even glued the end with NC only and have never had an ignition failure. My "NC" is the ping pong ball/acetone variety.


The cheat method is to slit the time fuse for 5mm and wedge it open with a single large grain of BP. No glue no problem so far.


Great idea, I'll have to try that sometime.

Those are made for SEARS and K-Mart and are called "Handi-Cut" shears. Gerber also has a good version that is a little cheaper called "Superknife".

I have several pairs of shears but these are my favorites and can easliy be transformed into precision time fuse cutters.


There is also a type made by Henkel(?) that are excellent, but hard to find. Usually can be found in high end knife/cutlery/pots and pans places.

#16 Weirdo

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Posted 03 September 2010 - 08:41 AM

Thanks, I think I will buy one soon. I really like the idea of a precision timefuse cutter.

#17 808goboom

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Posted 02 July 2013 - 09:24 PM

How do you replace time fuse with visco fuse on the passfires....help me out....tutorial would be great

#18 Tim1877

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Posted 03 July 2018 - 06:30 PM

What if you put a little meal dust in the pass fire tube would that work?
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#19 Mumbles

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Posted 03 July 2018 - 09:45 PM

I would feel a little more comfortable with granular bp. It has more paths for fire to catch and transfer.

I've seen it done successfully with WASPed shells.
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#20 Arthur

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Posted 07 July 2018 - 02:09 AM

Most masking tapes are made with a short life adhesive, it's done to facilitate removing the tape after a painting job. If you intend to build a shell then fire it within a few days then it's fine but if you intend to have professional stock which might stay in a (hot) store for months then masking tape is not good and gummed paper tape should be used. 






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