Beraq Insert Timing - Maltese Slurry Method

[cmjlab]

I've made many timed insert shells using Chinese Timefuse (TF).  However, the price of TF is much less attractive these days, and I've been wanting to mess around with the Maltese method of timing their inserts using a B.P. slurry with Gum Arabic or some other binder.

Has anyone messed around with different timings by varying the percentage of binder?  I'd like to start with this first, before changing other variables (as I've seen discussed in the past). 

My thought was to start with mill dust and make 100 gram batches with a varying percentage of binder, starting at 1% and increasing by 10% with each batch / timing.  (I.e. 1st ring has 1%, 2nd ring has 10%, 3rd ring has 20%, etc.) 

Anyways, I was hoping someone would have some prior experience they'd be willing to share.  I did ask about general beraq inserts over on FW.com, but was looking for some different perspective on the actual slurry timing element of it all. Thanks!

Chuck

[FrankRizzo]

Mumbles re-uploaded Karl's excellent tutorial in this thread a few years back -

Discussion off-site with a few fellows that use the technique suggest adding the GA in increments of 5%.

 

[cmjlab]

Appreciate the link to the file, as well as the increment suggestion.  That was primarily what I'm hoping to learn - so I will start with 5% increments, I only plan on 2 and 3 timings to begin with.  The more I add, the longer the shells gets.

I'm still having an internal dialogue about piercing before vs. after.  I realize that some old timers promote piercing the hole prior to full, for obvious safety reasons.  Yet, I am curious why in Malta after years of beraq shells, they still pierce the hole after the insert is finished.... it would seem to me that it would remove additional variations between inserts. 

I will prob make a couple shells both ways to compare results.  

  Thanks!

[Carbon796]

The beraq cases aren't self supporting until they're filled. So piercing them afterwards is probably just a faster/cleaner/simpler more consistent way of producing them. Piercing them before hand will require an additional step to support the case while it's being pierced. 

I've also heard that the pierced hole size is also varied to affect timing.

There is a very slight variation in timing among the inserts. There is a certain "crash" when a ring of beraq inserts go off. Its easy to pick up on, when American amateurs try to copy it with TF. The the timing can be too exact. And they just don't sound/look right. They often also use too few inserts/rows per displayed ring.

Edited November 25 by Carbon796

[cmjlab]

5 hours ago, Carbon796 said:

The beraq cases aren't self supporting until they're filled. So piercing them afterwards is probably just a faster/cleaner/simpler more consistent way of producing them. Piercing them before hand will require an additional step to support the case while it's being pierced. 

I've also heard that the pierced hole size is also varied to affect timing.

There is a very slight variation in timing among the inserts. There is a certain "crash" when a ring of beraq inserts go off. Its easy to pick up on, when American amateurs try to copy it with TF. The the timing can be too exact. And they just don't sound/look right. They often also use too few inserts/rows per displayed ring.

Appreciate the input.  That makes sense about piercing the inserts after they are filled due to being too soft prior.  

As for number of inserts, I would like to do a 5" shell with a single ring of earrings (I've seen them called) since I can fit a lot in a single row (25 or so).  Then 2 rings of inserts for 2nd and 3rd timings.  They start to get really long at that point, and I don't have the confidence to build a multibreak with shells that long put together.......yet.  But I'm getting ahead of myself, I still have to figure out the slurry fusing/priming.

[Carbon796]

Are you referring to the length of the individual breaks or the total length of the shell ?

[cmjlab]

Length of the individual breaks and I suppose overall shell too.  I've built 3 break (with last containing bottom shot), and had it be up to the top of the mortar for 4" shells. For 4 or 5 rings, they must stick out the top of the mortar for even 5" and 6" shells?

Lengths of tubes I've been using for timed report inserts have been:

- 1 3/4":  Single Ring, small diameter (3/8" ID) inserts (4" Shells) // 2 Rings for 5" & 6" Shells)

- 2 1/4"":  2 Rings tall, medium diameter inserts (1/2" or 5/8" depending on nominal shell size).

- 2 1/2": 2 Rings of 5/8" (4" Shells)

- 2 1/2":  2 Rings of 3/4" ID (5 & 6" Shells)

I don't know how people have achieved 5 & 6 rings of timed inserts.  I struggle to get my hands down 4" and 5" shells to stack and put shims between inserts.  Plus those individual breaks must get close to 20" long?  Wish I could join a local builders club to learn from others more experienced, in person.  

Edited November 26 by cmjlab

[Carbon796]

It sounds like you're relying on commercially available tube's. Traditionally they would be hand rolled cases. If I wanted to build a 5 or 6" beraq shell. I would probably be rolling cases on a 3/4-7/8" former. So that the finished OD was 1". Which fits nicely into a 5 or 6" case without needing shims. And a finished length of 1" to 1-1/4".

All of the timed rings do not need to be stacked vertically. You can have a second or third timed ring nested inside of the outer timed ring. 

[Carbon796]

There is a natural progression of size/technique/skill. That the Fulcanelli papers follow, for building 5" cylinder shells.  In PT IX & XI. I would start there to become confident/competent with larger shells.

For filling smaller shells that your hands don't fit well in. Once your case is rolled up on the former. Slide it up the former until you have the length needed for, your pleats/end disk and 2-3 rows of inserts/comets. Lightly tape the case to the former, so it won't slide down. Fill inserts/comets, insert the end disk/spolette. Flip the case over on the former. And finish the last 2-3 rows of inserts/comets. Fill with burst, add end disk, pleat/outer disk, or tongue fold the end. Flip the shell over on the table to finish the first side. Pleat and add outer end disk. This saves you from having to reach all the way to the bottom. In smaller cases/inserts.

Edited November 26 by Carbon796

[Mumbles]

There is some wiggle room in shell length, but I start to get kind of nervous when the breaks are more than about 1.5-2x the diameter of the shell. That can be nominal diameter or actual ID, it's not that different. I take a certain degree of care when building so I haven't had a lot of flower pots in my day, but disproportionately they've been from really long breaks. If I were rebuilding some of those shells today, I know what I'd do to try to prevent it, but it's not something I'm all that keen on experimenting with either.

One method that can be used to accommodate a seemingly exaggerated number of timings from what amounts to a single break is known as a "compartment shell". It gives the effect of what would normally be a comically long break with most of the structural integrity of a typical length break. They're built exactly like a normal multibreak, but the spolette has no BP rammed into it, just some sticks of blackmatch tied in place to ensure good fire transfer. When the first break goes, they should all go.  I've only made a couple of shells coupling two breaks together this way, so I don't have a lot of advice other than generalities of how it's supposedly done.  In those cases I was playing around with different bursts in different breaks, trying to go with a heavier hand on the flash booster than I was comfortable with in a single casing. It was more than just a dusting, and I was worried about migration. The shells worked, but I can't say if it was more effective than just building them all in one casing. It did seem like I got better spread on the inserts, but there were a few variables at play.  

I agree with Carbon, there's a certain appeal to the tight but slightly random timing of good Maltese Beraq. I've been told it can be replicated with time fuse by dipping the flush cut end in slurry and dipping that in granulated BP. It gives just enough randomness to it to make it from being too perfect.  It's only from pictures on the internet and third party information, but it seems builders in Malta are using a lot more time fuse and machine wound cores these days. I can't argue against the romance of being able to do it the traditional way however.    

[cmjlab]

Gentlemen - thanks for the feedback and suggestions. I like the idea of a "compartment shell", I can't recall where I saw an article on that though (it must have been Passfire.com since my subscription expired a while ago).  Also an excellent suggestion for filling those tighter shells 4" and 5")!!

The "Fulcanelli Articles" are the first book I purchased (FW.com combined them both into one book / document) and my most studied/read book as well.  It does contain excellent information, up to a certain point.

I now have my flash granulated and ready to start filling inserts.  We shall see how it goes!

[Carbon796]

If you look at the larger single brk shells in PT XI. Like Hammer shells/SoS/Timed Spiders. That are over 1.5 x length. As Mumbles describes above.

They are more about audible cadence and timing, than the actual shell display symmetry. Usually you're actually trying to remove any displayed symmetry from them. They only have 4 inserts per row. There's not a whole lot of symmetry your going to be able to pull out of them.  But, if your more on the order of 10+ inserts per row and and over 1 X in length. And symmetry is a primary concern. I would definitely be looking at a compartment type build, that Mumbles mentions above.

Edited November 26 by Carbon796

[cmjlab]

So based on some feedback - I did roll some tubes of my own that were shorter to make inserts with. Just enough to test a couple smaller 4" shells, before putting the large amount of work it would take to make much more.  Some were rolled a bit thicker to see if that helps provide a bit of timing between rings as well. 

I have them filled and closed, but they will get one more round of glue to fill inn any pin holes.  

I know this is a departure from real beraq inserts, but this is meant to be an exercise in slurry fusing / priming, and to see if it's something I can even dial in, or if I continue to buy super expensive TF (which would become a significant expense).

[Carbon796]

If you're piercing those after the fact. Make sure you're using a blast shield.

Elemer's had a fortified wood glue that dried nicely for fillets around CtoR inserts. It dried with very few if any, voids/air pockets. 

 

[cmjlab]

I am piercing them once they are complete (minus slurry).  I'm tracking on the risks associated with flash, and flash inserts, but thank you for bringing it up. Since I want to share my progress here, I should also include my safety mitigation steps.

To be honest, I'm still not sure I care for the idea, but I want to see firsthand what difference there is between punching before fill vs. after.

I will punch them out away from anything else, using an extra 1 ton Arbor Press I dont use anymore.  Since the press ram is pre-drilled to accept a 1/2" OD accessory, I will use a 1/2" OD AL round stock, turned down to 1/8" ID at the end as a depth guage to ensure a consistent depth on each insert (which consistency is the most important to timed inserts IMO).

To hold and center the inserts under the punch, I will use a wooden V block clamped to the press table. This also mitigates accidentally punching through the tube and hitting the steel press table.

For a shield, I could use the shield off my 3t Arbor press, but more likely will use a sheet of 3/4" plywood, setback a couple feet from where the inserts will be punched.  In my experience, that should be plenty of setback to ensure the plywood doesn't turn into shrapnel if the worst should happen while punching the inserts. In order to rraxh the handle on the press, i have a 4 ft. extension fir the press handle, which puts me more than enough behind a shield.  

I will wear eye protection....bit that will be a large part of the assumed risk.  Shrapnel from an accident getting my eyes which won't be behind the shield (I still need to see what I am doing).  Gloves, cotton clothes, and other obvious stuff will be used.

In the end, I hope there is no difference between punching before and after - the safest way is not to punch them after they are filled.  However, I still bet there is a noticeable difference......

 

[cmjlab]

Just an update to track my progress....

I dug out my old 1t arbor press, bolted it up to some scrap wood and drug it out to the yard.  The ram was not pre-drilledlike I thought (similar to my 3t arbor press), so I just hose clamped the brass punch to the front face of the ram (see 1st photo below)

I used scrap wood to make a V block to act as a centering jig and hold my inserts in-place while they were punched.  I put a wood "bridge" over the V block to wipe the inserts off the punch when the ram is lifted.  I used scrap wood blocks as a depth guage by placing them under the ram to restrict its travel and prevent the punch from piercing both sides of the tube.

The photo is a bit fuzzy, but here's a look at my quick set-up (minus the plywood shield I scrapped together which stood betwen me and the press, only exposing my gloved hand to the insert if the worst happened).

(The long handle extension is also obscured, but it was just electrical conduit pipe slipped over the existing handle.)

For safety, I set up a good distance from my house (my shed is pretty far from the house anyways, about 25 - 30 feet behind where the canopy is.)

I ended up getting all my inserts punched with this setup, by just changing the depth blocks for the different sized inserts.

In full disclosure -  I will say that I did not enjoy the suspense of waiting for an insert to be set off by the friction from the punch, since I granulated the comp.  I had a lot of safety in place and knew the risk of being seriously hurt were minimal - yet the suspense was not any less.  Thankfully, it did not happen.

( I only show the larger inserts here, I went back and finished the smaller inserts after taking this photo)

I made up some small 5/16" inserts to test the Gum Arabic (GA) slurry timing out of a star gun.  My plan is to determine if  5% incremental increase of GA is enough to provide time / separation between rings of inserts.  They were made up with 10%, 15%, and 25% GA slurry, which I hope will provide the rhythm you hear in Maltese beraq videos.

[cmjlab]

Also an observation from punching filled inserts....

I did notice that because the tubes were filled, the punch created a small, completely enclosed, tube like opening of paper which extends past the inside edge of the tube and into the granulated flash. The tube was formed from the paper it pushed out of the way to make the hole, but not torn as much because the fill acts as a support of sorts (like using sand as a casting mold around a object you want to cast, except in this case it's paper around a punch). 

So I tried piercing an empty tube from the same batch of homemade tubes, it did push paper into the tube, but it did NOT make a fully enclosed tube like the filled inserts. 

I believe Mumbles speculated on this as being a potential factor that could affect timing, and may be a reason at least some of the Maltese shops still pierce them filled. 

I think I agree in concept based on what I observed, in my mind its like a mini spolette once filled with B.P. slurry, where the length of the formed mini tube extends the time it takes to get to the comp inside the insert.  I also realize that I may not have the consistency in my process *yet* to capitalize on this factor and manipulate the timings on the inserts.

Sorry for the long posts, I wanted to capture and share what I learn along the way (for better or worse, success or failure), in hopes it will help someone else.  At worst, I didn't want to put everything into a document that people would have to download and/or may eventually get lost.

[DecimusMaximus]

18 hours ago, cmjlab said:

Just an update to track my progress....

I dug out my old 1t arbor press, bolted it up to some scrap wood and drug it out to the yard.  The ram was not pre-drilledlike I thought (similar to my 3t arbor press), so I just hose clamped the brass punch to the front face of the ram (see 1st photo below)

I used scrap wood to make a V block to act as a centering jig and hold my inserts in-place while they were punched.  I put a wood "bridge" over the V block to wipe the inserts off the punch when the ram is lifted.  I used scrap wood blocks as a depth guage by placing them under the ram to restrict its travel and prevent the punch from piercing both sides of the tube.

The photo is a bit fuzzy, but here's a look at my quick set-up (minus the plywood shield I scrapped together which stood betwen me and the press, only exposing my gloved hand to the insert if the worst happened).

(The long handle extension is also obscured, but it was just electrical conduit pipe slipped over the existing handle.)

For safety, I set up a good distance from my house (my shed is pretty far from the house anyways, about 25 - 30 feet behind where the canopy is.)

I ended up getting all my inserts punched with this setup, by just changing the depth blocks for the different sized inserts.

In full disclosure -  I will say that I did not enjoy the suspense of waiting for an insert to be set off by the friction from the punch, since I granulated the comp.  I had a lot of safety in place and knew the risk of being seriously hurt were minimal - yet the suspense was not any less.  Thankfully, it did not happen.

( I only show the larger inserts here, I went back and finished the smaller inserts after taking this photo)

I made up some small 5/16" inserts to test the Gum Arabic (GA) slurry timing out of a star gun.  My plan is to determine if  5% incremental increase of GA is enough to provide time / separation between rings of inserts.  They were made up with 10%, 15%, and 25% GA slurry, which I hope will provide the rhythm you hear in Maltese beraq videos.

Looking forward to your results! Did you test the different GA concentrations in a star shooter as well? It would be interesting to see what % GA increase correlates to what timing. 

[Zumber]

On 11/30/2024 at 9:20 AM, cmjlab said:

Just an update to track my progress....

I dug out my old 1t arbor press, bolted it up to some scrap wood and drug it out to the yard.  The ram was not pre-drilledlike I thought (similar to my 3t arbor press), so I just hose clamped the brass punch to the front face of the ram (see 1st photo below)

I used scrap wood to make a V block to act as a centering jig and hold my inserts in-place while they were punched.  I put a wood "bridge" over the V block to wipe the inserts off the punch when the ram is lifted.  I used scrap wood blocks as a depth guage by placing them under the ram to restrict its travel and prevent the punch from piercing both sides of the tube.

The photo is a bit fuzzy, but here's a look at my quick set-up (minus the plywood shield I scrapped together which stood betwen me and the press, only exposing my gloved hand to the insert if the worst happened).

(The long handle extension is also obscured, but it was just electrical conduit pipe slipped over the existing handle.)

For safety, I set up a good distance from my house (my shed is pretty far from the house anyways, about 25 - 30 feet behind where the canopy is.)

I ended up getting all my inserts punched with this setup, by just changing the depth blocks for the different sized inserts.

In full disclosure -  I will say that I did not enjoy the suspense of waiting for an insert to be set off by the friction from the punch, since I granulated the comp.  I had a lot of safety in place and knew the risk of being seriously hurt were minimal - yet the suspense was not any less.  Thankfully, it did not happen.

( I only show the larger inserts here, I went back and finished the smaller inserts after taking this photo)

I made up some small 5/16" inserts to test the Gum Arabic (GA) slurry timing out of a star gun.  My plan is to determine if  5% incremental increase of GA is enough to provide time / separation between rings of inserts.  They were made up with 10%, 15%, and 25% GA slurry, which I hope will provide the rhythm you hear in Maltese beraq videos.

Eagerly waiting to see results...

Nice job, wel done .!

[cmjlab]

19 hours ago, DecimusMaximus said:

Looking forward to your results! Did you test the different GA concentrations in a star shooter as well? It would be interesting to see what % GA increase correlates to what timing. 

I hope to test them tonight, as I don't want to slurry all of the inserts until I know how the timing will work out.  I made the smallest little shell ive ever made to test 3 of each timings. My worry is that how much you slurry you press in needs to be perfectly consistent as well.  

Either way, good or bad, ill share my results.  

[Almostparadise]

🍿

[Carbon796]

I recall reading/hearing somewhere. That's it's very important for the slurry priming to dry well, for precise timing. Like on the order of weeks not days. I can see the higher concentrations of GA. Possibly taking longer to dry. Just an FYI not trying to discourage you from testing them.

Edited December 1 by Carbon796

[cmjlab]

Wish I got on here before firing that test shell..   🙂  That is interesting and probably right, I forgot that it was water based slurry and it was prob not dried on the inside yet.  (I will have to make another test, and see if it improves the results).  

As promised, for better or worse......  It did not work great, I need to figure out how to get more consistency between inserts, when applying the GA slurry  There are 3 timings, but there is a 4th straggler which I knew probably would happen when I saw ot had a thicker B.P. granules layer than the others.  I should have fixed it.  

Photo 1. Shows 9 Inserts + one spacer insert (nothing in it) to make them fit.

Photo 2. The smallest shell I've made.

First test (though my slurry may not have been primed as one pointed out to me. ) Never good when the excuses come before the video....

I will make another shell up, but I think I will focus on consistency between inserts to improve timing, and I'll make a real shell with a full amount of inserts.