The Armour Archive

Posted: **Fri May 13, 2011 10:28 am**

BdeB wrote:I have talked to the marshall of the Atlantian practice that had a polypro fail, rather epically this week. It was purchased from Brast Industries and this was its second time being used. It sounds like there was an inclusion or bubble in the rod material. The break was L shaped and the part that flew off travelled some distance (it was nearer the foible than the forte). The marshall has taken pictures and was on his way to another practice to inspect the broken part of the sword last night to see if the smaller portion of the breakage could have entered a legal helmet grill. He is reporting his finding to our Earl Marshall and I suggested and he copy Sir Omarad on that.

The most distressing part of this breakage is that unlike rattan the poly, when it failed, did not simple mush up, but became a projectile (still larger than a thin shafted arrow but... ). Also since the break was closer to the tip it moved at a high arch with some velocity. (When a similar rattan weapon breaks it is usually at the grip rather than at the tip, and the long body of the sword tends to drop over to the ground rather quickly.)

From what I understand this sword was wrapped in duct tape, which did nothing in and of itself to keep the end of the sword from falling off. I asked if strapping tape was used and the marshall did not believe it was. I believe that an application of strapping tape might have made a difference in how this thing broke, but I can't prove that as of yet.

I am of course, a fan of this material for practice purposes, but I think in the interest of disclosure we need to report the good and the bad as they happen to have a clear picture of wheither or not this should be allowed for general use.

I want the good and the bad.
But we also need to remember that there are hundreds of these out there and have been for years.
We also need to rememberthat rattan does break just like that sometimes.
I've seen 6"-8" chunks of rattan fly into crowds in the past.
It just depends how it breaks.
I will call Brast myself.
The other Breaks were McMaster and another supplier.
Both mushed or broke clean but hung from strapping tape.

Posted: **Fri May 13, 2011 11:11 am**

See I think strapping tape is KEY. I know it adds weight and these are heavy already but from a safety standpoint, even one wrap half way down the sword would help a 'fly off'.

Posted: **Fri May 13, 2011 11:22 am**

BdeB wrote:See I think strapping tape is KEY. I know it adds weight and these are heavy already but from a safety standpoint, even one wrap half way down the sword would help a 'fly off'.

I agree

Posted: **Fri May 13, 2011 12:57 pm**

Corby de la Flamme wrote:If you paid $30 for 36" of it, you either got something different, or really overpaid.

Amos is getting them for <$15 per 36".

I count shipping cost in the purchase as well.

Posted: **Fri May 13, 2011 1:23 pm**

Mcmaster Carr just charged me $13 for a 3 foot stick, plust $4 for shipping. Total bill of $17.

Posted: **Fri May 13, 2011 1:35 pm**

The piece I got says - Tecafine P/P Dia 1.250 - on it and I did have it wrapped from tip to hilt in the crossed pattern 2" strapping tape and an outer layer of 1.5" athletic tape with a single strip of electrical tape to mark the "blade"

When it broke it basically shattered into 3 pieces. The piece I had in my hand, a small wedge shaped chunk in the middle of the break and about a 6" chunk that flew off and fortunately hit the ground a few feet away since the swing was at a downward angle.

As you can see from the picture below the small wedge would easily go into a helm and could pose a potential issue. The larger chunk off the end could have also easily flown 20'" to 30 feet no problem if it had been a sideways stroke rather than a downward stroke.

I took these pictures after I had cut the jagged end off of the main section of the stick which I then used to make a pell stick for my kid and I used another portion to make quillions for my secondary sword used at Estrella. It did work well for that application. :wink:

Posted: **Fri May 13, 2011 2:09 pm**

These swords make you think they are landing with more force somehow, but they don't seem to transfer as much energy through the helmet and into the head.

Posted: **Fri May 13, 2011 3:36 pm**

I wouldn't know, I broke mine on my opponenets leg.

Posted: **Fri May 13, 2011 8:59 pm**

Vitus,

I'm sure this won't be a surprise to you, but I haven't found this to be the case.

Got a representative sample of hits at most parts of the blade, both forte & foible?

Posted: **Sat May 14, 2011 4:24 am**

Vitus von Atzinger wrote:These swords make you think they are landing with more force somehow, but they don't seem to transfer as much energy through the helmet and into the head.

Sounds like a good subject for a high speed video.
Lets see if we can set it up for Border Raids.

Tom

Posted: **Sat May 14, 2011 7:31 am**

We had a spun-top helmet nearby and we were smacking each other pretty damn hard with it. It was strange, because one guy would have a reaction like "I felt that all the way down my spine. Don't hit me with that again." while the next guy would say "If you think that hits harder than your usual rattan sword you are seriously mistaken."

When it was my turn I noticed that the sound the thing made against the helmet was wayyyy louder than normal, but it really didn't seem like it was giving me that pain-in-the-center-of-your-head feeling at all.

It was extremely confusing.

Posted: **Sat May 14, 2011 8:30 am**

Vitus,

Were these variations on feel at all related to where on the sword someone was hit?

Posted: **Sat May 14, 2011 12:18 pm**

Vitus von Atzinger wrote:We had a spun-top helmet nearby and we were smacking each other pretty damn hard with it.

Well that's the problem right there. Don't hit each other with helmets. It's not a good way to test these sticks. :lol:

Posted: **Sat May 14, 2011 12:19 pm**

so anyway Tecafine P/P ,<--- is that the right stuff or not?

Posted: **Sat May 14, 2011 12:22 pm**

Count Johnathan wrote:so anyway Tecafine P/P ,<--- is that the right stuff or not?

yes.
Use google for gods sake.

Posted: **Sat May 14, 2011 12:52 pm**

OK then. This material is crap and breaks in a manner that can and has produced small slivers of jagged plastic that can enter into the eyeslot of a helmet as well as throwing large heavy chunks of rigid material great distances regardless of strapping tape.

I provided pictures for your viewing pleasure. Please do not disregard them.

Posted: **Sat May 14, 2011 6:27 pm**

Yes, if you hit a person in the sweet spot of the stick it was obviously bending UPON impact. We didn't do any mid-stick or short stick kablasting. There were just wildly different reactions to being hit with it. It just seemed outrageously loud to me.

Posted: **Sat May 14, 2011 8:34 pm**

Sir Omarad wrote:
Count Johnathan wrote:so anyway Tecafine P/P ,<--- is that the right stuff or not?

yes.
Use google for gods sake.

Depends, there are different types of polypropylene.

http://www.bpf.co.uk/Plastipedia/Polymers/PP.aspx

Homopolymers - A General Purpose Grade that can be used in a variety of different applications.

Block copolymers - incorporating 5-15% ethylene, have much improved impact resistance extending to temperatures below -20oC. Their toughness can be further enhanced by the addition of impact modifiers, traditionally elastomers in a blending process.

Random copolymers - incorporate co-monomer units arranged randomly (as distinct from discrete blocks) along the polypropylene long chain molecule. Such polymers typically containing 1-7% ethylene are selected where a lower melting point, more flexibility and enhanced clarity are advantageous.

Different PP grades are available dependent on the application and chosen processing method.

TECAFINE™ PP (Polypropylene)
http://www.totalplastics.com/products/328
"Tecafine™ PP (polypropylene) is a polypropylene, random copolymer polyolefin engineering plastic"

Now if you go back to the previous page, my posts towards the top I posted an image of the label that came on my 3' rod from McMaster-Carr. It is listed on the label as co-polymer 7823. A google search on co-polymer 7823 turns up a product call Pro-Fax 7823 by LyondellBasell. That matches the information on the MSDS I requested from McMaster-Carr. Pro-Fax 7823 is a Polypropylene Impact Copolymer.
From that I can gather from the MSDS, property specs on the Lyondell Basell website, and specs found online for the different types of Polypropylene, I'm thinking that Impact copolymers are a class of Block copolymers or specialized Block copolymers that have become a new type in the industry. It is not a Random copolymer of any type that I can see.
So, In my opinion, what I have and Count Johnathan have/had are both polypropylene rods but are of different types of polypropylene makeups. If anything, this means we have to pay attention to the type or polymer makeup.
Has anyone that has gotten a stick from McMaster-Carr had an issue?

Posted: **Sat May 14, 2011 9:36 pm**

From http://www.fhr.com/chemicals/polymers/p ... ymers.aspx

Impact copolymer polypropylene is a crystalline polymer which exhibits high stiffness, excellent impact strength at temperatures well below freezing, and good electrical insulation properties. The commercial grades of polypropylene impact copolymer are available in a wide range of melt flows, impact strengths and molecular weight distributions.

http://www.lyondellbasell.com/Products/ ... propylene/
Polypropylene (PP) impact copolymers are thermoplastic resins produced through the polymerization of propylene. Copolymers are created by introducing a heterophasic structure
inside a semi-crystalline PP homopolymer matrix.

http://www.borealisgroup.com/innovation ... haList='H'
Heterophasic copolymers
Heterophasic copolymers (HECO) also contain ethylene (and possibly higher a-olefins) as comonomer. The production is however carried out in a two-stage process, resulting in a multiphase structure with a homopolymer matrix and inclusions consisting of amorphous EP-copolymer (rubber) and crystalline PE. Variations of molar mass and composition of the elastomeric phase in relation to the matrix allow a wide variation of properties (stiffness, toughness and transparency).

Posted: **Sat May 14, 2011 10:04 pm**

every bit of data I get is taken into consideration.
No decision on this stuff will be made until after Pennsic anyway.
There's no rush.

Posted: **Sat May 14, 2011 10:17 pm**

That is interesting and makes sense. What I saw in the BAmos video was definately a different kind of break so I guess not all polypropylene rods are created equal.

So I will correct my previous statement and say Tecafine PP is crap. If you get it send it back and get the right stuff.

Posted: **Sun May 15, 2011 3:35 pm**

This is exactly why we conduct experiments and why we need as many Kingdoms as possible to try things out.
Styles, usage, temps/climate, all vary.
The more we have, the better the end result data.

Posted: **Sun May 15, 2011 6:01 pm**

Vitus von Atzinger wrote:We had a spun-top helmet nearby and we were smacking each other pretty damn hard with it. It was strange, because one guy would have a reaction like "I felt that all the way down my spine. Don't hit me with that again." while the next guy would say "If you think that hits harder than your usual rattan sword you are seriously mistaken."

When it was my turn I noticed that the sound the thing made against the helmet was wayyyy louder than normal, but it really didn't seem like it was giving me that pain-in-the-center-of-your-head feeling at all.

It was extremely confusing.

Since every helmet and every strapping and padding system is different I'm finding it very hard to believe this was any sort of useful test. Also, I am still concerned that you equate a telling blow with Pain in your membrane, which you have in several posts in different forums. I'd suggest seeing a doctor, and or an armourer, V. That isn't normal.

I also don't tend to stand flat footed and let people hit me as hard as they can in the head and call that any sort of acknowledgement test.

Posted: **Mon May 16, 2011 5:05 pm**

We weren't hitting as hard as we could.

Posted: **Wed Nov 02, 2011 11:57 am**

Does anyone have any updates on recommended suppliers and part numbers?

Posted: **Wed Nov 02, 2011 2:12 pm**

I'm still using mine, going on it's 14th month. I need to shoot some more pictures and re tape it!

Posted: **Wed Nov 02, 2011 3:32 pm**

BdeB wrote:I'm still using mine, going on it's 14th month. I need to shoot some more pictures and re tape it!

Where did you buy it & part number?

What modifications have you made?

Posted: **Wed Nov 02, 2011 3:33 pm**

I have some pieces and I cant use them where I live.

Posted: **Wed Nov 02, 2011 4:02 pm**

Nissan Maxima wrote:I have some pieces and I cant use them where I live.

PM Sent.

Posted: **Wed Nov 02, 2011 8:05 pm**

The experiment is going well and with very few problems.

Posted: **Wed Nov 02, 2011 9:27 pm**

Sir Omarad wrote:The experiment is going well and with very few problems.

Really? I can still use my polypro swords in the midrealm?

Posted: **Wed Nov 02, 2011 9:42 pm**

If there are different versions of this material with different physical properties as Johnathan's and some other posts suggest, is there any way for a marshal differentiate between them?

Posted: **Wed Nov 02, 2011 9:49 pm**

Not without a mass spectrometer.

Posted: **Wed Nov 02, 2011 10:14 pm**

Thanks, that's what I was thinking, I wanted someone a bit more knowledgeable to confirm it before I looked like an idiot.

Posted: **Wed Nov 02, 2011 10:40 pm**

bigfredb wrote:Does anyone have any updates on recommended suppliers and part numbers?

McMaster Carr. Take a look at my posts starting with the last post on page 13.

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