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Tom_Restorer
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It is a hand grenade Rüdiger.
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It is a hand grenade Rüdiger.
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Tom_Restorer
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Just happen.... I looked inside with a candle because my endoscope had a black out.......... Booooooooom
I will post photos of the grenade parts, my destroyed lab and the dead cat from my neighbor when I stoped bleeding
Btw. C A N Y O U I M A G I N E how it hurts to type with just one bleeding finger
! LOL The positiv on it, I am looking like a real pirate now without a sinlge hair !! Aaaaarrrrrg
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Tom_Restorer
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Here are the removed ropes (Fuse) before cleaning. Front and backside
Hope you can see the tar wich was used to fix them on the grenade.
Tomorrow I upload pics from the cleaned pieces.
Still working on the removal of the canvas.... It is heavy stuck on the rust layer.
Hope you can see the tar wich was used to fix them on the grenade.
Tomorrow I upload pics from the cleaned pieces.
Still working on the removal of the canvas.... It is heavy stuck on the rust layer.
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Tom_Restorer
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Update:
Canvas is now removed and the plug pulled out.
The grenade gets now an air abrasion cleaning (with round micro glass beads, becasue they don´t damage the surface of the black iron oxyde like sharp abrasion material does) and than it goes into controlled electrolysis.
In this time I clean the removed canvas from the backside.
The iron is approx 1 cm thick. The black powder was scretched out and got safed. The plug was fixed with rope and resin - as it is to see on the last picture.
The plug has a drilled hole of 6 mm diameter and a larger one with 19 mm on the top wich is half filled with a very hard material - so just the fuse can pass to the hole.
The weight of the gun powder - also from inside the plug - will be posted later, as well as the weight of the empty grenade.
Canvas is now removed and the plug pulled out.
The grenade gets now an air abrasion cleaning (with round micro glass beads, becasue they don´t damage the surface of the black iron oxyde like sharp abrasion material does) and than it goes into controlled electrolysis.
In this time I clean the removed canvas from the backside.
The iron is approx 1 cm thick. The black powder was scretched out and got safed. The plug was fixed with rope and resin - as it is to see on the last picture.
The plug has a drilled hole of 6 mm diameter and a larger one with 19 mm on the top wich is half filled with a very hard material - so just the fuse can pass to the hole.
The weight of the gun powder - also from inside the plug - will be posted later, as well as the weight of the empty grenade.
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Tom_Restorer
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Not yet Mate! Let´s wait until it is finish! :-)
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Tom_Restorer
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Weight:
Grenade: 443,2 Gramms
Black Powder - from Grenade: 19 Gramms
Black Powder from inside the Plug: 0,6 Gramms
Diamater of the grenade: 7.8 cm
I guess it has had a complete weight of approx 0.5 Kilo in 1686
Even if there was a heavy layer of corrosion, this Rust has not much weight at all. The corrosion is often some thousand % of the iron wich was converted.
Anyway, 0.5 Kilo is a good weight to throw it a nice range to an other ship.
The exact thickness of the iron is 1 cm
Sorry that I don´t convert it into inches and lb, but I WILL NOT use this kind of "measurment" :-) :-)
The wooden plug is in great perfect condition. The resin has completly saved it and there is absolutly no need for an PEG treatment.
On monday comes the pics of the grenade after air abrasion.
The endoscope view from inside comes after the electrolysis. Makes no sense yet when rust and traces of powder cover everything.
Regarding my question in my first post: I found out now that the canvas was completly fixed at the plug and the grenade with resin and the part around the plug down to the neck of the grenade was also covert with resin from the outside.
I think now it had two reasons.
1. to protect the gunpowder from humidity
2. to hold the plug in position until the grenage explodes and to avoid that just the plug gets blown out.
So they fixed this two problems with it.
Grenade: 443,2 Gramms
Black Powder - from Grenade: 19 Gramms
Black Powder from inside the Plug: 0,6 Gramms
Diamater of the grenade: 7.8 cm
I guess it has had a complete weight of approx 0.5 Kilo in 1686
Even if there was a heavy layer of corrosion, this Rust has not much weight at all. The corrosion is often some thousand % of the iron wich was converted.
Anyway, 0.5 Kilo is a good weight to throw it a nice range to an other ship.
The exact thickness of the iron is 1 cm
Sorry that I don´t convert it into inches and lb, but I WILL NOT use this kind of "measurment" :-) :-)
The wooden plug is in great perfect condition. The resin has completly saved it and there is absolutly no need for an PEG treatment.
On monday comes the pics of the grenade after air abrasion.
The endoscope view from inside comes after the electrolysis. Makes no sense yet when rust and traces of powder cover everything.
Regarding my question in my first post: I found out now that the canvas was completly fixed at the plug and the grenade with resin and the part around the plug down to the neck of the grenade was also covert with resin from the outside.
I think now it had two reasons.
1. to protect the gunpowder from humidity
2. to hold the plug in position until the grenage explodes and to avoid that just the plug gets blown out.
So they fixed this two problems with it.
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an amazing find. This was found on land?
I imagine the tar help protect this from the elements, correct?
Any idea on the wood material type the plug is made from?
Concerning the weld, any speculation on how this weld was completed in the 1686 time frame? Today such a weld may be harder due to being heat treated but in 1686 would this welding process be hot enough to heat treat the material as much, or just enough to bond together the halves?
I imagine the tar help protect this from the elements, correct?
Any idea on the wood material type the plug is made from?
Concerning the weld, any speculation on how this weld was completed in the 1686 time frame? Today such a weld may be harder due to being heat treated but in 1686 would this welding process be hot enough to heat treat the material as much, or just enough to bond together the halves?
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Tom_Restorer
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It comes from the wreck of the Princess Maria wich sunk in 1686. (stands at the begin of this thread)
Tar was only used to fix the ropes/fuse on the iron. The canvas on top was fixed and covert from outside with resin.
No idea yet wich type of wood was used.
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Tom_Restorer
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Forgot something...
Not one of the three "fuses" (?) gone into the plug! As I said before, the canvas on top of the plug was complete flat.
Could it be, that they cut off the canvas before use and put a seperate fuse into the plug ??
The plug itself was completly filled only with black powder and just the bigger hole on top was half open (to put a fuse in ?)
I also saw on the cleaning on the ropes that they didn´t have any tiny traces of gun powder inside, so the question is, was this realy fuses or was this ropes only used to hold the plug in place until the explosion happens?!
I think the lenght of the plug has also something to do to avoid that it easy can popp out before the explosion happens!
If someone has any ideas, please l et me know!
About the welding:
On one side of the hole there is approx 2 cm of the welding missing and it is clear to see that there is no V-shape were the to halfs put together. So the welding is only put on the outside and covers only the line were the two halfs was put together. Now we know that this is indeed the weakest point of the grenade
Not one of the three "fuses" (?) gone into the plug! As I said before, the canvas on top of the plug was complete flat.
Could it be, that they cut off the canvas before use and put a seperate fuse into the plug ??
The plug itself was completly filled only with black powder and just the bigger hole on top was half open (to put a fuse in ?)
I also saw on the cleaning on the ropes that they didn´t have any tiny traces of gun powder inside, so the question is, was this realy fuses or was this ropes only used to hold the plug in place until the explosion happens?!
I think the lenght of the plug has also something to do to avoid that it easy can popp out before the explosion happens!
If someone has any ideas, please l et me know!
About the welding:
On one side of the hole there is approx 2 cm of the welding missing and it is clear to see that there is no V-shape were the to halfs put together. So the welding is only put on the outside and covers only the line were the two halfs was put together. Now we know that this is indeed the weakest point of the grenade
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I am guessing the wooden plug was pounded in before filling with powder and the whole thing was filled through the hole in the plug, and the wrap and rope used to help ensure that the detonation blew the cast into fragments (not popped out the plug). Insert plug, fill, wrap and secure... The cast shell looks crude, why the cracks? Intentional weakness? Pretty dangerous looking device 
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Tom_Restorer
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I am guessing the wooden plug was pounded in before filling with powder and the whole thing was filled through the hole in the plug, and the wrap and rope used to help ensure that the detonation blew the cast into fragments (not popped out the plug). Insert plug, fill, wrap and secure... The cast shell looks crude, why the cracks? Intentional weakness? Pretty dangerous looking device
I agree with your postings! Same what I thought, exept the part with the filling.
The plug goes so deep in it that a filling is not possible. Also the powder in the plug was pressed in. This was to see when I pullt it out. At the bottom the powder was on exact same level and flat as the bottom of the plug.
The cracks came after they was put in fresh water for 8 years. You don´t get the salts out on this way and it cracks later as to see here. After the restoration they are no longer to see.
So the wooden plug functions not just to seal the device but to provide a shielded path for ignition down to the center of the black powder charge. I was thinking that it was installed first as otherwise the part that extends into the grenade would compress the charge and might be dangerous - but it would be more difficult to fill with the plug in place. I am guessing oak for the plug, but any hard, dense wood would probably be suitable.
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Tom_Restorer
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I think so. I will make a sketch later.
Black powder burns with 800 meter in a second and the distribution of pressure is importend here. My englisch is to bad to explain this but it can be shown in a sketch. The deeper the plug goes, less presure will be happen to the bottom of the plug to popp it out. I also wondering why there was only approx 19 gramms of powder in it but this makes absolutly sense. When the powder burns, the most presure comes from the sides to the plug and not from the bottom.
The plug is cleaned and ready to put it back in. I will post a good foto later. may someone can tell what kind of wood it is!
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Use of " match cord" / fuse is mentioned. 16th century Knights in this link.
It mentions the fabric around the " top" , and how the match cord was shaped into a loop then inserted in the " plug"/ top ( early clay grenades prior had a necked top) and then both ends were wrapped around the plug . Allowing both ends of fuse to be lit ,and better assurance of detonation.
http:// http://warfarehistorynetwork.com/daily/military-history/the-grenade-a-brief-history/
It mentions the fabric around the " top" , and how the match cord was shaped into a loop then inserted in the " plug"/ top ( early clay grenades prior had a necked top) and then both ends were wrapped around the plug . Allowing both ends of fuse to be lit ,and better assurance of detonation.
http:// http://warfarehistorynetwork.com/daily/military-history/the-grenade-a-brief-history/
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Tom_Restorer
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