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A few 30,5 cm cases

thekees

thekees

Well-Known Member
This months haul. Three cartridge cases of the SKL 30,5 cm L/50 gun. All the same manufacturer date. These were fished out of the Northsea. Most likely belonging to the Lutsow. all dated X-1914 and made by "Machinefabrik Karlsruhe". Two are restored by me (undented and free of almost 100 year of sealife). The other one will will stay in the "as found" condition.



.30,5juni.jpg
 
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WOW!
Impressive.
How do you restore them so well? Do you grind off the sea life or is it some sort of Chemical dip you use?
Dave.
 
thekees said:
This months haul. Three cartridge cases of the SKL 30,5 cm L/50 gun. All the same manufacturer date. These were fished out of the Northsea. Most likely belonging to the Lutsow. all dated X-2014 and made by "Machinefabrik Karlsruhe". Two are restored by me (undented and free of almost 100 year of sealife). The other one will will stay in the "as found" condition.
.
Click to expand...

So these were manufactured in 2014? :tinysmile_fatgrin_t

Sorry, I just couldn't resist the temptation!

Any chance for pictures of the headstamps?

Thanks!

Brian
 
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2014 should be 1914. X is October 1914, XI is november.

to remove the first layer of salt and chalk, I will clean it on several ways. Knocking with a wooden or rubber hammer will loosen a lot. soaking it in water, and heating up the spots with a torch etc will remove a lot, just by expending the brass. At the end a mixture with hydrochloric acid, water and a lot of fresh water will remove the last chalk.

To remove the dents, it will happen in a few stages:

1st stage:

i made two 120 degrees segments out of hard steel, supported with a horizontal plate, see picture. the diameter is the same as the inside diameter of the cartridge case.
with a hydraulic car jack between them, i will line up the plates with one of the dents. Then i put full pressure on the hydraulic jack it will remove 90 percent of the dents already.


2th stage:
After the first attempt, a few dents are too tough to get them out at once. The next step is aligning one of the plates up with the dent, and putting the hydraulic jack on it. I have a piece of steel, small but with the same radius as the case. This piece is aligned with the dent and put on the receptacle of the hydraulic jack. Now all the pressure is concentrated on the dent. then again putting pressure on the jack will remove the dent or even better, just add a bid more material to the outer surface, making a little bump.
3th stage:
Now the two segments are lined up again with the jack in the middle. Hammering with a
Special hammer, hollow and filled with lead grains will flatten the “bumps” and again remove a lot.

Repeating this process (mind your ears, sounds like church, but very close) will end up in a 99 procent dent free case.

After the cleaning an d undenting, the case should be clean and free of damages etc, so grinding with waterproof form 120-180-320-400-600-800 and finally with special brass polish, called Unipol, the best I found out, the case is finished.

Now getting back the old brass look. First wash it with water, several times, and later mix a bid ammonia with it and wrap this with cloth over the case, within days the case looks good and not as a mirror. After it, cleaning it with water/soda will neutralize the most.
 

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Added a picture with both segments and jack in use. You can make these for every staright case there is, problem is finding a jack that fits between.
these segments are made for 28 cm cases, but will work for this diameter too.

malinhuls.jpg
 
And as requested a picture of the headstamp.
 

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Yes a brilliant job its nice to see them being brought back to life, well done that man, :)
regards
Andy
 
Dave, yes its a heavy, noisy and dirty job too. Always ending up with bruses, blue nails, acid spoiled on the skin, and smelling like a brass factory for days.
Still i like it. I like the "been there" part of these cartridges.
 
Are these cases 1220mm long with a rim diameter of 350mm? Or is the rim 386mm?
Thanks very much for sharing your recovery methods. Fascinating and informative. So the series 120-180-320-400-600-800 is referring to sandpaper (or emery paper?) I presume. I had not realized that one could do that. I suppose one would need power tools on such large cases. .....Cheers!
 
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Charly, i use waterproof emerypaper, only of the brand KWB, the black paper. As a power tool i use a sanding machine, but a kind of excentric machine. At the end, i use an 1800 watt polishing machine. I modified this machine and now it adapts a polish device you find normally on a work bench. I must say it is a lot work, but after trying a lot of options, i figured out this is the best way. Especially finding the correct brand per tool or sanding material is important.

The rim diameter is 350mm.The length is 1220 mm. The weight aprox 70 kg.
 
Hazord,

i looked overhere for a set for a reasonable price, but none to find. So i used the jack i had. This fall i have to go to the US for training, so i good moment to bring one with me.
it has to withstand a reasonable ammount of abuse with a hammer. It cracked the first jack's seals.
problem is the diameter of the jack i use now. it limits the proces to about 24 cm diameter of the cartridge case. your option will be much smaller i guess. So i have to look into it.
 
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