Torpedo engine 18 In Mk XII* relic

[Michel]

I have had this torpedo engine in tapwater for months to lessen the saltwater effect the problem is that it was so full of mud/sand/concretion that it is almost impossible to get the salts out. So I started to clean it but it is more of an archeological dig. The main problem is the iron and steel parts the engine has they start to sweat corrosion. This is not the first sea recovered artifact I have cleaned but this one is tricky due to size and weight. The use of WD40 on the project has taken a big chunk out of my pub money so better/cheaper tricks are welcome. Linseed oil does not do the trick...
It is a 18inch airdropped Mk XII* engine. This is all thats left of the weapon the airvessel / warhead where dealt with by maritime bombdisposal. The generator igniters (cordite/magnesium) were fitted and dated 40/3 and torpedo number 6** . So probably used in the early part of ww2. The gyro has lost its steel rings, the bronze cover of the gyroscope I have not cleaned yet but repositioning the whole just to take a look is not a easy. Many many hours are already spend to get here.

 

[tigbrand]

Great thing Michel, diesel is a good cheap alternative to WD 40!

 

[Dronic69]

Hi Michel,

Firstly - Great find!

An interesting restoration project to say the least.
So you have 2 x challenges here:
1) Rust removal
2) Mechanical dis-assembly

For (1) above, there are various documented methods including electrolysis, vinegar (mild acid) etc, which works well for smaller objects.
Due to the size (& pub money $$$), farmers use Molasses + water to derust large farm equipment - (molasses is the first stage from sugar cane and cheap!!!)
> ratio 1 part molasses to 9 part water, soak for 2-3 weeks. (I know this works as several artillery collectors I know have used this to restore large calibre field pieces)

For (2) Yes a good diesel bath is good to soak it in first and get the mechanical parts apart (plus heat and the "big hammer" :wink: )
Save the WD40 /rust busters for later

Great job so far!
Cheers
Drew

 

[Michel]

Hi Drew, the molasses seem a bit hard to get over in Holland the thing I can find is a product that is already in the food stage. So it will be diesel what I am using. I was not planning to take it apart because I am afraid I can’t put it together again, so good cleaning it will be.
Thanks for the diesel tips Drew and Tigbrand!

 

[kiwieod]

if you have an air compressor you can set up a small nozzle(or several) that will make tiny bubbles and greatly help cleaning(it will be like and ultrasonic bath)

 

[Dronic69]

Hi Drew, the molasses seem a bit hard to get over in Holland the thing I can find is a product that is already in the food stage.

Actually it may be marketed under a different name - trying looking for "Treacle", which is black molasses and should be readily available in supermarkets - well here in Oz it is.
"Golden Syrup" is a more refined version.
Cheers
Drew

 

[SimonBrown]

I had one of these, but in slightly worse condition. I scanned it into 3D before donating it to the local sea cadets:

https://sketchfab.com/3d-models/18in-torpedo-drivetrain-assembly-9c22db7a110f4ecd88d96b789acf442f

The corroded remains of the steel had embedded the bronze parts in a concretion.