Richie's Mk1 Restoration

[shaun]

kevin, what are the Canadian hammer marks? If you are refering to the (chisel like marks) they are on most armour British as well (including Ferrets, 432 Saladin etc). its part of the process for straightening the armour plates after production to remove any distortion.

[eddy8men]

there's been a few discussions on the "chisel marks" on armour plate some of the ideas were, descaling or hardness testing. do you know for a fact shaun that it was straightening ?

eddy

[Richard Farrant]

Originally Posted by eddy8men

there's been a few discussions on the "chisel marks" on armour plate some of the ideas were, descaling or hardness testing. do you know for a fact shaun that it was straightening ?

eddy

Eddy,

You will often find these marks on hull plates that have apertures cut into them for ports, etc. During the heat treatment process, distortion can occur and the hammering is to relieve it. It is definitely not hardness testing, that is done more accurately, by grinding a small part of the surface and then doing the Brinell test or similar, where the surface is indented and the depth of indent is measured to ascertain the hardness.

[eddy8men]

thanks guys for the info, it's nice to have another puzzle answered.
the pic is my cromwell drivers compartment and clearly shows the hammering marks.

cheers

eddy

[kevin powles]

Shaun, Yes the chisel like hammer marks, when I made my gunners front plate i devised a method of applying those marks, get a fairly large size quality new hardedend allen key, hold the short bent over end in your hand and lay the other end against the plate with one of the allen key ridges touching the plate, hold it at angle and hit the opposite allen key ridge with a good size lump hammer once only. What you get then on the plate is a triangle indent mark, do the same thing 180 degrees round from your first mark, carefully aligning the allen key to the first mark. What you end up with is a almost exact replication of those marks, practice first on a piece of metal to perfect it, where gloves when doing it, the allen key will be no use after making say 20 marks but you can then use the remaining ridges on it until all the allen key points are peaned over and then it's no use for anything.

Go to a car boat sale and get aload of allen keys for next to nothing.

A little time consuming but it is the detail in a restoration that matters.

Kevin.

[shaun]

Good method Kevin, they are not accutaly hammer marks, the process uses a very large press with a row of finger like tools prushing down and supports below. the sheet of armour is slid into the press by hand and the skilled operator eyes up the high spots and then places it under the fingers, he then brings the tool down on that area, some times the plate will need to be turned a little to get a different area, hence the differt angles and spacing of the marks.

[RichardT10829]

yes i do want to do it, i was going to ask one of our Canadian cousins or someone on our rock to take a rubbing on grease proof paper for me (for each pannel) then tape this to the plate and hammer a special chisel i am making over each mark until the entire plate is done

as for the rivets the bottoms ones you see are screw type as per previous discussions... however a pal of mine as a chicago pneumatic rivet gun so i may go back to solid riveting pending on a few things i have to iron out as yet.

i can turn the rivets out quickly on the lathe drilling them then running an m6 tap down
them. The lathe i had access to was at a college and they are running night classes now so cant get access again (hence my advert wanting a lathe)

[RichardT10829]

well now that the carrier is out of the way and i cant do much with it i have started to clean and degrease my engine. usually i like to send these off for steam clean and chemical clean but this time around i went for gizer and preasure wash... the block came up rather nice.. the mains are shot (well the center and front main) the crank has been reground so just need to get some shells sortid for it i am still trying to figure out which engine it is, it appears to have the 81A heads.... there is 99 embossed in the block which i am unsure of ?

one thing i have found out is the 1060 number i queried on the top of the pistons is also in the block and i have noticed that this refers to the job number which was put in by Torgis engineering march 1945 this is also on the brass plate on the bell housing.


i have yet to extract the studs using a stud box (i despise seeing stilsons being used to take studs out) that will be done tomorrow followed by some rubbing down and then painting ready for when its rebuilt.

there is a small hole in the sump tray in the bellhousing section and although it does not need to contain oil it looks unsightly so will weld it up.