How to weld 1/2"armour plate?

[Richard Farrant]

Originally Posted by Darrin Wright

After info and advice on how to weld 1/2" mild steel plate into the existing front armour of the BGC (Australian).

Over the years I have heard of reverse polarity when using welding rods, also to pre-heat the armour with oxy and then to mig weld it or just weld away like normal.

What are peoples experiances when conducting welding repairs on this type of steel? In the next couple of weeks I want to get this repair work done to my hull.

Thanks

Hi Darrin,
I don't know about Australian armour plate, but British armour was welded with Nickel Chrome electric rods, hence the shiny welds. I do have a copy of a War Office booklet on armour plate welding. One thing for sure the edges of all plates to be butt welded have to be vee-ed out in order to get penetration. If armour plate is welded with normal rods, it can crack down the side of the weld, so best to use the correct procedures. I would think Colin Jones from Adelaide will be your local man on the subject.

regards,
Richard