Metal stitching

Well done Ron for my money they were way beyond repair

Cheers MAX

Juan Track, I hope you will hop back in here with some details of how you did it. We all miss your informative input.


Sarge....

I am with sarge here, mammoth, is it possible you could give us over view of the missing parts of the repair
Cheers Max

Ron was in the Cat Chat room a while back , I asked him how this was going .
He posted up some photos of the "during " To see the Finished after ,all i can do is take my hat off to him .

While Swish is away buying up more supplies of Alka Seltzer here is an extract from Onetrack's progress report, and a pic to show the doubting Thomas' that it is not a JB weld jobbie;

The corrosion in the cylinders was worse than anything I have ever encountered, and it was a real pain.
I have no idea what solutions or chemicals were put in these cylinders, but they had not only the visible regular brown rust, but a thick layer of hard black scale (magnetite) as well.

Here is advice from a forum friend as regards black scale rust ...

"People don't realize that rust exists in two basic forms, Free and Reactive. In the Free state it is easily removed by sanding or rust conversion products; but in its Reactive state, rust has achieved an electrochemical bond with the metal surface. In extreme cases black rust is formed. Black rust (magnetite) can be a thick hard scale which usually forms in a harsh chemical environment where high concentrations of chlorides, sulfates, and nitrates are present. Removing rust in its Free state usually involves simple sanding or the use of rust converters, but in its Reactive state, more extreme measures are required. When Reactive rust changes into black rust, high pressure sandblasting is the only removal method available. In any case, after removing Reactive rust, a wash down using various chemical detergents is needed to remove chemical residue, or premature paint failure will occur."

This is the reason I had to send the cylinders out to be sandblasted. It wasn't cheap, but it was very effective and they did an excellent job. Naturally, removal of the magnetite revealed the extent of the very deep corrosion.
This very deep corrosion was fortunately limited to one particular side of each cylinder casting - but the corrosion had effectively reduced big areas from the original 4mm casting thickness to less than half a millimetre - with perforations where daylight appeared.
There was only one course of action - to remove the badly damaged sections and replace them with new metal. The worst part was trying to gauge the extent of the severe corrosion areas.
One cylinder has had to have a huge section of the side removed, and I'm not going to show you pics of it yet, you'll probably have a heart attack!

The No.1 cylinder is a "work in progress". To put it bluntly, it is driving me insane with constant thin patches appearing after I've thought I've removed all the excessively-thin sections.
The thin sections show up by cracking badly after I have welded an area extensively. If the metal is around 2.5-4mm thick, it won't crack.
If it's less than about 2mm, it will crack when the weld cools - despite peening the weld and carefully monitoring heat input. As a result, I am spending considerably more time on this cylinder than I could have imagined in my worst nightmare.

It's slow going, as welds can only be around 25mm long, they have to be extensively peened as they cool - and then I have to move to some other area, to allow the first area to cool.
There are 77 rods to every 2.5 kg packet and I am up around 85 welding rods consumed at this point - with probably another 25-30 rods to go before completion of the last cylinder.
The Magna welding rods are $270 for 2.5 kgs.

Re: black rust - as a kid I used to dig around inside an old car engine which was half buried upside down and was exposed every low tide. There were two old vehicles which had become bogged on the mudflats near home (Godwin Beach at the time), perhaps 10 years before we moved there. I remember the timing gears being in amazing condition once dug out, but had been encrusted in this black concretion, maybe 1/4" thick. (the sump had long since rusted through.

I wonder if your engine had had salt water in it?


Jarrod.

there is some special skill in doing that, my hats off Juan Track. :silly:

Sarge
Probably a dieing art / skill

He was/is a clever bugger! I do miss his input on the forum. great outcome.

Onetrack,
You do magic with metal!