Metal stitching

Hayseed - Yeah, the main difference between bush mechanics and professional repairers, is that the former does repairs to get you out of a bind .. and the latter makes repairs that are considerably longer-lasting.

I can do, and have done, both .. but we're not in a bind here .. we're in the doctors surgery, now .. and we're aiming for some lasting and substantial repairs ..


Of course .. a pro operator always keeps last-resort, serious back-up material, on hand ..

A real education Ron, and the reason for the cracks now makes more sense. As you say, to do a proper job there is just no other way.
Nervous, who me? nah............can't watch!

Looks like Juan trak haz dun a Speed corse @ the local Uni in cameras 'Wot n how 2 use m



Spose Mamoth can now order piss tins n rings etc to suit

LOL



Cya

[ch9787]

Ron, well done mate, thanks for the pictures & explanation. As I said before,glad it's you & not me. I'd pulled the pin yonks ago, that's if I'd have even taken it on. Keep up the good work & the piccies too. cya Tim

O.K., this week, I've started on the washing soda electrolysis bath. Washing soda is easily obtained, Woolworths and Coles stock it in the laundry detergents aisle.
Sometimes it's called "lectric soda", as this batch from Woolies is named. It's the same stuff your Grandma used to wash with, before fancy laundry detergents came along. It's about $4 for a kg bag.

You don't need a vast amount .. the Yanks reckon a tablespoon to a gallon. They didn't say whether that was a level or heaped tablespoon.
A level tablespoon of washing soda is about 10 or 12 grams, and a U.S. gallon is 3.8 litres, so a kilogram of washing soda should be good for somewhere between about 300 and 350 litres.
What we're doing is adding the washing soda to water to get an electrolyte, because pure water alone isn't conductive.

The next thing we need is a tub, big enough to hold what you want to clean up. Poly tubs are best, but they're expensive, and difficult to find in large sizes.
I settled on an el-cheapo PVC storage container that I had laying around. They are just barely strong enough, so be careful if you use them.
They aren't resistant to UV light, so don't leave them in strong direct sunlight for a long period of time, or they'll get brittle and fracture.
They need to be in the shade, or have a cover of some kind above them, to keep the direct sunlight off them.

This one is 137 litres, and is just the right size for the two cylinders. I supported it on a couple of 100mm wide short planks.

Once again .. it's important that you set this electrolysis bath up, OUTSIDE. Gases such as hydrogen and oxygen are generated with electrolysis, and you need a well-ventilated area.





Next job, we have to construct a sacrificial anode, or anodes. A single anode that surrounds the item, or items, is best.

The anode has to be metal, and plain iron is ideal. DO NOT use stainless steel for the anode, no matter what you read! Stainless steel produces Hexavalent Chromium, which is BAD NEWS.
Hexavalent Chromium is a known carcinogen, and is extremely dangerous. You don't want it around anywhere you're working.
Breathing in the fumes from Hexavalent Chromium, results in lung, nasal and sinus cancers.

I fabricated an anode from a length of 1.6mm steel sheet, about 175mm wide. I folded it to follow the internal contours of the tub, and then tack-welded a joining piece and an upright to attach the leads to.

The cylinders are now fitted inside the tub, and are surrounded by the anode. I fabricated some fancy brackets to lift the cylinders clear of the bottom of the tub.
Mammoth doesn't know it yet .. but those fancy brackets are going to cost as much as a half a packet of Magna rods ..

You need to have the item/s you're cleaning, lifted clear of the bottom of the tub. This ensures that all the crap can fall to the bottom, and you're getting all surfaces exposed to the electrolyte.
You must also ensure that your items are located well clear of the anode. You should be able to stick your hand between the item/s and the anode.

A bit of judicious use of some appropriately-sized lengths of wood, sees the cylinders lifted well clear of the bottom of the tub, and with a good gap between them and the anode.

Note the short length of copper wire connecting the cylinders. This is vital to ensure that the current flow gets spread evenly to both items.

O.K. .. now we fill the tub with enough water to cover the cylinders by at least 25mm .. and we add the kilogram of washing soda, and connect the battery charger.

I estimate the tub to be holding about 80 or 90 litres of solution, as the cylinders displace quite a bit of volume, and the solution is about 100mm short of the top of the tub.
As result, a kilo of washing soda is probably more than adequate for this amount. Half a kilo is probably adequate, but I'm using the full kilo, anyway.

It is VITALLY IMPORTANT, that you connect the NEGATIVE lead to the item/s you're cleaning .. and the positive lead to the anode.

Connecting the leads the wrong way around, will see your item dissolve .. as it becomes the sacrificial anode .. rather than the item to be cleaned.

After a short period .. a problem arises, that no-one mentioned before. The 4 amp battery charger doesn't have enough "grunt", to provide adequate current flow to this amount of solution.

The battery charger circuit breaker is continually tripping out, and breaking the current flow for about 1 minute in every 2 minutes. This isn't satisfactory in the least.

I tried my Vane 5 amp charger, and the same thing happens .. the circuit breaker trips out regularly, resulting in electrolyte charging that is only happening about 50% of the time.

I tried a 4 amp regulated power supply transformer that I had laying around, and the same thing happens. We need more grunt. Unfortunately, I don't have a big industrial battery charger.

The answer is simple enough. Insert a substantial power source into the system. It's called a 12V heavy duty battery.
I made up a set of leads to go between the battery and the tub, and hooked them up .. and then hooked the battery charger to the battery, to keep the battery going.
I ensured the charger leads were in contact with the battery poles, and not touching the leads to the tub, to ensure the load is coming off the battery, and not the charger.

We obviously need about 10 amps, so I used 10 amp wiring in the leads I made up. It's important that you use light duty wire, so that the current flow to the tub isn't excessive.
I checked the current flow to the tub with a multimeter, and I'm getting about 10.8 amps current flow. That appears to be highly satisfactory for this job.




After about 3 hours, the results are dramatic. The solution is bubbling nicely, and the top of the brew is covered with a disgusting-looking brown/green, frothy scum.

Underneath this horrible-looking muck, the cylinders are looking good. All the rust is dissolving, and a black film of ferrous iron is taking its place.

It will take about 12-18 hours in total to get the results we want. I'm not leaving the brew going overnight, it needs to be watched, so it's switched off overnight, and it will be switched on again tomorrow.

JuanTrak
Gudday M8

L@@kn Good
the bit eye'm not rapt in
is u're yello jumper wire
Looks like sumthing eye'd do on a saturday night
LOL
me thinkz a heavier cable sandwiched between a cupla washers n nuts, az in lok nuts

x2

But

Wadda eye kno
Cya
[ch9787]