Older but no Wiser

[Deafhead]

On 04/03/2020 at 22:38, openspaceman said:

The hydrogen from the ruptured bags went upward and only burned as fast as oxygen diffused into it, your oxygen and hydrogen were premixed as they were produced at anode and cathode of in the same cell.

 

I did the same with our old MF35 in 1972, I knew both batteries were knackered so I was in the habit of sticking the starter boost on my oxford welder across the terminals I disconnected the clips before switching the welder off.

I remember seeing the tractor in the barn. Be sure your sins will find you out.?

[openspaceman]

2 hours ago, Deafhead said:

I remember seeing the tractor in the barn. Be sure your sins will find you out.?

No one left to answer to now. 

 

The MF35 always was a pig to start, the later 35x with the three cylinder engine was better. Before I got to it it had been left with no antifreeze and a piece had cracked off the block by number 2 injector, I araldited it back in and ground off the lump so the injector clamp no longer bore on it. That one ended up being sent to Pakistan, after I had used it to haul elm cord wood on the buckrake and various other jobs.

[Billhook]

8 hours ago, Daniël Bos said:

The battery won't explode unless the combustible mixture within is exposed to a source of ignition.

What most likely happened in your case was that there was a cloud of combustible gas in the air, near the battery. This cloud got ignited by the sparks, the flamefront will have either travelled to the inside through the battery's vent tube/holes, or the cloud combustion was so powerful it cracked the case getting the ignition to the perfect explosive mixture contained within.

 

Ventilation won't do anything to remove the combustible gasses inside a battery.

But if there is no way for the source of ignition to reach those gasses there is no explosion. The forced ventilation of our box removes any potential build up of gasses near the battery, so if there is any sparking there is still no explosion as there is a "buffer" of (non combustible) air all around the battery.

To prevent sparking, the charger is only powered when the door is closed (simple door switch with a relay).

Thanks for that

I remember now that when the mechanic caused the first explosion in the workshop a bit of battery casing flew up and smashed the strip light, so there is a lot of force especially if it hits you on your face.

When this last one went of a bit of plastic hit me on jacket sleeve, which luckily is pretty heavy material, but I still felt it perhaps with the force of someone throwing a stone at me.

Again we laugh about these things but it could have been my eyes.

 

Any more confessions out there??

[scbk]

3 hours ago, Billhook said:

Any more confessions out there??

Not in any way battery related, but years and years ago some friends etc were round, someone I didn't know had left behind an old rucksask, just full of rubbish etc.

 

Cheeky sod, so the next day I chucked it on a bonfire, then 5 mins later I was poking round the fire and the thing blew up!

Little did I know there was an aerosol can in the bottom of the bag!

I got hit in the face by a bit of molten plastic, had a burn/scar for weeks

[Daniël Bos]

Also not battery, but still explosive related:

 

I worked with a company that had a car detailing and body shop department, they did amazing renovations of old cars as well as polish and clean up high end new cars, removing all the protection the car manufacturers put on for transport, removing all the glue residues from protective foam stickers, polishing to a very high level etc.

My colleague Anton had been working on a nearly new porshe that had needed some small bodywork. He'd unexpectedly come across the need to respray part of the inside of the boot (bonnet, frunk, storage space at the front, porsches are weird). This was a problem as the car was otherwise finished and due to be delivered back to the customer by the end of the day.

Anton was a hairy fellow, he had a mullet and though never grew a full beard he always had some form of dirty moustache. It was not all his fault, his facial hair was so thick and grew so rapidly out of his delicate skin that when he was a conscripted private in the army he had a special dispensation: he didn't have to shave. They'd tried to make him shave, and he tried, but he'd be profusely bleeding from the face at roll call every morning and looked like he hadn't shaved for a week by noon.

So my hairy friend was in a pickle: he needed the paint to be dry to be able to refit all the carpet and trim, but there was no way it was going to be dry in time for the afternoon delivery the customer was promised. So Anton got a hot air gun and tried to gently heat the whole boot space, after having left it for a while he went in to give the patch a final bit of close up heat. It was at a very hard to get place though, so with his body twisted like a filipino contortionist he dove right down in there, turned the heat gun back on and.... Boooom!

Now the porsche's boot lid was flat against the windscreen, the heat gun was dangling from the ceiling light, and Anton was smoldering.

His hair had fused into a solid crust, tight against his scalp, his eyebrows, lashes and moustache were crumbled to dust.

For the next few weeks Anton was a lego-head, with only drawn on facial hair and a hard cap of "hair", he had to wait until enough hair had grown back underneath his crust to be able to cut underneath to get it off. The smell didn't leave him until  he finally was able to shave his whole scalp.

 

Surprisingly, the car was fine after some additional buffing, the paint was dry, put back together and delivered on time.

 

Here's a picture of what Anton looked like pre-whoosh (though this isn't actually our Anton as this happened some time ago, in an era where taking photographs was not a daily thing for most people...)