Optimus 8R, has no pressurizer, what could I use in lieu?

About £19 with VAT.. there would be a delivery charge too... It can be had for around £2.70 per litre if bought in serious bulk.

 

What accident would that be? I ask as I wonder if it is related to the issues I was having yesterday. Also is it easy to find replacement parts for these since I know I saw they are pretty expensive to buy the whole item on ebay so wonder how hard, and/or expensive, individual parts would be to come by.

EDIT - ah just the seal I see seems easy to get hold of and only £1.80 on the first site I have looked at.

To start with when I tried to run it that morning the turning crank was jammed tight and with as much force as I could muster I could only move it the tiniest bit. I figured I would try again once I had primed it and things had warmed up. I did so and it moved freely again. Why such a big difference there?

That is inconsequential but note it if it may be related to the bigger issues below.

It was running fine to try and cook a big pot of stew for about 30 minutes. After that it puttered out. I thought the tank was empty and so waited a bit for it to cook and looked and seemed dry so refilled about to I guess about 1/3 full.

Here is where the big issues start. I was then unable to get it to make a consistent flame at all after several priming attempts but most worrying was the tank refill cap went on fire and wouldnt go out. Initially I thought it was because I spilled some petrol on it so was waiting for it to exhaust itself. I waited 1 or 2 minutes and it would look like it was about to go out then fire up again. It eventually went out for a while before igniting again.

Also I was still not getting a proper flame. I was refilling the primer with alcohol this time the last couple of times since the petrol priming is so smoky and was not getting it to catch. When it was working ok before this I would just turn the jet on as the fuel in the bottom was about to go out but now I heard the hiss of the jet but it wouldnt turn into the gaseous jet like before. There would be a small candle-like flame which would then go out.

Oh also, one time when the pot was still on there was a rather large flame that arose around the bottom and up the edge of the pot. I am guessing the jet blew some unignited petrol onto the pot at some point which then ignited.

I tried this a few more times and managed to get a half hearted jet but then the tank was catching alight again seemingly of its own accord. I began to get concerned the filler cap may be leaking and it could cause and explosion so I decided to pack it in. I wanted to get on with some work on my van and the stew was a-waiting to cook. So I let it go out and returned to my trusty trangia which I felt confident I could leave burning without having to constantly nurse it and went off to do my DIY.

I am interested to know what the failure might have been and what safety concern you, blackdog, flagged about the filler cap. Regardless, I do not see this replacing my trangia for daily usage. I love my trangia as there is very little to go wrong with it and this, while very effective when working, seems like it has quite a few possible points of failure not to mention greatly increased risk when things go wrong. The whole reason I have gravitated to alcohol stoves over gas has been the simplicity and thus these pressurized types do not seem to compete with this niche.

My mum made a good point that maybe it would be useful if I wanted two stoves on the go. This would be much more suited for cooking things which require high heat and constant monitoring anyway like frying vegetables to go with the main substance of the meal. So perhaps could be used for that but I think trangia would still be fine for that which takes only 5 extra minutes or so and not having to haul around the smelly petrol and such required for this as well as the possible breakdowns or general, possibly risky, misbehaviour.

 

Please don't use the stove again until you have at the very least replaced the cap seal, and immersed the tank and burner in hot water (Ideally after putting it in the firdge or freezer for a while) to check there are no bubbles from other places, signs of a leak.

A hard or perished rubber seal in the tank cap may make the stove unable to build up the required pressure to run properly. More dangerous is that it could leak petrol vapour under pressure. This can burn with a small flame, or if enough collects before igniting it could fireball. If not put out, a fire could lead to a tank explosion. Serious injury or death.

You may well need to replace the cotton wick inside the stove, if charred or blocked this can cause erratic running.

You may also need to replace the graphite packing on the control spindle. If worn this can cause leaks.

You may also find the small ruber 'pip' inside the safety release valve (SRV) needs replacing. Do a search here for all manner of opinions on what is best to do in this regard. If hardened, it may not cause a seal, preventing the pressure from building up properly and also causing leak and a flame.

Have a read of this thread for a how-to-guide on changing the cap seal and wick.

These stoves are safe and reliable as long as they are properly serviced. Not quite as simple as a Trangia but more powerful. It is well worth the effort, they are fantastic bits of kit.

In the same way that you wouldn't roll a car out of a barn that hasn't moved for a few decades and take it straight on the M25, a stove which has sat for a few decades isn't going to be reliable and may not be safe. Stoves as well as vehicles have service parts which need to be changed now and again.

Fix it, and enjoy it!

 

@stove-user27854
The fettlebox (the site sponsor) is a great resource for seals and does the cap seal for£ 1.80 for two and they are made of viton which has superior fuel resistance to nitrile which many seals are made of Filler Cap Seal - 123/123R, 111, 8/8R 71 etc. Pack of 2 - The Fettlebox