Old School....Monitor Stove

[Toadflax]

Thanks johnboy for the suggestions so far.

I think I've released the NRV with your suggestion of filling the pump tube with paraffin and pumping it. On releasing the air screw, there was a small hiss of air. I realised afterwards that blowing into the pump tube isn't likely to work, as I don't think the lungs can generate enough air pressure to unseat the NRV.

I still can't get the unit to pressurise pneumatically, as there is a kink in the edge of leather seal which isn't evening out even after soaking, so I think it's a trip to eBay for some new leather seals next.

Following that, I may need to replace the burner unit washer (seems like it may be lead, or some sort of metal /fibre mix) as the original one seems to have been 'graunched' and doesn't look like it is sealing well, but the stove came with two spares of these, though I'm tempted to get one of the service kits that rik_uk3 mentioned.

Overall, I think it should be a good unit once working, but it seems to be a bit of pot-luck whether it will work first time like Red's, or need some work like mine. However, I don't blame the seller, after all something that has been stored for 53 years is likely to need a bit of maintenance to get it going.


Geoff

 

[Twodogs]

Has any had the space heater attachment ,
http://cgi.ebay.co.uk/PRIMUS-MONITO...Collectables_Militaria_LE?hash=item3ca04cd62a
Twodogs

 

[johnboy]

Hi Toad flax,

In reality there is relatively little to go wrong with a 2 pint stove...

If it's making and holding pressure and the jet is in good nick and it's complete than it's all go. One thing to remember is Monitor and a lot of the british stoves from the post war period were made from slightly cheaper grade materials than a Swedish stove from the same period. Some manufacturers also cut a few corners on production as well. It's part of the charm really..

I had an Ex MOD 2 pint stove brand new ex stores issue that had a leak from a tank seam.. It's all part of the fun...

Base camp sell a specific Monitor spares kit...

http://www.base-camp.co.uk/Monitor .htm

Have fun....

 

[rik_uk3]

Has any had the space heater attachment ,
http://cgi.ebay.co.uk/PRIMUS-MONITO...Collectables_Militaria_LE?hash=item3ca04cd62a
Twodogs

Looks like it could be part of this setup. If its the same size dome you would have to mod it to fit.

 

[Toadflax]

Waiting for my new leather washers to arrive from Turkey, but a bit more experimentation this morning suggests that the stove is airtight and the NRV is now working OK.

I'm pretty sure this is the case, but I'm assuming that the leather washer is retained by the brass 'nut' that sits inside the cup of the washer, and that this should unscrew to release the washer. On mine, the nut is very tight so it's going to need clamping up very carefully in a vice to try and release it. I'm wondering whether heating it might help release it (e.g. differential expansion between the brass nut and what I assume is the steel pump rod).

Any thoughts from the experienced stovies?


Geoff

 

[MrEd]

Waiting for my new leather washers to arrive from Turkey, but a bit more experimentation this morning suggests that the stove is airtight and the NRV is now working OK.

I'm pretty sure this is the case, but I'm assuming that the leather washer is retained by the brass 'nut' that sits inside the cup of the washer, and that this should unscrew to release the washer. On mine, the nut is very tight so it's going to need clamping up very carefully in a vice to try and release it. I'm wondering whether heating it might help release it (e.g. differential expansion between the brass nut and what I assume is the steel pump rod).

Any thoughts from the experienced stovies?


Geoff

dunno, but did you get 5 from turkey? if so do you want to see me one or two?

 

[johnboy]

Waiting for my new leather washers to arrive from Turkey, but a bit more experimentation this morning suggests that the stove is airtight and the NRV is now working OK.

I'm pretty sure this is the case, but I'm assuming that the leather washer is retained by the brass 'nut' that sits inside the cup of the washer, and that this should unscrew to release the washer. On mine, the nut is very tight so it's going to need clamping up very carefully in a vice to try and release it. I'm wondering whether heating it might help release it (e.g. differential expansion between the brass nut and what I assume is the steel pump rod).

Any thoughts from the experienced stovies?


Geoff

Sefa's pump leathers are very good and hes really good to deal with I did a good swap with hm a load of jets for a load of 1 and 2 pint leathers... I'm almost out of 2 pint ones now...

I tend to grip the pump rod in a pair of pliers with a piece of cloth as a soft jaw and then use an 8mm socket to undo the the nut... The end is sometimes peaned over to stop the nut unscrewing in use

The way to check if it's air tight is to pump it up and the immerse the tank with the air release screw in a sink full of cold clean water. Any air leaks will show up a a trail of tell tale bubbles...

Have fun....


John

 

[Toadflax]

Woo hoo! It works!

After more soaking in oil I had another go this evening and the pump kicked in. I boiled up a pan of water, well, almost to boiling as my wife called me back in the house for dinner so I had to switch it off.

Only thing was it kept blowing out, it was quite breezy in the garden and I suspect that it is going to need fairly good shielding.

I haven't got the washers yet, only ordered them yesterday.


Geoff

 

[johnboy]

Woo hoo! It works!

After more soaking in oil I had another go this evening and the pump kicked in. I boiled up a pan of water, well, almost to boiling as my wife called me back in the house for dinner so I had to switch it off.

Only thing was it kept blowing out, it was quite breezy in the garden and I suspect that it is going to need fairly good shielding.

I haven't got the washers yet, only ordered them yesterday.


Geoff

Congratulations on getting it going...

Does it have a roarer burner or silent burner??

 

[Toadflax]

It is most definitely a roarer. And it is sustaining pressure very well.

This stove does seem pretty susceptible to breezes (not too surprising, given the principle on which it works). I tried it again in the greenhouse later last night, and it burned much better. Still took a fair while to boil up a can of water (I'm guessing up to half an hour) but it was a nearly full 14cm billy (about 2.5 pints) with an ambient temperature of less than 10 degC.

It's interesting to see the flame pattern when it's dark. The burner ring glows a nice red heat, but the jet must be slightly off-centre, as you only get flame out of the top of two of the four quadrants of the burner.

Thanks for all the advice.


Geoff

 

[rik_uk3]

It is most definitely a roarer. And it is sustaining pressure very well.

This stove does seem pretty susceptible to breezes (not too surprising, given the principle on which it works). I tried it again in the greenhouse later last night, and it burned much better. Still took a fair while to boil up a can of water (I'm guessing up to half an hour) but it was a nearly full 14cm billy (about 2.5 pints) with an ambient temperature of less than 10 degC.

It's interesting to see the flame pattern when it's dark. The burner ring glows a nice red heat, but the jet must be slightly off-centre, as you only get flame out of the top of two of the four quadrants of the burner.

Thanks for all the advice.


Geoff

It should boil quicker than that, you need to give it a good pump, maybe 30 to start you off.

 

[johnboy]

It is most definitely a roarer. And it is sustaining pressure very well.

This stove does seem pretty susceptible to breezes (not too surprising, given the principle on which it works). I tried it again in the greenhouse later last night, and it burned much better. Still took a fair while to boil up a can of water (I'm guessing up to half an hour) but it was a nearly full 14cm billy (about 2.5 pints) with an ambient temperature of less than 10 degC.

It's interesting to see the flame pattern when it's dark. The burner ring glows a nice red heat, but the jet must be slightly off-centre, as you only get flame out of the top of two of the four quadrants of the burner.

Thanks for all the advice.


Geoff

It should boil quicker than that, you need to give it a good pump, maybe 30 to start you off.

I agree with Richard... It should fairly chuck out the heat and boil quicker than your stated time... Pump it right up as Richard says 30 full strokes with 3/4 of a tank of Paraffin it should humm along nicely....
The low pressure might be why it's blowing out in a breeze.. Roarer burners are generally pretty wind proof...

Cheers

John

 

[Toadflax]

Just took 13 mins to boil 1 pt of water in a covered billy. Given the problems I had with the leather washer, I'm wondering if the leather washer is sealing, but not perfectly, so I'm not getting sufficient pressure in the main tank - though the stove is roaring quite loudly. I'll see what happens when I get a new leather washer in. BTW I don't think the jet isn't obstructed, I've run the pricker through it a couple of times.

On the burner, I assume that you only have a sealing washer below the meths cup (that's how it came) - i.e. you slip the meths cup on the threaded stem of the burner, then push on the washer. I put a new one on, as the old one was damaged, but when the stove is running, there's a little bit of paraffin seepage (only a little bit of weeping, nothing significant) at the top of the meths cup. It made me wonder whether there ought to be one both top and bottom of the cup (though the exploded diagrams suggest otherwise). This may be normal, or maybe the burner needs tightening up a bit more. I'm reluctant to go too far in case of stripping the threads.

[EDIT]
Wondering if it is my paraffin. The paraffin is starting to go a bit dark, and has (probably wrongly) been kept in the greenhouse for a couple of years. Just found a couple of articles that suggest it can go off a bit if not kept in the dark.
[/EDIT]

:You_Rock_


Geoff

 

[johnboy]

Just took 13 mins to boil 1 pt of water in a covered billy. Given the problems I had with the leather washer, I'm wondering if the leather washer is sealing, but not perfectly, so I'm not getting sufficient pressure in the main tank - though the stove is roaring quite loudly. I'll see what happens when I get a new leather washer in. BTW I don't think the jet isn't obstructed, I've run the pricker through it a couple of times.

On the burner, I assume that you only have a sealing washer below the meths cup (that's how it came) - i.e. you slip the meths cup on the threaded stem of the burner, then push on the washer. I put a new one on, as the old one was damaged, but when the stove is running, there's a little bit of paraffin seepage (only a little bit of weeping, nothing significant) at the top of the meths cup. It made me wonder whether there ought to be one both top and bottom of the cup (though the exploded diagrams suggest otherwise). This may be normal, or maybe the burner needs tightening up a bit more. I'm reluctant to go too far in case of stripping the threads.

[EDIT]
Wondering if it is my paraffin. The paraffin is starting to go a bit dark, and has (probably wrongly) been kept in the greenhouse for a couple of years. Just found a couple of articles that suggest it can go off a bit if not kept in the dark.
[/EDIT]

:You_Rock_


Geoff

If you are getting a bit of a weap of parraffin then you've got a leak, combine this with the less than perfect pump washer then you're not going to be getting full pressure..

Also old fuel might be dirty and you risk blocking the jet...

 

[Toadflax]

For anyone else interested in these, you may want to have a look at this site: http://www.parafinalia.biz/monitor-pressure-stove-p-136.html

Same price as the one I got off eBay, but you also get the service kit, NRV valve key and fire dome, plus they have been pressure tested.

No connection to the seller, but you seem to get a bit more for your money.



Geoff