Hi there, I am new to this so forgive if needed. I am restoring an old blow torch, well 2 in to 1 and mostly going well, I have it burning now, but I have a leak coming from the pump nut area. There is no washer there but I don't think there should be? Someone I know said, just from a video I sent them, that the safety valve isn't working? The pressure release valve certainly works. Please advise, I am trying to sort this as a gift to my son as he wants to get a new canal boat with a Bolinder engine and a blow torch is how you get them started . Thank in advance for any suggestions offered.
Welcome @Mash Anscombe - some photos would help as the names of things get a little muddy. If you have fuel appearing in the pump tube it can be three things, the non return valve is letting fuel back up, or it is not seated properly, or worst of all there is a split in the wall of the pump tube.
I thank you for the welcome and the support. I think it is possibly the NRV that is not as good as it should be, I can see a split in the tube. Can I make a replacement or would I need to source one from somewhere?
The pump tube is normally soldered in so can be heated and removed with care. You mentioned you had two - perhaps some cannibalisation ? - perhaps a link to your video or some pictures would elicit more help
I don't understand what you are meaning by removing the pump tube, sorry, new to this. The pump on the left is the one I used, the one on the right has no NRV at all. In the pic of the torch you can just see the seepage reflecting my legs. Other than this issue the torch seems to be working okay.
Now I understand - there are many designs of these and many have the tube soldered to the tank. Yours unscrews and I would have thought that there should have been some sort of seal. Is the fuel coming from the top or from the nut that holds the pump in ? In any case I would try a fibre washer to seal the nut.
I think possibly both but not 100%. Should I try unlit to see if it happens then to help with identifying the problem(s)?
@Mash Anscombe In your photo there should be a Viton or cork pip in the small brass cup of the NRV; and a washer where the pump meets the tank of the torch. Cheers Tony
So wise advice from Tony above. If the NRV is allowing pressure to come back up the tube, it may be pushing fuel as the fuel level is higher than the base of the pump. So a small pip needs to be replaced. Measure it and see if it matches any of the commercially available ones (it probbly will), or if you have a hole punch buy some viton (like rubber but fuel resistant) sheet of the correct depth and make one. Or as Tony says make one out of cork. You can test the pump body/tube by holding a finger over the hole at the bottom amd pushing the pump down. you should not feel the presure drop. You can do this underwater as well so you will see any leaks by the bubbles. You can test the whole lamp by pumping it up with no fuel and putting it under water to see if anywhere else is leaking. For fibre washers look at tap washers, if you can measure the size and let us know I may have some (I bought one of those kits of tap washers a few years ago) If you do find a leak in the pump tube body - as it is made of brass it can be soldered. Pump leathers can be oiled to improve performance (3 in 1 or olive oil etc) Chris
Hello @Mash Anscombe and welcome! I would give base camp stoves a ring There are some bits listed for blowlamps on the website but you have to hunt around a bit www.base-camp.co.uk regards pb
I trust my piggybacking on this older post meets protocol but I was seeking enlightenment on stemming a leak on my 'new' Companion (Max Sievert clone) blowtorch and as Mash Ancombe's device discussed above closely resembles my Companion I decided to hop onboard. I refer to his photograph 'with legs', specifically the large nut clamping the burner to the tank. This joint leaks. Unlike most stove burners it needs specific orientation and the big nut clamps the burner after the style of a flared pipe joint. The nipple has a taper (photo) that would suit an olive joint but there is no room for such, or an o-ring but how long would that last? Another issue relates to the non return valve and I can again refer to the earlier photographs. The pump was ineffective, there being nothing between the brass spring end and the pump outlet - no pips or cork. I added a small ball bearing and this kinda works. A punched Nitrile disc Viton didn't do the business. Any thoughts on the proper Sievert setup would be appreciated. Regards Bill
@Billtong Companion blowlamps are an iconic Australian blowlamp, though based on the Sievert Models 42 and 43 under licence from Max Sievert. The pip you require is 3.7 mm diameter and about 3 mm thick and is the same pip as used on many stoves so The Fettlebox should be able to assist you too. The filler cap washer should also be replaced witha Viton 23 mm washer of about 1.6 to 2 mm thickness. Where your big nut holds down the burner dip tube it is a pain occasionally to get a good seal and a few solutions will work. You can try a small amount of teflon plumbers tape or an appropriate O-ring, small lead washer or fibre washer of an appropriate size. My experience has been that these all work but I can't speak for the longevity, but the heat from the metho seems to not affect it as much as you would expect. A commercial petrol resistant sealant will probably do the job too as it is probably a very small gap as usually it did not need anything. Perhaps the nut needs annealing to soften it. Have fun trying and dunk test it in a bucket of water to ensure it is sealed. The nut should rotate since it is not clocked to a particular position in relation to the burner.
Blow lamps were often used in engineering trades by bench fitters in the course of their daily works .. I'll bet that the pump has been swapped from another BL unit.. a fitter wouldnt think twice of doing it ..you do not want that oil coming out and it would help pressurise the tank .. just saying.
Thankyou gentlemen. I have had success with an o-ring under the big nut and the ball bearing seems to have accepted its role in the NRV. A good flame with very few pump strokes and I turned it off after about 5 minutes without needing to pump in between. We will see how long the o-ring survives. Thanks again for sage advice Bill
