Stumbled onto this tracing back some personal history. As a lad (mid-70s), I used to work at Icknield Instruments making these gauges. You're plan was good, but as others have noted, it's essential to get the right volume of either for the tube and also to evacuate the air before filling. No real manual calibration, so you have to get it right first time, or you do over. Your approach of using the screw to seal the hole before soldering was spot on. In the factory I was lucky - had a machine that held the bulb, extracted the air, measured the ether, filled the bulb, seal the bulb with a tapered plug and then I manually soldered the end. All done in a sealed room with plenty of ventilation (fans). Cracked up when you talked about ether and falling unconscious, as I had to be picked up off the floor more than once :) Hope you're projects are going well.
Hi Alan Yes, would never have worked. I was watching a Car SOS episode where they had one done. Clearly you have to evacuate all the air then introduce the ether. I'll have a go at most things but this was a bit daft.
I have been following you Matthew for som time now, and this is the iceing of the cake :) I hope to get my hands of a big healey to restore some time :)
Hi and thanks so much for watching. I'm glad you have enjoyed the videos. It's been about 7 years since I made the last one so it's great to still be receiving comments. I have an MGTD to work on now, but I'm not sure that I will do another series. We'll see. Cheers Matthew
Thanks for your videos. I have a 59 3000 in my garage going through what your doing to yours. If I had your skills it would be much further along. Thanks again for your inspiration.
From my understanding the Bourdon tube is under a vacuum and then the ether is placed and the system sealed. The residual air in the system is most likely the issue.
Tom Hamilton my car is a1937 Morgan. I considerably doubt if they would have created a vacuum in one part and not the other prior to assembly and soldering. I remain convinced that the assembly and production would have been quick and simple, we just haven’t sussed out how they used to do it yet, although I am very close to the answer.
Thanks Tom yes i think you're right. I have read that somewhere. Really, what I was trying to do was just an experiment. Some things are beyond me, but it was interesting. I'll leave this one to the professionals.
Been there done that and failed, mine when done read lower than it should, the problem is air in the bulb caused by the either bubbling out of the end hole? I suspect that a very low temperature solder was used originally, what I am going to try is making a modified bulb with a 5BA tread in the end, fill it with either and seal it in with a brass screw from a 3 pin plug then solder it sealed? This might well work?
Thanks Matt, been there done that....and failed, mine only recordred about 40 degs too so “Snap!” I didn’t use a screw and the ether boils out. I thought of using a tinned brass screw and will try it again what I also realised and showed me what a plonker I am is that solders come in varying melting points an I will need a low melting point solder but a bit above water boiling point. Where I think you might be wrong?? Is that I think that the capillary tube should all be full of ether? If it’s air or ether gas it will compress and give a low reading where liquid ether will not compress and that’s where I suspect we have a mutual problem? Knowing the capillary tube is full is the head scratcher? I’m having a go at mine again soon. I use old fashioned soderin irons and warm them up with a gas torch or the forge fire.
Hi Les Yes, somethings are beyond me but I thought I'd give it a go. Difficulty was getting hold of ether, and you're right, hard to know if there is no air in the tube. Cheers
All of these type of repairs have been guess work as to the repair method, having persevered with the problem I think I have sussed it, I’m still waiting for some info on solder, then I will post the method that I have adopted.
Thanks again Matthew, very informative. Some naive thoughts/questions on my behalf, feel no obligation to answer them: (i) when in operation, the temperature of the fluid in the Bourdon tube and capillary connector may change independently of the fluid in the sensor bulb (here in Florida the ambient air temperature can range over a year by around 70 deg F, and then of course parts heat up and cool down with the operation of the engine and motion of the car) - presumably the fluid capacity of the gauge and connector are small compared to the sensor bulb, or are these things just not that accurate? (ii) in the factory, was it just the sensor bulb that was charged with ether, or was the complete system charged? (iii) is the temperature of the system when it is sealed (and thus its standing fluid pressure) significant - I guess I have no feel for the pressure ranges experienced by the ether across operating conditions.
Hi Ian you have to understand that I am no expert, but I'll try. Here in Australia the temperature can change significantly too. I guess that the bulb submerged in the water jacket means that the water temperature is going to be more consistent and not altered too much by the air temperature. Also, most gauges don't start measuring at zero, but maybe 80-100 or so degrees. So you have to reach that pressure in the Bourdon tube before anything happens. The Bourdon tube relies on pressure, not temperature, and there is clearly some equation that links the two, but don't ask me. I don't think the ambient air temp would affect it. It's only the heat on the bulb that matters. I think they are fairly accurate though. the fluid capacity seems to be small: about 2/3 cc and the bulb is filled not the capillary. There is a blob of solder on the bottom of the bulb. the capillary is very fine. I don't think the temperature of the bulb when it's sealed makes any difference, as long as it's not warm enough for the ether to evaporate. That was the issue I had with soldering it. While it was an interesting experiment and probably would have worked if I could have found a suitable donor gauge, I have decided to have it professionally repaired. There is a company in Melbourne who do it. Costs about $150. cheers Matthew
Thanks Matthew. Good to know that there are companies that will make these repairs. The gauges on my 100-6 all work at the moment but there are no guarantees. I look forward to your next video. Ian.
Stumbled onto this tracing back some personal history. As a lad (mid-70s), I used to work at Icknield Instruments making these gauges. You're plan was good, but as others have noted, it's essential to get the right volume of either for the tube and also to evacuate the air before filling. No real manual calibration, so you have to get it right first time, or you do over. Your approach of using the screw to seal the hole before soldering was spot on. In the factory I was lucky - had a machine that held the bulb, extracted the air, measured the ether, filled the bulb, seal the bulb with a tapered plug and then I manually soldered the end. All done in a sealed room with plenty of ventilation (fans). Cracked up when you talked about ether and falling unconscious, as I had to be picked up off the floor more than once :) Hope you're projects are going well.
Hi Alan
Yes, would never have worked. I was watching a Car SOS episode where they had one done. Clearly you have to evacuate all the air then introduce the ether. I'll have a go at most things but this was a bit daft.
I have been following you Matthew for som time now, and this is the iceing of the cake :) I hope to get my hands of a big healey to restore some time :)
Hi and thanks so much for watching. I'm glad you have enjoyed the videos. It's been about 7 years since I made the last one so it's great to still be receiving comments. I have an MGTD to work on now, but I'm not sure that I will do another series. We'll see. Cheers
Matthew
Thanks for your videos. I have a 59 3000 in my garage going through what your doing to yours. If I had your skills it would be much further along. Thanks again for your inspiration.
Thanks for the comment Bronco Billy. I'm an amateur really. But I'm glad you enjoy them. Good luck with your restoration.
Matthew
From my understanding the Bourdon tube is under a vacuum and then the ether is placed and the system sealed. The residual air in the system is most likely the issue.
Tom Hamilton my car is a1937 Morgan. I considerably doubt if they would have created a vacuum in one part and not the other prior to assembly and soldering. I remain convinced that the assembly and production would have been quick and simple, we just haven’t sussed out how they used to do it yet, although I am very close to the answer.
Thanks Tom
yes i think you're right. I have read that somewhere. Really, what I was trying to do was just an experiment. Some things are beyond me, but it was interesting. I'll leave this one to the professionals.
dents on the hood near the windscreen may have been made when laying down the windscreen that some of the 100/6 models had.
Hi
Thanks for the comments. It was only the 4 cylinder cars BN1&2 that had the lowering windscreen though.
Been there done that and failed, mine when done read lower than it should, the problem is air in the bulb caused by the either bubbling out of the end hole? I suspect that a very low temperature solder was used originally, what I am going to try is making a modified bulb with a 5BA tread in the end, fill it with either and seal it in with a brass screw from a 3 pin plug then solder it sealed? This might well work?
Thanks Matt, been there done that....and failed, mine only recordred about 40 degs too so “Snap!” I didn’t use a screw and the ether boils out. I thought of using a tinned brass screw and will try it again what I also realised and showed me what a plonker I am is that solders come in varying melting points an I will need a low melting point solder but a bit above water boiling point. Where I think you might be wrong?? Is that I think that the capillary tube should all be full of ether? If it’s air or ether gas it will compress and give a low reading where liquid ether will not compress and that’s where I suspect we have a mutual problem? Knowing the capillary tube is full is the head scratcher? I’m having a go at mine again soon. I use old fashioned soderin irons and warm them up with a gas torch or the forge fire.
Hi Les
Yes, somethings are beyond me but I thought I'd give it a go. Difficulty was getting hold of ether, and you're right, hard to know if there is no air in the tube.
Cheers
matthew randell I got a small bottle of ether of the internet, I think it was e bay?
All of these type of repairs have been guess work as to the repair method, having persevered with the problem I think I have sussed it, I’m still waiting for some info on solder, then I will post the method that I have adopted.
Thanks again Matthew, very informative. Some naive thoughts/questions on my behalf, feel no obligation to answer them: (i) when in operation, the temperature of the fluid in the Bourdon tube and capillary connector may change independently of the fluid in the sensor bulb (here in Florida the ambient air temperature can range over a year by around 70 deg F, and then of course parts heat up and cool down with the operation of the engine and motion of the car) - presumably the fluid capacity of the gauge and connector are small compared to the sensor bulb, or are these things just not that accurate? (ii) in the factory, was it just the sensor bulb that was charged with ether, or was the complete system charged? (iii) is the temperature of the system when it is sealed (and thus its standing fluid pressure) significant - I guess I have no feel for the pressure ranges experienced by the ether across operating conditions.
Hi Ian
you have to understand that I am no expert, but I'll try. Here in Australia the temperature can change significantly too. I guess that the bulb submerged in the water jacket means that the water temperature is going to be more consistent and not altered too much by the air temperature. Also, most gauges don't start measuring at zero, but maybe 80-100 or so degrees. So you have to reach that pressure in the Bourdon tube before anything happens. The Bourdon tube relies on pressure, not temperature, and there is clearly some equation that links the two, but don't ask me. I don't think the ambient air temp would affect it. It's only the heat on the bulb that matters. I think they are fairly accurate though. the fluid capacity seems to be small: about 2/3 cc and the bulb is filled not the capillary. There is a blob of solder on the bottom of the bulb. the capillary is very fine. I don't think the temperature of the bulb when it's sealed makes any difference, as long as it's not warm enough for the ether to evaporate. That was the issue I had with soldering it. While it was an interesting experiment and probably would have worked if I could have found a suitable donor gauge, I have decided to have it professionally repaired. There is a company in Melbourne who do it. Costs about $150.
cheers
Matthew
Thanks Matthew. Good to know that there are companies that will make these repairs. The gauges on my 100-6 all work at the moment but there are no guarantees. I look forward to your next video. Ian.
well, thereabouts!
Hahaha ether boils at about 34.6 C. Lol
Well, thereabouts! :-)