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Post by 92220 on Mar 13, 2019 8:34:55 GMT
Roger, I like the comment 'it's good enough for you' with you and Peter my ME world is becoming harder and harder, BUT, if i get half as good, then i will be happy As an aside your comments re soldering I know about the tippex, but your comment on leaving the flux for 40 mins is a new one to me. Now the weather is getting warmer i can get back outside to do the expansion brackets ( 13 pieces in total) so it does interest me. What is the theory behind it? Regards Ron Hi Ron. I must admit I never wait before silversoldering.....too impatient!! That's why I feed wire into the flame rather that use Roger's method, which, incidentally, usually provides a neater joint. The reason that it works is that when the flux is wet, the water in it boils off and bubbles, so causing movement of the flux wire. Waiting 40 minutes allows the flux to dry out and so there is almost nothing to cause movement. Bob.
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Post by andyhigham on Mar 13, 2019 9:20:02 GMT
That is the method of silver soldering I was taught as school
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Post by delaplume on Mar 13, 2019 10:17:31 GMT
Hi Bob,
I just wanted to use this handy quote to start off my input...it's not meant to be a negative against you personally....
Quote}--- "That's why I feed wire into the flame rather that use Roger's method, which, incidentally, usually provides a neater joint"
Alas, you're not alone in using that method as a lot of "Amateur" boiler soldering will testify to.......The generally accepted rule is that Silver solder should be melted by the heat of the metal it's being applied to, which is what Rogers technique is using after all..
Agreed that there is a world of difference between say a 7.25" gauge Duchess boiler for example and a Mamod - type one but the fundamentals still apply.....
You only have to look at the quality of the Professional Boiler Maker's product to see what the Bench-mark is.........
I must admit to a similar personal shortcoming to Bob's inasmuch that I too become impatient but when you see just what is obtainable purely through a little bit of self-control aided by skilled advice ( Such as Roger's ) then it becomes worth the effort..........That idea of all-over flux and let it dry first is new to me and one I'll be trying out soon...
The "Bible" for Boiler work IMHO is}-------- "Model Locomotive Boilermaking" by Alec F. Farmer.......Fully illustrated in both B&W and colour along with a tutorial involving building a Martin Evan's Torquay Manor Boiler.. ISBN = 1 - 85260 - 007 - 1
If you can find one then it's worth every penny just to have it in your tech. library..
Thanks Bob
Alan
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Post by simon48 on Mar 13, 2019 10:46:47 GMT
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barlowworks
Statesman
Now finished my other projects, Britannia here I come
Posts: 874
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Post by barlowworks on Mar 13, 2019 11:32:56 GMT
For the impatient amongst us, why not run a hairdryer over the flux to dry it before applying the flame to the dried flux and solder. Not as fierce as a flame but should be more controllable.
Mike
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Post by delaplume on Mar 13, 2019 12:47:46 GMT
Thanks Simon..........I wasn't aware of that re-print..........I wonder what a signed original is valued at then ?? Best put a padlock on my library case then --LoL !! Alan
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Post by 92220 on Mar 13, 2019 17:09:58 GMT
Hi Alan.
Actually when I was an apprentice draughtsman and did my 18 months in the workshops, back in pre-historic days, I was taught silversoldering and because we used oxy-acetylene for the heat source, most of the time, we were taught how to melt the silversolder at the edge of the outer envelope of the flame, which is much cooler than the inside. We also used a much smaller, intense flame, which heated the parts up quickly but the silversolder could be got really close to the parts before it started to melt. When I'm being 'impatient' (which is most of the time!) I always heat the job until the flux turns transparent and the parts start to show red, before applying the solder. That way only a minimum of solder melts off the wire. Also, using oxy allows the parts to be brought up to heat and the flame moved away only a short distance so that it still applies heat via conduction through the metal. I must admit I've never really thought about it until now, but that is how I was taught and have always done it. To be honest, I've never got on with putting pieces of wire into the flux before heating as it always moves. I'd never thought of Roger's idea of allowing a drying time, as my impatience has always got the better of me!! I must try it.
Hi Mike.
The hairdryer is a thought, but it might still cause the flux to bubble. Next time I have some silversoldering to do I'll try Roger's method, and your idea, 'cos I've always been impressed by the neatness of Roger's silversoldering.
Bob.
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Mar 13, 2019 18:50:42 GMT
This is getting seriously off topic, but
1. Silver solder should never be melted in the flame when the job to be silver soldered might not be up to the melting temperature plus a bit of a margin
2. For the last 3 boilers I have silver soldered I have always fluxed up then left the flux to partially dry out. It then stays where it is wanted rather than bubbling and running off. I always have some made up in a jar to add just in case
3. You can do what Roger has done in certain situations and apply silver solder in rings etc to the job, then heat up, but this must be heat applied away from the silver solder to heat up the job to the required temperature and not melt the silver solder prematurely
Cheers,
Julian
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Post by Roger on Mar 13, 2019 19:02:22 GMT
I think you will find that most methods of accelerated drying will cause bubbles in the flux unless it's pretty gentle. If I don't want to wait and the Silver Solder pieces are quite large, I don't worry too much about them moving because once the bubbling has stopped, you can prod them back into place in the sticky flux. Putting it on a radiator is probably as good an idea as any. Personally, I'm not often in a rush to do anything. There are always other jobs to get on with while something is drying!
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Post by Roger on Mar 13, 2019 19:21:13 GMT
This is getting seriously off topic, but 1. Silver solder should never be melted in the flame when the job to be silver soldered might not be up to the melting temperature plus a bit of a margin 2. For the last 3 boilers I have silver soldered I have always fluxed up then left the flux to partially dry out. It then stays where it is wanted rather than bubbling and running off. I always have some made up in a jar to add just in case 3. You can do what Roger has done in certain situations and apply silver solder in rings etc to the job, then heat up, but this must be heat applied away from the silver solder to heat up the job to the required temperature and not melt the silver solder prematurely Cheers, Julian Hi Julian, I've found that if you put enough flux on the Silver Solder that's resting on the job, the flux melts first and conducts the heat around the job and the wire so that the wire doesn't melt prematurely. If you're mean with the flux, it will do as you say and melt into balls in places.
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jma1009
Elder Statesman
Posts: 5,901
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Post by jma1009 on Mar 13, 2019 20:44:18 GMT
Hi Roger,
I don't understand the logic of your above reply, for someone so careful and particular over such matters! We are probably at cross purposes over semantics. I am sure you would not apply a flame direct to a silver soldered joint with silver solder placed in position in direct contact with the flame before the metal has heated up to the required temperature!
Cheers,
Julian
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Post by Roger on Mar 13, 2019 21:17:03 GMT
Hi Roger, I don't understand the logic of your above reply, for someone so careful and particular over such matters! We are probably at cross purposes over semantics. I am sure you would not apply a flame direct to a silver soldered joint with silver solder placed in position in direct contact with the flame before the metal has heated up to the required temperature! Cheers, Julian Hi Julian, I mean that I apply heat to the whole job, which will inevitably be directed onto the Silver Solder resting on the joint. It's certainly preferable to heat away from the Silver Solder, but that's not always possible and it's really not a problem if the joint is prepared as I described. It's really not a problem if there's enough flux and the Silver Solder has been shaped to hug the joint it's expecting to fill. As you heat it up, you end up with a clear molten pool of clear flux with the Silver Solder wire laying in it. That means the temperature of the Silver Solder wire is kept the same as the flux, so it doesn't melt. You'll be surprised what you can get away with if you do it like that.
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Post by ettingtonliam on Mar 14, 2019 0:20:08 GMT
In my recent boiler work I've been using Roger's method for the first time, and it does seem that pre applied solder stays under the flux, in close contact with the boiler plates, and stays at the temperature of the plates, so it doesn't melt until the plates are ready for it, if you see what I mean. Certainly there didn't seem to be any tendency for the solder to 'blob'
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Post by 92220 on Mar 14, 2019 9:29:05 GMT
All this is why I am experimenting with a cheap single plate induction hob - to see if it can be used to bring a whole assembly up to temperature for silversoldering. I am trying to find the ideal insulation material (about 3 or 4mm) to prevent the hot assembly damaging the hob surface. I used the hob to boil up a stainless tub of water to clean off a soldered joint I had previously made. I took the part out of the water, forgot to switch off, and went to do another little job. The water boiled dry and the base of the stainless dish got bright red hot, so it can get hot enough to silversolder. Very interestingly it only marked the hob surface and didn't damage any internals, though it wasn't there very long before I caught it. However, I still want to find a suitable insulation material that doesn't limit the magnetic field but is still good enough to protect the hob surface. The 3mm ceramic fibre 'paper' I bought, I used underneath a piece of 1mm mild steel sheet, to get up to temperature. It did, but when I lifted the steel pl;ate off the ceramic paper, it had burned it and the shape of the steel plate just fell out of the centre of the ceramic, so still investigating. Maybe a different brand might work better. My previous experience was with Kaowool, the inveters of ceramic fibre, but the stuff I bought for this experiment was just something I got off Ebay at half the price of Kaowool paper. The hob will certainly get up silversoldering temperature but the surface still needs to be protected from the heat. Experimenting to continue.
Bob.
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Post by Roger on Mar 14, 2019 9:58:06 GMT
All this is why I am experimenting with a cheap single plate induction hob - to see if it can be used to bring a whole assembly up to temperature for silversoldering. I am trying to find the ideal insulation material (about 3 or 4mm) to prevent the hot assembly damaging the hob surface. I used the hob to boil up a stainless tub of water to clean off a soldered joint I had previously made. I took the part out of the water, forgot to switch off, and went to do another little job. The water boiled dry and the base of the stainless dish got bright red hot, so it can get hot enough to silversolder. Very interestingly it only marked the hob surface and didn't damage any internals, though it wasn't there very long before I caught it. However, I still want to find a suitable insulation material that doesn't limit the magnetic field but is still good enough to protect the hob surface. The 3mm ceramic fibre 'paper' I bought, I used underneath a piece of 1mm mild steel sheet, to get up to temperature. It did, but when I lifted the steel pl;ate off the ceramic paper, it had burned it and the shape of the steel plate just fell out of the centre of the ceramic, so still investigating. Maybe a different brand might work better. My previous experience was with Kaowool, the inveters of ceramic fibre, but the stuff I bought for this experiment was just something I got off Ebay at half the price of Kaowool paper. The hob will certainly get up silversoldering temperature but the surface still needs to be protected from the heat. Experimenting to continue. Bob. Hi Bob, I think this is really interesting. I've been looking for a suitable material for the insulation, and this might be what you're looking for. It's rigid and thin, and goes to very high temperatures. At the moment I can only see it being shipped from overseas, so it's not cheap. If you could find a source in the UK, that would be an acceptable price in my opinion.
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Post by silverfox on Mar 14, 2019 12:28:33 GMT
Thanks all
Method i will use is
paint it with tippex for stop solder running/sticking where not reqd
Fluxing up
go for lunch
do the soldering
cool and pckle and clean
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Post by 92220 on Mar 14, 2019 19:40:08 GMT
Hi Roger.
Thanks for that. I shall have to investigate it further as they are only offering pieces 6.4" x 3.5". I need at least 12" square as a single piece, but it does look as if it is the ideal insulating material. Just got to find a source of larger pieces now. If an induction hob can be protected from the red heat, it will be a massive advantage for complicated steel assemblies, as they would heat up uniformly and not distort. Feeding wire to a joint would also be so easy with no flame around. If I can get it working for steel parts I will then look at ways of transmitting heat to non ferrous materials. This might have to be done by using some kind of steel box to heat up and transfer heat to the non ferrous.
Bob.
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Post by 92220 on Mar 14, 2019 20:32:10 GMT
This is getting seriously off topic, but 1. Silver solder should never be melted in the flame when the job to be silver soldered might not be up to the melting temperature plus a bit of a margin 2. For the last 3 boilers I have silver soldered I have always fluxed up then left the flux to partially dry out. It then stays where it is wanted rather than bubbling and running off. I always have some made up in a jar to add just in case 3. You can do what Roger has done in certain situations and apply silver solder in rings etc to the job, then heat up, but this must be heat applied away from the silver solder to heat up the job to the required temperature and not melt the silver solder prematurely Cheers, Julian Hi Julian.
I always melt the silversolder wire in the flame. It doesn't matter if the metal is not quite up to temperature as, even if the solder melts and a blob drips off, it will flow out as soon as the base metal gets to temperature. I was taught how to silversolder in my apprenticeship and it has stood me in good stead for more years than I care to remember!! But my methods may not work for others.
Here is a photo of the sort of silversoldering I do with the wire melted in the flame. The screw is included in the photo for size comparison. It is a 14BA hex head screw. The numberplate brackets (0.6mm thick) are silversoldered onto the smokebox door (2.5mm thick) with the 0.5mm silversolder wire melted in the oxy/propane flame. The fillet has not been touched in any way to tidy it up. It is just as silversoldered.
There are many ways to silversolder and really it is all down to working out what works for you. What works for me may not work for you and what works for you may not work for me, but that doesn't mean that either way is wrong if the results end up as expected.
Bob.
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Post by Roger on Mar 14, 2019 20:35:24 GMT
Hi Roger. Thanks for that. I shall have to investigate it further as they are only offering pieces 6.4" x 3.5". I need at least 12" square as a single piece, but it does look as if it is the ideal insulating material. Just got to find a source of larger pieces now. If an induction hob can be protected from the red heat, it will be a massive advantage for complicated steel assemblies, as they would heat up uniformly and not distort. Feeding wire to a joint would also be so easy with no flame around. If I can get it working for steel parts I will then look at ways of transmitting heat to non ferrous materials. This might have to be done by using some kind of steel box to heat up and transfer heat to the non ferrous. Bob. Hi Bob, I think it's worth an experiment with just a small piece first. I've sent off an enquiry to a UK company to see if they have something suitable. It might be sensible to use several smaller pieces anyway, one large one is more likely to break. Then you can put as many on the hob as you need for any particular job. I think it's a brilliant idea, well worth more R&D
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Post by Roger on Mar 16, 2019 16:10:33 GMT
I've been looking again at the balance pipe now that I need to know precisely where everything goes on the Pannier tanks. I can put these in the correct position fore and aft, but not on the width because they join the tank right on the inside edge, only just outboard of the frames. I need to be able to join the curved inner face of the tank to the edge, and I also need room for some insulation, so that necessarily moves these slightly further out. I can't go as far as I'd like because the tube that takes the feed water to the top feed arrangement is next to it. Although I could move that a bit, I'd rather it was in the right place since you can see where that's supposed to be, whereas the underside is mostly hidden. Anyway, this is how it looks with a modified and much more rounded balance pipe which will now be made from Copper sheet instead of Stainless Steel. Balance pipe by Anne Froud, on Flickr The Copper pipe will be made in two halves, cut like it's sectioned below. Originally I was stumped about assembling the two halves for Silver Soldering, and then I remembered that I could tack weld them with the TIG welder in as many places as I want. Since these are big parts and the assembly may not be as precise as I might like, I've fitted the biggest possible O-ring which turns out to be a respectable 3mm cross section. I'm trying to avoid as many tiny bolts as possible, even though on the injectors that's simply not possible. Here it's a different matter though, I can put dummy ones on the flange and use the space saved for the O-ring. The cutout on the left of the top piece is to allow for a wire spring catch that slots into the holes below in case it needs retaining. The plan is to run without any positive retainer, the fit will be pretty tight, but I need a plan B in case it tends to work itself out over time. Balance pipe seal arrangement by Anne Froud, on Flickr The idea is to make it all out of Phosphor Bronze so it's strong even though the sections are quite thin. The colours shown are just to differentiate between the parts. There's a very fine shoulder on the bottom of the O-ring retainer so it sits down onto the bottom flange. The Copper balance pipe pushes up underneath that and it's all Silver Soldered in one operation.... at least that's the plan so far! Balance pipe flange seal by Anne Froud, on Flickr
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