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Post by builder01 on Feb 5, 2017 3:07:19 GMT
Nothing to "fall apart". The smoke box tube sheet is fixed in the barrel, by small screws (not soldered yet). The fire box tube sheet, with tubes now soldered, can be removed for inspection of both sides of the joint and the smoke box tube sheet is left in the barrel, it is soldered last after everything else.
Better give this thread back to Roger, sorry about this!
David
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Post by builder01 on Feb 5, 2017 0:42:23 GMT
I can appreciate if you are assembling the tubes into the boiler and soldering them up once in final position, assuming thats how you mean, then yes you have no risk but when I have seen these done with just tube plate and firebox tube plate and tubes in between with no barrel how can you then ensure it is all set up correctly? hence where something like this Jig comes in very hand. Adam Yes, the barrel is used as part of the jig! The barrel should have the throat plate and forward part of the foundation ring installed. The smoke box tube sheet is fastened in position to jig the forward end of the tubes. After the tubes are soldered to the fire box tube plate, the whole assembly (tubes and fire box plate) can be removed from the barrel for inspection and preparation for the next joint(s). The back plate of the fire box and back head are not installed at this point. David
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Post by builder01 on Feb 4, 2017 22:42:39 GMT
Hi Cro,
"I can appreciate using the tube plate but whats to say that the two plates are dead lined up and not twisted or at an angle? at least this way Roger can be fairly confident that there won't be any of these potential errors creeping in."
The plates will not be twisted or out of alignment. Both plates are marked with a center line and then these lines are are used as a reference. All the plates should be installed exactly as they will be when finally soldered in place. I used a few very small copper and bronze screws to locate the plates. In the final heat up, for where each of these screws are, they are soldered over. Works better than rivets as you can "dry" fit all of the parts and take them back apart while getting the correct fits.
As an aside, no boiler has all of the plates attached to the barrel within .001". There is really no need for this tolerance, just make sure the water fits inside! LOL!
David
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Post by builder01 on Feb 4, 2017 20:33:16 GMT
Hi Roger,
Actually, I did it all in one heat up. I was pretty amazed that it worked so well. Maybe I was just lucky, but, it went exactly as Julian showed in his thread.
Instead of time spent making a jig, I used the fire box tube sheet as the jig as I had to make it anyway. In fact, I drilled and bored both the firebox tube sheet and the smoke box tube sheet at the same time. Not only are both sheets done exactly the same, I only had to do it once. It looks like you may have to drill your tube pattern three times. But, as you say, time is not a consideration for you.
As for "fiddling" about to get the tubes through the sheets, it is no more fiddly than a separate jig, which requires tubes to be threaded through the jig and through the tube sheet. It's not a big deal either way, except for the extra time spent on the jig.
Your explanations are quite good in explaining why you are doing it the way you are. I understand. Keep up the good work.
David
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Post by builder01 on Feb 4, 2017 19:10:05 GMT
Hi Adam and Roger,
Wow, I believe what you are saying, but, I would never consider bunching the tubes together, soldering them, and then bending them to fit the smoke box tube sheet. Bending them back is not a defence of that method, at least for me, for doing it that way. I don't like that either.
Roger, what you are doing looks good. If you have experienced help, that's probably the most logical way to go, even though, not the most simple.
David
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Post by builder01 on Feb 4, 2017 14:42:01 GMT
Hi Roger,
Actually, if you use the barrel and the smoke box tube sheet to hold the tubes while soldering the fire box end, the tubes will be in perfect alignment after soldering. No need to worry about "distorting" the fire box tube sheet to get things aligned, they already will be!
If you remember from Julian's Stepney thread, the tubes are not simply bundled together at the smoke box end, soldered at the other, and then bent to fit the smoke box tube sheet later on. No one does it like that. (I hope not!) The smoke box sheet is the jig for the other end.
David
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Post by builder01 on Feb 4, 2017 13:27:40 GMT
I did mine Julian style with the tubes horizontal and rings on the water side of the tube sheet. I used propane, just play the flame directly on the tube sheet. The entire assembly does not need to come up to soldering temperature, only where you are working. The tubes and tube sheet do not have much mass and are quickly brought up to temperature;
When the tube sheet and tube ends come up to temperature, the rings melt and are drawn toward the heat source. You don't need to heat the entire length of the tube, as you are only soldering the end that goes into the tube sheet. All ends of the tubes are exposed to the flame and heat up together, it is easy and works quite well! By the way, the time to make a few silver solder rings will take much less time that to create the jig you are about to use. I simply used the boiler barrel to jig everything in place for alignment purposes.
David
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Post by builder01 on Feb 3, 2017 14:46:29 GMT
Of course, picking a diameter and pitch is not unique to the metric world, you can do it in imperial measurements also if you are cutting both inside and outside threads.
David
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Post by builder01 on Jan 22, 2017 13:34:53 GMT
If you need more draft, could you just add some sort of blower in the smoke box? Sounds like you will have plenty of steam to do the job.
David
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Post by builder01 on Dec 30, 2016 21:29:35 GMT
Hi Julian,
I had a feeling that "don't worry about it" might be the answer. The bath tub will absolutely be the place when I really get this thing washed out. Thank you.
David
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Post by builder01 on Dec 30, 2016 20:47:25 GMT
I'm getting close to finishing my boiler. It is copper with bronze bushings for the fittings. I have partially threaded the bushes before silver soldering them into place. It was recommended to finish threading them after all the heating was done in order to not possibly damage the threads while heating.
Question is, what is the best way to minimize debris (metal chips) from the the finish tapping process, from falling into the boiler. Should I avoid cutting oil? Tap the bushes upside down so the chips fall out, rather than in? Or, don't worry about it and just make sure everything gets washed out of the boiler?
Thanks,
David
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Post by builder01 on Dec 29, 2016 20:38:19 GMT
Yes, I think we all agree that a silver brazed joint has a higher re-melt temperature. I realize this also. My question was always, why? Now, I understand that the reason seems to be that there is a change in the brazing alloy when it mixes with the base metal. Thus, raising the re-melt temperature. Maybe everyone already knew this, I did not.
David
p.s. "wedding tackle", awesome!
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Post by builder01 on Dec 29, 2016 20:02:46 GMT
Ooops!! Looks like others found the same information that I have.
Here's some interesting information about silver brazing (silver soldering) from Wikipedia.
Quote:
For successful wetting, the base metal must be at least partially soluble in at least one component of the brazing alloy. The molten alloy therefore tends to attack the base metal and dissolve it, slightly changing its composition in the process. The composition change is reflected in the change of the alloy's melting point and the corresponding change of fluidity. For example, some alloys dissolve both silver and copper; dissolved silver lowers their melting point and increases fluidity, copper has the opposite effect. The melting point change can be exploited. As the remelt temperature can be increased by enriching the alloy with dissolved base metal, step brazing using the same braze can be possible.
Unquote.
There is, of course, much more information. But, this was probably the most interesting. Not only does Wiki confirm that the base metal dissolves with the brazing alloy, but the melting temperature of the formed braze can be exploited such that step brazing can be done. This is why is it possible to complete a boiler with only one type of silver solder. It also explains why a good silver solder joint is incredibly strong. Interesting indeed.
David
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Post by builder01 on Dec 25, 2016 22:54:26 GMT
Hi Roger,
Yes, if you trim the inner wrapper back just a little bit, so the radius of the firebox does not leave that little radiused gap, you can shape the foundation ring to fit well enough to leave almost no gaps anywhere. The "trimming" of the inner wrapper need be no more that the depth, or thickness, of the foundation ring. Pretty easy to do with a file.
David
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Post by builder01 on Dec 25, 2016 22:23:28 GMT
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Post by builder01 on Nov 22, 2016 17:28:13 GMT
If your slitting saw breaks, in a piece of cast iron, it may be possible that a small part of the saw will now be imbedded in the cast iron. It will be pretty much impossible to get out. If it is a casting, it may become scrap now. It is much easier to hack saw close, and then machine to finished size. before I got my band saw, I did a lot of hack sawing of everything from aluminum to mild steel. Then, machine to finished size.
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Post by builder01 on Nov 18, 2016 0:51:11 GMT
Hi Roger,
I don't know about using an aluminum mallet on copper. You can certainly try it and see how it works. One thing about using a mallet that is too soft, is that it prevents you from "feeling" what is going on. To me, freshly annealed copper is dead, almost like lead. As it starts to work harden, it gets very springy, almost like steel! You can feel this change right through the mallet. If you are sensitive to the change, there is no risk of cracking the copper.
As for your barrel and formers made exactly to the print, what could possibly go wrong?
I am not suggesting that you should not make things as the drawings show. But, my point is, the copper boiler parts will never fit together exactly as they come off the formers and will require some amount of hand work to get the fit you need for silver soldering. It will be much easier to adjust the flanged plates to fit the boiler barrel, than the other way around. We'll have to see what happens.
Making a boiler is not a "machine operation". By spinning your smokebox tube sheet, you cheated yourself of making the most easily fabricated (and fun) tube sheet by hand. I have found that making the flanged plates to be the most fun part of making a boiler.
David
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Post by builder01 on Nov 18, 2016 0:01:36 GMT
Yes, I agree with Julian, you need to get those corners in. The large straight parts and curves will not be a problem.
For "belting" the copper, I use a hard plastic mallet, it leave no marks. Rawhide will work if the mallet is heavy enough. Rubber and dead blow types are a bit soft to do the job.
As for making the boiler barrel first, this is because you can easily adjust the flanged plates for a nice fit in the barrel. If you make them first, you have nothing to fit them to. The barrel cannot be easily adjusted to fit the flanged plates.
David
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Post by builder01 on Nov 17, 2016 23:52:18 GMT
Instead of just posting facebook links, maybe a little bit of text to let us all know what's really going on. A photopgraph, as Roger suggested, would also be helpful.
David
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Post by builder01 on Nov 5, 2016 22:49:25 GMT
Looks pretty good! I hope mine turns out as well!
David
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