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Post by davidimurray on Sept 10, 2006 15:39:06 GMT
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Post by greasemonkey on Sept 10, 2006 19:13:34 GMT
Hi Dave
We have a similar set down the club. They are okay for pipe work but forget it for the big stuff, either invest in a large oxy-propane set or get a sievert cyvlone burner.
Andy
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Post by Jo on Sept 11, 2006 9:10:30 GMT
You are going to get a very hot hand with one of these, and you are also going to need a second heat source such as a roofing size blower on your servert to get the general boiler up to temperature to avoid cracking.
I cannot imaging that these small sets will have the nossle size to cope in the resulting environment (I think I use a number 10 on my big set) and even if they did they will chill very quickly.
Jo
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Post by ron on Sept 11, 2006 10:39:38 GMT
David, I used to have a similar small set that was marketed by 'Benzormatic' but it became impossible to get replacement oxygen cylinders due to changing EEC legislation so I'd be a bit wary in case you spend the money and are left with unusable kit like I was.  Although at the time I had it I used it mainly for automotive jobs, ie spot brazing door skins to doorframes, it was very good and supplied a lot of heat locally but I have no experience of it on copper and get the feeling it might struggle a bit. If you get one I'd be very interested how you get on with it. Ron |
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Post by baggo on Sept 11, 2006 14:17:41 GMT
I bought an early version of these kits about 30 years ago when I was building the boiler for my Allchin as I had problems getting enough heat inside the firebox. The problem that I found was that it's difficult to regulate the flame temperature and if you are not very careful you can melt the ends of the stays before the copper is hot enough to solder the joints. This no doubt applies to full size kits as well.
It's usual practice not to fit the firebox backplate until the side stays are fitted and silver soldered. This leaves the back of the firebox open and allows you to get a decent flame inside. The firebox backplate is fitted and then the backhead last. Not much help though if you have already fitted them! One possibility might be to get someone to heat the outside of the boiler with a biggish burner to supply the main heat while you use a smaller narrow flame burner inside the box, if you can keep it alight.
If all else fails, have a word with your boiler inspector and ask him about using Comsol on properly threaded and nutted stays as in the 'old' days. Some clubs do frown on it's use and their boiler inspectors may not accept it, but there's nothing wrong with it. There's plenty of boilers running around with soft soldered stays.
The 2-1/2" gauge Association is perfectly happy to accept Comsol caulked stays on new boilers as confirmed by their boiler tester who lives locally. I shall be using it inside the fireboxes of the 2-1/2" gauge boilers that I'm building at the moment (the outsides ends of the stays will be silver soldered), but to be fair, the fireboxes in these are often so narrow that it would be virtually impossible to silver solder them, even with Oxy-Propane. The worst that can happen if you let the water level drop too low is that the solder may melt on the higher stays and let them leak. There will be no loss of structural strength in the boiler so long as the stays are threaded and nutted.
John
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Post by ilvaporista on Sept 15, 2006 7:10:58 GMT
Like an earlier poster I use this as a spot heat source for stays, AFTER bringing the boiler up to temperature. The Sievert torch is used with a cyclone burner and then spot with the oxy propane. You need to be carefull but it means that you can work on a small group of stays before moving on to the next.
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Post by chris vine on Sept 15, 2006 11:33:12 GMT
Oxy Propane.
One useful nozzle is like a little pepper pot. It has 6 little nozzles and produces a bigger flame. It is still seriously hot but the heat is spread around a bit. I find it useful for all sorts of work but have never used it for silver soldering stays inside a fire box.
Chris.
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