CWS Model O Lead Welding Torch - Complete with oxy/propane tips
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Oxy / Propane model "O" lead welding tips allow this set to be used with propane instead of acetylene.
Our CWS model "O" torch is a good replacement for the original model "O" torch.
Due to the difficulties we continue to experience in obtaining supplies of the original BOC type Model "O" blowpipe, which is still being manufactured in the UK, means that we are generally "out of stock" hence we needed a good quality Model "O" torch of our own to keep our customers satisfied and able to lead weld with confidence.
Due to the poor supply situation we decided at Noz-Alls that we had to do something for our customers, the situation pushed our company into seeking an alternative product, we have taken time and tested various Far Eastern manufactured torches and found most were poor or very poor, some even dangerous.
We now source from a higher cost reliable Chinese manufacturer, when the blowpipes arrive at Noz-Alls we strip, test and reassemble every torch, make a few amendments to improve the performance and this now means we are able to supply our own version of the Model "O" blowpipe plus have confidence in the performance as well as its safety.
Every blowpipe is tested to ensure it conforms with and meets BS EN ISO 5172 as well as being tested for performance and flame stability. See our video of the generally available cheap variants of the model "O" and how easily and annoyingly the flame setting varies just by touching the control knob!
Of course our CWS Model "O" blow pipe does not suffer with the same problem.
Our control valves are a little stiffer to turn but they stay fixed in position and the flame does not alter even with a #1P nozzle on a very low setting.
CWS Model "O" blowpipe comes complete with neck & 5 nozzles, 1 off each #1P, #2P, #3P, #4P & #5P
Spare necks are available as well as individual Model "O" nozzles - GB 0401A.........
We also supply a neck with a 90 degree bend - standard neck is 60 degrees.
We have super flexible 3mm bore hoses suitable for use with this blowpipe.
Due to the nozzle orifice size the Model "O" blowpipe / nozzle does not require high gas pressures, operating data is supplied with each nozzle along with a chart showing the nozzle size, lead weight and welding position.
The small rent free Hobbyweld oxygen and acetylene cylinders will easily operate the Model "O" nozzles from #1 to #5 without any flow problems. With this set being supplied with oxy / propane nozzles means that there is no flow rate restriction. You will need to remember that the oxy / propane flame cone is typically longer than oxy / acetylene this is because the oxy / propane flame burns at a much slower rate plus requires 4 times as much oxygen.
Set includes the CWS Model "O" shank, neck and 5 nozzles 1 each of #1P, #2P, #3P, #4P & #5P
The last image shows what our own model "O" used to look like. We now have them coated.
Pictures added of the parts stripped down, some machined, some yet to be machined and then cleaned before being assembled and tested. We fit new "O" rings and discard the old ones. You will appreciate from the pictures that the Model "O" torch is completely stripped down, reworked, some parts machined and modified to suit what we require so the torch functions correctly at the very low flows required.
Lead Welding and the myth of the “ball” flame
Noz-Alls being a gas equipment specialist company and with the author being a nozzle design engineer I feel the need to let the wider lead welding community understand the “ball” flame expression and the Myth behind it with respect to lead welding.
The need for explanation has come about due to the number of our lead welding customers who telephone us and announce that they cannot set a “ball” shaped flame? When asked why they want to set a ball shaped flame they explain that there is a lead welding expert on U-Tube who carries out really good lead welding and in the video he expresses that you need to set the correct “ball” flame.
Firstly – a ball flame would be and is completely wrong – if the flame is a ball then there is a problem with the nozzle. On a small orifice of a welding nozzle the flame will always be a cone shaped, albeit a very small cone to a long pointed cone this being true for all lead welding tip sizes 1 to 5.
I watched the video in questions several time to be sure of what I was understanding. There are a few safety issues and procedures which are incorrect in the video so make sure when you operate that you follow the correct lighting up and closing down procedure.
The artisan is completely correct that setting the correct flame is essential to the success of the lead welding, when the artisan is explaining what you need to do, he hesitates, as he says, “ you must set the………ball flame correctly”. The issue is that the artisan does not know the term used for the inner flame cone or primary cone. As the artisan sets the flame, he terms the inner cone as a “ball” rather than a cone, I believe that this is where the confusion of setting a “ball” flame stems from.
The lead welding cone is generally very small for Model “O” sizes #1A, #2A & #3A or the #1P, #2P or #3P when viewed through a shade #5 lens you will see that the cone is triangular in shape – almost an equilateral triangle – unlike the larger sizes which appear more conventional in shape with a longer sided cone with a rounded tip.
Lead welding technique demands “dipping” of the nozzle in and out of the lead to give the instant melt and puddle, lead can stick to the tip face, this can cause the flame cone to be mis-shaped and difficult to weld with – do not prod the orifice. Warm up and wipe away the lead.
With the correct Noz-Alls Model “O” lead welding tip it is possible to use oxy / propane because the nozzles have been designed flow the appropriate amount of gas, whilst providing a stable flame even in a wind, the flame cone does not blow off.
Oxy / propane cannot be used for fusion welding of steel, stainless steel, aluminium or copper this is due to the oxidising nature of the flame.
Any questions concerning lead welding or our lead welding Model “O” blowpipe, which has secure stainless steel valve spindles, which don’t adjust the flame setting when you tap them or work with the torch, please give Noz-Alls a call on 01242 681052.
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