Terry's Technical Tips
This section is dedicated to incredibly useful tips that should help keep you safe while working and may even save you money through proper use of equipment. Watch out for new tips and you may just find out a useful nugget of information.
If you would like more information and specific help on various aspects of buying a welder or buying the right consumables / equipment for your needs then please click through to our Customer Advice Page. There we have various pages all with useful information on.
The blink of an eye.
Recently we had a customer come to us for a new helmet. He old was which was working perfectly ended up sadly having the auto darkening lens cracked. One of the questions we were asked about our new CWS ES 5-13 was how quick is it to react. This got me thinking of how best to explain the reaction time of our own welding helmets.
The blink of an eye is averaged at about 1/3 of a second (0.33) and research has shown that the human eye can detect images in as little as 13 milliseconds (0.0013). Our helmet reacts to the arc in just 4 milliseconds (0.0004). This makes our helmet over 8000 times quicker than the blink of an eye and over 3 times quicker than the human eye / brain can even detect an image.
Make your next helmet a good one and buy from Noz-Alls. Remember - if the helmet doesn't have the spec listed it is probably the seller hiding something.
"I need Stainless MIG Wire..." Fine but come prepared.
We often get approached at the Trade counter by people who are welding stainless steel which is great but so often they don't actually know what type of stainless they are welding. There are many types of stainless steel but often the chances are you will be using 304L or 316L (the L simply stands for low carbon).
Below is a simple table of the most suitable filler materials for the two types of material to be welded. Of course others could be used and the strength of a weld will typically rely more on your own welding ability,
Use the grey cells to match your two pieces of metal to be welded together and then see the filler rods you require for the job. Stainless 410 & 430 typically use 309L filler rod and 310 use 310 rods more often than not. If you are still unsure just give us a call or email.
|309L||308L||309L||309L||Mild Steel||Mild Steel|
Gas gouging a health and safety officer's dream come true
Gouging using gas equipment is generally much quieter than using 'carbon arc' or 'arc/air' gouging method plus generally liberates less fume / dust. Where Health and Safety requirements are important it makes sense to use gas process gouging. Always wear eye protection and ear defenders for your protection. It is also preferable to wear an approved dust mask - available from Noz-Alls PPE section of our website.
Safe storage and sensible use
Acetylene cylinders should only be used in the vertical position. If a cylinder has been transported or stored laying flat the cylinder should be stood in an upright position for a minimum of one hour before use begins. Check with your gas supplier as they may require a longer period. If it has been transported at 45 degrees then stand in an upright position for 30 minutes before use.
Acetylene gas is unstable at high temperature and pressures. To enable us to use acetylene safely the acetylene gas is dissolved into a holding agent. - mostly acetone. This liquid solution is itself stored in a monolithic ,ass, like a solid sponge, which breaks the acetone/acetylene as it effervesces.
The action is similar to opening a bottle of cola, as the cap is undone and the pressure released above the liquid, the CO2 bubbles out from the cola. This is the same action as when the valve on the acetylene cylinder is opened.
The rate at which the acetylene gas bubbles out of the acetone is the maximum rate at which you can use the acetylene gas from the cylinder. When you draw off acetylene too quickly acetone is drawn off with the gas. To help prevent acetone withdrawal no more than 1/5 of the cylinder contents should be consumed in an hour. Acetone drawn into gas equipment causes damage and malfunction as well as giving operator flame stability problems. Equipment damaged by acetone should be replaced with new equipment.
For your safety and to extend the useful life of your gas equipment system you should note that when using nozzles to cut more than 150 mm ,up to 350mm thick mild steel at least two standard 8kg. acetylene cylinders should be manifolded together. However the possibility exists to cut for up to 5 minutes in any consecutive half hour period so long as the acetylene cylinder (8kg) is between 3/4 and 1/4 full only.
The bRight spark
Only use a proper spark lighter when igniting your nozzle. A spark lighter requires a greater volume of gas to obtain the ignition. Cigarette lighters or flames from another source will ignite the smallest amount of gas and may be the cause of a flashback, igniting the gases before they have begun to flow. Always follow the correct opening and closing down procedures for your safety.
Purge like your life depends on it
Having set the correct operating pressures, and before igniting your nozzle always purge your hoses / torch system. For 10m hoses, open the oxygen valve, count to 3 sec. close the oxygen valve. Now open the fuel gas valve a full turn, count three seconds and light the fuel. When using acetylene continue to open the fuel valve until no black smoke is visible, now introduce the oxygen and adjust to the desired flame characteristic.
Set acetylene sensibly
Acetylene preheat cones should be conical and pointed with a small spherical tip for maximum heat input. The best heat input is with the cone 1.6mm above the plate surface.A single cone on a welding nozzle should be perfect, a cutting nozzle should ideally have 6 equal cones.
Bang, out of order
In normal circumstances when you turn off your torch you should turn off the fuel first, closing the valve completely before closing the preheat oxygen valve. The flame should not "snap" or "bang" when it is extinguished, if it does your nozzle may have a fault or you may not have sufficient fuel flow to maintain a stable flame. Check your nozzle and fuel supply - NOW!
Check before use
When using injector type cutting torches ensure you have the correct injector style for the fuel you are using. Using acetylene fuel with a torch designed for use with propane will result in an unstable operation and render the torch susceptible to sustained backfire the result of which will be injector damage making further stability problems more likely and may require complete torch replacement.