Don't let welders chip away profits!
The Works
Productivity in welding is a major issue. A recent survey demonstrated that 20% of a welders time is wasted spent cleaning the weld they have just made. This is money being literally chipped away according to Graham Stevens of Stevens Industrial Services.
There are few welding operations that do not create spatter. These often-tiny droplets of metal create unsightly finishes to products and in many cases can lead to premature rusting or corrosion. To remove the spatter is time consuming, counter productive and wasteful. In the worst case witnessed by Stevens Industrial Services, welders spent more time fettling and de-spattering than welding. Yet, with a simple, effective, pre-treatment spatter can be removed at the conclusion of a weld with a simple wipe.
This begs the question why spatter removal remains such a drain on the welder’s time. The answer lies in a number of factors: denial; lack of evaluation; lack of co-operation; and health and safety. While this seems an odd combination when considering a process as fundamental as applying a spray before welding, as this article explains, it’s never quite that simple.
First impediment is denial. Many companies still fail to recognise the damaging effect of spatter. A good illustration in point is earth-moving equipment. Huge, rugged machines that are covered in mud almost from the day they’re delivered surely need little consideration to the aesthetic effect of their paint finish. But, the evidence shows that on delivery, unsightly spatter can lead the customer to perceive that if so little attention is paid to the finish, then equally slapdash care may be paid to the mechanics. More seriously, when the drops of spatter come off, as they inevitably do, then bare metal is left exposed to rust and eventually require remedial maintenance.
Second, is a lack of evaluation. Assuming the manufacturer has recognised the need to remove spatter, little or no attention is paid to the effectiveness of the treatment being applied. Most pre-weld treatments do not work very well – even those containing health-damaging dichloromethane don’t. However, even poorly performing pre-weld anti-spatter treatments are accepted as being as good as it gets. More about the horrors of dichloromethane will follow.
Third comes a lack of co-operation. Effective welding pre-treatment is dependent upon the acceptance by the welders that the pre-weld is a good idea. One company, that as will become obvious, has to remain nameless, carried out a survey to assess the efficiency of its substantial welding operation. A typical welding cycle at this company’s factory took about 45 minutes, it then took 10-15 minutes to remove the spatter using chisels and grinders. A trial using Stevens “The Works” anti-spatter treatment enabled all the spatter to be removed in a minute. The potential saving was assessed by the customer to be in the order of £750,000 a year. It was a no brainer to use the treatment, but the company did not place a single order. The welders, refused to hand back the 10-15 minutes of fettling time!
Finally, there is the thorny issue of health and safety. The most effective ant-spatter welding treatments always used dichloromethane. This is a carcinogenic substance that has a number of equally unpleasant side effects. The chemical is not outlawed in the welding industry, but frankly no right-minded business that understands its effects would ever condone subjecting its welders to it. As a chlorinated solvent, dichloromethane treatments, if still wet at the time of the weld, thermally decompose to give off phosgene (mustard gas) and hydrogen chloride (which burns). A measure of the hazard imposed here is that the HSE gives a short term exposure limit (STEL) of 15 minutes in the presence of just 0.06 parts per million (that is 0.000006%) of phosgene and 5ppm (0.0005%) of hydrogen chloride. Yet, dichloromethane based pre-weld treatments were once commonly used when welding inside pressure vessels. Alternatives to dichloromethane-based products did not work as effectively; hence the dangerous pre-treatments can still be found in some places.
So much for the negative issues, there is now an effective alternative that has come about as the result of years spent addressing both the efficiency and safety of anti-spatter. The Works range of spatter control treatments, the best example of which is “Pre-Weld”, contains no dichloromethane. The product is applied as a fine spray delivered from air-pressurised cans that do not damage the ozone and can be disposed of in standard refuse. Most significantly, the product works much better than its hazardous counterparts. One compelling case study comes from an earth moving equipment maker in Northern Ireland, where over two and half years since adopting “The Works” anti-spatter, savings of £127,000 a year have been recorded.
