By guest blogger David H.
Having worked in shipyards for seven years, I’m familiar with how dirty this type of job site can be. Ship repair worksites and welding surfaces are often filthy with rust, dust and other contaminants. Even in shops and yards where fabrication is ongoing, cleanliness is often lacking. If fabricated or refurbished pieces are being installed onboard, the surface to which the piece will be welded could be rusty, coated with scale, or have other types of corrosion.
It is hard to overstate the importance of having a clean surface when welding. Welds made on unclean surfaces can become contaminated and fail; this is especially true with certain metals, such as aluminum, and certain types of welding, such as TIG, but for all welds at least some level of cleanliness is important.
Methods and Equipment
There are numerous methods available for cleaning surfaces. The most basic are simple wire brushes and scrapers; these are ineffective beyond removing common dirt and simple surface contamination. Some hand-held tools, such as grinders and reciprocating needles are slightly more effective.
A surface that is properly prepared by blast cleaning can help you ensure fewer problems with weld quality.
Deeper cleaning processes can help to ensure high-quality welds. This is particularly important where a failed weld could be costly or create shipboard dangers for the crew. For corroded or contaminated surfaces something stronger is required. Some of the best systems available are blast cleaners. Red-D-Arc has a number of blast cleaning rental options. Dry-ice systems are environmentally sustainable, non-destructive, and use inexpensive, readily available dry-ice pellets. Recycled glass systems, which reduce dust by as much as 95% compared to dry-blasting, are available too.
Take a look at our selection of rental blast cleaners which can powerfully clean up the dirtiest weld surface. A surface that is properly prepared by blast cleaning can help you ensure fewer problems with weld quality.
Red-D-Arc will be exhibiting at Tube Düsseldorf trade show in April. Be sure to drop by booth 6F23 in Hall 6 to view our latest pipe welding and cutting equipment.
Red-D-Arc offers a comprehensive selection of pipe welding equipment for rent.
Importance of Preheating in Welding – Equipment Options
Preheating reduces the risk of cracking in weld metal and heat-affected zone (HAZ) by:
- Lowering the cooling rate of the weld – prevents formation of brittle weld metal/HAZ, allows more time for hydrogen to escape the molten weld.
- Removing moisture (hydrogen source) from the part.
- Reducing shrinkage by lowering the temperature differential.
Preheat or not?
The requirement and level of preheating for steel is determined by the relevant welding code and is dependent on the weld heat input, chemical composition of steel (carbon equivalent), thicknesses, diffusible hydrogen etc. Non-ferrous materials generally require preheat because of their high thermal conductivity.
We have a number of reconditioned used welders available for purchase including:
- TransPulse Synergic TPS 5000 MIG/MAG Package with wirefeeder and cooler
- Miller Maxstar 200 Autoline – Stick, TIG, Pulsed TIG, Air Carbon Arc Cutting
- Lorch T-300 TIG Welder – Stick, TIG, Pulsed TIG
Each of these welding machines comes with a 90 day warranty.
View our flyer for details.
Fronius TransTIG 1750
Miller Maxstar 200
By guest blogger David H.
How important is it to remove welding smoke from the work area? Ask a welder, or ask someone who has to work in the vicinity of welders working in enclosed or semi-enclosed areas.
I recall some years ago working on a Navy general cargo ship. The ship was undergoing extensive renovations and the hold had four or five levels. My employer, a small repair yard in San Francisco, unfortunately did not take air quality in the work area seriously. There were more than 20 of us working in the hold, and some number of us were welders. From a distance you could see where the work was being done — smoke and fumes drifting up out of the hold! In those days, safety requirements weren’t always top of mind. OSHA and other regulations aside, taking care of your workers by providing a safe work environment is simply the right thing to do. Without them your business can never be profitable. By failing to provide a safe workplace, you may lose workers due to health issues and employee turnover or face consequences for not complying with standards.
“respirators are hot and uncomfortable, and many welders simply refuse to use them”
There are a number of ways to deal with welding fume issues. One approach is the use of respirators. I often wore one, but they are hot and uncomfortable, and many welders simply refuse to use them. They can be remarkably expensive, over the long haul, given that filters must be replaced daily. If the mask is a disposable type, the entire mask must be replaced daily.
Portable smoke extractors – sometimes referred to as smoke eaters – are a far better solution. They extract a higher percentage of the fumes than respirator masks and protect everyone in the work area, not just the welders. They can be moved around the job site and from one job site to another, but can also be set up at permanent work stations. These machines can help make sure that your work space is a place where people can get their work done safely. Your employees will thank you.
To view the smoke extractors Red-D-Arc offers for rent head over to our smoke extractor rental page.
By guest blogger David H.
Some years back I was working in a shipyard in San Francisco. The yard had several small repair jobs going, plus a fairly large project building six ocean-going barges. The supervisor who was in charge of the barge-building project was looking for volunteers to operate semi-automatic wire feeders, using flux-cored wire, to weld stiffeners to the skin of the barges. I had never used a wire feeder before, so I volunteered out of curiosity.
After a very short training period, possibly all of 30 minutes but I think a bit less, I was off and running. I was impressed by the quality of the welds and the speed at which they were deposited. Without question I was outpacing anything that could be done by stick welding, and I felt it was easier to maintain a uniform weld size too. The machine itself was light enough and small enough to move without difficulty, and the spools of wire lasted long and were quick and easy to replace when the spool of welding wire was finished.
Red-D-Arc has nearly a dozen semi-automatic wire feeders available for almost any application. We also carry fully automatic wire feeders, which are faster still and appropriate in certain circumstances – like building storage tanks – especially for large-deposition welds.
Aberdeen: Red-D-Arc has teamed up with the Air Liquide Oil and Gas services branch in Aberdeen to provide turnkey equipment rental packages complete with welders, accessories, welding gases and consumables. Our equipment selection covers all welding processes and other applications such as plasma cutting and fume extraction. Multi-welder paks and induction heating systems are also available.
Call Air Liquide Oil and Gas in Aberdeen for more information +44 1224 877409 MAP
We currently have 3 Romar Growing Lines available at our main branch in the UK. (St. Helens). Growing lines are a great asset for the production of large diameter work pieces and are typically used for the manufacture of wind towers. Contact our UK Branch to learn more.
A Red-D-Arc customer based out of the UK was awarded three large offshore wind farm projects …all commencing simultaneously. This manufacturer was comfortable taking on so many large scale, specialized projects because they have a reliable, knowledgeable, tier 1 supplier capable of meeting all of their welding and weld automation equipment needs! Red-D-Arc was able to quickly accommodate all of the welding equipment requirements for the project, providing more than 150 welders and a variety of weld automation equipment. The equipment consisted of multi-operator welding paks, diesel welders, advanced power sources, wire feeders, submerged arc welding packages, and rotators.
Two Red-D-Arc technicians were assigned to the facility to install, service and maintain the equipment to minimize downtime. The facility allocated a permanent workshop and storage container for back-up equipment which could be used to quickly replace any equipment as necessary. With Red-D-Arc’s support, the customer was able to work on all three projects simultaneously and avoid lost time due to equipment breakdowns.
By guest Blogger Katarzyna K.
Katarzyna has an Msc in Materials Science and has worked in the oil and gas industry in jobs related to hydraulics, welding and the retrofitting of oil rigs.
Stainless steel is used extensively in the petrochemical industry due to its high resistance to severe conditions. When welding inox steels, the smallest details matter and have an impact on weld quality. The following are some tips for stainless steel pipe welding based on my oil rig repair experience:
During an oil rig repair project that involved 2205 duplex stainless steel pipe TIG welding, we could not achieve the required weld properties. Despite using the recommended filler metal with higher nickel content, compared to the base metal, and controlling the interpass temperature, the weld tensile strength was still too low. In order to reach the required weld quality we dug deeper and found a solution – (more…)