Repair Technology: Why weld when you can bond?

Adhesive bonding has come of age in applications and performance. But there is still some territory to conquer.
Steven Dew, Australian Warehouse Distributor’s, business development manager, says there has been a marked increase in acceptance of panel bonding over the past five years, and especially over the past two.
Panel bonding went through challenging times when it was first introduced.
"Change at the OEM level in material content and type, plus new assembly methods, required a new approach to repair," Dew recalls. "I guess there will always be some resistance to change; however, those who embrace change are the beneficiaries. Adhesive bonding should be considered as evolutionary, not revolutionary.
"When we introduced the Fusor product range back in 1997 there was not a lot of trust in adhesives when it came to metal bonding. Some people believed 'what you can’t see you don’t trust'. I am talking about the glue line! They thought that for more strength you had to throw more metal at it by welding, or add mechanical fasteners.
"There was also a lot of misinformation about previous adhesive failures with panel bonding. This stemmed from trying to panel bond using a windscreen installation urethane product which is not designed and was never intended for panel bonding. But when products like Fusor 108B became available they offered two pack acrylic adhesives specifically for metal to metal bonding. With them, we had a totally dedicated and different range of products.
"Also, back in the early days, while the Lord Corporation, manufacturers of the Fusor range, enjoyed a strong world-wide reputation in OEM as an innovator and supplier of adhesive coatings and sealers, it may have lacked credibility as a serious player in body repair solutions. That is no longer the case."
Dew makes the point that the acceptance of panel bonding has come about through evolution and education.
"For over 80 years welding has been the main joining method for sheet metal by the car plants,"he says. "However, over the past 10 years adhesives have been introduced as an alternative to both mig and spot welding as they offer design engineers greater flexibility with material choice, dimension, noise control and reduced corrosion. Other benefits include vibration control, handling characteristics, fuel economy, safety and cost savings for the car maker.
"Bonding versus welding is not that different to the mig issue of 20 years ago. A lot of shops then wondered why they could not or should not continue with gas welding or brazing. We now have car makers using weld bonding techniques for strength and safety and some have introduced 'quiet metal' which is bonded and riveted.
"As for education this is ongoing at the 'coal face and also for the work providers. Adhesives are fast becoming an essential part of the repair process and in many instances are listed as a spare part in OEM repair technical service bulletins (TSBs) such as GM’s 'TSB 64490 Metal Bonding Guidelines'.
"The number of TSBs relating to adhesive use from OEMs is quite extensive and continues to grow - which also helps our education programme. Lord Corporation, with its strong OEM connection, enables us to fast track information and adjust our education programme to fit OEM technology.
"It is important to understand the new thinking that the OEMs have with adhesives and the implications for the repair industry. This is why our education programme is at the top of our priority list."
Dew sounds a note of warning over the chemistry of adhesives. They can impose limitations in some areas and can be precluded from use on certain materials or have issues with work time, cure speed, flexibility, impact resistance or sandability. It is important to choose an adhesive supplier capable of providing products that cover the entire range of available chemistries which means they can provide products best suited for a particular repair or bonding solution.
Further information relating to panel bonding or the Fusor range can be obtained from Steven Dew on (03)9553 1977 or at stork.awd@bigpond.com.au