Weld Affairs
Why Nozzle Anti-Spatter Sprays Could
Be Doing More Harm Than Good
An Enduring Challenge for Today’s Welders
A persistent bugbear of today’s welding process is the
release of ‘spatter’: particles of molten metal expelled
from the welding arc and deposited throughout the weld
area.
The build-up of these ostensibly benign molten particles
has the potential to diminish the quality and durability
of weld joints, requiring immediate repair or, in many
cases, complete re-welding. A recent survey by one of
India’s largest auto component manufacturers, Badve,
observed that 12% of robot MIG welded parts were
deemed defective due to spatter-related defects, an
unacceptably high defect rate of for today’s efficiency
driven businesses.1
Reworking or scrapping sub-par welds can sap hours
of productive labour from your workforce. Indeed, if a
weld operator were to spend just four hours per week
repairing defects, this ‘non-production’ time would
equate to approximately $6,240 per year in lost labour.2
[I]f a weld operator were to spend
just four hours per week repairing
defects, this ‘non-production’ time
would equate to approximately
$6,240 per year in lost labour.
More Than Mess: Torch Head Damage, Impaired Weld Quality & Downtime
Delicate torch head attachments (or consumables) –
including diffusers, shrouds, contact tips and shielding
gas nozzles – are at the frontline of the welding system,
in direct contact with the welding wire before it enters the
weld pool.3 The integrity of these frontline consumables
is crucial to maintaining consistent weld quality and
maximal utility of labour.
Critically, both MIG and MAG welding rely upon a
steady supply of shielding gases to prevent oxidative
damage to the weld seam. During the welding process,
spatter can adhere to the contact tip and torch shroud,
and quickly solidify around the head, obstructing the
consistent flow of these protective gases. Solidified
spatter can also short out the contact tube to the gas
nozzle, reducing the concentration and effectiveness of
shielding gases.4 What’s more, excessive turbulence –
caused by spatter-obstructed gas – may contaminate
the weld seam and, in extreme cases, lead to porosity.
The inevitable build-up of spatter impairs connectivity
between these delicate torch head mechanisms,
resulting in inconsistent electrical transfer and increased
incidence of burnback (the formation of a weld inside
the contact tip) - a chief source of operator downtime.
Selecting high-quality consumables is a vital first step
to ensuring contact tips and diffusers can be secured
in proper alignment, maximising the consistency of
welds.5 However, judicious use of anti-spatter solutions
is considered necessary to ensure adequate spatter
resistance for delicate torch heads and consumables.
The Problem with Conventional Nozzle Anti-Spatter Treatments
Aerosol-based anti-spatter sprays have long been
regarded as a versatile, cost-efficient, and fast-acting
solution for overall spatter resistance. Yet despite
industry-wide adoption, welders have been quick to
recognise their limitations, particularly when applied on
delicate torch head consumables.
Conventional nozzle anti-spatter sprays are formulated
with an active silicone, petroleum or solvent base;
owing to the volatile properties of each chemical base,
these anti-spatter formulations are not only highly
noxious, but require frequent and time-consuming reapplication (upwards of 25 re-coatings per shift6) to
ensure continual protection of welding equipment.
Indeed, one of the critical drawbacks of anti-spatter
sprays is their poor performance on consumable
surfaces. Being highly reactive to heat, conventional
nozzle anti-spatter sprays evaporate quickly during the
weld, offering little protection against spatter accretions
in the torch head; the necessary manual removal of
spatter build-up requires frequent operational stoppages
(every 15-30 minutes), a major drain on productivity.
What’s more, both silicone- and petroleum-based
solutions are notorious for the deposition of greasy
residues across the weld torch, extending the post-weld
cleanup time significantly.
Of course, whilst anti-spatter ‘Tip-Dips’ provide a more
reliable alternative for the protection of torch heads
(offering excellent thermal properties), these creambased solutions are not only difficult to apply, but leave
behind unseemly residues.
The question remains: is there a viable alternative to
‘anti-spatter’ that can be applied across small- and
large-scale industrial processes?
[A]t 36% ceramic
filler concentrations,
coated surfaces
revealed next-to-no
spatter deposition.
‘Ceramic Shield’: Superior Nozzle Spatter Protection for the Modern Welder
Owing to their exceptional thermal and micro-spatter
resistant properties, composite ceramic coatings have
seen widespread adoption in precision laser drilling
and laser welding applications over the last decade.
Consumable producers have been quick to recognise
the outstanding potential of ceramic-based aerosols as
a safe and highly effective spatter-repellent for a broad
range of welding equipment, offering marked benefits
over traditional nozzle anti-spatter sprays.
Independent studies reveal that even low concentrations
of ceramic particles can vastly improve the resistant
properties of conventional anti-spatter coatings.
Indeed, numerous spatter tests have shown that while
0% ceramic concentrations (silicone elastomer base)
sustained ‘excessive transverse burning’ across coated
surfaces, a progressive increase in ceramic filler saw
drastic improvements in the spatter resistant properties
of the coating: at 36% ceramic filler concentrations,
coated surfaces revealed next-to-no spatter deposition.7
Due to their unique low-residue and thermally resistant
properties, ceramic-based sprays can be freely applied
across all welding equipment surfaces – including
torches, consumables and welding robots – with
minimal post-weld cleanup. >>
>> Resistant to the heat extremes of the welding
torch, ceramic sprays provide unsurpassed spatterresistance for shrouds and contact tips, drastically
reducing cleaning time (a nearly 20-fold decrease) and
replacement costs.
In terms of real-world commercial benefits, ceramic shields
offer unrivalled efficiency and cost dividends for business:
industry surveys reported a 7% increase in productivity
and a 40% reduction in running costs for consumables
as a direct result of using ceramic-based sprays.9
While conventional anti-spatter nozzle sprays require
continuous re-application (up to 25 re-coatings per shift),
a single application of ceramic shield for contact tips and
shrouds can resist spatter incursions for up to 8 hours
(including the thermal extremes of the torch head), allowing
uninterrupted welding for a full workday.8
The LOCTITE Solution
Henkel
launched
its
groundbreaking
Loctite
SF 7900 Ceramic Shield* in June 2014. As the
world’s leading producer of engineering adhesives
and sealants, Loctite is steadfastly committed to
delivering quality industrial solutions that maximise
business efficiency and reduce costly overheads.
As a natural successor to traditional ‘nozzle anti-spatter’
sprays, Loctite’s Silicone-Free SF 7900 Ceramic
Shield offers superior anti-spatter protection for today’s
industrial welding equipment.
To learn more about Loctite SF 7900, please contact
1300 885 556 or visit us at www.loctite.com.au/sf7900
*Please note: LOCTITE SF 7900 is not recommended for anti-spatter protection on welding surfaces.
Loctite SF 7900 Ceramic Shield vs. Conventional Anti-Spatter Spray
Conventional Nozzle
Anti-Spatter Spray
With LOCTITE SF 7900
Ceramic Shield
No. of replacements of shroud
and contact tip per shift
1.5
0.87
No. of coating applications per shift
25
0.87
No. of shroud cleaning operations per shift
37
0
No. of contact tip cleaning operations per shift
7
0
Time need for cleaning and coating of
shroud and contact tip per shift
32 min.
1.40 min.
Source: REFA Consulting
References
1. H. T. Goud, ‘Minimizing Excessive Spatters in MIG Welding’, Badve Auto Company.
2. Bernard Welds, ‘MIG Gun Mythbusting: Separating Fact From Fiction’, Bernard Welds, 2012.
http://www.bernardwelds.com/mig-gun-mythbusting--p152081#.U84YN_mSyXx
3. Ibid.
4. L. F. Jeffus, Welding: Principles and Applications, Cengage Learning, December 2002. pg. 266.
5. Bernard Welds, ‘MIG Gun Mythbusting: Separating Fact From Fiction’, 2012.
6. Loctite UK, ‘Loctite SF 7900 Ceramic Shield’, 2014, http://www.loctite.co.uk/loctite-sf-7900-ceramic-shield-8880.htm
7. D.K.Y. Low, L. Li, & P.J. Byrd, ‘Combined Spatter and Hole Taper Control in Nd:YAG Laser Percussion Drilling’, in Laser Materials
Processing, ICALEO 2000 Proceedings, Vol. 89, Laser Institute, pgs 11-20; D.K.Y. Low, L. Li, P.J. Byrd, ‘Spatter prevention during the laser
drilling of selected aerospace materials’, Journal of Materials Processing Technology, Vol. 139, Iss. 1–3, 2003, pgs 71–76.
8. Loctite UK, ‘Loctite SF 7900 Ceramic Shield’, 2014
9. Henkel Australia (in Ferret), ‘Loctite develops new spray on ceramic shields for welding’, 29 April, 2014. http://www.ferret.com.au/c/loctitehenkel-australia/loctite-develops-new-spray-on-ceramic-shields-for-welding-video-n2513858
www.loctite.com.au
Henkel Australia
Adhesive Technologies
135 – 141 Canterbury Rd,
Kilsyth VIC 3137
P: 1300 88 555 6
F: +61 3 9761 4539
Henkel New Zealand
Adhesive Technologies
2 Allens Road,
East Tamaki, Auckland 2013
P: +64 9 272 6710
F: +64 9 272 6735
www.loctite.com.au
www.loctite.co.nz
© 2014 Henkel Corporation. All rights reserved. 9294/LT-5021 (9/13)