110mm X 90mm Lenses FAQs
Practical answers on fitting, caring for and replacing fixed-shade filter lenses and cover lenses in this size.
What should I check just before I start welding after changing a lens?
Make sure the cover lenses are fitted, everything is seated flat and secure, and nothing rattles. Look into the helmet away from the arc for any light showing at the edges, because light should reach your eyes only through the filter. Check that the filter shade is the one you intended and is clean on both sides.
Then confirm the helmet still screens your whole face, ears and part of the neck from direct arc radiation. Eye protection also matters for people nearby, as flying slag and grinding particles cause many eye injuries, so make sure anyone close by is protected too.
Why does light show round the edge of my filter lens, and what should I do?
Light showing around a fixed filter usually means the lens is not seated or secured properly, or the holder, frame or gasket is worn or damaged. Do not keep welding. The helmet should screen the whole face, ears and part of the neck from direct arc radiation, and a gap defeats that.
Remove the lens, check the holder and gasket for damage, refit the parts flat in the order shown in the manual, and look for light before you strike an arc. If the gap remains, the holder or helmet may need replacing.
What goes in front of and behind a fixed-shade filter lens?
A fixed-shade filter is normally protected on both sides by clear cover lenses, usually made of polycarbonate or CR39. The outer cover takes the spatter and scratches so the filter does not have to, and an inner clear plate protects it from the inside.
Work in the order your helmet manual shows, usually outer cover, filter, then inner cover, with any gaskets or retaining parts seated flat. The exact layout varies between helmets, so follow the instructions supplied with yours, and do not weld with the filter exposed.
How do I tell when to replace a clear cover lens rather than just clean it?
Clean it first with a soft cloth. If it is scratched, cracked, pitted by spatter or hazy, and you cannot see clearly through it, replace it. Helmet manuals say that damaged cover lenses should be replaced immediately, and the decision is based on condition rather than a fixed time interval.
How quickly covers wear depends on the process, the amount of spatter and the position you weld in. A heavily spattered cover can also leave the filter behind it exposed to damage. Many welders keep spare covers to hand so a worn one never gets left in place.