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Hawkeye283
03-16-2015, 08:54 AM
Has anyone used a weld thru primer on an aircraft. Does it weaken the joint? Looking to use it on a doubler that gets welded about 80% around. Using a TIG weld and 4130. Thanks!

eiclan
04-06-2015, 11:57 AM
Gday mate,I have not welded 4130 tube before but just about everything else and any paint at all will change the properties of the shielding gas and thus the weld could be comprimised .I have never seen a primer that is designed to be welded through but I am an old fella ant the things that made these days are amazing .So as an old welder I always like to have clean bare metal to weld. Cheers Ross

Aaron Novak
04-06-2015, 02:23 PM
Has anyone used a weld thru primer on an aircraft. Does it weaken the joint? Looking to use it on a doubler that gets welded about 80% around. Using a TIG weld and 4130. Thanks!

Don't use any kind of weld through primer on 4130 in a structural application. Paints of any kind when using the tig process can lead to inclusions, oxide formations and hydrogen embrittlement. Weld through primer was "developed" for autobody type welding and/or on less sensitive materials using welding processes that do not rely on an inert atmosphere. When using the Tig process the base material must be free of all contamination, paints, grease, oil, mouse droppings, etc.