I have been wanting to fabricate some actual argon backer boxes for quite a few years now. I am tired of using aluminum foil wrapped around items with the purge hose stuck in through a poked hole. I don't think much about it until I need them and then I go on a rant that I never have enough time to get things done that I want to, always things I have to. Well, that is changing.
Back when I was fabricating a lot of ATV sand drag chassis I would like to back purge the tabs and brackets onto the 4130 chromoly chassis because they would get that similar sugary look like stainless steel does and if you wanted to weld the back side as well you were welding through it. I would merely wrap some aluminum foil around the back side of the bracket or tab and poke a small hole in it to place my purge hose. Well I am going to get out of the dark ages and fabricate some nice backer boxes.
Here is what I started with. Some square tubing, perforated stainless steel sheet, copper tubing/fittings and some silicon 1/4" hose.
Square tubing setup in mill vise to cut back areas where the perforated stainless steel will go as well as a hole for the copper tubing to protrude through.
Getting close to be completed. I was able to get the copper sweat together and the holes drilled. I also soldered the copper to the metal housing and merely pinched the ends closed to trap the argon. I made three different size of backer boxes and one 2"x3.5" box to lie small parts on for welding. Each will have a small 1/4" hose barb for the silicon hose to connect.
This one has the holes coming out each side and will have steel wool placed inside to act as a diffuser to evenly disperse the argon.
This one is actually a corner style with the perforated stainless steel bent at 90-degrees to form the corner.
Then lastly two different sizes of a plain backer box. One measures 2" long and the other 6" in length.
Those should give me a nice variety of sizes/configurations for most everything I weld and will be readily available for quick welding jobs. I will post up some final pictures when I get them completed.
Mike.