I'm going to qualifiy SAW procedures using Scarfing Powder (Oxweld 200), D1.1 @ Table 4.5 essential variable under Filler Metal shows the addition  of supplemental powdered filler metal or a increase in the amount of supplemental powdered filler metal . Where can I find information in regards to how much is allowable in a given joint? Running a square groove , 1/4" plate 572-50 with a root opening when using scarfing powder from 3/16 to 1/4, with L61, 3/32 dia wire. Square Wave  in CC mode? I don't think i've ever seen or read any thing on allowable limit of scarfing powder?

How are you going to control the addition?   How will you UNIFORMLY  add  a fine powder   to a coarse

agglomerated  material  ?   ?    ?    ?

Iron Powder (is also known as scarfing powder), Used it all the time building rail cars, working under AWS D15.1, It's primary use was on CZ material (center sills) , Arcelor was the only manufacture of CZ , it came from Germany, Do to the fact they was the only producer of CZ they laughed at the tollerances required by the AAR and FRA , we was running this CZ material with gaps up to 5/16" to 3/8" this material was 17/32 thick . We filled the root up to a 1/4" deep with the iron powder, we was running Tandem Arc ,front head was DC running L-61 , 3/16 wire ,rear head AC -5/32 wire. I no longer work under AWS D15.1 , but if I remember correctly the amount of iron powder was not a essential variable and the PQR didn't show the the amount ( ounces or pounds ) used.