by ctstaas » Mon Dec 15, 2014 8:51 pm
Hi felixx, The axle is something to never have fail and splicing sound like a cheap disaster yet to happen. Spend the $200 to make sure its the right size, capacity and the manufacture has liability insurance or deep pockets. I you do splice use "fish plates". A fish plate tapers at each end to the middle of the plate, almost like an arrow. A vertical weld across a tube under stress will cause the tube to break at the weld. Welding on the sides (points) of the fish plate produces diagonal welds covering more surface but more importantly will not transfer stress like a vertical weld will.
If you were shorting the axle you would only have one splice and it could be done with a single full penetration type weld. A full penetration weld will have a root gap equal to the thickness of the base metal and have each side beveled. The root gap will have a backup bar filling the gap and providing material to weld into so each corner of both side's roots can be incorporated into the root weld pass. My explanation of full penetration welding is general but a starting point of what to look for or say to a professional welder.
Enjoy, Chris