Hey guys... i have a project were i need to fillet weld a 4" X 18' X .5" to another piece with the same dimensions. So when its done it looks like a "T". Im using a aluma pro with 1/16th wire (5356). Do i need to preheat this piece for an optimal weld? This piece is going to be a vaccum ring on a vessel that is 6' in dia and about 40' long. So if there are any words of advice or wisdom i would gladly aprreciate them. Thanks guys