Welding Tips and Tricks

Ok so Im rather new to welding, but getting better with every mistake
I plan on extending my camper rear frame 10" to hold a storage box
The frame is 2x3x1/8 tube steel and the 10" insert sections are the same
I was planning on a butt weld to keep it clean, but question the strength
I can weld a stiffening plate to the outside of the 2x3 over laying the weld, but I would like it clean
Any thoughts on ensuring the weld will have the strength required

The total weight to be carried on the back of the camper will not exceed 300ibs
below is what I plan to do, only wanted to butt weld and not lap weld
[url=https://www.escapeforum.org/forums/memb ... re2677.jpg]

Thanks in advance
Rob69

I’d recommend adding an internal stiffener, order a piece of sq tube with an od that will fit in your existing I’d.

Internally is the way to brace that, but you won’t find a tube with an OD equal to the ID. Instead, take flat stock and make 3 plates (forget the bottom stiffener). Slide them inside and drill hole through the existing outer tube. Rosette weld them. Repeat for the new section. Then butt weld the new section tying all 3 surface together by leaving a 1/16 gap. Will be plenty strong and you can flush the rosettes down for aesthetics. I’d even consider using 3/16-1/4” flat stock for more strength.

thanks for the input and help...I'll use some 1/4 plate or angle iron internally and plug weld.