[amateurwelder]

Jedi-weldmasters,

Thank you for reading my post. I am having trouble with welding the inside of these mitered channels. Firstly, I don’t have much space to move with the jig attached, so I am looking just to tack it with some filler. When I try with the filler, only one side of the joint gets the filler and not the other... 3/16" 6063 - I am using 145 amps with 7 balance.

Any ideas? Should i preheat?

-Jonathan

[weldin mike 27]

I believe you will have to crank up your amps. As alum ducks the heat away quickly. (reduce for welding) and secondly, why do you need to tack right in the corner? Not only is this very hard, its also difficult to get out, should you need to cut a tack. I would do one on each extremity of the joint, that is, the corners.

[amateurwelder]

Weldmonger,

160 amps did the trick.

Thanks again!

Jonathan

[weldin mike 27]

No problem, (weldmonger is our rating based on the number of posts) Im Mick. Nice to meet you.

[crouchy]

Bevel your flats and weld butt joins and mabe finish with outside corner? That's how I would tackle it. A good butt join is just as strong as a fillet!

[dave powelson]

Bevel your flats and weld butt joins and mabe finish with outside corner? That's how I would tackle it. A good butt join is just as strong as a fillet!

1-Fit the outside end corners to create a corner weld as (I think) crouchy sez.
Beveling both the 45˚angle miter cuts to produce a bevel groove joint that can be flush ground since the weld is full pen. is
the way the grownups do it. Those 45's will need that bevel groove, ground flush weld--when flipping the frame to get to the other side and leave it flat on the table, not resting on those welds.

2-Those clamps will twist and roll whatever's clamped in them, so after tacking the full square or rectangular assembly....
you won't necessarily have square corners, parallel sides or most importantly--consistent outside, corner to corner diagonal measurements. (For 98% of all fitups, I don't even bother with corner clamps, there's faster and more accurate methods.)

3-Make 2 tacks in the outside corner joint, one at the top, one at the bottom.
Tack up the other 3 corners the same way.

4-Then, measure with squares, tapes--to see if you're holding the most important, functional, dimensional feature of the assembly (it might be squareness, or maybe width, maybe height, maybe composite of the diagonal measurements--that's up to the fabricator to decide---what is most important for form, fit & function.)

5-If need be, then cutting thru an outside tack is no big deal to make further adjustments--as opposed the inside weld.