Aluminum Welding

The first pair , you need to widen the vee a little , give the welder somewhere to put some filler . The other pair should also touch at the

If tigging a "V" is not necessarilly required - Autogenous welding doesn't even need filler (or much filler)

I thought that was a no-no when welding aluminum and that filler was required . Something about the weld area being subject to cracking .

I guess it depends on the alloy, the fit, and the application - but what would cause it to crack more from autogenous welding than from filling a "V" with filler? Particularly if the filler is identical to the base metal - which you want it to be if the weld is to totally blend in. We have often used strips of the metal being welded as filler where required You can't find the welds in the cowling for my plane (utility grade aluminum flashing material)

While autogenous welding works well with steel it does not work well with 6061 aluminum. What happens is that the aluminum tends to hot crack. This is why a filler metal is needed, the filler is a different alloy and when mixed with the base metal forms an alloy that is not sensitive to hot cracking. Eric

But remember, not all aluminum is 6061, and not all 6061 is T6. And not all aluminum is welded with a filler that is different in composition from the base metal.. Welding 6061 structural parts is always second or third choice for me

- much rather use rivetted or bolted construction than welded where strength is required. I didn't look -was 6061 speced in the OP's post? If so, my bad.

Other than pure aluminum, none of the common aluminum alloys are normally welded with filler of the same composition as the base metal.

When building aluminum coachwork it is not unusual to use strips of the body metal as filler. It is the only way to make a weld that can be metal-finished and have the weld totally dissappear.

That wouldn't surprise me if the sheet is 1100 or 3003 aluminum. 1100 is considered pure aluminum, and 3003 is around 98%. Both are easily welded and cold worked.

The OP did say it was 6061, which is why I used that alloy in my post. And the temper doesn't matter as far as hot cracking is concerned. Eric

It was 6061 which is normally welded with 4043. 6061 and 5052 are the two alloys I am most familiar with welding. You normally weld 6061 with 4043 filler, and 5052 with 5356. I also work a little bit with 7075 which is not easily weldable, although if there is a way I bet Ernie knows it.

... when I have "View"/"Threads"/"Threads with unread" set and all replies have been read?

So, this is a trial: maybe when I read this last reply, T-bird will stop showing the thread.

Back to our regularly scheduled programming.

Bob