aerobatic kit planes

"Maxwell" wrote in
:


"Bertie the Bunyip" wrote in message
.. .
wrote in news:a4e90596-4834-48d2-9236-
:


I've done a little welding but nothing my LIFE depended on!


You learn,. And you learn how to read the weld so if it looks good,
it is good.

Very bad information. How a weld "looks" has very if anything to do
with it's effectiveness.


Wel, if you're gas welding and it looks good when you;re making it, it's
a good weld. There's no other way to tell short of x-raing it and nobody
does that.


I had the same concern when I started learning to do aircraft
welding. I talked to the guy who dsigned my airplane, Dudley Kelly.
He told me to get some lessons and then weld it up and not worry. In
his words "If you get 25% of each joint right it will still exceed
design specs"

This is going to be entirely load or design dependant. Yes, two
sleeved tubes, laterally loaded can easily survive with just a couple
of tack welds, but if the joint is in tension 25% is seldom even
close.

Well, the thing is overbuilt to the nth degree. It is what Dudley told
me and he was a design engineer for Convair!
You can take it up with him when you die.


You should see the welds on old pipers! They're crap!
And Bellanca were using MIG to weld their fuselages for a long time
and to my knowledge, none of them has come apart because of that..
After I learned to do only a passable job ( i'm better at it now) I
found that I could take a piece I'd made, put it in a vice and beat
the hell out of it and the weld and the area around it would be the
last thing to fail. Ask in RAH, though. Plenty of guys building/have
built the kinds of airplanes you might be interested in.


Yes, a lot of good welds look terrible, and yes it is very dependant
on the design and load of the joint. But either statement taken in
general context is very incorrect.


You mean out of context.


Bertie