Welding: Recovering from a poor joint.

I have been given a patched landing gear. The weld looked like
bubblegum had been stuck to it and there were little pits where any
metal that had flowed, didn't flow around that impurity. I asked my
A&P if the embedded impurities hadn't been an issue, could I simply
remelt the joint and cause it to flow into the base metal? He
replied because there was so much 'joint' there, heating it up to
molten could cause more harm. He recommended I grind as much of the
old weld off as possible.

I have an angle grinder and a grinder wheel for it. I can get to the
weld, but even if I jig the work, it's going to be awkward to grind
with this tool.

Anyone have any suggestions how this might be made to go smoother? -
MikeH

On Jul 5, 6:23 am, mhorowit wrote:


Anyone have any suggestions how this might be made to go smoother? -
----------------------------------------------------

Wellll.... no. :-)

Oh, there's lotsa stuff you can try... if your angle-head grinder has
a blade-guard, remove it. Yeah, I know... but OSHA doesn't have a lot
to do with Reality. Instead, get into the habit of WEARING your
protection. Good LEXAN lenses that wrap around your I-balls PLUS a
full-face shield & ear muffs. GOOD gloves, tough yet supple (cheap
ones are usually one or the other). Lotsa leather, right down to your
toes. Hot & greasy but a little fore-thought can keep you working
long after the amateurs have set themselves on fire, blown themselves
up and gone home in disgust. (Nasty job, welding. Second worst in
the world. [Sand-blasting is First.])

You might also consider getting yourself a couple MORE angle-head
grinders, the cheapies from Harbor Freight. You want a narrow disk on
one, a thick disk on the other. Over on the THIRD one you want a
coarse flapper wheel.

Cutting away a sloppy weld, always made by someone else of
course :-) ...you use the thin wheel to get into the corners, the
thick one to get those chunks offa there, the flapper to polish things
up.

What you are in the process of Discovering is that 'Welding' with the
quotes is about 95% basic metal working and mebbe 5% spent with a
torch in your hand, if you're lucky. The grinding, fitting and
shaping of the metal TO BE welded is the real chore, not only for
initial fabrication but for all manner of repair work, be it airframes
or a flight-deck elevator. Once you have the disaster cleaned-up to
shop-class conditions THEN you get to don your Magic Goggles and play
Thor.

Kinda funny the way all the manuals and those $500 seminars seem to
focus on just 5% of the task, prolly because they're trying to get you
buy something. The 95% that you need in order to make the 5% USEFUL
is mostly experience and elbow-grease and the last I heard, both were
pretty hard to find in a vending machine. But you're on the right
track. An angle-head grinder is pretty much the Maid-of-all-Chores in
a welding shop, where good ones are worth the money. But if you're
only building a single airplane it's less expensive to simply buy half
a dozen of the cheap imports and throw them away when the bearings
give out, which they will quick like a bunny. However, if you'd like
to make them last longer than a fortnight, take the thing apart and
tap the gear housing to accept a small (1/16-NPT) Zerk fitting. Pack
the gear box with high-pressure MOLY grease as used for CV joints, and
give it a shot of lube when it starts getting noisy. I've had some
last as long as a year(!) (Of course, my Makita, purchased about
1995, is still going strong...)

Nice thing about a steel-tube fuselage is that you can keep it flying
long after most folks give up on wood or aluminum. (I worked on a
Cassutt fuselage that had been repaired so many times the only thing
left of the original was an itty-bitty piece of tubing in the tail.
Then the new owner decided to practice his Ground Loop...)

-R.S.Hoover

On Jul 5, 10:19 am, " wrote:
On Jul 5, 6:23 am, mhorowit wrote:



Anyone have any suggestions how this might be made to go smoother? -
----------------------------------------------------

Wellll.... no. :-)


-R.S.Hoover

Hey Bob - good to hear from you. Sometimes "things" just fall into
place and I get such a smooth seam I just amaze myself; othertimes (as
they say in the UK) it looks like dog's breakfast. The good news is
that I can recognize when things arn't going right and I stop. - MikeH

mhorowit wrote:
On Jul 5, 10:19 am, " wrote:
On Jul 5, 6:23 am, mhorowit wrote:



Anyone have any suggestions how this might be made to go smoother? -
----------------------------------------------------
Wellll.... no. :-)


-R.S.Hoover

Hey Bob - good to hear from you. Sometimes "things" just fall into
place and I get such a smooth seam I just amaze myself; othertimes (as
they say in the UK) it looks like dog's breakfast. The good news is
that I can recognize when things arn't going right and I stop. - MikeH


My welding improved tremendously when I bought a pair of maximum
strength reading glasses, way stronger than I need normally. Being able
to see the weld really close makes a huge difference. I can spot the
potential defects as they're forming and prevent them.

John

"mhorowit" wrote in message
oups.com...
I have been given a patched landing gear. The weld looked like
bubblegum had been stuck to it and there were little pits where any
metal that had flowed, didn't flow around that impurity. I asked my
A&P if the embedded impurities hadn't been an issue, could I simply
remelt the joint and cause it to flow into the base metal? He
replied because there was so much 'joint' there, heating it up to
molten could cause more harm. He recommended I grind as much of the
old weld off as possible.

I have an angle grinder and a grinder wheel for it. I can get to the
weld, but even if I jig the work, it's going to be awkward to grind
with this tool.

Anyone have any suggestions how this might be made to go smoother? -

You might try a die grinder, with an angle grinder cutting wheel fit onto
it, if the angle part of the angle grinder is getting in the way. g
--
Jim in NC

Morgans wrote:
"mhorowit" wrote in message
oups.com...
I have been given a patched landing gear. The weld looked like
bubblegum had been stuck to it and there were little pits where any
metal that had flowed, didn't flow around that impurity. I asked my
A&P if the embedded impurities hadn't been an issue, could I simply
remelt the joint and cause it to flow into the base metal? He
replied because there was so much 'joint' there, heating it up to
molten could cause more harm. He recommended I grind as much of the
old weld off as possible.

I have an angle grinder and a grinder wheel for it. I can get to the
weld, but even if I jig the work, it's going to be awkward to grind
with this tool.

Anyone have any suggestions how this might be made to go smoother? -

You might try a die grinder, with an angle grinder cutting wheel fit onto
it, if the angle part of the angle grinder is getting in the way. g

I've stuck larger cutoff wheels on my angle grinder to get deep in some
corners. Scary as hell, but it did what I needed.