Filling Aluminum

[Lou]

So,,, say you have an aluminum landing gear and the holes are not
drilled correctly.
Is there a good and bad way to fill these so they can be redrilled?
Lou

[Orval Fairbairn]

In article om>,
"Lou" > wrote:

> So,,, say you have an aluminum landing gear and the holes are not
> drilled correctly.
> Is there a good and bad way to fill these so they can be redrilled?
> Lou

NO! The holes create stress raisers, which can make the LG fail.

[Stealth Pilot]

On 21 Dec 2006 18:27:16 -0800, "Lou" > wrote:

>So,,, say you have an aluminum landing gear and the holes are not
>drilled correctly.
>Is there a good and bad way to fill these so they can be redrilled?
> Lou

any sort of welding is going to destroy the grain and the temper
strength.
if you cant drill a size larger to fit a bigger bolt size then you
should really remake them.

btw if you remake them do it in tempered spring steel. steel has three
times the strength and 3 times the weight thereabouts so making the
spring to the same strength should be about the same weight.

Stealth Pilot

[pbc76049]

There are ways to fix this as long as you have sufficient edge margin
AND the properties allow this to be done.
Use a freeze plug. Turn a slug of material to a shrink fit dimension.
Freeze it in dry ice, drive it in the hole. After the part is back to room
temp.
Redrill the holes in the correct position. This makes you do a little
figuring,
like the minimum size necessare to "clean up" the hole before machining the
slug.
If the gear leg is sandwitched and the plug is encapsulated, carrying only
shear
loads, this is a piece of cake. If the hole is for a tension load, then the
"bushing"
you machine will have a shoulder that is 2D, and an appropriate thickness.
It
isn't that hard to do....... Just engineer it correctly and march on.

If the hole is NOT in a place that will carry a fastener AND you have
sufficient edge
margin and mechanical properties........ Touch countersink the holes and
double flush
plug rivet. Use a countersink of about .030 depth on both sides. 100
degree will be fine
BUT the BOOK OF KNOWLEGE (ac43-13) calls for 82 degree NACA method riveting
to do this..............

Your mileage may vary,

Scott.