Welding closed a miss-drilled hole

[H. Ivan Haecker]

Looking for info on a good way to weld closed 3/16"diameter hole that I miss-drilled in a piece of 4130 plate (0.080"). I especially wonder if I need to use a certain filler as the new hole will be drilled partly through the original hole. To make matters worse, I am not a real proficient welder, but I sure try hard. Thanks in advance.

Ivan Haecker QB Patrol #150

[alaskabearhawk]

What is the part? Welding and re-drilling a part is not an approved method. AC 43-13B para 4-60 a (4):

(4) Elongated or worn bolt holes in fittings,
which were designed without bushings,
are not to be reamed oversize. Replace such
fittings, unless the method of repair is approved
by the FAA. Do not fill holes with
welding rod. Acceptable methods of repairing
elongated or worn bolt holes in landing gear,
stabilizer, interplane, or cabane-strut ends are
shown in figure 4-25.

[Mark Goldberg]

Bob Barrows has permitted the welding up/filling of a bad hole with normal RG60 filler rod. He does this himself. Ivan, if you have have any questions about technique or are worried that this particular hole is in a sensitive, high stress place - I would call Bob to confirm. But it is something that he does and has allowed us to do at the factory. Mark

[alaskabearhawk]

I meant to say certain parts aren't allowed to be repaired with filler rod. Also the welding method will dictate the rod used. RG60 is typically used with O/A, ER70S2 with TIG.

[Bradrock]

Mark- would that method be acceptable on flap hinges? I filled a hole with ER70S2, TIG welding.

[Battson]

If it's an important part (which they often are), it's also good to weld a doubler over the top, then backfill the hole by plug welding into the doubler from the other side. This will give a strong part that meets the design strength of the original.

[H. Ivan Haecker]

The part I need to weld the holes closed is not actually on my Patrol. It is on a bracket on my rv-4 that ties the engine mount to the fuselage longerons. The holes are in the middle of this bracket and nowwhere close to any edges. So I'm not really worried about the repair to the miss-drilled holes, just didn't know how to do it or what material to use. Sorry for any confusion. I just figured someone on this forum knew more about welding than those rv guys. I'll try using RG60 rod and see what happens. Thanks!
Ivan Haecker Patrol #150