[R-390] How I plugged a hole in my R-390A faceplate

[JAMES GREEN]

I just finished a successful plug of an extra hole in my R-390A and I thought I would share it with the group.
The offending hole was a 1/4 inch hole that was drilled in the lower left-hand corner and was placed there to accommodate a miniature switch.
First I chamfered the hole on both sides of the plate withe a counter sink bit.
Second I cut 3/8 inch long piece off the end of a piece of 1/4 inch round aluminum.
Third I placed the 3/8" by 1/4" dowel into the offending hole. I placed a 1/16" thick 1/4 inch washer on the back side and rested the back side on an anvil. Actually I don't have an anvil so I clamped a hammer in my woodworking vice and used that as an anvil.
Fourth I used a ball pean hammer to rivet the top side end of the dowel into the countersink in the hole. I then flipped it over, removed the washer and did the same thing with the back side.
At this point I had a slightly rounded rivet in the hole. Following is how I cleaned up the riveted heads.
I put an 3'4" end cutting straight flute carbide tipped router bit in my plunge router. I placed the router on a flat surface and put a piece of paper under the router bit. I lowered the plunge router until the router bit rested in the paper. This set the end of the router bit about .001" above the flat surface. I then locked the plunge router in this position.
Lastly I fired up the router and milled the riveted ends off the dowel on the back side (first) then the front side. The remainder is easily wet sanded flush. The hole is now invisible.
I see no reason this approach could not be used on larger holes. All you need is enough thickness to add the chamfers.
I hope this is useful to others.
Jim