Best way to fill dash holes

[OB6]

I would like to relocate a couple of small indicator lights (14mm holes) on my dash before I cover it with leather. What's the best way to do this? I'm thinking a scrap piece of aluminum behind the hole followed by some sort of filler to smooth everything over. I know aluminum can be challenging to bond.

What has worked for you?

Thanks.

[mrmustang]

I would like to relocate a couple of small indicator lights (14mm holes) on my dash before I cover it with leather. What's the best way to do this? I'm thinking a scrap piece of aluminum behind the hole followed by some sort of filler to smooth everything over. I know aluminum can be challenging to bond.

What has worked for you?

Thanks.

Metal tape behind, fill with body filler, sand smooth/flat.

Yes, it really is that easy.

[OB6]

Metal tape behind, fill with body filler, sand smooth/flat.

Yes, it really is that easy.

Really, just metal/foil tape? I would have never thought of that.

[BrewCityCobra]

Perhaps I did this with a bit of overkill, but I created a plug piece (to fill the hole) and a backing piece to hold it flush. To secure, I countersunk with a bunch of bolts (not sure of the size off the top of my head but I can certainly look up if needed. The whole assembly was then made flush using body filler and sanding.

Certainly makes for a secure patch.

I have some photos from when I used the process for the transmission hump - same process as the dash just a bigger patch.

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[Rebostar]

A traditional dollar and dime patch.
Used in WWII to plug bullit holes in aircraft aluminum skin. Requires the use of a counter sink or appropriate size drill bit and flush rivits. Cut one peice of aluminum the exact size of the hole you wish to plug, then cut another one one inch wider in diameter. Center the two togeather and clamp. Drill #40 (5/32) holes in any pattern you like then countersink the holes. Useing a rivit squeezer or rivit gun rivit the two together. Drill holes in the outer (larger diameter) plate, then install it from the back and drill the outer holes through the dash, counter sink those holes from the outer dash side and shoot flush rivits. If properly counter-sunk everything will be flush and it will all be aluminum. No bondo or filler required.
You can go to your local county airport and look for an aircraft repair hangar and ask the mech for a small handfull of AD426-3-4 rivits. Tell him/her its for your Cobra and he'll most likely give them to you free.

Happy Trails

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[mrmustang]

Really, just metal/foil tape? I would have never thought of that.

Since it is not a structural item, I use the same tape they use for ductwork, it's a little heavier than regular foil tape. don't need much, a 2"x2" patch of it should be more than enough for a solid backer for the filler.

[Jeff Kleiner]

Don’t agree with Bill on the foil tape. It can flex and subsequently let the filler crack. Bevel/chamfer the finish side of the holes and put a patch panel piece of aluminum on the back adhered with either JB Weld or 3M HSRF. After it cures then use body filler on the top side.

Jeff