If you're thinking of doing overlays on 71-74 gauges...don't

There are vinyls that use a special membrane on the back for these type of installations. These membranes allow air to easily escape when installing. Resulting in bubble free or warp free installation. Your picture proves the point I’m making. If the vinyl has this membrane on the back. ( It looks like a woven spiderweb. ) It will look fantastic and painted on when applied. In fact, it’s hard to screw up and that’s the point of the membrane. Looks like a poor choice of vinyl was used to make this decal.
Regardless, of what yours is made of. If you rest the gauge by a good heat source. Like a wood burner or vent for a furnace. The air will completely work itself out on its own. Sometimes it takes up to a week. But, they are guaranteed to completely disappear. If you’re patient enough. A hair dryer isn’t a good choice. Because the trapped air needs more, subtle consistent time. You need to use a consistent heat source over a longer period of time. A wood burner stove is perfect. Consistent heat, over a long period. Put it on a chair up against the wood burner. Or hang the gauge 3 to 4 feet above it.

The problem with concave surfaces that get decal treatment is that you have to get the edges on first, not the center. Sometimes it takes pieces of tape on the outside to hold in place. Once the edge is affixed, you can spiral in to the center. This will cause a slight stretching, but once it's all stuck there won't be any problem with excess material.

Photon440 said:

The problem with concave surfaces that get decal treatment is that you have to get the edges on first, not the center. Sometimes it takes pieces of tape on the outside to hold in place. Once the edge is affixed, you can spiral in to the center. This will cause a slight stretching, but once it's all stuck there won't be any problem with excess material.

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It doesn’t matter how it’s shaped if the advice I gave is used. Yes, with certain curves you can avoid as many air bubbles. Depending which direction it is installed. Regardless, slow consistent subtle heat will push the air out with no further assistance. The slow consistent heat, will cause the air to move to a place of no resistance until it’s completely removed. If you’re impatient, poke a hole into the bubble to allow air to escape. You risk, ruining the decal by having a visible pin hole remaining. You have to be patient. The air will remove itself on its own. With slow, consistent, subtle heat over a long period.

The problem as the OP showed wasn't so much air bubbles, but wrinkling caused by the concaved surface. Once the decal is wrinkled from an excess of material, it isn't a problem of air bubbles. You can have no air at all and still have a wrinkle from too much material bunching up, especially if the center is applied first.

Photon440 said:

The problem as the OP showed wasn't so much air bubbles, but wrinkling caused by the concaved surface. Once the decal is wrinkled from an excess of material, it isn't a problem of air bubbles. You can have no air at all and still have a wrinkle from too much material bunching up, especially if the center is applied first.

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I agree with you. Im just saying. Patience. Slow, consistent subtle heat will fix all circumstances. People make the mistake of trying to convince air removal by manipulating the vinyl one way or another. Introducing too much heat suddenly, stretching, pushing, rubbing, poking holes. Trapped air, moves over time on its own due to increasing heat very slowly and constantly. If patience is used through very slow consistent heat. The decal will look painted on.

Hi guys, sorry for delay. Pearl while you maybe right the issue is a normal person in the hobby will do this once, maybe twice in their lives and as such I recommend save time and frustration and have it done at an instrument shop. I'm thrilled with mine.

"Know when to outsource and when to DIY"