I have a tiny hole in the wing, it is about 2mm long. basically like a small rip in the shape of a U. This wouldn't cause anything bad to happen during flight would it? Should I repair it right away with something. It's on the monokote. What would the easiest way to repair it be. It is on the bottom of a low wing plane.

Use a patch of Monokote. Low heat on iron.

Lots of guys take tape with them to the field to temporarily patch things like that. Some actually do permanently repair them later.

Another handy one is stickers, the sort you get with just about every major product, and even off the shelf sticker sets, the range is endless.
I guess it depends on whether you are after an invisible repair or it doesn't matter.

It's important to fix the hole using any of the methods mentioned. A small hole could lead to a larger tear in flight. I've had most of the monokote on top of one wing ripped off in flight. I did land the plane safely but it was pretty hairy.

Dave

A small hole is not a problem. A small hole that tears (or suddenly goes "BANG!" and opens into a split the size of the panel) is a bad thing.

Clear packing tape is better than nothing if you don't have a color-match bit of Monokote or trim. I keep a small roll of "hatch tape" in my flight box for emergency field repairs.

Good place for a decal, too. Club emblem, Stars and Bars, etc.

My airfield closes after the first of October, so I go to a local park to fly during the off season.
It was a cold day, and I removed my Ultra Stick .40 from the back of my car and went to place it on the hood.

<BANG> I popped a hole in the botttom of the wing covering with my car's antenna. [:@]
Being cold and brittle, the hole ended up being about 3 inches by 4 inches.

I used packing tape that I just happened to have in the trunk to cover the hole so I could fly that morning.
It stayed on there for 2 seasons until I experienced Dumb Thumbs coming in for a landing on the first flight of the season.
I ended up fertalizing the corn field with balsa, but it was no fault of the tape. [:-]

Bob

Since you asked about the aerodynamic consequences of the hole.......................

There should be none. But if it enlarges, there is a possibility that there could be. And the AERODYNAMICS of losing the covering on one side of a wing can be huge.

A number of aircraft in WWI experienced real problems when their aerodynamics changed as a result of the wing covering blowing off.

Aerodynamics is sometimes a funny subject, sometimes not.