This is how to make a nice sort of retro-modern coaster from the lid of a Tuna can.
It has a cork lining for setting a drink on so that it absorbs any condensation that forms on your nice icy cold drink, and a felt bottom, so it does not scratch up your nice desk.
I had been wanting a nice coaster to use at my desk for a long time. But i didn't want just *any* coaster, I wanted one that fit in well. So i perused a lot of second hand stores (i only needed one coaster, not a set) and finally, decided to make my own. thus, the tuna coaster is born.

DISCLAIMER

This instructable asks you to use sharp things like scissors, exacto knives and pens. It asks you to use sticky things like glue. If you feel you are not responsible enough to use these items without harming yourself or others, please turn back now. I will not be held responsible for people injured, cats glued, or any other mayhem that may ensue due to improper use of the tools described herein.

Step 1: Parts and Tools

the items you will need are:
Cork gasket material
felt floor protectors
a can of tuna in oil
some sort of glue (i use elmers stix-all)

A few notes here. The tuna needs to be tuna in oil. I discovered when making this, that tuna comes in two kinds, Oil, and Water. And, surprisingly, the cans themselves are different between the two types. Tuna in oil, in all the brands my store caries, has 3 small ridges on the lid of the can. Tuna in water on the other hand has one very large ridge on the lid of the can. I knew that the flatter the can lid, the better the cork would glue into it, so the 3 small ridges are a better choice, thus, tuna in oil.

The tools you will need are:

scisors or an exacto knife (whatever you are comfortable using)
pen (a sharpie is a good choice)
maybe a pencil
enough coins to fill a tuna can
a special can opener. (SEE THE NOTE)

About the can opener. The can opener you need for this is special. It is the kind of can opener designed to break the seal, not cut the lid. when you use this can opener, it lifts up the crimp on the can, and lets you lift the lid off, instead of cutting the metal. there are no sharp edges left with this sort of can opener. (i recommend owning one if you have children, cats that eat out of the can, or are just prone to accidents.)

Step 2: Preperations

Use the special can opener to open the can of tuna.

Eat the tuna (optional. you can feed it to a kitty, or save it for later.)

Wash the can and lid with soap and water

Dry the can

we now have a clean tuna can lid, and the can. save everything, we need the bottom of the can later.

Step 3: The Cork

Now, we need to roll out some of the cork and trace the can lid on it. Make sure you set the can lid right side up, and trace the bottom of it with your pen. we trace the bottom, that way your cork will fit down inside the top of the lid. Once you have it traced, cut out the circle just inside the line. I ended up using the scissors for this, but if you want to use the knife, you can. be careful. Test fit the cork into the top of the can lid. If anything does not fit right, trim a little and try again. Once it fits nice, we can move onto the next step.

Step 4: The Felt

Now lets trace and cut out the felt.
For this, i ended up using a sharpie to trace, because the paper backing is sort of waxy, and the normal pen would not write on it.
again, trace around the bottom of the can lid, so that the felt does not stick out all ugly when its done.
once its traced, cut it out. I used scissors here again. (i have good scissors)
again, test it against the can, this time on the bottom. Trim it to make it nice if you need to, then set it aside.

Step 5: The Glue

Time to glue! I used this elmers Stix-All Gel, but hot glue would work also. just follow the instructions for whatever glue you use.
get ready by filling the bottom of the tuna can with coins.
put glue into the top of the can lid, making sure to get it all the way to the edge. Don't use to much, we don't want it squeezing out and making a mess!
Put the cork into the tuna can lid, and press it down a bit.
Now, set the tuna can full of coins on top of the cork!
this will hold it down nicely until the glue sets up.
Put everything to the side and wait for the glue to dry.

Step 6: Big Finish

We're almost there! now that some time has passed, and the glue is dry, you can take the tuna can of coins off of the coaster.
Bring back the felt circle we made, peel off the backing, and stick it to the bottom of the coaster.

its done! you can use your fancy new coaster!