Now we are starting to look at a nearly finished fan mount, but before we get too excited and mount up, we need to clean all the rough edges. Like most things of a modding nature, we can go about this a few ways - the slow clean way or the quick and dirty method.
Basically what we want to do is take off the rough edges and get everything looking nice and round, knocking off any excess edges. This of course can be done by starting with a coarse half round bastard file and working around the cut and finishing with a finer smooth half round file until we have a nice smooth edge.
The other way of getting things done is using your rotary tool and round grinding accessory. I would only suggest this method if you are confident with a rotary tool. With the tool set at a high speed run the grinding bit around the edge almost routing the excess metal away. It is extremely easy to skim away too much ruining your edge, so take your time and concentrate on a quarter of the circle at a time. You may still need to finish with a fine file to knock off any remaining metal burs.
Finishing it all off
So how do we hide the bare metal edge that we have remaining before installation? Simple! Let me introduce you to an essential item in modding, U-Channel Moulding. With various names depending on your location and widely available and inexpensive at most good hardware stores, U-Channel is used in a majority of mods that involve cutting panels.
Below I have added a guide for measurements on how much U-Channel is needed for the standard fan size holes. Using an X-Acto knife or scissors to cut the desired length, fit the channel around the inside of the fan hole. This will disguise exposed metal and to a small degree will hide uneven cuts.
80mm fan = 252mm
90mm fan = 290mm
120mm fan = 377mm
140mm fan = 440mm
The majority of the time the U-Channel will hold itself in place if cut to a perfect length. But if you find it swells away from the metal edge, you can use a small amount of epoxy glue on the inside of the channel to fix this. Mix and apply a small amount of the glue then clamp the channelling into place and allow to dry. You should find this will fix any problems with stubborn fitting U-Channel.
This is a simple mod for first timers which if thought out thoroughly can not only be inexpensive, but also an effective way to add a possibly unique cooling solution. Utilizing some basic modding techniques all of which can be used in a wide variety of applications and projects, why not get creative? You never know the cooling benefits you may be able to add to your rig.