Woops! Wrong size file

[sofasurfer]

I have a Echo CS490, .325 chain requiring a 3/16 inch file. Cut like mad when I got it. After a while I noticed that it takes a little longer to go through a log and the chips are smaller. Eventually it even started cutting arcs.
I also noticed that my file didn't seem to have much bite (was this because to the improper size or because it was worn out?) and I was not feeling the sharpness with my finger tip like it had when newer. So I looked in my manual to be sure I knew the correct file size. Turned out that I was using a 5/32 inch file, 1/32 inch too small. Hmmm. So I bought the correct file and tried it out. The new file tore into the steel like the other one never did. I also noticed (helps to open your eyes) that the gullet is no longer flat but have a peak in the middle of it. I assume I should file this flat. Anyway, long story short, The saw immediately cuts like new again. Goes through a log like butter. So from now on a pay attention to the manual, wear my reading glasses when sharpening and look closely at the chain to see whats happening.

 

[Mad Professor]

If you know how to free hand file a 5/32" can work fine on 0.325 chain.

 

[sofasurfer]

I use a file guide. Still trying to figure if I'm using it correctly. I know about the 30 degree angle mark on it. But I wonder if I should be holding it perfectly (as best I can level or on an angle. I thought I was supposed to lift up on the file a bit to get the upper part of the tooth sharp but now I learn that the both sides of the file guide should sit down flat on the chain.

 

[epo]

I use a file guide. Still trying to figure if I'm using it correctly. I know about the 30 degree angle mark on it. But I wonder if I should be holding it perfectly (as best I can level or on an angle. I thought I was supposed to lift up on the file a bit to get the upper part of the tooth sharp but now I learn that the both sides of the file guide should sit down flat on the chain.

I'm not sure what file guide you are using, but I assume the most common one. You can hold such a guide in 2 ways: on the surface of the top plate or simultaneously on the top plate and the depth gauge. The first method is recommended by, for example, Oregon, and the second by, for example, Stihl and Vallorbe.


The original Atkins/Borg-Warner patent described both methods.
In the first case, the file will be a little higher, so you get a greater top plate cutting angle and a greater side plate angle (less hook).
It will be easiest for you to hold the guide without using any down angle ("perfectly").