Originally Posted by Eric B
Edit: I'm guessing you would debur every pre-punched hole even if you don't final drill, just because of the process used to make the hole.
You can if you want, but it is not specified or required by Van's (and why it is not mentioned in the KAI).
The burden is still on the builder to make a determination whether deburring any given hole is required, but in the majority of instances on the RV-12, the only time deburring is required, is in instances where match drilling or final drilling has occurred (meaning it is a hole made by, or made larger by drilling).
There is a hidden danger with deburring, where in some cases a builder is making things worse by deburring, than if they didn't at all.
Deburring is an acquired skill. It is not uncommon for novice builders to go way overboard and be slightly chamfering/countersinking each hole. This is a more serious problem on the RV-12 because the skins are only .020 thick to start with.