Sparks possibly dropping down into the vent.

[Blaster]

After reading another thread, I thought of this potential problem and an easy solution (for me).
For many years one of my main concerns was having sparks drop down into the vent when lighting the fuse even if the fuse is bent at a right angle.  I have always taken a piece of modeling clay or similar material, about the size of a pea, and gently packed it around the already inserted fuse where it meets the top of the vent.  The clay has almost always been blown out upon firing.  Of course this potential problem of sparks dropping into the vent applied more when firing a cannon than firing a mortar since the vent of the mortar is at much more of an angle.  Works for me anyhow.

[Victor3]

 What I've done when there was a small fuse/large vent is wrap tape around the fuse to increase the diameter where it meets the vent.

[Blaster]

What I've done when there was a small fuse/large vent is wrap tape around the fuse to increase the diameter where it meets the vent.

That would work real well too and the fuses could be all made up prior to heading to the field to shoot em.  I guess my only concern would be if the tape could hold/contain a spark or some molten fuse which could possibly cause a fire in the weeds/grasses.  That'd be a real good reason to have a metal baffle or a frying pan directly behind the mortars to contain any molten fuse.....Thanks for that good idea!!

[Terry C.]

My vent punch closely matches the diameter of my fuse, so when the fuse is inserted in the foil packet, there is very little chance of anything getting by.

And I always bend my fuse. Not so much for the exclusion of sparks, but for the fact that if properly bent, the burning fuse sticks to the top of the barrel (which it doesn't hurt) instead of damaging the wood.

This only applies to standard visco. If using a quill or any other rapid ignition source, keeping sparks out of the vent is kind'a pointless.