what are plugs used for?

The plugs are used in place of staples. They give a nice even pull for concave pieces. It eliminates the staple, staple, staple, staple, more staples....and the removal of all of those staples. Create a plug, tape it, brad nail it and add the resin. Then after the fabric is cured you can pop off the plug. This assumes you added enough resin to the fabric/MDF contact patch so that it bonds. Otherwise...staple, staple, staple....

I dont like using plugs unless absolutely nessisary. An instance where a plug is a good idea is a sunken in sub, where the box extends beyond where the sub is to be mounted. U can use staples for this and make it work, but you'll wind up with an uneven mounting surface and have to sand for a week before the sub will mount properly. If your doing a volcano style sub where the sub is pushed out from the box, just wrap the fleece very tightly around the box and staple a few points onto the speaker ring."Shiny chrome when used in conjunction with bikini models is particularly effective in inducing brain deficit disorder"

02 Jeep Grand Cherokee

Monster System on its way.