What you do is: (this is for 2.5) 1. Bring the two halves as close as you can so they are in the right places. Right click on the move button to get a position dialog so you can enter exact values if need be. 2. Click on one half and slect Edit Mesh. 3. Click on the sub-object button so it is NOT depressed. The Attach button should appear. 4. Click on the attach button. It should stay depressed. Click ont he other face half. Now click on the Attach button again to deactivate it. Both face halves are now the same mesh. 5. Click on the edit mesh sub-object button to reactivate it then select vertices. 6. Go along the seam where the face joins and select each vertex pair. In the dialog below on the edit mesh there should be a weld vertices command. With the two vertices you want to weld selected click on the Selected button in the weld part of the dialog. If all goes well the two vertices will become one. You may have to move them a bit if they get shifted. Run through and do this for all the vertex pairs along the seams. Problems; Max may tell you there are no vertices within range. Just up the threshold number till they weld. Tricks: You can do the weld all at once. Just select all the vertex pairs at once then set the threshold to something small (dist between the two vertices) and click selected in the weld dialog. If all goes well the vertices will weld all at once with no cross overs. If it doesn't work (more than two vertices weld) you can reduce the threshold till it does work. After you weld the vertices the mesh is one mesh with no gaps. Hope that helps.