This post is a follow on to the introduction of this Mercedes UNIMOG, Part One shows photos of the unimog at delivery, and photos of the first stages of Module 2 fabrication. Part Two covers the Module 2 roof fabrication, and the Module 1 door inner structure reconfigured to take out the wheel arch.
This post takes a look at bonding the outer skin to the inner structure on module number 2. The bonding agent we use for this application is Lord Fusor Metal Bonding Adhesive (Slow)-112B, there is medium and fast cure times also available. The slow application allows us to adjust and set in multiple areas, especially in a large square footage situation like our body side on the Unimog.
Moving onto the roof structure shown in the second picture, all ‘top hat’ sections were welded up and ready to take the roof skin that is shown held into position with clecos in the third picture. Again, we used the Fusor 112B two-part epoxy on the surface of the top hats and the inner face of the roof skin. As a side note, for preparation to use this bonding agent, the metal area to be bonded must keyed with 36 grit discing pad or courser, then wiped down with acetone for a clean long lasting bond.
Unimog roof fabrication
Bonding inner structure of module 2 to outer sheet metal skin.
Inner module 2 roof structure shown here awaiting outer sheet metal.
Module 1 & 2 roofs are held into position with clecos.
Floor fabrication and bead rolling
These last photos take us to the Module 1 floor where the bead roller was working full time. A floor of this size needs two guys, one at each end of the 5-foot panels. After marking out the blank sheet metal and making a custom guide for our Baileigh bead roller, we set to task cranking the beads out. The 18-gauge sheet metal was then spot welded to 16-gauge sheet metal with our ProSpot PR10, which can handle welding two pieces of eight plate comfortably. The 16-gauge sheet is then MIG welded to the under floor cross members, making for a super rigid structure.
The access panels are made using the same procedure, but are easier to handle due to size. To close out the beads, we chased down the ends to square them off, which gives a pressed panel feel.
More bead roller work with the entry transition step into Module 1 from the cab.
Module 1 floor after spot welding.
Module 1 access panel creation with the aid of our bead roller.
View of module 1 interior showing ‘A’ and ‘B’ post close out panels and transition steps to the Unimog cab.
View of the module 2 built in roll cage.
Close up of floor details.