< Sandboxes 2 >
As I mentioned in the previous issue, I recently carried out the modification of the sandboxes. Specifically, the modification involved changing the rear bottom rounded shape of the sandbox into a sloped design.
Using a metal saw, I cut out the entire rounded section of the bottom. The metal saw made a full pass around the bottom, and I used two different saws to match the varying width of the cut.
Since the cut edges were rough, I then finished the surface using an end mill. I re-chucked the main body in the vice, using an angle gauge to ensure it was level for precise work.
The left one shows the section after the cut. The early-model sandbox follows this shape, and all that remains is to add the bottom plate.
I then cut out the bottom plate to match the section of the cut. I traced the inner curve from the original part to ensure an accurate fit.
The early-model sandbox was assembled with rivets rather than welding, so I drilled holes to install dummy rivets.
Just like the other parts, the bottom plate is attached to the main body using brass angle brackets. I attached the brass angle to the main body, then drilled corresponding holes in the bottom plate.
Next, I inserted copper rivets into the holes and secured them by swaging them on the backside. I used pliers to swage the rivets, and attached a softened copper plate to one side of the pliers to protect the rivet heads.
There are also rivets on the underside of the angle, where I could not use pliers. Instead, I fabricated a swaging tool from a flat bars, as shown in the photos. The copper plate on the bottom of a flat bar prevents head deformation.
Once the assembly was completed, I applied high-temperature soft solder inside to seal the sandbox. Although the first attempt didn’t completely stop the leaks, I added solder twice more to achieve a proper seal.
The sand traps I prepared last month are now attached. It is temporarily assembled here, but after painting, I will seal the flanges of the sand traps with sealing material during final assembly.
Finally, the sandbox has been mounted onto the main body’s bracket. The next step is to install a removable lid on the top plate. There will be a few more lost-wax parts used in this process, which I will detail in the next update.