Aluminum

Note: the aluminum assembly is occurring throughout the build rather than in one ‘push’.  I’m generally following the steps in the manual but I’m waiting for the final attachment likely until near the end.  The Cleckos are invaluable and, basically, I’ve got the Al positioned as I like them with allowances for removing panels for access or doing further work as needed.

Many Al panel photos are here.

The aluminum assembly actually started with disassembling the aluminum panels that came attached to the chassis with machine screws— 44 in total.  Working from the rear to the front, I numbered the panels according to the removal sequence and photographed each step.  For the most part the panels were in the correct position; even so final assembly required some wiggling and trimming in some cases.  The photos immediately below the DS footbox aluminum as it arrived on the chassis and then the final fitment, ready for bonding and riveting.

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Additionally, there are another 20 or so panels that need to be added; some are ‘patch’ panels to cover holes in panels not needed for some reason and others are smaller chassis parts.

Generally, I’m using the 1/8” rivets for attaching the panels to the chassis or together.  Each rivet hole is drilled by a #30 drill and then deburred using a counter sink.  As Carroll Smith points out, all drilling material needs to be removed for a riveted attachment to be considered good.  Before riveting, GE silicone II is applied to the area being mated to increase the bonding and decrease any potential rattling.

I’m using Cherry-Q structural rivets: in structural rivets the mandrel extends through both sheets being riveted together providing greater sheer strength.  Since the Al sub-frame adds to the torsional strength the panels should be riveted with structural rivets: they increase the shear strength by about 50% relative to non-structural rivets. Below you can see a test comparison of the F5 rivets and Cherry-Q rivets: the Cherry-Q rivets clearly have the mandrel through both Al sheets. The Cherry-Q rivets are to the right in the photo; the alpha-numeric labeling is the rivet number in the catalogue:  B = aluminum rivet material; S = steel mandrel.  The number corresponds to a grip range.

Rivets are spaced at 2” intervals for Al to Al attachment and roughly 3” intervals for Al being attached to the chassis directly.  I have about 1,200 rivets for the job. Below is a photo of the rivet spacing tool in action— it’s a huge time saver and ensures that the rivet spacing is uniform and in a straight line (good for attachment efficiency and aesthetics).

I purchased a hydraulic riveter from Aircraft Tool Supply.  It pulls the rivets uniformly and makes the process much easier.

The DS footbox floor riveted in place.  The brake line for the rear brakes passes below the floor.  I’m coating the road-facing parts of the Al panels with Rustoleum bedliner.  It looks ‘greenish’ in this photo but it’s flat black.  The photo below is the completed DS footbox.  I’ve probably taken the box apart and re-assembled it a dozen times.  I’ll leave it in this state for much of the build as I’ll need panels available for some further work such as a potential footbox vent.  The Cleckos hold the panels well and there is little need to rivet them in place at this point.

Early March, 2018:

At this point I’ve put together the aluminum footboxes and am working on the cockpit aluminum. The basic strategy I’ve been following is to Clecko all of the panels while working through the roadster, not riveting anything until all is in place.  The Factory Five build manual recommends riveting pieces as one moves along but I’ve found that I glad that I haven’t.  For example, the cockpit floor is suggested to be riveted in soon after the footboxes but I’ve found that I’ve needed to take the floors out on several occasions (e.g., the issue with the door panel Al described in the 3/3/18 blog) and having the panels riveted too soon would have complicated things.

I’ve also decided to paint the panels with Rustoleum Silver ‘Hammered’ paint.  I’ve considered powder coating, anodizing and polished Al with a clear protectant.  In the end, the Rustoleum gives an nice ‘metal-like’ finish, seems pretty tough and makes it easy to repair scratches, just by repainting.  

November, 2018:

The aluminum has been mostly installed, some held in place with Cleckos.  The DS aluminum will wait for riveting until all of the footbox work has been done, including the wiring and accelerator mechanism (maybe a mechanical linkage).  I used Rustoleum ‘hammered’ as the paint and like the look:

I’ve also used undercoating, also by Rustoleum, on the panels that will be adjacent to the body.

The trunk has been drilled for rivets but will remain unriveted until all of the electrical work has been done.

The cockpit Al:

The trunk Al: