LITHIUM BATTERY CABINET MOD ON AN AIRSTREAM INTERSTATE

Inch by inch, life's a cinch.  Yard by yard, life is hard.

There are numerous versions of that quote floating around out there, and we may never know who coined the original phrase. Given that Ms. Giffords is married to an astronaut and lived a few miles from us, and given that my husband works as a Flight Controller for the International Space Station, I thought I'd use this one.  

"Inch by inch" is my best piece of advice where DIY is concerned, and I'm going to give an example of what I mean with this blog post.  It's fairly unlikely that there's another person out there who will need to do this exact mod to their Airstream Interstate, but that's not the point.  The point is to illustrate the general headspace associated with tackling modifications when you possess no formal skill in the area of issue, which is the case with me when it comes to woodworking and metalworking.  I hear from people who express reservations about their own ability to tackle DIY jobs and van modifications.  A lot of that can be overcome by simply taking things one small step at a time.

Let me start from the very beginning and proceed incrementally with successive photos to show you what I mean.

Originally, the space under our coach's closet contained this conventional electrical converter and a bunch of miscellaneous electrical and water lines kinda tossed back behind it.  You can see that there's a mounting panel cut out of cabinetry material, to which this converter was attached.  

This is what that mounting panel looked like when removed from the Interstate.  It's a piece of OEM cabinetry material, but it was cut very crudely by Airstream.  You can see that the cut lines are jagged and the right side leg is a conspicuously different width than the left side leg.  Despite these limitations, I had to find a way to re-adapt this piece during our lithium battery upgrade project (blog posts on the technical aspects of that project itself are still to be published).  I had to re-use this piece because we did not have access to any more of this cabinetry material. 

This is what the lithium install looked like with the closet door removed, closet floor removed, and that front mounting panel also removed.  You can see the shallow tray on top of the batteries, a frame painted white, but the new electrical inverter had not been installed in that spot when this photo was taken.  Nevertheless, you get the general idea of this lay-out.  

This was my temporary protective cover for that under-closet lithium chamber - it's simply a piece of black coroplast (plastic cardboard) with some mosquito screen covering two ventilation cut-outs, with the mosquito screen being held on the back side using duct tape.  The coroplast piece was then screwed into the mounting frame using the same screws and holes that had held the original electrical converter. But that wouldn't do as a long term solution.  It was strictly a stop-gap measure. 

I knew that the final modified panel had to include a kick plate on the bottom.  In the tiny space of the Interstate, stuff gets bumped, kicked, and generally smacked around - it happens.  I didn't want anything to accidentally punch itself through that opening and impact the lithium batteries or other electric components.  We have a miter saw and I've gotten reasonably good at making precise wood cuts using it.  So I cut a strip of half-inch furniture-grade plywood to be added across the bottom.  The plywood was left over from my custom closet shelf project.  

You might observe that it's a very thin kick plate that I added above - possibly not very strong.  But knowing that the original converter opening had been crudely cut by Airstream, I knew I'd have to make an overlay for the ventilation opening.  There was no way to re-cut that panel to make it visually presentable, especially given that one leg was wider than the other.  So I began to measure for a quarter-inch furniture-grade plywood overlay to hold the ventilation screen.  Together with the half-inch strip at the bottom, it would be strong enough when all attached together.  

At that point I needed to size the opening.  I wanted as large an opening as possible for maximum ventilation, but I had to account for the irregularity of the underlying cabinetry mounting piece.  I settled on this size as represented by the blue construction paper, and my husband and I worked together to cut the opening.  Basically, he used a jig saw freehand, with me standing on the workbench, standing on top of this piece of plywood to hold it steady as he cut (we don't own a lot of sophisticated woodworking tools).  

OK, so now I'm one more inch further along in this process, with the overlay cut.  Next I painted it and the underlying strip using a Sherwin Williams oil-based enamel color formulation that matched our Interstate's counter tops.  

Once the paint had dried, I needed to determine how large to order the perforated aluminum sheet, which was by far the most expensive part of this process (about $37 with tax, shipping, and handling).  For that reason, I wanted it to be as large as the opening would tolerate, knowing that we might do further mods down the road and maybe I'd want to re-purpose that piece on a different future cabinetry mod.  So here you see the overlay opening in blue, and the aluminum plate sizing in pink.  Given that we are not professionals, we always create project mock-ups out of cardboard and/or construction paper.  It's a practice that tends to eliminate both accidents and unforeseeable sizing mistakes, no matter what we are working on.  

I ordered the piece from Online Metals, which also supplied the same perforated aluminum sheet for my custom computer table and my under-cabinet shelving projects.  They have given me really good service.   

After the aluminum piece arrived, the next task was to attach it to the gray painted overlay.  This was more challenging than you might first assume, because I was using the existing perforations rather than drilling holes electively in locations of my choice.  As such, I had to drill the small bolt holes partially blindly from the back side.  You can see that I'm a couple of millimeters off being completely centered with those bolts.  As my husband would say, "If you could achieve better than that on a first try, then you wouldn't be called a DIYer.  You'd be called a professional instead and you'd be getting paid accordingly."  

I had originally planned to add a second quad of small bolts to hold the overlay to the original cabinetry mounting piece.  But once I realized that my first four bolts were slightly off center, I didn't want to add any more because it would visually amplify the imperfection.  For that reason, I decided to attach the overlay to the original cabinetry piece using 3M exterior grade double-sided tape, one of the few applications in which I would agree to use that product (adhesive products generally don't stand up well here in the Deep South).

However - next inch please - using the 3M tape caused a domino effect in that the overlay was now standing a bit proud of the cabinetry mounting piece.  Which means that my strapping for the bottom reinforcement strip was no longer flush.  So I added a spacer washer on either side in order to close the gap between the kick plate strip and the small mending plates I was using to attach it to the cabinetry mounting piece, as you can see above.  

In order to create a good seal along the bottom of this workpiece, I had to add something flexible and compressible to exclude dirt or spilled materials from potentially penetrating the bottom edge and entering the lithium chamber.  This is what I chose.  

And here you see it applied to the bottom edge. 

My husband wants to be able to pull off key cabinetry pieces quickly without having to mess with screw drivers and hardware.  For that reason, we've used neodymium magnets to attach certain structural pieces, rather than fixed screws.  Several of them were attached to the back of this workpiece to hold it in place against the cabinetry frame below the closet.  

This and the jig-saw cut to the overlay were the only parts of this project that my husband assisted with - I could have done the entire job without him, but two heads are better than one, and he decided that he wanted to counter-sink screws into the steel washers that would go on cabinetry frame, to which the neodymium magnets would attach.

"You don't have to make every last thing fancy," I noted to him as he was purchasing the counter-sink drill bit needed to do this.

"What's the point of doing any project if you're not learning at least one new thing in the process?" he asked.

I replied (paraphrased), "I've got four additional projects stacked up on the heels of this one.  I'd never get them all done if I don't simplify and choose a path of least resistance at times." 

Here's the counter-sunk screw sitting in its metal washer, stuck to the neodymium magnet in the workpiece.  

And this is what it looks like from above, peering down into the small gap created as the new front panel stands a bit proud of the existing cabinetry frame.  That small gap allows one's fingers to pry the piece off the cabinetry - in other words, we designed it this way intentionally.  Those neodymium magnets are very strong, and leverage is required to dislodge them.

The mat you see lining the closet floor is an IKEA Oplev which I cut to the shape of the closet.  Its purpose is to trap grit and dirt that falls off my folding bicycle which I store here.  I don't want that dirt making its way down into the lithium chamber.  

And after proceeding through this little project all those incremental inches one at a time, here's the final result.

I think it looks pretty good.  It does a good job of resurrecting a badly-cut cabinetry piece while meeting the ventilation and chamber protection goals.  

This project represents one more small step in the life of a couple of van DIYers.