Another round of sanding and filling. Took the car out for a short drive – the plan had been a much longer drive but felt it was more important to get as much done on the composite in the time available. Tomorrow the wife’s back and it’s back to work for me. Overall a fair bit got accomplished.
A great deal of composite work is preparing the surface for paint. Shown are some of the touch ups; Bondo wasn’t used because it dries harder and the softer still epoxy/micro gets sanded down more, resulting in a donut-shaped depression around a high spot. The plan originally was to let the epoxy set up while Midlana was taken out for a drive. Nature laughed and sprung some much appreciated but unexpected light rain on us, so Midi came in to keep me company and to see where all the times been going not spent on him. With car stuff done for the day, attention turned to researching how the koi pond will be redesigned. Midi has his own chair right behind my PC chair and periodically taps me on the shoulder letting me know he needs another tummy rub.
The last section is finally complete, well, laid up at least! It feels good to be done with the lay-up chapter and move to the next phase – smoothing the surfaces for paint. I may switch to Bondo for that, for cost reasons, a faster cure, and not having to worry about glass micro balloons floating around the garage. As the last picture shows, when working with composite, scissors become consumables, unless they sit in a jar of acetone.
In other news, a Locost builder who had spent many years constructing his chassis only now discovered that his chosen seats wouldn’t fit and that his offset differential requires the center tunnel to be widened. I felt sorry for him but at the same time wanted to reach through the Interweb and dope-slap him. It amazes me that any builder would assume a chassis will blindly fit any seats and any drivetrain. No, all non-negotiable parts (engine, tranny, rear axle, seats, pedals, etc) need to be on the build table first and the chassis built up around them. Being three-dimensional objects it’s very difficult to accurately measure them beforehand and having the parts in position absolutely guarantees this sort of thing can’t happen.
Bah, it took all day to sand the plug so there was only time for two coats of wax before the day was over. This type of composite construction doesn’t technically require a smooth surface on the plug – which becomes the inside of the final product – but because I know it was rough it was smoothed down any way just because. There are still small low spots sprinkled about but they’re gentle and unlikely to affect airflow.
After applying the second coat of wax, the car was taken out – it was nice to drive her again! For the first time in over a year, gasoline was added, diluting the ethanol roughly 50/50 just to see how it ran. It should have run fine but even with an ethanol detector it was good to see that it still does no problem. There are plenty of back country destinations around here that don’t have ethanol* so it’s nice to know the car handles either. Also, 85% ethanol (“E85” around here) cuts fuel mileage by about a third, a significant dent in range, so knowing gas works is reassuring when low in the middle of nowhere.
*I don’t understand that lack of availability out there, the desert attracts all kinds of people with crazy off-road vehicles and the higher power ones run on E85 – which owners have to transport from home. Why the small towns out there don’t take advantage of that I don’t know. Instead, E85 pumps show up here in larger towns where it’s great for people like me, but makes zero sense for anyone else, short of those wanting to “buy American” at a premium, since it’s not cheap enough to make up for the decreased range. I suspect there’s some sort of kickback thing going on with stations to install them because the only cars I ever see at the pump are one strongly suspected of running tweaked engines. It’s always fun to ask the STi and Evo owners about that and listen to them swear they’re stock. Of course they are 🙂
Coated the foam plug of the largest section. Tomorrow it’ll get sanded then covered with mold release wax, though how long that’ll take depends how smooth the surface turns out, and how long each coat of wax takes to harden. If time is short then the first two sections – also coated today – will be sanded to see what’s what, or said another way, to see how many go-arounds of epoxy/micro and sanding might be expected before it’s deemed smooth enough to paint.
With both sections set aside to cure today, the car was warmed up (for the first time in a long time!), then an oil change done with full synthetic (mineral-based oil was used for break-in). The car was vacuumed out to remove as much foam dust as possible because I don’t want it blowing into my eyes while driving (never mind inhaling the stuff).
The last picture is a used “magnehelic” meter I picked up off ebay. It’s a very sensitive (1″ H2O) meter for measuring pressure differences, useful for testing airflow in ducts, intercoolers, radiators, but especially for determining proper placement for vents, measuring diffuser effectivity, airflow around wings, all sorts of interesting goodies 🙂
Ordered enough fiberglass cloth to ensure stock for the last and largest subassembly. There’s enough carbon already on hand that should suffice for stiffening the larger surfaces (by the way, when fabricating, curved surfaces in composite or metal are much stiffer than flat). Expect a lot of progress over the next couple weeks, and after endless sanding, it’s on to paint!
In other news, Lulu is running a 30%-off sale through 24 Oct, code “OCTHIRTY”, book links: coil-bound and regular-bound. Lulu doesn’t notify authors when they have these promotions but I try to pass them on when I see it.
Spent the day touching up the two front pieces to get them ready for a thin layer of epoxy/micro – a layer easily sanded in preparation for paint. Part way through that I figured the middle section should be riveted on as part of becoming a permanent assembly, so that was done. Then I figured there’s no point in fully prepping the front sections with the intercooler section still sitting there in foam.
First up was making a proper aluminum frame that’ll become a permanent part of the assembly, a frame so I don’t have to worry about the attachment points tearing out for whatever reason. It also allows a close tolerance on the fit-up between the composite and intercooler to minimize leaks. With that done, the foam was pushed into place and (not shown) a few areas had epoxy/micro added to bond the aluminum to the foam for now.
In the last pictures is this little guy I found at work – “little” being relative because a praying mantis is really big for a bug at about 3″ long. It was really cool how how his head could turn just like a person’s and it was intimidating how he’d turn his head and track my movements. In this picture he’s looking at the camera upside down.
If you’re thinking about buying the Midlana book, or hinting about it for Christmas, Lulu has a special offer right until Oct 17:
25% off print book and calendar orders equal to $100 or greater, plus free mail or 50% off ground shipping!
Use Code: FALLBOOKS25
This is an especially good deal because it includes free shipping, effectively lowering the price even further.