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.
“Composite Dave” corrected me on a couple things.
One, there’s no requirement to use one sheet of a layer; using smaller pieces and overlapping them by 1″+ is perfectly reasonable, especially for something which isn’t hardcore structural in nature.
Two, he warned me about painting composite a dark color, where sitting in the sun can cause the epoxy to soften. Not enough to melt exactly, but enough that it can slowly flow/bend/sag if there’s a load on it, taking a set in a different shape once it cools. For this reason I’ll go with the lime green, which is okay by me 🙂
The forward section is done. As with the middle section, it’s not perfect but “pretty good”, with not too many goofs. The first picture shows the unfortunate-but-necessary pattern orientation, necessary so the strands aren’t asked to bend sharply around corners. Orienting the pattern at 45 degrees to the weave cuts the bend angles in half but with the unfortunate side effect of it being more wasteful of material due to the fairly narrow width of the composite roll.
There’s still work to be done (on all pieces), consisting of a thin coat of epoxy/micro, finish sanding, then paint. That decision is a ways off since the rear piece is next in line. Due to the amount of composite needed I may stick to fiberglass for this one; I’ll have to see how much is left over and whether there’s enough for at least one layer and preferably two.
The color of the ductwork hasn’t been decided. Dark green to keep it low-key (but dark paint shows surface imperfections), or lime green to make it more of a feature but risk making the car look more visually top-heavy? Weigh that against a bright color up high aiding visibility to other cars and being more forgiving of surface imperfections. The only reason the flat black is on there is that it was a spare can of heavy content filler and I was keen to see what it looked like without the oddball colors it had previously.
So me and my dog-buddy Midi, our 60-lb Pit/Lab, were on our regular walk. For the first time ever it went slightly wrong because on the way back, an 80-lb dog ran across the street and immediately started a fight so I let go of the leash (I was bit the last time I got in the middle). In general, dog fights don’t last long though it sure feels like it, ending as soon as both understand the pecking order. What was odd was how they then just stood there next to each other contemplating the outcome. The dog took off down the street so expecting the worst I checked over Midi but he was fine and surprisingly calm, like nothing had happened at all. The owner walked out to see what was going on and was very embarrassed to find that his dog got out by accident. It all turned out fine, all things considered.
The epoxy showed up so there’s nothing stopping good progress this weekend, assuming our current earthquake swarm out here at the south end of the San Andreas Fault isn’t a precursor to anything larger…
Finally added a Contact page to the main page of this site.
So I ordered more epoxy, a gallon of that and the hardener is $137. But wait, there’s more, in the form of $47 for hazardous shipping and $11 for tax, for just short of $200, or said another way, the product comes with a 43% overhead expense. Just, wow. Yes I know I’m whining about unimportant things, yes I know other people have much bigger problems, and yes I know this falls into the “first-world problems” category, but still, wow.
I know, I know, always bitching about something…
At least I have enough composite for the next section, but we’ll see if there’s enough for the last and largest section.
Spent about 6 hours sanding the the front portion of the ductwork (and ground down several of my fingernails to a shocking degree). The front section is being handled differently than last week’s center section; this “plug” being a permanent part of the finished product so it won’t be coated with wax… probably. With the epoxy having cured from last week, the “side pockets” were dug out down to the inside surface of the epoxy. This allows the cloth to extend around the lip and into the inlet scoop, bonding to the outer skin and forming a sandwich, which is far stiffer than a single layer. The foam I’m using isn’t technically structural (it’s very weak in compression) but it doesn’t need to be in this application.
A pattern was made and a layer of fiberglass draped over to see where the seam should go since the assembly needs two pieces due to the inlet. That’s as far as I got today because laying it up is an operation that once it’s started it shouldn’t be stopped. Also, with the pattern defined I can see whether there’s enough cloth and epoxy; running out of either part way through would trouble.
I included a couple pictures of the rear section and the air cleaner because I’m wondering how much the air coming through the duct gets heated as it passes through the intercooler. It’s sort of tempting to have the air cleaner draw from that same duct since it’s right there. The interesting thing is that under full throttle, the engine sucks in so much air that it would actually increase the cooling air flow through the intercooler. It would be warmer than ambient by “some” amount, but that might be made up for by pulling more air through. Something to think about.
During our errands we saw an old and new Mustang nose to nose. Seeing them side by side, the new one look both bulky and large compared to the first generation. As good as the new ones are, the original has a timeless shape.
Speaking of Mustangs, I happened across this video of a trackday held yesterday at Willow Springs. The reason I mention it was that in watching all the cars heading out onto the track, it was interesting how much has changed since my brother and I did this back in the 1980s. Back then, probably 90% of the drivers drove older cars which they worked on themselves. Watching the video, it’s pretty clear that percentage is more than reversed; probably less than 5% do their own work (Mustang owner included). Of course, what is there to do? Go buy a Ferrari, Porsche, BMW, Lotus, or Corvette, and you’re good to go. I can’t help feeling that we’re losing our familiarity with things mechanical. That’s driven home where if one of these cars has trouble, the owner just pushes it into the enclosed trailer and drops it off at the shop Monday morning. I guess it’s neither good nor bad, it’s simply the new normal.
This is the first time in my career that I’ve felt really stressed – enough that I thought how unhealthy it was. Coincidently, a Midlana builder mentioned that he’ll be making much faster progress since he retired this week. That brought to mind the topic which has been bouncing around in my head, rising to the surface more and more frequently as I approach “that age.” As I’ve said before, it’s that impossible series of questions: how long might I live, how much is needed for retirement, how many good years are left?
I’ve seen articles where elderly people are interviewed, asked if they have any regrets. The responses the writers like to tout are things such as “I’m glad I retired early”, or, “I should have retired earlier.” It was then that I realized that the writers are unwittingly introduced their own confirmation bias because of where they’re drawing their data from – nice retirement homes. By definition, the residents pay a small fortune to be there, so money in retirement – for them – is a non-issue. I wonder if the writers’ conclusions might change had they interviewed the elderly living in cardboard boxes next to freeways or in broken-down trailers in the desert. As I get older, I see more and more biases in reporting and it makes it hard to know what is fact.
I recently switched to a Google Nexus smartphone, mostly to get away from ATT’s ridiculous monthly fees. I was well aware that I was hooking into Big Brother, where Google now knows a lot more about me, what I do, what I visit, where I am, and as a coworker joked, “and now they have your fingerprints as well.” It’s not all bad and when it all works it’s pretty cool. For example, unprompted, the phone knows when I’m leaving for work or home and tells me how long it’s going to take to get there. More impressive was how accurately it translates voice mail into text, though I don’t see the point of doing so. Then there’s the voice interface, where much like Apple’s Siri, you can ask it just about anything. Playing around with it, I asked it to navigate me home and it started playing a podcast I had previously downloaded and couldn’t fine – so it’s a mind reader to, but still a bit confused about priorities.
In related news, I was working on the website and had to sign into my provider’s site. I guessed wrong on the password and could suddenly no longer access the website or the forum from this PC – but only this PC and only the Midlana site. After much fussing about I went into the router software and by coincidence it said an update was available. I figured why not and upgraded, and everything started working again. Yeah it’s fixed but I don’t know why, and the next time it happens, if there’s not a upgrade to purge the problem, then what? Yes, I tried rebooting the router first but that was unsuccessful.
There’s a saying about insanity: “Doing the same thing over and over and expecting different results.” I think the converse is more true: “Trying the same thing and always getting different results.”
Between the heat and work, nothing was done this week. We’ll see if tomorrow is more productive, but being on-call means never knowing how the weekend will pan out.
Oh, one thing I’ve thought of implementing is the dash-mounted knob. It was originally added for traction control but I’m not feeling compelled to set that up because traction is really good above second gear even at max boost thanks to the rear weight bias and sticky tires. A couple times the knob has been used when calibrating the boost control solenoid; the knob adjusting the duty cycle and noting the resulting boost. That’s done now so the knob is currently unused. The thought is to make boost adjustable per the knob instead of by gear. When I feel like a 16-yr old hooligan it can be set to 20 psi, spinning the wheels for dramatic effect. When just cruising around it can be set to as low as 7 psi. Another perk is that, say I get a bad batch of fuel. Granted, the knock sensor should catch it but it would be nice to be able to cut boost way down if needed. Another fringe cause is driving on a damp, wet, or sandy road; no point in having 4-500 hp on that. It’s free so I might set that up for fun; it’s easy to put back to boost-by-gear.
Lastly, I get annoyed when I read people’s car blogs and find instead of car content, they often go on and on about their most recent medical issues. I then realized I’m doing much the same, just not about medical concerns – at least not until I start having them!