The Midlana archives are now complete, containing every post and picture back to the beginning.
The Midlana archives are now complete, containing every post and picture back to the beginning.
It went pretty well. The first shot is the waxed plug ready to go. The second shot should have a caption of “Who says hot chicks aren’t useful in the garage?” Sorry girls, but you’re only useful as a pattern for cutting the fiberglass and carbon plies. When it was all said and done, I give the first part a “B+”, pretty good though I forgot to angle the plies so it more easily bent around the sharp back edge corner of the roof. As a result I had to clamp the plies which of course glued my clamp to the material. It was fun trying to remove it without cracking anything but eventually succeeded. The good news is the goofs are functionally harmless though I know they’re there. The foam plug was removed very easily thanks to the wax and in fact about a third of it came out intact. The end product still needs some work to prep it for paint but it’s very usable. A big thanks to Dave for instilling his years of composite experience and trying to keep me from going too far wrong, and the next two parts should go much smoother.
After the first piece was done it was on to the second, which required some thought due to how I made the “sort-of” plug. That is, the plug isn’t exactly that; parts of it are permanent and other parts are expendable, due to my inexperience. After staring at it a while, it can be used as-is but doing it over it would have been done differently, albeit ending up with the same product. The “icing” (epoxy and micro) is on the parts which either stay or get hollowed out, and the parts of it without will be dug out more to allow the inside surface composite layer to flow out to the outer layers. Pictures as it progresses.
In other news, one of our koi fish died so I bagged it, tied it up tight and put it in the trash can. That would have been fine had it not been for our hot weather and the smell was something that has to be experienced. I needed to get rid of it so went to put it in the truck and just reaching into the trash can was enough to imprint the smell into my clothes, nearly as strong as a skunk – ewww. Anyhow, I’m sure the shoppers at our local shopping center appreciated me putting it into the trash can in front of the grocery store…
The 2009 archive has been added – I’m slowly working my way back.
In other news, when a company does something I consider uncool*, my inner child can’t help but poke at them for payback. Their recent announcement of a product that displays CAN bus data provided just such a chance. The idea was good but they used 7-segment LEDs (remember those?) to crudely display alphanumeric values. That’s what us electronics hobbyists used back in the 1970s before there was anything better, so I posted on their forum, “I feel like I’ve gone back in time 40 years seeing that display.” I must have hit a nerve because they deleted my post.
On the composite front I have the epoxy, mixing containers and fiberglass cloth, but also ordered some carbon, so in preparation of that arriving, the mold plug was sanded and the first layer of release wax applied. Apparently it’s kind of a big deal because right on the can they strongly recommend something like 5 coats. Good thing I checked because there’s at least an hour for each layer to dry.
*I took offense because after telling the manufacturer that my car is 100% road legal, they thought I was lying and don’t want their name used. If you care you can figure it out by searching.
The third and smallest subassembly was completed, connecting the inlet duct to the intercooler assembly proper. Several pictures show the overall flow – I’m pretty happy with how the three turned out, somewhat subtle yet all-business (granted, a lot of finish-up work remains on them).
The second-to-last picture shows how well imperfections show up with the good lighting. All of this was corrected by simply using my figures, more on that below.
I’m trying something that might work great – or might not. Instead of following advice from composite experts, I’m going to: smooth out the foam plug, coat with epoxy/micro, let it cure, sand smooth, coat with mold release, cover with fiberglass. The theory is that the epoxy/micro will fill the voids in the foam, resulting in a much smoother inner surface when the foam’s removed, which the mold release will theoretically allow to just magically happen. Guess we’ll all see how well this works.
I’m debating whether to: treat the foam/roof panel as a surface upon which to lay-up the fiberglass, then pop the finished parts off the roof for finish-up work, or lay it up permanently. I started with the smallest (and least visible!) subassembly and plan to pop it off for cleaning after it cures. The inlet section though is more challenging because of how I made the plug – perhaps incorrectly in hindsight. Some of the foam is (or was) intended to be become a permanent part of the final assembly, specifically the foam ahead of the inlet proper, along with the stiffening ribs. This type of foam isn’t structural – it’s very delicate, just running your finger across it visibly removes material. It’s great for forming and finishing, not great for bearing any weight; in fact it’s why the assembly can’t be vacuum-bagged because the 15 psi of air pressure will completely collapse the foam (pretty proud of myself for figuring that out before finding out the hard way)! Meh, a solution will present itself one way or another.
Oh, and I’m using slow-cure epoxy so I don’t rush. I’ve used fast-cure and they aren’t kidding, in a matter of minutes even small batches get warm and it must be quickly spread and the composite applied. The slow-cure allows plenty of time to make sure each layer is in place and any bubbles dealt with. The only downside is that once it’s applied, work on that part has to stop for the rest of the day.
Started in on the third segment of the ductwork which couples the inlet to the intercooler ducts. Also drilled holes into the cage to mount the inlet section – something I should have done earlier but got away with it. After that, the last top segment was epoxied in.
In the last picture, I found something disconcerting with the fishpond filter housing – see it? When constructed 25 years ago it was carefully leveled to ensure an even water level, but now look at it. Best I can tell, gophers dug under it and it’s now settling unevenly. It’s not a huge deal since the whole fishpond, deck, cover, and filter are coming out, but it is something of a conformation that the system as a whole is nearing the end of its reliable life, with everything wearing out at about the same time.
Work continues on the intercooler ducting, which breaks down into three sub-zones: the duct feeding the intercooler proper, the duct transferring air from the top of the roof to the above duct, and the scoop above the windscreen. The theory is that while the shape of the ducting varies as the air moves through it, the cross-sectional area remains fairly constant. The first pictures are show how with heat, the fiberglass board is permanently curved in order to retain a downward curve toward the windscreen without stress. Looking at the later pictures, visually, the inlet part of the duct may need to be widened with a gradual upward bend to each side, rather than it just jumping straight up out of the panel. The last picture shows the inlet relative to the windscreen. Earlier, highly-scientific hand testing showed that air coming off the windscreen curves smoothly aft just a couple inches above the top edge, so the inlet was placed above that threshold to catch strong flow. The metal pieces are just weights to keep the panel flat while the epoxy sets up, to preload everything with where it’ll be once screwed down.
The tough part (for me) comes later when the fiberglass goes on, with its wrinkles, bubbles, bumps and low spots that suck up all the time trying to pretty it up in preparation for paint.
Here’s progress on the intercooler duct. The 36″ x 72″ red fiberglass board arrived by truck in a 48″ x 96″ cardboard container! I won’t say what shipping was due to embarrassment since I didn’t notice the amount until it was too late. Anyway, the fiberglass paneling helps speed up fabrication – thanks to my brother for the suggestion. Cut to fit, it became the roof* and is flexible enough to follow the tubes down to the windscreen. The front half of the intercooler duct will get built on this and the ducting will drop down below the main roll hoop to connect to the section shown.
The next delivery included a big piece of foam and about 15 hours was spent shaping it. Moldless-construction means once the foam is shaped, fiberglass is draped over it, epoxy is added, it cures, then the foam is removed. As seen, a band saw sure comes in handy, and a die grinder, and sand paper, and sanding blocks, and a hacksaw blade, etc. Doing it over I’d buy thinner material and stack sheets appropriately instead of cutting it from one large piece. What you see here is probably 90% done, complete with a few goofs though they won’t be visible.
So what’s with the shape? A couple things. I learned that the inlet duct should be roughly 25% of the core area, which works out to 3″ wide as seen from the rear. That’s when it hit me, that it could be shaped such that my coveted rear view mirror might still be useful. So far it looks promising, check out the last several pictures. Mostly by coincidence, the intercooler duct lent itself well to having a minimal frontal area right along the rear sightline. The last picture is what I see from the driving position, where visibility goes right through the “waist” of the duct. The last picture was taken early during shaping, ignore the duct’s asymmetries.
Debating what to do tomorrow. On the one hand I’m kind of beat and am thinking of taking a day off and going for a drive. On the other hand I’m making great progress and hate to give up a day. On the third hand, driving tomorrow would be nice since it’s unusually cool here (for the first time I can remember, the first week of September isn’t the hottest), but uf course, cooler weather is good for working in the garage. Since Monday’s a holiday, that’s when all the motorhomes will be clogging the back roads, leaving tomorrow relatively quiet. I don’t know, we’ll see.
*I was right to be concerned about the roof; getting out of the car with it in place is a pain. Still haven’t figured out how to adjust my routine to make it easier.