3rd gen Prius aeromod thread

[BamZipPow]

What are you using to bind the Foamular together?

[Vman455]

Originally Posted by BamZipPow

What are you using to bind the Foamular together?

I wasn't sure what type of glue to use when I started, but after reading around it seemed like pretty much anything would work. I ended up going with Elmer's Probond Advanced, which is supposed to bond to pretty much any surface. So far it seems to be working well.

[Vman455]

Got some more work done on the cargo box today, and it's approaching its final shape.

Mocking up the solar panel:



Then I shaped the top and sides with a surform.





Next up, patch some of the chipouts with expanding foam, smooth with a sanding block, finish the door and weatherstripping layout, then on to fiberglass.

[freebeard]

Fiberglass sounds like a lot of work. Can't you just wrap it with vinyl? Maybe two layers?

How will it attach?

On track for the April road trip?

[kach22i]

Originally Posted by freebeard

Fiberglass sounds like a lot of work.......

On one of my projects because of the complex curves of a layered foam making a tail-cone spinner for my hovercraft fan hub I left the fine weave thin fiberglass cloth off.

I used some micro balloon filler mixed with epoxy where I had to, but most of it was just West Systems epoxy with graphite additive to make it black and glossy (also thickens it).

Sort of a rough and lazy way to do things, but saved a lot of time.

If you want a professional finish and strength I suspect the glass cloth is a requirement.

On my pick-up truck I got the epoxy mix perfect somehow, it was so hard that I never had to change the sand paper on the orbital sander, it just never gummed up. I'm pretty sure that was the epoxy and graphite again (over foam), no fillers. It was a black truck, just figured I'd save some on black primer coats.

My point is, more than one way to do it, but shortcuts will look like shortcuts.

[freebeard]

Two or three Plastidip rattle cans and you could put off the fiberglass work until you're done tuft testing.

[19bonestock88]

I agree about the plasti-dip... could save you some time and get you tuft resting quicker... another positive is that if you went that route you could adjust any deficiencies you found in tuft testing, before you did any glass work...

A caution though, plasti-dip is usually thinned with either xylene or toluene, so go light on first couple coats to help avoid damage to the foam

[Vman455]

Test fit:





After some radiusing of the front edges:





Hucho has some suggestions for mitigating that gap in Chapter 5; radiused corners and a fin down the center gives almost the same drag reduction as a full gap-filling treatment on a trailer. Since this will probably behave better than a trailer, being closer to the body than any trailer could be, I'll go that route and see what it does.

[Vman455]

Originally Posted by freebeard

Fiberglass sounds like a lot of work. Can't you just wrap it with vinyl? Maybe two layers?

Without fiberglass, the foam might be strong enough with resin; without resin, definitely not. It punctures quite easily, which a vinyl wrap wouldn't really protect against.

With two layers of fiberglass, 1/2" foamboard is as strong as 1/4" aluminum sheet, according to an engineer I talked with yesterday (who is building a 240-mph motorcycle streamliner to take to Bonneville and skinning it with foam/fiberglass--it's quite a sight, but with no body yet).

[freebeard]

I was thinking about prior to your road trip and tuft testing, before you commit to the final shape. Only trying to be helpful, not contrary.

It looks pretty good. I'd radius the horizontal edges because otherwise the smooth wake your working for will be disrupted in the last foot. It might anyway, that notch is big enough for recirculation.

The forward facing fins are called Vortex traps on semi-trailers (lower right).



You might put clear plastic vortex traps in the taillight cutout, now that I think about it. Are you going to have turn signal repeaters?