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MetroMPG 02-25-2013 09:12 PM

Making a durable (removable) upper/lower grille block for the UFO: 2000 Honda Insight
It's coming up on 2 years since I got the Insight. I figured it's time to lose the taped-on plastic, and make something a bit more permanent/durable (but also removable). I've taped and re-taped this thing so many times, I've messed up the paint a little bit.
(Photos from: )

Last time I made a permanent block was for the Firefly (Metro). I made a custom vinyl "bra" for that car:
(From: )

Worked well, and is aesthetically fine since the car is black. But I didn't want to put a black bra on the radioactive-snot-green UFO, and finding colour-matching green material seemed unlikely. Also, closing the upper opening wouldn't be easy with material.

I'm inspired in particular by the quality work CigaR007 did on his Echo:

So I'm making this one out of rigid foam insulation.

Actually, this is my 2nd attempt at using foam - I started work on an expandable foam upper block last year, but abandoned it. I've had no luck with the expand-o-foam approach to building mods. Each time I've tried to work with it, it seems too soft, doesn't shape easily, doesn't cure if you put it on too thick, etc. etc. etc.

I got started this evening. Should have some pics tomorrow.

2000neon 02-25-2013 09:16 PM

Cool! Be sure to post pics, I'd love to see progress and how it turns out.

MetroMPG 02-25-2013 10:17 PM

Step 1: failure!
1 Attachment(s)
Well here's how it didn't turn out, using the old expanding spray foam in a can trick:

Too hard to shape, big voids in the middle, not evenly cured, not stiff. Blah blah blah.

Foam board-based version 2.0 will be much more betterer. Pics tomorrow.

2000neon 02-25-2013 10:22 PM

That's not failure. That is being very successful at finding out what didn't work. :D
The rigid foam your using, is it like styrofoam insulation? Will you be coating it or covering it with anything?

Daox 02-26-2013 09:18 AM

You might have to apply the foam in two or maybe even three thinner layers so it sets up without sagging and falling out like you have shown in your picture. When I did mine it set just fine, but it wasn't any thicker than 1-1.5" thick and that 1.5" was between the slats of the grill. Also, there is nothing stopping you from still using what you have there. Make sure its cured, maybe shape it a little, and you can always add more foam on top of it. It'll stick together.

MetroMPG 02-26-2013 10:46 AM

1 Attachment(s)
Nah, the foam isn't going to work for this part. It's too slow, bendy, soft, messy, nasty, dumb.

Also, I just don't like it. Several attempts at making various parts with it over the last 5 years, much disappointment.

Working the rigid foam is easier, faster, more precise.


The rigid foam your using, is it like styrofoam insulation? Will you be coating it or covering it with anything?
Exactly - rigid foam insulation. (Not styrofoam... more dense. I'll get the name off it later.) I started shaping the parts last night, and it's much better to work with than the bendy, soft, messy, nasty expanding foam.

I'll be coating it with 2 part epoxy (doesn't eat foam).

I'll post up pics of my progress later, after today's session.

Enemy number 1:

Daox 02-26-2013 10:52 AM

Another option is to fiberglass first, then fill in with foam, then fiberglass over the top of the foam. If you fiberglass first, you can remove the fiberglass 'form' and then fill it with expanding foam. The form should be rigid enough to work with. I think if I was to redo my pretty prius grill block I'd go this way. The foam is hard to form and if you want to finish it nice that means lots of sanding and the foam eventually gets squished. If you do it this way, there is a hard backing that will prevent this.

MetroMPG 02-26-2013 10:56 AM

Or you could skip steps 1 through 17 and just use rigid foam board. :P

Blue Angel 02-26-2013 11:41 AM

Ever thought of using some type of modelling clay to make the shape of the insert, then use that to make a mold? You could produce a light weight, tight fitting piece from fiberglass or something similar.

This might be a bit more work than doing a one-off from rigid foam insulation, but the easy sculpting nature of modelling clay might produce a nicer final product. Not to mention, if you screw up with clay you just add a bit of material back on and re-work.

This is how most surfaces are defined in the studio when styling a car, but instead of pulling molds the body is digitized and modeled in CAD.

MetroMPG 02-26-2013 12:46 PM

I have thought about it, but have zero experience with sculpting. (Though I do have a friend who's a potter... maybe she could hook me up with materials & advice...)

That said, these particular parts are pretty simple: no compound curves involved, so the foam board lends itself really well here. A bit of shaping around the edges, kerfing to make bending the board easy, figuring out an attachment method (that's the harder part), and Bob's your uncle!

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