Designing a tail extension for the first-gen Insight

[3-Wheeler]

Originally Posted by jimepting

...I know that fiberglas cloth/resin needs support to hold any shape while hardening. Therefore, it must be laid down over some sort of full support. I also know from personal experience that resin is not compatible with styrofoam. I have tried to mix it in syrofoam cups and it just disolves the cup. A while back I discussed this with someone in the ecomodding community who indicated that this problem could be sidestepped by painting the finished styrofoam shape with a water based latex paint before fiberglas overlayment. No direct experience, but I've heard it....

My vote is for foam/fiberglass.

For a method on how to do this, please look here....

http://ecomodder.com/forum/showthrea...els-10638.html

Last summer was spent making under body smoothing panels.

Using styrofoam, the steps are something like this:

1) Place hard mounts on the frame.
2) Start gluing bits and pieces of foam to the hard mounts.
3) Get the entire shape done with adequate support.
4) Remove the panel, and using epoxy resin, wet out the glass on the top side of the panel. This is the side that touches the car frame.
5) Place Saran wrap over any portions that touch the frame, then mount in the usual fashion. Think of Saran wrap as a peel-ply layer that keeps the wet resin from sticking anywhere it shouldn't.
6) Mount the panel back on the car and allow to setup.
7) Remove the panel and the Saran wrap and inspect. There still might be areas that stick and you will work carefully to get the area unstuck, with any thin objects that can be slid into position to break the glue bond.
8) Glass the other side of the panel, and place with the wetted area facing up, and let gravity do it's work.
9) There may occasions where you need to vacuum bag something, but if not done properly, the vacuum bagging process can distort the shape, and make a useless part.

The comment about resin and styrofoam not being compatible needs to be put into context. Polyester resin will attack styrofoam. It's the stinky stuff, and less costly.

Epoxy resin, such as West System will not attack styrofoam, and in fact is compatible with it. So is covering the styrofoam with Latex outside house paint first, then laying up the glass with Polyester resin. Just make sure all surfaces are covered with the paint first, or the Polyester resin will eat the foam.

You're correct in stating that fiberglass needs to be supported properly, for a good layup. The styrofoam itself actually works to make this happen. Assuming the foam board is thick enough for the task, laying the fiberglass cloth on the board and wetting the glass, will make a very good part, with hardly any flex during the hardening process.

You can use whatever you need to keep the panel in a neutral state while allowing the glass to setup and harden.

Hope this helps.

Jim.

[jime57]

Thanks Jim for that information. After I posted I did some EcoModder searching and realized that much of this had been covered before right here on our site in earlier discussions. I found your post very helpful. I'll not waste more "bandwidth" on materials, unless I come up with something both practical and reasonably inexpensive

Jim e

[jime57]

Originally Posted by COcyclist

jimepting, will you take the tail off the car and stand it up to fiberglass it or does it need to be attached so it doesn't change shape as it cures?

Don't really know yet. Would do some material testing. Best way I think is to shape the tail while installed on car and lay up the outter layer on the car.

I'm beginning to realize I have a serious problem with the whole thing. Wife and I travel extensively by motorhome. The Insight front end gets bumped up onto a car dolly for towing. A boattail is gonna be just that much lower to the pavement and obstructions. If it goes on/off quickly enough, that could be a solution. She wants a used Metro and that would be even better

[moorecomp]

Originally Posted by Tygen1

Those tail lights look like the generic "jeep" tail lights. You can get them at most auto parts stores, maybe even walmart, JCWhitney, Harbor Frieght, etc... They aren't flush mount, just a box that bolts on, but looks like they flush mounted them in this application.

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REAR TAILLIGHT - JCWhitney

[123]

Good information. I am looking forward to seeing how much of an improvement this makes.

[aerohead]

I've had success using Elmer's Glue and also polyurethane as a barrier coat on Styrofoam before glassing with polyester resin.

[3-Wheeler]

Originally Posted by aerohead

I've had success using Elmer's Glue and also polyurethane as a barrier coat on Styrofoam before glassing with polyester resin.

Hi Aerohead,

How about taking this a step further to save more cost...

Instead of using Elmer's glue as a barrier, why just use the same glue to hold on the fiberglass itself, as in this example (about 3/4 down the page).

http://ecomodder.com/forum/showthrea...s-10638-3.html

It's lasted over 15 years so far, as still looks good!!

Might just use the same technique on the tail extension. You never know!!

Jim.

[aerohead]

Originally Posted by 3-Wheeler

Hi Aerohead,

How about taking this a step further to save more cost...

Instead of using Elmer's glue as a barrier, why just use the same glue to hold on the fiberglass itself, as in this example (about 3/4 down the page).

http://ecomodder.com/forum/showthrea...s-10638-3.html

It's lasted over 15 years so far, as still looks good!!

Might just use the same technique on the tail extension. You never know!!

Jim.

Jim,the linear thought progression was too much for my pea-brain! Hiding in plain view,I would have never even thought to just use the glue as resin.
I do like the 'drying' qualities of polyester,where I can continue laminating as rapidly as I can batch and then get into body filler.
But no doubt,short of a crash,a panel or fairing would rarely have to demonstrate maximum compressive strength or adhesion,so the Elmer's obviously is "there" as far a a matrix counterpart for the glass.
That's quite a revelation ! I like it! Thanks for the brain tickle.
I've kept hoping over the decades that I might be able to respect my mind by using it,however,it looks I must consider leaning on others,and their novel ideas to help me along.
P.S. I use the Elmer's Carpenter's Glue,and once it goes off it appears to be fairly immune to moisture.I've experienced Gorilla glue failures and will no longer trust it.

[3-Wheeler]

Originally Posted by aerohead

... P.S. I use the Elmer's Carpenter's Glue,and once it goes off it appears to be fairly immune to moisture...

Hi Aerohead,

Actually Elmers Wood Glue does get affected by moisture later on.

It will soften and come back off, even after a year. It just takes a while.

I found this out first hand with another motorcycle fairing. The fairing got a crack in it, and the spring time rain kept working it's way into the small opening.

Eventually the delamination was enough for me to perform surgery on the fairing and fix the bad section.

I keep close tabs on the current fairing, looking for cracks, which are really obvious and small chips of paint that get knocked off by pea-gravel hitting the front of the fairing.

And the main reason I started using Elmers Wood Glue, is that at the time I had no way to isolate the Polyester resin from attacking the foam underneath. I never heard of Epoxy resin, and with two young kids growing up, probably could not have paid the steep price for it either.

Like you mentioned previously, now we have Elmers Glue, Latex paint, and/or Epoxy resin to allow the usage of Styrofoam in our composites.

As mentioned, Elmers Glue is pretty robust overall. I would have no qualms about using it on the tail extension.

Jim.

[jime57]

Originally Posted by moorecomp

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REAR TAILLIGHT - JCWhitney

Saw these lights today on a Jeep CJ. They look perfect for a boattail truncation panel. They appeared to be about 7 inches high and that puts them is same ballpark as a license plate. Nothing prevents them from being mounted sidewise either.

Pictured is just the replacement lens of course. One might want to find a junkyard CJ and get the entire light. Some sort of cheap yellow sidelight would also be required.

Thanks folks