Plug Making Help - specific question

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#1

I’m making a plug for a carbon fiber headlight delete panel for a Mazda RX-7 autocross car. Its my personal car, and my second composites project. Last winter I made a carbon fiber sunroof delete panel, which saved 20 lbs and looks great.

Where is what I’m planning so far. I made a wood base box, which includes an angled surface. The angled surface matches the mounting surface which I’ll attach the headlight delete panel to. I plan to mounting the factory headlight cover (has pop-up lights) to the wood base panel, at very specific distances from the base panel. This will set the height of the delete panel and thus ensure alignment with the hood, fenders, and bumper when installed.

So I’ve done quite a bit of measuring, and have all the angles, and distances that I need to set. I’ve got some pictures which show the cover panel setup where it needs to be.

Pics:

IMG_7416.jpg by Kevin_Doe, on Flickr


IMG_7418.jpg by Kevin_Doe, on Flickr


IMG_7419.jpg by Kevin_Doe, on Flickr

The sides needs to be filled in, so I can make a mold from this plug. So here is my question. How would you attach the cover panel to the wood base, and hold exacting dimensions? Then, what would you use to fill in the sides. The mounting needs to be rigid enough to withstand some shaping of the sides, and sanding to make the plug look very nice.

I’ve thought of hot glue and several dowels but that seems like it would be difficult to get the dimension right and wouldn’t be rigid enough to hold it in place while I’m filling in the sides and sanding.

I’ve thought that tooling dough may be nice. I could build up quite a bit of the tooling dough and then press the headlight cover panel down into the dough until I’ve got the dimensions and angles correct. Then shave/scuplt the overflow down to get the side “walls” correct, then let sit till cure. I’ve never worked with tooling dough. Will it be thick enough to hold shape w/o sagging or “flowing” till it’s cured? Any thoughts about this idea?

I’m looking for some ideas, so please let me know your thoughts.

Thanks!

#2

I think I would epoxy the part to the wood. Thickened probably.

The problem with tooling dough is that most the manufactures have a maximum thickness of 1/2-3/4", they don’t want it to build too much heat during curing. You could probably just maintain the thickness. If you decide to go the tooling dough route I would apply some epoxy between the tooling dough and what ever your bonding to, wood or the part. This will make sure that the tooling dough is securely joined to the adjacent material. I’ve used this method for bonding tooling dough to styrofoam plug for the same reason with good success.

#3

Adtech 323 tooling compound can be used at any thickness above 1/4: without problems. I’ve done 4.5 inches before.

#4

With the Adtech 323, is the consistency thick enough to allow a large lump to be placed on the wood base, and then press the cover plate down onto the lump to the desired height? Would you consider a different approach all together?

Thanks for the comments guys!

#5

Another option would be modelling clay. Does not cure, but can be polished easily.

#6

Hey Kevin, just curious, With this “delete panel” I’m assuming you removing the stock headlights, motors, and not running any lights at all? If thats the case Why not just mount the stock headlight covers with 90* angled aluminum like most of the sleek (evo-r, Re-Amemiya, Rmagic etc) do?

If you’re doing this for the fun of a composite project thats cool, but it just seems like there is easier/cheaper options to achieve what you’re going for so I’m just curious if I’m missing something…

looking forward to following another one of your projects either way!

#7

Yes, I have removed all headlight related parts in the car. The only part that remains are the wires for the headlights and brights. I left those in the car because I plan on making a LED headlight solution in the future.

I thought about just bracketing the stock covers to the car, but I don’t like that sort of halfway done looking stuff. I’m really looking forward to a composites project this winter. I’m excited to incorporate everything I learned from my sunroof project. Should be super light.

I also plan on keeping the plug, in case I want to try some other variations (to potentially mount my LED headlights in), or NACA ducts, or whatever else I may dream up. I pretty much never drive the car in the night, or winter, so I’m not too concerned with having functional lights.

I like the idea of modeling clay. That would be easy enough to form under the headlight cover. Maybe do clay for the center, then tooling dough around the edge so I have a solid surface to do the body filler/smoothing work to. Thanks for the ideas guys, keep them coming!

#8

I understand the bracket look isnt appealing to some… This maybe thinking too far ahead, but how will these be mounted? I’m curious as i loved your solution for the sunroof delete =)

(Plus i’ve followed your build on rx7club and you do some great work =))

#9

Here is what I came up with. It worked great.

I traced a line down to the surface. Then glued a strip of square dowel rod down to wood base with high temp hot glue. Then I glued in the “walls” also with hot glue. I’m using high temp hot glue, and this stuff really works well. The piece is very solid, and its super easy to do.

IMG_7422.jpg by Kevin_Doe, on Flickr


IMG_7423.jpg by Kevin_Doe, on Flickr

Now I’ll just apply some body filler to smooth everything out, shouldn’t be too bad. Thanks for all the help.

#10

Crafty idea Kev!

I really like that and will be using it myself soon, excited to see your progress with this!