Updating (backdating?) the TJ grille

bedhed

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I'm with Chris on this one, I think either one would look good. For some reason though, the one with the turn signals in the grill look a little better to me.

Not to derail your thread though - I think the CJ grill looks awesome on those custom fenders.
x2 with that. Man, that looks really good.
 
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jscherb

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Were you ever able to get the MB fenders to production?
Almost. Here's the story on them... around the time I decided to build them, I met Tom Troll at SEMA - Tom was a founder and the CEO of Kentrol. Tom and I became friendly and I visited Kentrol several times to see Tom. On one of those visits I showed him concept drawings of what I had in mind, and he instantly said he wanted them (at the time Kentrol was a manufacturer of fiberglass parts). I asked him for a set of their MB fenders to use as starting patterns for the mold masters and he readily agreed. I took the MB fenders home, made the TJ mold masters and delivered them back to Tom. Shortly after I delivered the mold masters, Tom decided he wanted to sell Kentrol and retire. Since their fiberglass business wasn't as profitable as it used to be, he decided to shut that part of the business down in preparation for selling the business. I visited him after he made that decision and I took my mold masters back - they had already started making the production molds but hadn't quite finished yet. So they almost became Kentrol products and would have had Tom not decided to retire and sell the business. Since then I haven't done anything with them.
 
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jscherb

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I think I'd move the headlights a little closer to the center and maybe widen the slats in the grill (1/8" each?) to make the openings narrower.
I've designed this new grille as an overlay just like the factory chrome grille overlay, which means it installs over the factory grille/core support. No sense recreating the entire core support when an overlay will do the job just as well. But being an overlay, the headlights need to be in the factory location so I couldn't do what you suggest.

By doing it as an overlay, it's a pretty easy install and a very easy piece to mold.
 
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jscherb

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X2 on all of that. For the turn signal enclosures you added to the lower-right grill (my favorite) the OE JK turn signal enclosures are ideal. They have the right proportions and accept the factory turn signal bulb enclosures without any modification.
Any way to make the turn signals a little bit larger like the original CJ? I'd be all over it if it were. I like the CJ look on the TJ, been wanting to do something like this for a long time and then fill in the signals on the fenders.
I like that idea too. Maybe use the Crown or Omix-ADA CJ housing for it?
The way I've designed the mold, grilles with any size or type of turn signal (or no turn signals at all) can be molded. The recesses for the turn signals are done with mold inserts, so to make a grille with no turn signals, no inserts are put in the mold. To make a grille with recessed for JK turn signals, the appropriate size inserts are put in the mold.

Last year I made a JL-style grille for the JK and I did the mold the same way. This photo shows a pair of those grilles, the one on the left has recessed for JK turn signals and the one on the right has recesses for slightly smaller LEDs.

Grille3Lit1_zps0p8b6fzy.jpg


Grille3Lit4_zpspwreo004.jpg


So with the mold I'm making, any of the above are possible.

BTW CJ turn signals are basically surface mount, they don't need recesses. They mount on the surface and only require a hole behind the turn signal for the back of the housing to go into, so for a grille that will have CJ turn signals installed, what gets molded is a grille with no turn signals and holes are made for them to sit in.

Here's a CJ turn signal posed in front of a factory TJ grille BTW.

CJTurnSignal_zpslvcfkqzm.jpg
 

bedhed

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I think the larger CJ housing looks great. I'm guessing this next idea would require a second mold, but I think it would look good to add in a slightly raised area for the turn signals, like the CJ grill. Have it looking like it's supposed to be there, instead of just being surface mounted. That's nitpicking, but it would give it a little extra touch for the CJ look.
 

scottgraham

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@jscherb Thanks for the response, I remember reading that somewhere before. Was just curious as to if anybody else picked them up since then.
I'll prb make steel ones.
Thanks again!
 
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jscherb

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I think the larger CJ housing looks great. I'm guessing this next idea would require a second mold, but I think it would look good to add in a slightly raised area for the turn signals, like the CJ grill. Have it looking like it's supposed to be there, instead of just being surface mounted. That's nitpicking, but it would give it a little extra touch for the CJ look.
The CJ grille is perfectly flat, there's no raised area. This is a photo of a CJ-7 grille, you can see it's flat with a simple hole that the back of the turn signal housing goes into. The hole is 3 5/8" in diameter. The rim of the turn signal is larger than the hole so the turn signal basically surface mounts over that hole and is held in place with two screws, the holes for which are visible in this photo.

A CJ turn signal can mount on any flat surface that's large enough for the outside diameter of the bezel and has a 3 5/8 hole.

CJTurnSignalMounting_zpszrz8rhue.jpg
 
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bedhed

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The CJ grille is perfectly flat, there's no raised area. This is a photo of a CJ-7 grille, you can see it's flat with a simple hole that the back of the turn signal housing goes into. The hole is 3 5/8" in diameter. The rim of the turn signal is larger than the hole so the turn signal basically surface mounts over that hole and is held in place with two screws, the holes for which are visible in this photo.

A CJ turn signal can mount on any flat surface that's large enough for the outside diameter of the bezel and has a 3 5/8 hole.

View attachment 140316
Ah! Okay nevermind. I was thinking it was raised a little.
 
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jscherb

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I'll be happy to show all the steps it took to make the mold for the grille if people are interested, but for now I'll just jump ahead in the project a bit in this post. This is the "mold master", the part used to make the final mold from.

MasterClearcoat1_zpstjgs72jk.jpg


MasterClearcoat3_zpskvbsiff3.jpg


And this is the mold made from that master. It's been prepped with mold release and it's ready for a grille to be molded in it.

GrilleMoldPrepped_zpsiapk0iuo.jpg


You'll notice that there is no provision in the master for mounting turn signals. I did this so that the same mold can be used to make grilles without turn signals or with recesses for turn signals. In the photo of the mold above you can see gray disks in the mold, these are removable forms for making turn signal recesses. To make a grille without turn signals these disks are not inserted in the mold; if they're in the mold the result will be recesses for mounting turn signals in. Different size inserts can be used - they could be sized for JK turn signals but in this case they're sized for sightly smaller lights.
 

Fouledplugs

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I'll be happy to show all the steps it took to make the mold for the grille if people are interested, but for now I'll just jump ahead in the project a bit in this post. This is the "mold master", the part used to make the final mold from.

View attachment 140378

View attachment 140379

And this is the mold made from that master. It's been prepped with mold release and it's ready for a grille to be molded in it.

View attachment 140380

You'll notice that there is no provision in the master for mounting turn signals. I did this so that the same mold can be used to make grilles without turn signals or with recesses for turn signals. In the photo of the mold above you can see gray disks in the mold, these are removable forms for making turn signal recesses. To make a grille without turn signals these disks are not inserted in the mold; if they're in the mold the result will be recesses for mounting turn signals in. Different size inserts can be used - they could be sized for JK turn signals but in this case they're sized for sightly smaller lights.
I would love to see the steps you took to get the mold.
 
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jscherb

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Since you guys won't let me get away with skipping to the end, here are the steps for making the mold master and mold :).

The goal of the mold master is to be a perfect replica of the final part to be made, usually with extra margins around the edges to facilitate molding and later trimming of the part to exact dimensions. My goal for this project is a grille overlay that exactly fits on the factory grille and looks like it could have come from the factory. It will have wider slots that intersect the headlight buckets.

I want the wider slots to look exactly like the factory slots, only wider. The way I decided to do that was to make a mold for one wider slot and then use that mold to make seven identical slots.

Starting with a factory grille, I masked off two slots and prepped them for molding.

SlotMasterMoldRelease_zpso50tf0cx.jpg


I shot the unmasked area with gelcoat:

SlotMasterMoldGelcoat_zpsbw1gpisk.jpg


And the laid up several layers of fiberglass:

SlotMasterLayup_zpse2z87dcm.jpg


Once everything cured, I popped the molded slots off the grille and removed the masking:

SlotsPopped_zpsgygz9pyf.jpg


What I've got now is a reverse of two slots. The bottom of the slots is a little rough because I closed the slots off with masking tape before I molded them, but that's fine, I'll fix that in a later step.
 
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jscherb

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Having the slot mold, I proceeded to mold seven of them. The process is the same for all molding - mold release wax, spray PVA mold release over that, apply gelcoat (for these small parts I used a brush rather than spraying the gelcoat) and then laying up fiberglass. Here's one with fiberglass laid up on it.

SlotMolded_zpszeiet5gq.jpg


Here's a slot immediately after popping it off the mold. It's green because the PVA mold release sticks to the part rather than the mold. PVA is water soluble, so it washes off the part.

SlotPopped1_zpsoq0ymy4r.jpg


Partway through, here are 4 slots, they've had the rough edges trimmed off and the mold release washed off.

4Slots_zps43kp1p9w.jpg


All seven are now molded. Also in the photo is a printout of the new grille design, I do drawings for everything I build and use them to guide me during construction.

AllSlots_zpshj3fcdno.jpg


All seven slots are the same; the outer two will need to be modified in a later step to curve to match the headlights.
 
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jscherb

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The next step is to assemble the two slots into one wider slot, so I cut one side off each one and epoxied them together side-by-side to arrive at the new width. It's pictured next to the factory grille so you can see that the new slot is wider.

SlotMoldAssembled_zps5b7cp2ug.jpg


I fixed the rough bottom of the new wider slot with body filler and gave it rounded edges (fiberglass doesn't like to conform to sharp edges) and shot it with clear.

SlotMoldDone2_zpswsczthdx.jpg


The finished wide slot mold. It's got a uniform smooth surface; the different colors underneath aren't important.

SlotMoldDone_zpsoo4exajv.jpg
 
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jscherb

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Next I need a grille to splice the slots into. Because I plan to make this as an overlay, I started with a factory overlay:

Overlay_zpsj9anmrlq.jpg


I don't want the factory slots, so I used double-sided tape to cover the slots with a layer of thin aluminum sheet.

OverlayMoldPrep_zpsx5sfvplx.jpg


I then prepped it with wax and mold release, and made a mold. The masking tape around the edges is to give the master more margin so the mold can be larger than the final part.

OverlayPrepped_zpsnbewptsx.jpg


Skipping a photo of the gelcoat applied, here's the no-slot grille after fiberglassing.

OverlayMoldLayup_zps8anx23v8.jpg


And once it cured, this is the resulting mold.

GrilleBlankMold_zpsbyxxkkwa.jpg