Homemade Headlight Lenses

[StevenGuthmiller]

After several failed attempts to resin cast headlight lenses & a lot of wasted time trying, I thought I'd go back to what I know.......styrene.

I decided something as small as a headlight lens should not be difficult to form from heated clear sprue. I was correct.

I found a suitable donor lens & made a mold from it in Alumilite mold putty.

Then took a simple piece of round clear sprue, (I'm sure any clear plastic round rod would work) heated the end until very soft & pressed it into the mold.

After a few seconds of hardening, I sawed off the back to the thickness I wanted, gave the back of the lens a quick sand & a light polish to clear it back up a little & viola!

Looks like I'll have all of the headlight lenses I'll ever need for future builds.

 

Steve 

 

[SfanGoch]

Excellent solution and best technique yet, Steve. I'm going to try it with Magic-Sculp since I have a lifetime supply.

[Greg K]

great idea, and looks fantastic.  think i might have some lenses lying around to give it a try.

[StevenGuthmiller]

I'm guessing this technique might work even better by using something harder to make the mold.

Plaster or something along those lines would give you a harder mold to press into.

The softer mold that I used may have a tendency to distort a bit if pressing the heated plastic into it too hard.

I have some quick set drywall mud laying around that I may try. Although this seemed to work ok.

 

Steve

[Ace-Garageguy]

Looks great. Desktop injection molding, sorta. 

[Kit Basher]

That looks great! What did you use to heat the sprue with?

[StevenGuthmiller]

That looks great! What did you use to heat the sprue with?

I just used a candle.

 

Steve

[rsxse240]

As seen above, a candle works well, but make sure not to get to close.  I tried and found that the candle I was using gave of a lot of soot or other impurities that clouded the "GLASS".  I tried again using a heat gun for heat shrink (butane torch with a sort of heat reflector shield thing) and it softened the plastic and left it crystal clear, although my mold was less than what one would consider poor quality, it still turned out a nice crystal clear part.

 

As for mold material, wouldn't plaster or drywall mud be too grainy and brittle?  I had to mash mine in pretty good.  I might consider an epoxy resin mold or maybe JBWeld or some of that 2 part plumber's putty, tamiya 2 part, miliput or any other hard 2 part putty.

 

I have SO MANY kits I haven't built because of the headlights being poorly cast, not clear or otherwise ugly.  This trick is going to be a great motivator for me!  Thank you so much, Steve, for sharing this great tip!

[BigTallDad]

Instead of using a flame-oriented heat source (candle, lighter, etc.) consider using a soldering iron. Consistent, controllable heat!

You can also vacu-form headlights:

 

[StevenGuthmiller]

I hold the sprue close to the base of the flame where there's little chance of getting too much soot.

My biggest issue was with the sprue catching fire before it was melted enough to mold.

I'm also toying with the idea of placing the silicon mold in the oven with a small piece of clear plastic in each mold & see what happens.

 

Steve

[Foxer]

Lenses I used Bondic to cast.

[Deathgoblin]

I've cast them out of clear acrylic before and they turned out well.  Clear epoxy will work too, although it tends to be yellow-ish.

[Can-Con]

I cast all the round lenses on my Warlock with a "crystal clear" casting resin I got at Michaels.

 

[restoman]

I tried this today, using two-part putty as the mold material.

For a first try, it worked out really well and the mold still looks great. Some file work should be all that's needed for some really decent lenses.

I'm impressed!

[StevenGuthmiller]

They look pretty much the same as mine right after molding.

I just saw them off with a razor saw & do a little trimming & sanding.

Another good tip is to drop them back into the mold after you've got them trimmed & sanded to the right thickness & shape & then hit the back side of the lens with a little more heat.

It will slightly "re-melt" the back of the lens & clear it up after sanding.

Saves having to do a bunch of polishing on such small parts.

 

Steve

[Tom Geiger]

 

My headlight problem is on the Dodge Caravan. It's keeping these two from completion.  See the slot?  Looks like a World War II black out headlight!   The lens has the corresponding piece sticking out of the back of it.  Cut that off and the ghost of it is all the way through the lens.  Also, the lens grid lines (just horizontal) are on the back side!   I've tried vacuforming lenses but the shape is a problem.  And once I've sanded the original lenses they lose shape was well. 

[AzTom]

Looks great. Desktop injection molding, sorta. 

Hmmm,  I have a bench top injection mold machine that I have never used.  Hadn't though about light lenses.  

I tried the "crystal clear" casting resin from Michaels with no luck. It would not harden. I sent the company an email and they said my part was too small.  It hardens on heat and there was not enough resin to make it happen. I even tried adding heat but that didn't do it. 

Here is a lens I made from the original chrome lens using the putty type rubber mold. I poured floor sealer, the type you use over acid finishes, into the mold. It takes several fills because of shrinkage. The problem is they are VERY brittle.

[StevenGuthmiller]

Hmmm,  I have a bench top injection mold machine that I have never used.  Hadn't though about light lenses.  

I tried the "crystal clear" casting resin from Michaels with no luck. It would not harden. I sent the company an email and they said my part was too small.  It hardens on heat and there was not enough resin to make it happen. I even tried adding heat but that didn't do it. 

Here is a lens I made from the original chrome lens using the putty type rubber mold. I poured floor sealer, the type you use over acid finishes, into the mold. It takes several fills because of shrinkage. The problem is they are VERY brittle.

It does look good though.

Give this "sprue" thing a try.

You may find it simple & the finished lens is every bit as tough as a regular kit lens.

A larger lens like the one pictured may be a little tougher though, requiring a larger diameter piece of clear plastic.

 

Steve

[restoman]

I'm pretty happy with these...

Got a little carried away with the black wash, but the lights themselves are definitely presentable. I used the chrome headlights from the kit as the base for the mold.

[Greg Pugh]

Mmmmm....pretty cool idea!

[426-Hemi]

NICE work! I got me a dilemma currently, I've got a '78-'79 Dodge truck, with a swept-side bed (straight bed) 8 footer, BUT the bed itself, is missing BOTH tail light lens, anyone got a way to form those? (I'm gonna go digging to see what I might have as others and see if trimming them to fit may work, BUT, I'd like to get them to look as close as the originals, BUT those are long gone (I got the bed used so. the truck its going on is new however, but came with a step-side bed to go to the Little Red Express.

Any suggestions?

[StevenGuthmiller]

NICE work! I got me a dilemma currently, I've got a '78-'79 Dodge truck, with a swept-side bed (straight bed) 8 footer, BUT the bed itself, is missing BOTH tail light lens, anyone got a way to form those? (I'm gonna go digging to see what I might have as others and see if trimming them to fit may work, BUT, I'd like to get them to look as close as the originals, BUT those are long gone (I got the bed used so. the truck its going on is new however, but came with a step-side bed to go to the Little Red Express.

Any suggestions?

If you could get a hold of an original, or something close that you could use to make a mold, you could use this same technique with red tail light sprue.

Problem is, if you have a "left & right" tail light situation, you'd need both to make molds anyway.

 

Steve

[426-Hemi]

Steve,

Thats just it. it is a left & right lens!!!!! As they (that I need) are on a late '70's Dodge straight bed "corner" so......I'm trying to think up a way to make them.... I may have to mill out some clear chunk plastic (Lexan) and polish it and then use clear red on it to get the look..... Don't know yet, unless someone else has a better way!