Making Moulded Replacement Lamp Lenses

C

chrisyork

Active Member
A while ago - a long while ago - there was a thread from someone, I think in the USA, who had been making side/tail lamp lenses in a colour of their choice by creating moulds - perhaps latex or similar - and pouring a form of plastic into them to produce new lenses.

I've had a search and can't find it. Can anyone remember this and point me to where it is?

I have a freind in Thailand trying to do the same technique to produce rare/expensive lenses there.

Chris
 
I've done this professionally in the past. (I've been a professional model maker/prototyper for 28 years).

Not with Rover parts surprisingly (cobbler's children... :) )

Normally I would suggest a clear silicon rubber mound in shore 40A hardness. The clear helps you gauge is your part has bubbles during the pour. For a resin I use BJB Enterprises WC782 clear polyurethane resin. (Shore hardness is 82D) it pours nicely, takes transparent pigment well and had very good UV resistant properties.

Things that help with successful mounding include a vacuum chamber to de-gas rubber and resin after mixing (this removes air bubbles trapped) and a heated pressure pot (aka autoclave)

For a vacuum chamber I would suggest an AC serving vacuum pump (some motor factors in the US will rent you one for fixing your AC) and a paint pressure pot. These are the tanks that hold about a gallon of paint and have fittings to pressurize the paint feed to spray gun without a reservoir. I used a drum heater to keep it at around 60°C and would pressurize to around 80psi. Leave poured mound in pot for about four hours then carefully demould the part. Rinse and repeat for more parts.
 
This is interesting. Coincidentally I've been researching casting resins this week, with the end goal of casting a steering wheel rim. I hadn't considered the uv stability. It needs to be the deepest black and able to be fully polished. I had settled on polyurethane I think, one that comes pre tinted black.
Jim
 
chrisyork said:
A while ago - a long while ago - there was a thread from someone, I think in the USA, who had been making side/tail lamp lenses in a colour of their choice by creating moulds - perhaps latex or similar - and pouring a form of plastic into them to produce new lenses.

I've had a search and can't find it. Can anyone remember this and point me to where it is?

I have a freind in Thailand trying to do the same technique to produce rare/expensive lenses there.

Chris
Click to expand...
That was me Chris. I used a kit from this company: Alumilite Corporation
 
UV stability is only a problem with clear resins. The pigments in darker colours does a good job of blocking UV radiation.

Good idea with the Venturi. I've always found a good high vacuum really helps though.
 
sdibbers said:
Good idea with the Venturi. I've always found a good high vacuum really helps though.
Click to expand...
If you already have a compressor, it makes sense, but if not, a dedicated pump as used by the HVAC Trade will also do it.
I have used venturi pumps for packing helicopter float bags into their housings and also for composite repairs.
 
I always use an AC vacuum service pump. I think we are talking about the same thing. Not sure about the uk but in the US chain auto parts stores will lend you one for AC repair.
 
You must log in or register to reply here.
Back
Top