Thread: How to: Duplicating a radio bezel.

yeah you pour into the pouring channel, but the resin would not go into the mold unless the air could escape - so you have venting channels for the air. You keep the channels as small as possible to prevent the amount of clean up after the mold has cured.

You put a small piece of material (mini straw/thick toothpicks, coat hanger, etc) to take up room when you make the mold. Then when the mold has cured, remove the toothpicks and you have an empty area that becomes the vent.

i see. where are the channels at? anyone have any good links i might could read to get myself more familiar with this stuff?

edited my above post about the channels

check this out
http://www.alumilite.com/howto.cfm

I have been fooling with molds the past couple weeks. very interesting and I love this thread.

Originally Posted by brrman

yeah you pour into the pouring channel, but the resin would not go into the mold unless the air could escape - so you have venting channels for the air. You keep the channels as small as possible to prevent the amount of clean up after the mold has cured.

You put a small piece of material (mini straw/thick toothpicks, coat hanger, etc) to take up room when you make the mold. Then when the mold has cured, remove the toothpicks and you have an empty area that becomes the vent.

Good answer!

The channels themselves don't have to be tiny, but it's usually a good practice to make the channel contact points (ie, where the channels contact the piece) narrow so that there's less material to cut off - the plastic that cures in the channels is usually referred to as the "sprue".

A channel width of 1/8" is usually sufficient, but for larger pieces it's not unusual to have a channel of 1/4" wide, which is what I'm going to be doing - it makes the pouring slightly easier.


The resin pours into the mold through the channels, and balances itself out by gravity.

For example, if you had a plastic tube shaped in a U, and poured water in, it would self-level at each end, which is why you need to have both the pouring and venting channels come out the "top" of the mold.

Here's an obviously photoshopped image of what I expect the modified and finished bezel to look like.

I'll probably end up painting it a pretty blue color to match the car..

I've got some specialized hobby paints that will do the job nicely - they're acrylic lacquers, so they go on real smooth and are real durable.

Originally Posted by Giuliano

I'll probably end up painting it a pretty blue color to match the car..

I've got some specialized hobby paints that will do the job nicely - they're acrylic lacquers, so they go on real smooth and are real durable.

On second thought...

What better way to make it look "factory" than to paint it using factory paints?

Subaru Touch Up paints, that is - they're about $5 for a 1 ounce bottle, and for my WRX, I believe the matching color is World Rally Blue.


Now, you might think.. 1 ounce of paint is not enough!
It is if you airbrush it! (which I can, I've got like, 3 of them)

Combine the radio bezel with the center, left, and right A/C bezels, and you've got a paintjob on the inside that will look factory...


Did I mention that if I spray the inside of the mold with primer, and let it dry before I pour the resin, the resin will bond with the primer? Instant pre-primed part, ready for painting.

A quick post to say how great this thread is and i look foward to the continuation

If you have an air compresser you can buy an airbrush kit for that dirt cheap from Harbor Freight tools, it should do the job.

Originally Posted by Pudge

If you have an air compresser you can buy an airbrush kit for that dirt cheap from Harbor Freight tools, it should do the job.

If you meant me, I already have at least 2 airbrushes now, both meant for hobby-size work:

• Airbrush: Iwata Eclipse HP-BS (~$89)
• Airbrush: Badger Sotar 2020 (used for $50)
• Compressor: Kopykake Airmaster Plus C3000A ($200)

The air compressor is pretty silent, and only runs when I press the airbrush trigger - I added a low-pressure regulator so I can dial down the pressure to 5-10 psi for detail painting.