Car grill mold help

General Composites Discussions Composites Talk
#1

I’m planning on making a mold of my car’s grill and need some help.

First, I hear that using rattle can paints won’t work with the tooling gel coat as it reacts and lifts the paint. To counteract this should I get my hands on Duratec?

Next, the grill is basically a large oval with two flaps that hold the piece to the car that would require a two piece mold (I think). Would I make the parting line underneath the flaps? See the pic below for a reference.

With this kinda odd shape would there be any other pieces of advice? This is my first mold. In the end it really doesn’t matter if the plug is destroyed as long as I get a good mold out of it.

#2

Hey Burrito,

I am no expert in this, but just a few things to consider:

Is this going to be a one-off part? Or are you planning to make a few different plugs/moulds/etc.?
The reason I ask is that I recently looked into using Duratec surfacing primer for my own project, but it turns out it’s quite expensive. Way over my limited DIY budget and I believe you have to buy it in large quantities.

From what I have read here I learnt that 2 pack paints will be more of a sure bet, you can polish them to a high gloss finish and the surface is hard so it makes a good finish for your plug. (But again, there are so many different materials out there, so you should always test when using new products. That seems to be the key to avoid lots of problems.)

Definitely looks like at least a two piece mould would be needed. Hard to say exactly without seeing the part. You just need to check that there won’t be any undercuts that get caught…

A suggestion if this is your first time working with composites - you might like to do some simple test pieces first before attempting this plug/mould. This will just help you become familiar with the materials you’re using, which IMO goes a long way towards avoiding problems.

Especially if you are expecting that you will have any trouble releasing the plug from the mould… I know it’s tempting to think that way, more so if it’s a one-off job, but if you have problems with that, you will most likely end up with defects on your mould… better to do test parts, then do the real part properly.

Hope that helps! There is a bunch of information on the forums here, keep having a search around, keep reading, you can definitely learn a lot here!

#3

Thanks for the feedback mugget,

I plan on making around 4-5 finished items off the mold and possibly more if the members of a car club show enough interest. There is a some what local supplier (US Composites) that ships a quart for a fair price to me, around the same amount I paid for the tooling gel coat.

Check out this link of the actual product on a vendors website. NOTE: im not trying to sell this item, just showing the various pics of the original in different angles.
http://www.autopartswarehouse.com/details/QQNissanQQSentraQQReplacementQQGrille_AssemblyQQ20042006QQN070126.html

You know, you’re absolutely right with doing simple test pieces! I started right out of the gate with a pretty tough piece instead of something much smaller and simpler so I can learn on. Thanks for the reminder to KISS: Keep It Simple, Stupid!