Working with Foam

**GoHybrid** · 12-10-2006, 12:29 AM

i'm excited to see a thin-wall casting! Do you have any thoughts on which resin system you might use to make the final part?

**Giuliano** · 12-10-2006, 02:08 AM

I've done this before...

Last time I did this, I used Polytek's Poly15 series of resins:

http://www.polytek.com/products/poly15.html

Read up on the two threads I started nearly 2 years ago:

How to: Duplicating a radio bezel.

8.4" LCD in WRX dash.

They're long dead threads, so don't add anything to them, but they're still interesting reading.

The problem I ran into during the mold making was that the container wasn't rigid enough.. I used 1/2" thick posterboard, which was too flexable for the size of work required.. MDF is much better.

Back then, I didn't have a tablesaw to cut MDF, and I didn't have a X2 mini mill.

I got this model from MicroMark:
http://www.ares-server.com/Ares/Ares...oduct&ID=82573

It's the same as this one from Harbor Freight:
http://www.harborfreight.com/cpi/cta...emnumber=44991

Now I have a table saw, and a mini mill, and hope to convert the mill to CNC within the next few months, with this much larger table:
http://cncbridges.com/mmb85265.htm

They're coming out with a slightly larger table soon that can cover a full 26"X by 12"Y of travel, more than enough to mill anything I want - including complicated radio bezels.

Anyway, getting off topic there..

My current plan is to buy a replacement lower center console (the area where the radio is mounted) and a replacement radio bezel - both available for less than $50 each - and to carve / mill blocks of foam to fit.

This lets me work on the project without having to have my dash torn apart.. :-)

**Yevmeister** · 12-10-2006, 03:43 PM

Originally Posted by GoHybrid

i'm excited to see a thin-wall casting! Do you have any thoughts on which resin system you might use to make the final part?

well go to smoothcast.com
to check out what thet have, i really recommend ordeting from www.farwestmaterials.com
this is their phone number, if they are still in business last time i worked with them were 5 months ago
(509) 522-0556

they have a great support, look at smoothcast 300 it's a 50/50 compound resin sets with in 10-12 minures, very durable, if you want smoother rubber like finish, i highly recommend dragon skin, i believe you can get a quart trial kit for about $15 USD.

I am a professional scale modeler, and have been casting, molding, and sculpting & painting miniatures for over 5 years

I hope they are still in business, plastics has been tough business laterly

Yev

**Giuliano** · 12-10-2006, 03:51 PM

Originally Posted by Yevmeister

well go to smoothcast.com

I think you meant www.smooth-on.com - smoothcast.com doesn't resolve.

**Yevmeister** · 12-10-2006, 03:53 PM

yeah sorry i haven't been in this business since i got my car

yev

**Yevmeister** · 12-10-2006, 03:58 PM

Dakar m3

if you don't want to drop too much money into quality stuff i suggest starting with florist foam, it's cheap, and very easy to shape, you can get it in any craft store

here is some pics from fiberglassforums

sorry little off topic, but this might work for the budget

Yev

**blacklancer** · 12-11-2006, 04:10 PM

can you fiberglass right over the floral foam??

**GoHybrid** · 12-11-2006, 04:51 PM

I think the resin (unless you were using an epoxy) would chew it up to some degree. If you're going to spend a month sanding the fiberglass and fillers and hack out the foam later, then no big deal, but if you're trying to make a mold and keep it accurate, I'd look at a different kind of foam or resin.

**Yevmeister** · 12-11-2006, 10:41 PM

Originally Posted by blacklancer

can you fiberglass right over the floral foam??

yes you can

**Yevmeister** · 12-11-2006, 10:49 PM

Originally Posted by GoHybrid

I think the resin (unless you were using an epoxy) would chew it up to some degree. If you're going to spend a month sanding the fiberglass and fillers and hack out the foam later, then no big deal, but if you're trying to make a mold and keep it accurate, I'd look at a different kind of foam or resin.

floral foam is heat resistant, and even with slight chew ups, they can be easily fixed with evercoat body fillers.

make a mold from the final product after you are done.

the reason that solution caught my eye is because of the price you can get a case of 60 9 x 6 x 3 blocks for under 40 usd. and it's a good practice before you get to work with expensive stuff, my philosophy is, basic bondo fillers are crap, i learnt hard way but i got good experience is sanding, before i went with better evercoat products.

I would recommend floral foam to any first timer, then you can get to the professional equipment which is pricier, but get's you better results, as Hybrid pointed out

He is professional in what he does though

Yev