Talk Composites - The Forum for Advanced Composites

misty finish out of mold

http://www.talkcomposites.com/Topic22055.aspx

By willlii - 9/30/2016 9:32:21 AM

hi all ,  using glasscast resin how do i  prevent the piece from looking dull and misty on the side that is inside and making contact with the actual  white  melamine mold,  which is the back and the edges      the top is fine clear and glossy  . also something i cant fathom is the extra resin i have by mixing too much  i pour into a plastic disposable  cup (left to set and used for turning on the lathe at a later date) which  is easily removed from the cup and is glossy all over .. also  to repeat the process to make multiple objects  what liquid  silicon molding material  should i use to have a reusable mold .... and would the piece come out glossy all over . help  needed signed willii
By Rich (Staff) - 9/30/2016 10:55:59 AM

Hi willii and welcome to Talk Composites!!

Melamine is a great, temporary, low cost tool surface but it doesn't have a perfectly shiny surface and as with any type of resin, the finish on the part is related to the finish of the tooling surface. A perfectly glossy tool surface will result in a perfectly glossy part; a more matte appearance surface will give a matte texture/appearance to the cured resin. The great thing about GlassCast is that it is so easy to polish to a high gloss finish because it cures so hard - flatting with wet dry abrasive paper up to a 1500-2000grit wet paper before moving to a polishing compound will yield impressive results with very little work.

If you were doing this on a commercial basis and thus could justify the time and effort, you could look at making a mould tool which had a glossy surface from the off to help to cut down on the final finishing and polishing stage but for one off projects; melamine is cheap, effective and importantly, easy to fasten together.