I need to make a really simple, small, one-time-use positive mold. I first tried the fabric stretching technique, it worked OK but I need more control in the final shape than I had originally thought. My next idea was to just use some Klean Klay to shape the mold. Would I then need any type of mold release? I know you could always peel off any clay that stuck to the finished piece but if I can make it easier, why not. I don't have any PVA though. It'll be a fairly light lay-up so hopefully heat wont cause the clay to distort. I have polyester and epoxy resins and will probably go with the epoxy. I haven't decided if i want to use FG or CF. Any tips are appreciated.

 

have you thought about using any high density foams to create your positive shape?

after your object is made, plaster of paris/sand/paint/PVA. I know you said you don't have any release agents, why not order some?

I personally think the clay will melt or distort from the heat of the resin.

 

I have thought about foams but wasn't sure which to use.

I'm really going for quick and easy with this one, not perfection as the final part isn't critical. I'm making a shroud that'll sit behind a bezel in a HID retrofit.

I do have release agents but they're the kind you buff on and off, not something that would work with clay, albeit rather hard clay.

 

why won't take the clay and get a rough shape and take any ester based resin/bondo and pour it over the clay and then reshape the bondo to your specs

 

I've made some sand molds before, and we used baby powder as a release agent.

 

I worked with a guy who swore by yellow Joy dish soap cut 1:1 with alcohol and just painted it on. alcohol flashed off and left noithing but soap.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jweller &raquo;</TD></TR><TR><TD CLASS="quote">I worked with a guy who swore by yellow Joy dish soap cut 1:1 with alcohol and just painted it on. alcohol flashed off and left noithing but soap.</TD></TR></TABLE>

holy ****! i just read the cuddle bitch link. ingenious

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.E.G. &raquo;</TD></TR><TR><TD CLASS="quote">holy ****! i just read the cuddle bitch link. ingenious </TD></TR></TABLE>

I just read the entire link. Its so true, every man should read that.

 

They do actually make a mold release wax, i worked in a fiberglass shop and that was what they alwayes used, the more coats you put on the better it would release. We used it on a car mold and it worked great. any fiberglass store should carry it or some version of it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GT35R_EF &raquo;</TD></TR><TR><TD CLASS="quote">They do actually make a mold release wax, i worked in a fiberglass shop and that was what they alwayes used, the more coats you put on the better it would release. We used it on a car mold and it worked great. any fiberglass store should carry it or some version of it.</TD></TR></TABLE>
yeah i have the wax type but it can't be used on clay (the wax is harder than the clay). I think i'll try the dish soap method.

for reference here is what i'm doing. This was my first version using the stretched cloth (fleece) method. It worked fine but I need more control over the contours because clearance is tight in some spots.

*the black part under the chrome bezel*

 

be careful which matrix you use as it may not work with the sizing on the fibers.

I use PVA.... works like a charm.

 

Alumminum Foil conforms to stuff well then just pops off