Followers

Thursday, June 18, 2015

More Shield Press molds

While I am still working on the units for Oldhammer USA weekend, I've taken a slight detour trying to figure out how to reproduce the old plastic shields.

So here's what happened.


I showed you the molds I had made last time. Here they are stuffed with green stuff. I used a roller to squash the balls of green stuff into the molds. It stuck pretty horribly to the roller, I used water to try and stop that. Next time I might use vaseline. It was particularly difficulty to get the green stuff to stay in the instamold.




A comparison of the two molds. I apparently rocked the roller in the making of the instamold molds. The bottom shield on both is a little uneven and malformed. Overall the sculpey mold is a tad crisper although the upper two instamold shields are very nice in both cases. The white marks are from the tool to pry the green stuff out of the sculpey mold.


Instamold on the outside edges, sculpey mold next, originals in the center. Each have pluses and minuses.


Since the green stuff had been tricky, I wanted to see what molding in super sculpey would be like.


Following the directions on the box, 325F for 15min had obviously burned the mold I made. On their web site they now say 275F for 15min per 1/4" of thickness.


Using the same procedure, I rolled balls of sculpey into the molds. I did dust the sculpey mold with cornstarch to try and act as a mold release. I think the real problem is the over baking of the scculpey has made it inflexible.


After about an hour in the freezer to get it to firm up for handling, I pried everything out of the molds. Instamold just pops off when you flex it. You can see how i tore and deformed the pieces coming out of the sculpey. So back to the drawing board on that one.


I cut away the excess and saved it for reuse, then backed the casts at 275F checking every 5min for 15min.


As you can see I did not burn the sculpey this time, they stayed pink.


Here's the big comparison shot after trimming all the flash. All of the molds are a little too thick, about 1.5 to 2 times, so I'll have to trim that down. But so far pretty fair results. I need to find my large bit for my pin vice to bore out the rest of those holes.  The xacto knife is a tad fiddly.


I bought this product yesterday, I'll give it a go soon.


I thought it felt  little hot today. Stay comfortable everyone.

10 comments:

  1. Nice work. The shields look good to me.

    ReplyDelete
    Replies
    1. Thanks Stefan, I'm probably a little too critical.

      Delete
  2. That is good work, living in the UK, it never gets that hot, ever!

    ReplyDelete
    Replies
    1. Hi Stevo, thanks. Yeah but it's a dry heat. I did about an hour of yard work yesterday morning and thought it was a little warm. It was probably only 90 something. I guess I've lived here long enough that I've gotten used to it.

      Delete
    2. That's the difference between where you are and where I am. It gets that hot here in Oz but can easily be 60% humidity with it. :-(

      Delete
    3. I take it you don't live in Alice Springs. ;)

      Delete
  3. It looks as if you have got some perfectly usable shields there, even if there were a few mishaps along the way :-) . Cornstarch is an interesting choice as a release agent - did you see that recommended somewhere or is that your own idea?

    ReplyDelete
    Replies
    1. Hi Hugh, thanks. Somewhere cornstarch was listed along with talc as something you could use to dust onto a mold. I also knew I had some, so I thought I'd give it a try. I think the real problem is the rigidity of the over cooked sculpey mold.

      Delete
  4. Those look pretty good. Might I suggest mixing talc with a little water to make the greenstuff less sticky? works well for me, and when the water dries, you can remove the talc with a soft brush.

    ReplyDelete
    Replies
    1. Hi Mattias, thanks. That sounds like a top tip. I was also thinking of using vaseline, as I have plenty of that lying around still from when the kids were in diapers.

      Delete

LinkWithin

Related Posts Plugin for WordPress, Blogger...