I am using alumilite slow set 7 to cast miniature picture frames. My frames are way too flexible when they are done. The resin is not "uncured", its just that they are not rigid. The picture frames are anywhere from 1.5" x 1.5" square up to 3" square, and from 1/8" wide at the sides.
Here is what I have been doing. I have warmed up the molds before casting. GThis does not seem to improve the rigidity of the finished product. I have NOT warmed up the molds prior to casting. This has not improved the rigidity either.
WHAT am I doing wrong? Do I need a different product? I know rigidity is possible, I have frames that I have purchased that are perfectly rigid!
Post by carol - Alumilite Corp on Jun 18, 2018 10:41:11 GMT -5
I would recommend using the AlumiRes RC3 for that application, those are very small pieces. The Slow Set has a 2-3 hour demold time yes you would need to heat the mold prior to casting and then do a post cure with heat...especially in those small of pieces. With Pre and Post cures with heat yes they will/should cure as long as the product was measured and mixed according to directions. If off ratio or not blended/mixed WELL it can remain flexible but still feel rigid. Regards,
You can do some of the post cure with a hair dryer - I use it cause mine is one of those that has a warm and hot setting and have sped up a full cure on Amazing Clear by up to 2 days early. I've been working with RC-3 this week and had to help the full cure along a little on casting a resin original that was 1 /1/2"x1 1/2" and 1/4" deep due to its small size and they were close to full cure very quickly. I like to use clear plastic shot glasses for my measuring and mixing since I use smaller amounts in my castings and even the leftover coating in the mixing glass is fairly rigid and that's almost paper thin in spots. Just make sure you are steady but quick when mixing the RC-3, on a smaller casing it's easy to go off ratio while eyeballing the two amounts. Of course my "eyeballing" the measurements involves putting them on a level surface and bringing my eyes down to even with the glasses to eyeball that I've got them on the line I made on each glass when I poured water in one, marked it then poured that into the second glass and marked it. Also on a slow cure you might not be mixing as long as you need to, it was the thing I had to learn the first couple times I used the Clear - to go the full time it says to mix and not skimp on that time. I was used to the RC-3 being mixed at 30 seconds and needing to be poured asap.
Also if you are painting the frames, make sure to either paint the mold (and let it dry) before pouring the RC-3 in or spray it with a primer as soon as you de-mold it when the cure time is up. It's not that easy to paint it if you leave it too long without a primer coat on it. The casting needs to be warm to the touch for it to bond with the primer but the primer can be any color you want, even clear.