Looking for info on making a casting

[LoyalNine]

I have an old plaster sign that is about 16" height. I would like to make a plaster casting of it as a gift and am looking where to find info on how to do such a project.

 

Any info or help pointing me in the right direction (books, videos, materials.. To get me started) would be greatly appreciated.

[Biglou13]

Funny. I just finished making plaster hump mold/bats today. There is tutorial here on making plaster molds.

In a nut shell

1. Apply mold release to original. ( Murphy's oil soap)

2. Make cottle board or use aluminum flashing to surround original with approx 2 inch margin larger than original.

3. Apply mold release to pouring surface and cottle boards

4. Make plaster. Weigh for both water and plaster.(for now)

5. Pour 1.5 inch in form

6. When just thicker than cream press original into plaster. See notes

7. Wait 30 min for plaster to set up.

8. Remove original

9. Allow plaster to fully cure!

10. Clean up.

 

Now you have a negative.

 

Clean negative mold

Apply mold release to negative

Pour plaster to make positive

 

Ok that's the quick and dirty

 

Notes:

Hard to tell but it looks like you get away with one piece mold.

Lettering and some details may be problematic.

Make sure you take care of bubbles in plaster. With alcohol spray trick

Never made mold with such detail, But mold I'm using the plaster molds mfgr lettering, which pretty fine detail. Maybe paint plaster into detail when making negative. Hopefully a professor of plaster will comment

Clean up detail on negative before making positive

Work on level surface

Google making plaster mold

Try to get permission to copy original artwork!!! (MSAsaftey.com now Owns cairns). You might find you could sell to them. It may be public domain But best to seek permission.