| In order to give you some idea of the process | | | | fall over just when you get to the top! |
| involved in making a rubber or latex mold, here is | | | | Part 4 - Take the rubber off the original. Be |
| a quick rundown. | | | | careful! It will be inside-out. Now you can sprinkle a |
| Part 1 - The easy part, decide what it is you | | | | little talc on it and turn it inside-in. Put it into the |
| want to copy or make your mold of and get one. | | | | fiberglass case you made, bolt or clamp the case |
| Part 2 - This is the long part. It could take 5 or 6 | | | | closed, invert the case so that it is sitting on that |
| days if you are only able to paint a couple of | | | | big base we where talking about. Mix your |
| times a day. You cover your original - lets say it | | | | concrete and fill the mold. Let it sit to cure for a |
| is a frog - with release agent. You may not | | | | couple of days. This is the test run for this mold |
| always have to do this. Some plastics and resins | | | | and case so you want the concrete extra hard |
| do not need it. Now paint the frog with the rubber | | | | when you do your first de-mold. |
| paint. Let it sit until it is almost dry - you can put | | | | Part 5 - Unbolt the case and take out your |
| your finger on it and no paint sticks to your | | | | casting. Carefully take the rubber mold off the |
| finger. Paint it again and again. Do this until you | | | | casting. If you are a skilled mold maker it should |
| have built up a thickness of about 3/16" or so. | | | | be right the first time!! If not you need to look at |
| You can judge this by painting a piece of wood or | | | | any problem areas and decide what you can do |
| something every time you apply a coat to the | | | | to correct them. |
| frog. Look at the wood to see how thick your | | | | Now you can see why the rubber or latex molds |
| test paint is. | | | | cost so much and why they take a couple of |
| Part 3 - After the paint has dried for 2 or 3 days | | | | weeks or more to make. |
| you can start to make the support for the | | | | The building time can be shortened by using fast |
| rubber mold. If you can picture the mold as a | | | | drying silicone based rubber, it is a little more |
| rubber glove, when you fill the glove with water it | | | | expensive but.... Plaster can be used instead of |
| will stretch. You have to stop the stretch. Most of | | | | fiberglass if the mold is not going to be used a lot. |
| the time this is done with a fiberglass case or | | | | This is cheaper but not nearly as good as |
| backing that you will make to go over the mold. | | | | fiberglass. |
| You may have to make this case in 2-3-4-5 or | | | | My thought is that for a person to start into the |
| more pieces that will bolt together. This is so you | | | | casting business the best way is to start with a |
| can take the case off easily. If there are a lot of | | | | few plastic molds - no fiberglass backing needed - |
| undercuts in your frog then chances are your | | | | do a few pours and see if you want to keep at it. |
| case will be several pieces. You can avoid having a | | | | If you decide you do, then as your skills increase, |
| lot of pieces by filling undercuts on the outside of | | | | start to think about investing in a simple latex |
| your frog before you start to make the case. | | | | mold. You may be able to find a used one in good |
| This means more time painting on the rubber | | | | shape. Try it and see if you want to do that type |
| paint. This is a good thing because the fewer | | | | of casting. |
| pieces in the case the easier it is to use. When | | | | The results are great once you have mastered |
| you make your case it has to have a good big | | | | the process but it is not a cheap or easy thing to |
| base, it will be holding the rubber mold upright | | | | do as a novice. |
| when you fill it with concrete. You don't want it to | | | | |