I need to make a flexible mold of a boat accessory. I just want to make a few epoxy parts from this mold. I would like not to harm the original part if possible in making this mold. Can anyone offer some advice on what to use, where to start? One item would require a simple one part mold. Another piece will need a two part mold.
I’ve had some success with products by Smooth-On. Check their website. They have a how-to page with a lot of answers. They offer an introductory package which contains both rubber and resin. Check too their distributor list. There is one nearby to me where I can buy over the counter.
I use their OOMOO-30 rubber and the Smooth-Cast 300 casting resin.
That is the exact stuff I use also. Talk to them and ask the questions. You will not be their only hobby builder. The distributor I use gave my email to one of his customers and I had all my questions about casting small stuff answered right away. Their products are great! They have a book for about $15 and it isn’t much help for hobbiests. Just a warning.
Alumilite casting is a good place to start too. One of the guys that moderates/works therecasts large hot rod bodies and the likes he’s got mounds of info on casting for the beginner and hobbyist.
I’ve cast ship turrets, main and secondary gun barrels even a replacement cowling for the monogram P-61 black widow. Started off by buying one of their casting kits at hobbylobby during one of their 1/2 off coupon sales. Then ended up ordering the white casting resin directly from them due to the longer working time for the white versus the tan. I’ve got plenty of other stuff to cast too it’s pretty easy with their stuff, their silicone for the molds will only stick to itself and nothing else so you can cast anything. they include mold release in their kits for 2 parts molds also.
Would you consider the alumite castings to be stronger than epoxy castings like from Smooth-On? The last catalog I have from HL is # 45 I couldn’t find any casting kits for sale. Do they list the kits someplace? I couldn’t even get it to show up on a search on their page. Why do they hide these things?
Alumilite has a forum and you could ask them which of their stuff is the stronger. Not having dealt with Smooth-on I couldn’t really say for sure. The one thing I have learned though is the time mentioned to demold the parts (take them out of the molds once cured) is true they can be taken out relatively quickly but for the parts to be good and hard and resist warps it’s a good idea to leave them in the mold for at least an hour or so, so they are good and cured.
Tracy
P.S. I don’t believe HobbyLobby has a rhyme nor reason for the way they do stuff in advertising or catalogues.
I think an hour is a really good turn around time to cast an item. HL has a toll free number I will give them a call in a bit when they open for more information.
I think HL is a good company to deal with. I used to see them at the model shows when I went. The guys were always outgoing and friendly.
I ordered my Smooth On silicone starter kit this morning. After contacting several companies this seemed like the best option to both get started in this and try out their product. I contacted a hobby shop not far from my home and they wanted $80 for a Alumilite starter kit. I thought that was a bit too much to just try out. The total for the Smooth On kit including shipping was $34. The distributor I contacted told me to contact Smooth On directly to order the kit. I am guessing it was too small an order for them to do. Wish me luck.
well the $80.00 is about 12 dollars over list for the alumilite. i’m sure the smooth on will work well also. I bought some plastic syringes from the drug store used for giving babies liquid medicine for measureing out my portions of resin for mixing just a tip. They come with an adapter that fits on my alumilite bottles that seal up when not in use. I bet they will do the same on the smooth on bottles. Should be a piece of cake once you get it all sorted out. Waiting’s the hard part [:D]
No, actually the standard Smooth-on container is a wide mouth (~1 1/2 inch) jar. Stop by the local Hobby Lobby (thats where I got mine) or pharmacy and buy some measuring cups (30 - 50 ml /1 - 1 1/2 oz). Smooth-on mixes 1:1. I use 2 different cups (mark them A & B) to measure and mix in a plastic bathroom cup. I grabbed a bunch of stirrer sticks from the coffee mess at work. Do not mix up the 2 measuring cups. Once you have poured the material out into a cup - never pour it back into the bottle if you poured too much. Just waste it. Contamination WILL occur and the whole bottle will harden (not immediately, but while in storage).
Once open, seal the remaining stuff in the jars with some wax paper & tighten the lids tightly to prevent air from getting in. If you don’t use the wax paper the lid on the yellow container will fuse to the jar. I’m keeping my left-over rubber & resin in the refrigerator to help extend its shelf life. (I make batches of small parts - I may use a few ounces now and not use it again for a few months). Take it out of the refrigerator a few hours before use to warm to room temperature before using. Although the chemical reaction is exothermic (i.e. it generates heat) the cold materials really slow down the setting time.
Standard domestic protection instructions apply. Don’t use the wife/girlfriend/mother/SO’s kitchen stuff to measure, mix, & pour. Protect the kitchen table/work surface from spills. It does smell a bit but is not overly offensive.
Before you commit your master to rubber, mix a trial batch & see how it behaves. Then make your mold. Before you cast your first parts, mix the resin & see how it behaves, how much free time you have, and what happens when the resin starts to kick
TracySW thanks for the tip about the baby syringes. I will pick some up next time I go to town. Figuring out what to use to measure and stir the mixture was my next step. I think I can get sticks at Michael’s crafts. I saw some mixing cups on one site I was hoping the pharmacy would have some of those as well.
Yes now that I have ordered the kit I can’t wait to get started. Too bad we can’t get our shipments tranported to us like they transported people in Star Trek. POOF! you walk out the house door and there sits your package.
This advice is great to know in advance. I will have to get some wax paper I know we don’t have any. I have a small fridge downstairs in the basement I’ll be using that to keep this stuff cool along with my CA glue. I never work in the kitchen for any reason if I can help it. I am too afraid the wife will find out I am there and put me to work. Believe me when I say you don’t want to eat my cooking.
Good to know that the pharmacy has the cups I will be needing. We don’t have a local hobby shop here. The closest thing to it is Michael’s Craft store. Thanks again
Another tip i’ve found that helps during mixing is to keep the stirring stick on the bottom of the cup as much as possible for some reason it keeps the amount of bubbles in the resin reduced
Yesterday I got into town. I checked both Walgreens and CVS pharmacies. They no longer carry any small plastic measuring cups.Wally’s didn’t even have any. Finally I ended up at Lincare and bought several packs. I was able to get the baby syringes without a problem. Micheal’s had all the stirring sticks I will ever use. Now if the UPS man would ever get here I could get started.
I finally got to cast up my critters today. The wife has had me on a long honey do list. I don’t know how to post photos on this site so I will just post the link to the photos. Any suggestions or advice is welcomed.