The Bloopers Blog
March 1, 2018
I’ve done a lot of projects in the last 7 years I’ve worked here. Which means I’ve messed up a lot of times as well. In this blog post, I’ll go over some mistakes I’ve made and how you can avoid them.
- The most common problem I had when I first started was not having my work area properly set up before I began mixing products. I would carefully weigh out my silicone and catalyst and suddenly realize that I forgot to grab a mixing utensil. Or, I would start mixing epoxy and find that I forgot to tape up the edge of my tabletop to make a dam. After a few of these problems, I started taking a few minutes to walk through the steps I would take for the project, after I gathered my materials but before I started measuring, mixing, and pouring. This quick extra step has saved me countless headaches and wasted product over the years.
- Always read the directions on materials you haven’t worked with before AND give them a brief read if it’s been awhile since you worked with the product. I’ve always been good about reading the Technical Data Sheet the first time I use a product. However, after messing up the mixing ratios a couple times, I learned that I shouldn’t rely on my memory for product directions. I always double check mixing ratios and product directions now. Obviously, if you only ever work with one product this isn’t an issue. If you have a lot of different types of projects using different products, it is always good to give the Technical Data Sheet a quick read before starting.
Product Specific Bloopers:
- Epoxy: The epoxy resin 300 and 400 resins can freeze at a pretty high temperature, 50F. However, unless it’s really cold, the resin doesn’t freeze entirely. Instead, it partially freezes, usually at the bottom of the container. You might not notice the white, frozen crystals until you are adding the hardener. At least that’s what I’ve done. If you notice the epoxy is partially frozen before you mix it with the hardener, it’s easy to defrost and use. However, if you miss it and mix it with the hardener, you will have cloudy epoxy that can’t be fixed. So, now I always inspect the whole bottle, give it a thorough shake and turn it around, before I measure out the resin to be mixed.
- Urethane: The most frequent mistake I make when working with urethane is mixing it with wooden stir sticks. Urethane is very moisture sensitive before it cures. Any moisture that might be in wood or paper products will create bubbles, discoloration, and result in a poor quality rubber or foam. So, do not use wood mixing utensils and/or paper mixing cups for measuring and mixing urethanes and do not use urethanes on rainy or humid days.
Moisture damaged Urethane Rubber
- Silicone: My most common silicone mistake is not mixing up enough silicone for the mold I’m making. Instead of measuring and calculating the volume needed, I have often just decided I can eyeball how much material I’ll need. Several times this has ended with me frantically mixing another batch of silicone to make up the difference. Now, I always measure my mold box, measure my part, then subtract the volume of the part from the volume of the box. This gives me the cubic inches of silicone I need. I can mix it accordingly.
Specific Project Bloopers:
- Small Epoxy Tabletop with embedded pictures: This was my very first project, just a few months after I started working here. I glued down some photographs to a square piece of scrap wood about 12 inches by 12 inches, made a tape dam that rose about an inch and a half from the surface of the wood, mixed some 300/21 Epoxy and poured it a little over an inch thick onto the wood. Everything looked awesome for the first 10 minutes or so. Then, I saw a bubble, then another bubble, then oh man, so many bubbles everywhere! I had poured the epoxy way too thick for the small surface area of the tabletop! The epoxy had boiled, resulting in a bubbly, uneven mess. It looked like a pot of boiling water frozen in time. This project has long since been thrown away because I was so ashamed of this terrible failure, though I wish I had taken a picture. I have since reminded everyone who is pouring a tabletop or bar top that it’s best to keep the pours under 1/4 inch at a time and do multiple pours to build to the desired thickness.
- AeroMarine Products Logo Block: This wasn’t too bad, but it was frustrating. I was trying to make a small silicone block mold of a small cube that has our raindrop logo on the top. I was trying to save time and not wait for the hot glue gun to warm up, so I used some clay to stick the cube to the bottom of my mold box. I have successfully used this method with small pieces in the past. This time I mixed and poured the silicone and when I came back the next day the block had dislodged and floated to the top of the silicone. So I cleaned it up, used a dab of hot glue to anchor it to the bottom of the box again, mixed and poured the silicone. Again, I came back the next day and it had floated to the top. I applied a very thick layer of hot glue to the bottom of the cube the third time and it finally stayed put. You can see in the picture, the cube is hollow and I should have known it would need to be anchored very securely to the bottom of the mold box. Lesson learned.
Hollow cube that likes to float in silicone.
- Foam Pumpkin in a Latex Mold: Everything went wrong with this project. I decided to do a latex mold for the blog. I had a pumpkin that would be fun to use because it was Fall. I wanted to demonstrate casting with foam for the blog as well. Generally, you don’t want to use urethane in the latex because the heat the urethane generates can damage the latex over time. However, I only needed one cast so I knew the latex would be okay for that. I also didn’t want to take the extra time to make a mother mold to back the latex. I figured on setting it in a box of sand to support it for the cast. This has worked for me in the past with small to medium sized pieces. Making the latex mold went fine. Latex doesn’t heat up as it cures so it’s fine to use on organic things, like pumpkins.
Making the latex pumpkin mold.
I removed the finished mold off the pumpkin and placed upside down in my box of sand. I sprayed a little urethane mold release into the mold, mixed up some urethane pour foam and urethane colorant and poured it into the mold. Almost immediately, I can tell I mixed and poured too much urethane foam and its going to overflow. That’s fixable because I’ll trim the excess off after I de-mold it. Then, I noticed that the expanding foam is distorting the mold. Okay fine, maybe the pumpkin will be a little rounder than the original. When I de-molded my foam casting, I had trouble getting the pumpkin out with the foam overflow. The pumpkin foam casting stuck to the latex in some places where I didn’t spray enough mold release. So, I had to cut the mold apart to remove the pumpkin foam casting. This is where I noticed that there are large voids, probably from the mold distorting. Unfortunately, both the piece and the mold are both complete loss. So, because I didn’t want to do two projects to demonstrate two products, and because I didn’t want to take the time to make a mother mold, I ended up with nothing to show for hours of work. Lesson learned: always take the time to do the project properly. Don’t cut corners!
If you have any project questions, or projects you’ve messed up and are looking to fix, please call us at 877-342-8860 or drop us an email at [email protected]