SDoxey
Member
I read the articles in the library but am still a little confused.
Anyone got a easy cheap way to get started?
Anyone got a easy cheap way to get started?
I thought that Epoxy resins need pressure & Polyester resins do not need pressure, it is entirely possible I had it backwards all these years ...Polyester resins need pressure. Epoxy resins need no pressure.
yes you did sorry.I thought that Epoxy resins need pressure & Polyester resins do not need pressure, it is entirely possible I had it backwards all these years ...
Polyester resins need pressure. Epoxy resins need no pressure.
Incorrect. Neither require pressure or vacuum. Polyester will release the entrapped air with vibration, or better yet, don't introduce the air to begin with. Epoxy will release entrapped air using heat. Again, don't introduce the air in the beginning.yes you did sorry.
good luck with that. been casting for a long time. I need pressure on poly and no pressure on epoxy. My opinion.Incorrect. Neither require pressure or vacuum. Polyester will release the entrapped air with vibration, or better yet, don't introduce the air to begin with. Epoxy will release entrapped air using heat. Again, don't introduce the air in the beginning.
Urethane on the other hand, does require pressure.
Precisely. You base your opinions on one resource.good luck with that. been casting for a long time. I need pressure on poly and no pressure on epoxy. My opinion.
Wouldn't you at least agree that all casting could benefit from using a pressure pot. Vibration is just another means of release air bubbles. If that is what you are holding against my statement then I stand corrected. Just because you said and all your info say that poly does not need pressure is it not better to walk on the caution side of the sidewalk? Because epoxy resins take a long time to kick is why they can withstand no pressure but with poly alot can depend on the amount of catalyst used. Air bubbles is the culprit. When you say do not introduce air. Again a hard thing to do because we all stir. You can maybe get away with it if the resin is heated before mixed. It thins it out. Remember it is amateurs here that are asking because if they were pros they would not be asking. I believe each and every question asked here the responses are based on one's experience and not so much as scientific data. Sorry I will never change my opinion. I could be totally wrong in my response but it works for me.Precisely. You base your opinions on one resource.
There are actual professional resin experts, that are willing to share any information that one is willing to ask for, as opposed to the weekend casting warrior. I've seen reports of those that are regarded here as casters, or the go to people, have inconsistent casts, air inclusions, etc. Some of those, are even sold through popular suppliers.
A lot of manufacturer's have dedicated representatives based across several platforms, that help anyone that uses their products.
They have simple, and precise video's for their products as well.
I have learned more about resins, than I even thought there was information. Seek this information, and you'll likely change your opinion.
Absolutely use what works for you.Wouldn't you at least agree that all casting could benefit from using a pressure pot. Vibration is just another means of release air bubbles. If that is what you are holding against my statement then I stand corrected. Just because you said and all your info say that poly does not need pressure is it not better to walk on the caution side of the sidewalk? Because epoxy resins take a long time to kick is why they can withstand no pressure but with poly alot can depend on the amount of catalyst used. Air bubbles is the culprit. When you say do not introduce air. Again a hard thing to do because we all stir. You can maybe get away with it if the resin is heated before mixed. It thins it out. Remember it is amateurs here that are asking because if they were pros they would not be asking. I believe each and every question asked here the responses are based on one's experience and not so much as scientific data. Sorry I will never change my opinion. I could be totally wrong in my response but it works for me.
Very very very sound advice from someone who is recognized as a top caster here. This advice goes for anything we try to do.Best advice I can give you is figure out what you want to cast, then look at the "how" by checking out how others do it successfully. There are many Pro's and Cons's in every style and methods of casting and your goals and set up will help you narrow down how you want to do it. It really doesn't matter if your a "weekend caster or an expert" because we all share our process and opinions based on our experiences. Usually new ideas come from new casters because they are the ones experimenting and not stuck in their own process yet. Whatever you decide, keep a notebook. What doesn't work is just as important as what does. Keep it fun and try new stuff!
I believe you should write a tutorial for the library. I am sure Wayne would love to have it. Sharing your knowledge from many years studying resins would go a long way here because many people want to try their hands at casting. Thus the questions that come up. Good luck.Absolutely use what works for you.
Polyester, when mixed properly, has plenty of pot life to eliminate any air.
If you are getting the gel reaction in less than 15-20 minutes, then there is too much catalyst added.
If air is introduced, several things can eliminate it without a pressure pot. A pressure pot doesn't eliminate the bubbles, it just compresses them. If they are large, they will still be prevalent in the final cast.
-Horizontal casting reduces the distance the bubble needs to travel to the surface vs. vertical (tube) casting.
-Warming the resin (as you mentioned) can reduce viscosity and help the bubbles to surface easier, but it comes at the cost of increasing the temperature of the resin, and reducing pot life. This could be your issue with gelling too soon.
-Vibration will force bubbles to surface, since the air is lighter than the resin.
-Mixing the color into the resin before catalyzing, will allow the resin time to evacuate the bubbles, and some gentle tapping of the container on a table will help speed the process.
-Adding the catalyst to each color, and gently mixing, will reduce the air introduced, and make elimination easier.
-One method to prevent the introduction of air, is to have a magnetic stirrer. It's not exactly practical for most casters, but with variable speeds, it works well to keep air out of the mix.
I doubt a tutorial would be beneficial. It would be plagiarism if anything, because it would state the same as any manufacturer's instructions.I believe you should write a tutorial for the library. I am sure Wayne would love to have it. Sharing your knowledge from many years studying resins would go a long way here because many people want to try their hands at casting. Thus the questions that come up. Good luck.
Keep in mind, those are two different types (urethane vs. epoxy) of resin. They have different characteristics, as well as casting requirements.The secret to casting is it isn't that complicated. I use a kitchen scale to measure resin, PVC or CPVC pipe depending on the diameter of blank I want. Use some release agent. Masking tape to seal the end, a wire with the tip bent over to mix. If you don't bend the tip over you poke holes in the tape. I made a pressure pot out of a piece of galvanized pipe that holds 3 blanks. It has a cap on one end and an assortment of fittings to get down to an air hose fitting on the top. Mix some resin, use powder make-up, oil-based paint, I like Testors, or anything else Not water based to add color. Add the colored resin to the molds and don't mix too much. Clamp the pipe to a table leg, drop the molds in, put the cap on and connect to the compressor and wait until it's set. I like Alumilite slow or Diamond cast resin. Keep notes on what you did, how much of each color and how you mixed it. If you have any other questions let me know and I'll be glad to help you out.
I have noticed they turn and polish differently as well as one takes a lot longer to cure. I must confess I don't know much about the technical side. It would be interesting to look into. I also have a theory/ think blanks cast under higher pressure, I cast at between 70 and 90 PSI turn better than those cast without pressure. Not sure if it's true or not just something I noticed when I tried to cast one without using any pressure. Any thoughts?Keep in mind, those are two different types (urethane vs. epoxy) of resin. They have different characteristics, as well as casting requirements.
Can you use a metal tin (with silicone spray) as a mold in a pressure pot? Thx.If you cut out the pressure pot, you can use anything for a mold. I still use cardboard and duct tape when doing bigger things. Then all you pay for is resin and dye.
You could but even with mold release it would be problematic getting the cast out of the mold. You would likely have to destroy the tin during removal, at least that has been my experience.Can you use a metal tin (with silicone spray) as a mold in a pressure pot? Thx.