Alumilite Mini Casting Kit

[James Flowers]

I just bought one and was reading on the box. Says you can use a microwave to warm the mold. Question will this affect the use of my microwave for food use? How bad are the fumes or vapors ? Do you need a respirator ? Thaks for any information you can give me.

[monkeyclaw]

Once the mold is cured; the heating of the mold in the microwave will not have any ill effects on the microwave....there are no fumes to worry about....I do it all the time; in fact I bought another microwave for my shop, just for heating molds....nothing to worry about....in fact; you can now buy muffin pans that are made from silicone; and some fancy chocolates are also made in silicone molds.....I hope this helps.....matt

[CAL]

it's just silicone. It's not going to hurt you, unless you eat a whole bunch of it.

[Aaronw]

When I was at the IPMS nats last year, there was a vendor selling resin casting supplies. One of the things he had was food grade silicone so you could "cast" baked goods. That gave me some ideas, look honey '57 Chevy cupcakes.

Thats a good idea with the old microwave, I have one I was about to toss.

[James Flowers]

What about the rest of my question ?

[Jefbo]

What about the rest of my question ?

Hi Mustanglover1951,

You wrote:

I just bought one and was reading on the box. Says you can use a microwave to warm the mold. Question will this affect the use of my microwave for food use? How bad are the fumes or vapors ? Do you need a respirator ? Thaks for any information you can give me.

No, none noticeable & no.

I would recommend warming the molds, the results are better, however I would not recommend warming the molds while cooking food

I have called the folks at Allumilite, and they are very helpful and friendly.

Jefbo

[Smart-Resins]

Yes, it is safe to warm the mold in the microwave. That is the quick way.Is supposed to better to kepp it warm on a hot plate though. There is a smell to it after warmin it, but it is non-toxic to you.It does not affect the micro-wave, mold or food to be nuked later. A respirater is not needed either.Maybe when grinding the resin parts when you munk up, esp. if theres TA on them LOL. Otherwise, very safe.Do have fun and always ask wuestions, dont get discouraged.By the way, what are you planning on casting?

[James Flowers]

Thanks again for the info . I don't know what I will try to cast yet. I was thing about some bus wheels from a Hubly school bus it has one wheel missing. The bus looks to be close to 1/25 scale. I am thinking about a drag bus from it. Has anyone else had or seen one ? You can go to e-bay and look on Hubly Toys and see what I am talking about. I will have to learn how to post pictures one of these days.

[dustym]

Well I have to ask. Why heat the mold?

[Dave in Seattle]

Well I have to ask. Why heat the mold?

When you mix the two parts of the resin together, they actually harden by a chemical reaction. This process is an exothermic reaction, meaning it creates heat as it happens. The heat created needs to go somewhere, and is typically absorbed by the mold itself. That heat absorption is controlled by how much heat the mold already has when the transfer starts. Therefore, when you heat the mold, you are slowing down the speed of the reaction by raising the temperature of the mold so that it's capacity to absorb exothermic heat from the chemical reaction is diminished.

Pouring mixed resin into a cold mold is sure to "freeze" the pour before all of the cavity is filled.

Hope this helps.

Dave VanderWal

[Smart-Resins]

In short term, heating the mold helps to reduce air pockets. Now to also help reduce air bubbles in the resin, it is also common practice to use a poweder like talcom powder or baby powder.This helps to "de-gas" the resin orhelp minimize the air bubbles.Also while mixing make sure you mix slowly to help ensure you dont add air bubbles to the resin, and also try to pour slowly.With the alumilite, I know by experience this can be difficult as time is very short.Practice helps here! also, if you go onto thier forum and ask around, you may find that leaning the mixture may give you a few seconds if you are not looking for resale quality.Without a pressure pot, you will have some air bubbles.On rims, these tend to be where your lug bolts ect. are. So do expect it and plan for it.Make sure you have a air escape on your mold to help reduce this.Also, if it is a one piece mold, you can take a pin and pop any visual bubbles until the resin begins to kick.With Alumilites, this will be evident as it will start to go from semi-clear to a milky color. Hope this helps.Jody

[James Flowers]

Where do you put yhe baby powder or talcom powder ? You guys are making it sound like it is alot of trouble to due this. Seams like know one wants to give a straight answer about this . I don't want to sound ungrateful but you folks are confusing me.

Edited January 15, 2008 by mustanglover1951

[lordairgtar]

Usually on a babies bottom

[James Flowers]

Usually on a babies bottom

Thanks alot. just what I need. Ha, Ha. A good laugh. I mean that in a good way.

[Aaronw]

Nobody is trying to confuse you, there are a lot of tips and tricks to casting, and for every one you get someone will disagree.

Alumilite has some good tutorials on their website, I'd start there. When you have an idea what you want to cast, come back for some specific tips, because there are different ways to design the mold and what works for one part may not work so well for another.

People can give you a lot of advice but a good chunk will be trial and error on your part.

I have never heard the talcum powder technique so I can't help you with that and am kind of curious myself.

Start small and work with small amounts of material, when I first started I made this big mold with all kinds of parts. Well that was kind of stupid because I didn't need as many transfer cases as wheels, but since I couldn't always remember what was under the pour hole that is what I got. Also some parts wear out the molds faster so I still have some pieces of that mold that are good and part of the mold that isn't so good. I also used to waste a lot of resin because I'd mix up too much and couldn't get it all poured before it started to cure. Always keep a useful mold handy for any excess, you don't want to have to start looking around for a mold while the 10 ml you have left sets up. I usually keep something on the larger size with a largish pour hole, A single sided molds of something like a spare tire is a good choice.

[Smart-Resins]

It was someone on LSM that told me about the talcum powder trick. For the amount of resin, there is a formula to try to figure out close to the amount you will need.I will have to dig it out later. Also, you can buy a small digital scale on ebay for a few bucks that will help you mix up about what you need. I am not trying to confusse you.Just give ya some tips.I went through a couple of boxes and got very frustrated and was about to give up when I started talking to other casters and getting tips to do better resin parts. I am a stickler about air bubbles and loss of detail, so I try to do good parts.Thats wy I just bought the pressure pot.Have not had a chance to try it yet, but had to pick it up since it was only $40 on harbour frieght.As for the fumes ect., think I gave ya straight answeres on that?

[Modelmartin]

Regarding the Talcum or Baby Powder - it gives you a much better surface finish. I just pour a little in the mold and rotate it until the talc covers all of the casting surface and then shake off the excess. It works really well, is cheap, and gives you a better part. I haven't ever put it in the resin but don't see why it wouldn't work. Whatever you add whether it is a filler like the powder or colorant - add it to one side of the resin (A or B ) and then mix the A and B together. It gives you more time for pouring.

Regarding heating the mold - I do it when I want to make sure a hard to cure resin like some of the soft resins are being used. If you heat up the mold for your regular resin it speeds up the cure. I like to give my molds more time to de-air by extending the cure. I store my resin on the basement floor to keep it cool!

I have never used Alumilite's resin but I have never been tempted to try it due to everything I have heard about it. I use a brand that my local supplier repackages and I have about a 3 minute pot life for fresh resin and cooler temps.

Mustanglover, you just have to start pouring and get your hands in it. As you can tell there are lots of opinions and techniques and there are also lots of different resins. There are at least 10 different ways that will work well. You just have to figure out what works for you. You will make mistakes and waste rubber and resin. WE all did and even someone like myself (have been casting since 1980) still makes the occasional boo-boo. Good luck!

Edited January 15, 2008 by Modelmartin

[James Flowers]

Thanks to all for the info. I will try it and see what I come up with. Part of the learning of a new skill is the furstration of doing so. Thanks again.

[Aaronw]

How you pour can help reduce bubbles too, this is easier with the silicone but can be done with the resin too. Try to pour with a thin "string" of material from as high as is practical without missing your target (12" for silicone, 4-6" with resin), this will make the larger bubbles break, while they would remain intact if you just glopped it in a big blob.

[CAL]

Thanks to all for the info. I will try it and see what I come up with. Part of the learning of a new skill is the furstration of doing so. Thanks again.

Like model martin said. You just got to get in and do. Figure out what works best for you. There is a pretty good learning curve and a number of different products that give different results.

Throwing away product is part of the learning curve. Some things just don't work out or a mistake is made. I have thrown away a lot more parts than rubber.

So far I have liked Smooth On 320 the best, but I have found a good Smooth On rubber. I use Experts Choice RTV.

I also found, when not casting with vacuum or pressure the more shallow the mold the better the results. I try to pour the resin in a slow steady stream and then go back and push out the airbubbles with a tooth pick. It has worked pretty good with 320, and not so good with Pur-A-Cast.

I haven't heard of or used baby powder either, but I am interested in giving it a try. I have always used Smooth On Universal release agent, which has always worked well as long as it's dry when you pour your resin.

Eventually you will probably want to start vacuuming your rubber, and pressure, spin or vacuum cast you parts, especially with more complex masters and molds.

Probably the single biggest thing that is a problem with casting resin is moisture and humidity. Second is temp.

[Smart-Resins]

A quick couple more tips for ya. First, I use Price Discrolls Ultra 4 polyester parfilm paintable mold release. You get a large can for not too much and a little goes a long way.Great item. Second, if you want to have your part come out colored, you can paint the inside of your mold before casting.The resin will pick up the paint and give you a fairly decent colored surface. If you want your molds to last longer, they have stuff out there to prolong its life.I have not used this stuff yet though.They also have dies and pigments to change the resins color. There are as several have said, other resins out there with longer pot life.When I am done using up my alumilite, I will try the resin from micro-mark as they have 3 minute and 7 minute pot life. Now another one, if you ever decide to use a pressure pot, bump the mold rubber from #3 down to #2, if you havnt already so it will hold up better. Now also to help with bubbles, you can use a sterynge(spelling) to "inject" your mold with. If you want a better how to, send me your email addy and I will forward a copy of a tutorial I got from Chris Buck wich is focused more on molding bodies, but it does have some really good info including the equation to figure out how much resin you will need.Hope all info is helpfull, and does not bog you down too much. My suggestion is to start out simple and as you go, try some other trick as you get better at it as to not get overwhelmed.Good luck and most importantly, have fun!

[Smart-Resins]

A quick couple more tips for ya. First, I use Price Discrolls Ultra 4 polyester parfilm paintable mold release. You get a large can for not too much and a little goes a long way.Great item. Second, if you want to have your part come out colored, you can paint the inside of your mold before casting.The resin will pick up the paint and give you a fairly decent colored surface. If you want your molds to last longer, they have stuff out there to prolong its life.I have not used this stuff yet though.They also have dies and pigments to change the resins color. There are as several have said, other resins out there with longer pot life.When I am done using up my alumilite, I will try the resin from micro-mark as they have 3 minute and 7 minute pot life. Now another one, if you ever decide to use a pressure pot, bump the mold rubber from #3 down to #2, if you havnt already so it will hold up better. Now also to help with bubbles, you can use a sterynge(spelling) to "inject" your mold with. If you want a better how to, send me your email addy and I will forward a copy of a tutorial I got from Chris Buck wich is focused more on molding bodies, but it does have some really good info including the equation to figure out how much resin you will need.Hope all info is helpfull, and does not bog you down too much. My suggestion is to start out simple and as you go, try some other trick as you get better at it as to not get overwhelmed.Good luck and most importantly, have fun!