Extend the setup time of Resin, possible?

Confusion · Post by **Confusion** » Mon Jun 27, 2005 1:33 pm

For a project that me and a buddy are doing, we are casiting a number of small parts. Using an eye-dropper to help force the air out. The problem we are running into, is that if we mix enough resin to actually do each piece, it starts to setup in the cup before we have done more that two or three pieces.

So what can we do to lengthen the time to setup? We would actually like to get a 'full run' of all the pieces.

We are using the Alumilite Regular Resin, so if there is another brand, that would good info to have. Micromark's claims 7 minutes, can anyone attest to this?

Marcal · Post by **Marcal** » Mon Jun 27, 2005 1:57 pm

Is it a 2 components resin??

If it is so, try find out which of them is the catalizator. When you are sure, try to do a mixture with more resin than catalizator. Usually the mixture is 1:1, you can try 1.25:1 or whatever... But it will need more time to get completely strong...

hope it helps !

Confusion · Post by **Confusion** » Mon Jun 27, 2005 2:00 pm

Yes, it's a two part resin.
I think I have already answered my question though, in appears that different types setup at different rates. I really should actually complete looking into something before asking the question rather then doing them at the same time.

Post by **TER-OR** » Mon Jun 27, 2005 2:10 pm

One word of warning - the 10 minute set-up time resins like Smooth CAst 310 or 322 are kind of sensitive to mixing. I measure in two cups, add to a third to mix, then pour into a fourth and mix again, then in the mold.

Reason? You will never completely mix the resin, and a local concentration of one part along the side of the cup will screw your batch.

Injecting with a pipette is a good idea, though. It will save you a lot of frustration when doing detail parts at home.

I find SC321 with a 5-min potlife is good enough for what I do.

macfrank · Post by **macfrank** » Mon Jun 27, 2005 4:29 pm

Alumilite has a web page.

Alumilite FAQ wrote:7: Can the set time be increased?

Yes! To get an additional 30 - 60 seconds, cool the 'B' side of Alumilite in the refrigerator for 3-5 hours. When you cool the resin it is important to remember to pour into a warm mold for proper curing.

I use Alumilite, and like it, but you should use a resin with a longer working time if the extra 30-60 seconds isn't enough.

modelbaseguy · Post by **modelbaseguy** » Tue Jun 28, 2005 11:55 am

I cast small projects all the time and while the refridgerator trick does buy you a little extra time it is all relative. What you are doing is chilling the resin to slow the process but when using small amounts of resin it will come back to room temp very rapidly. I would mix larger amounts of resin and use a serenge like you get for despencing liquid medicines orally. These don't have needles but rather a plastic tip like a pipette, maybe a little larger. Mix the resin and quickly fill the serenge trying not to hold onto the serenge where the resin is as the heat from you hand only heats it up faster. Needless to say you will waste some resin but that is the price you will have to pay. The thing about using pipettes or serenges is that you have to clean them immediately or trash them. I prefer using a funnel because gravity will force the resin into the mold and it is reusable. You may want to rethink your molds, perhaps you need another vent or two to get rid of the bubbles. A vent does not necessarily have to be eposed either. If you have a trouble spot that you cannot vent to the surface try adding a small vent just to absorb some of the trapped air. You still end up with a small plug to cut off but at least it is not a hole.

If you are going to be casting parts on a regular basis you may want to invest in a pressure pot. You can make one yourself from a paint pot that can be purchased at a supply house such as Northern Tool or Harbor Freight. They are relatively cheap, less than $100.

Also contact the manufacturer to see if they have something with a longer pot life. Altering the part A and part B mix ratios will only give you a big gooey mess.

Good luck with your project, let me know if I can help.

macfrank · Post by **macfrank** » Tue Jun 28, 2005 12:53 pm

I've seen these mixing tips used with 1:1 rubber compounds and epoxy and they really work great.

I wonder if there are refillable versions of the epoxy containers - just fill them up with Part A and B of Alumilite (or a similar 1:1 mix resin) and have it mixed as you fill the mold.

Confusion · Post by **Confusion** » Tue Jun 28, 2005 3:36 pm

hmm.. Looks like an interesting idea, not sure I want to spend $42.00 to find out though.