Alumilite White Pot Life seems short?

[johndtuttle]

hey there,

Casting a large spook (~6oz volume) with a slightly greater than equal amount of microballoons. I need a light body as the lure has lead internal ballast for action needs.

Anyways, the problem I am running into is a very short pot life. I was expecting 2.5-3 minutes but am finding that it is becoming impossible to pour after only a minute or so.

Is the high amount of microballoons decreasing the reaction time (ie sets up faster)? Temps in the room I am working in are ~70F so should not be contributing.

Is there something I can do to increase pot life?

Because I failed to poor the full volume the first attempt due to this problem I mixed up more and added it on top, the bonding to the first seems strong (and is strong enough for testing) but wonder if there would be any strength issues going forward?

Thx for all replies and best regards,

John

[rocko]

John,
My own experience is the same. Microballoons greatly decrease the set up time for Alumalite and make it quite a bit thicker for pouring. It also expands a bit while curing. If you plan on using them for your bait, I would make the mold a bit different to account for this, with a bit larger pour hole. Perhaps skipping the heating of the mold will help a bit. Once the reaction starts, there's not much we can do to slow it down. The different versions of Alumalite all have a bit different cure time, so you might want to choose the one with the slower cure to use. I am sure Mike will chime in on this one for you.

Rocko

[aka anglinarcher]

No issues with bond strength, you cannot get the two to come apart.

My testing wth Alumilite White and Microballons is indeed the same as yours. If you are pouring a large amount, it is hard to mix it up well and still get long pour time. Pouring in two or more parts works fine to fix this.

Try mixing part A and part B together first. You will see that it clouds first, then clears up a bit when mixed. Now dump the microballons and give it a quick stir. This speeds the mix time substantially.

Like rocko said, use a larger pour hole. No need to pre-heat the mold at all with Alumilite White. Pre-cooling the two parts will slow the reaction, but it also thickens it - not much help.

[Watchhiller]

............................

[dahlberg]

Hey Watch
IMO, you're on it. You always have more time on a thick mix by ballooning A and B individually. Stir like mad after mixing and pour a very thin stream as possible, trying not to let the liquid hit the sides of your pour hole if possible. With lots of balloons it should expand enough to loose any bubbles, especially if you give the mold a gentle squeeze once or twice and then top it off.
L

[aka anglinarcher]

Seems like you have a lot of options to consider now.

I had some problems with high balloon mixes not setting up completely. It stayed sticky to the touch. It turned out that even though I was mixing half the balloons in each side and then "starting the clock", I was not getting a good enough mix with the time allowed before it started to set.

The best answer was that the thick parts were not mixing well enough, so as Larry said, mix like crazy.

I still think that is faster and better to quickly mix parts a & b, it will take only a few seconds, then add the balloons. The balloons do not need to be perfectly mixed to make a great final end product.

Try both options and let us know what works for you.

[johndtuttle]

Thx for that to all. I made my pour hole bigger so that I could pour my mixture faster and get it in before hardening. I was trying to avoid as much wastage as possible (these bigguns' are pricey to pour) but a larger hole lets me get it in there fine. Just have to accept a little more to trim off after curing.

Thx again and best regards.

[Mike - Alumilite]

Another trick of the trade is to chill both the A & B side for a half an hour prior to pouring. Yes, this will thicken it initially (only for the first minute until it begins to react and generate heat in which it will thin back down ... typically by the time you are ready to start pouring). The microballoons will actually delay the reaction and slow the cure down as well as flatten the cure. It won't go from liquid to solid nearly as fast when you add that many particles in the way of the resin reacting by itself.

When I pour small parts, I measure the A, B and microballoons all at once and just stir thoroughly. When pouring bigger pours, I premix the microballoons just to make sure I have time to break all the clumps of microballoons up and don't waste pot life doing it if I've already mixed the A and B together.

Whenever you put dye or filler into the resin it becomes much more difficult to tell when you have the A and B mixed homogenously. Therefore, always overmix it to make sure you cover yourself. My rule of thumb, is when you think you have it good and mixed, mix every part one more time ... middle, scrape the sides, and the bottom one more time.

Higher temperatures directly affect the open time ... mid 70s in your shop compared to mid 60s will reduce the open time more than you think ... same goes for higher and lower than those temps. Temp and mass of pour directly affect the open time.
Mike
Alumilite

[johndtuttle]

Thx very much for that Mike. All in all things are going fine, my most recent cast turned out great. Little bit larger hole and more aggressive mixing of A and B after separately adding the micro balloons to each.

I'm off and running .

ps. thx again for all of your feedback.