Alumilite Resin question

[Sledsel]

Which part is the hardener? "A" (brownish color) or "B" (yellowish clear)? I have mixed 1:1 and have had a few casts remain pliable and think I need to add a tad more hardener.  Thanks! 

[Mark]

Four things:

-Are the two parts meant to be mixed in equal portions?  If so, the bottles should be the same size.  Everything else being "right", you shouldn't need to alter the mix.  Just make sure the two parts are properly measured. 

-Don't allow utensils or containers used for "A" to come into contact with "B".

-How old is the stuff? It does have a shelf life, which drops off drastically once opened.

-Make sure "A" and "B" are each mixed individually prior to combining them.

[Sledsel]

9 minutes ago, Mark said:

Four things:

-Are the two parts meant to be mixed in equal portions?  If so, the bottles should be the same size.  Everything else being "right", you shouldn't need to alter the mix.  Just make sure the two parts are properly measured. 

-Don't allow utensils or containers used for "A" to come into contact with "B".

-How old is the stuff? It does have a shelf life, which drops off drastically once opened.

-Make sure "A" and "B" are each mixed individually prior to combining them.

Well, it has not been opened for long, a month with periodic use.

Mix is to be 1:1  equal mix. about 3 times I have had casts stay soft. Dry but soft and pliable.

Seems all is done right otherwise. Maybe I need to mix longer? 

[Mark]

More mixing would be the next thing to try.  I wouldn't even try to cast any parts; just mix a small amount, observe what happens, and test the results.

Resin is cheap compared to mold material.  Losing/"wasting" some of it is preferable to wasting one or more uses of a mold in my opinion.

[NOBLNG]

I prefer Smooth-On resins over Alumilite. I have also found that the Alumilite stuff stays a little soft after the advertised full cure time. I find they do eventually harden up though. 

[Steamboat]

Try preheating the mold and resin before you mix it.  I usually put it in the oven on an old cookie sheet on Warm for about 2 minutes (when my wife isn't looking). 

I was able to get Alumilite to cure using preheat, but I never liked the results.  The castings were very porous.

I have been using MPK Enterprises resin for about 10 years now and have been very happy with it.

 

[peteski]

Are you measuring by volume or weight?  What kind of quantities are we talking about?  I used to get successful mix of resin even in quantities of like 20 drops of each part from an eye dropper.  I cast some really small items!

I used to use Alumilite (back when they only carried the fast setting tan resin) but I moved on to Smooth-On. Not because Alumilite is bad - I found Smooth-On had more varieties of resins with different setting times. I think Alumilite now also has a larger variety of resins available.

Yes, thorough mixing is important, but if the resin is not mixed properly you will see swirls of sticky uncured liquid in the hardened resin.  Catalyst is the coffee colored liquid which if sits for several minutes develops a clear oily layer on the top surface.

[Sledsel]

Thanks everyone

I have been mixing by volume and probably rushing the mix fearing setting up while pouring. I mixed a batch longer than before and seemed good this time.