Mixer options for Hard Sand home foundry

[not-a-number]

I am having issues with my hardsand going off too quickly. 5-10mins

I am using the resin system Techniset 6700 with Catalyst 17-712
This is supposed to be the longest setting option and should have about a 30min work time.

I use a dual mortar mixer in a bucket. The room temp is about 70F.

I believe the mixing is too intense and heating the mix, causing it to go off too quickly.
Im using 3% catalyst but I will reduce it to the minimum suggested (2%)


My questions are:


Is the intense mixing likely to be the reason for it to go off so quickly?
What do people normally do to mix hard sand at home in big batches (10+kg)?
Does anyone make small continuous mixers?




Thanks for the help.

[clear out]

As no one else has replied here’s a my experience in batch mixing exothermic stuff.
I was making stupas for Buddhist temples in a 10 to 1 sand and epoxy mix.
These took a long time to ram as the mould had a very small aperture due to the finished products wall thickness and delicate detailing in a MDF mould.
I ended up having a helper hand mix in small ongoing batches as I rammed up.
Not a very sophisticated method but worked well on the 3 I made.
Hows the Bugatti progressing?
H.

[not-a-number]

As no one else has replied here’s a my experience in batch mixing exothermic stuff.
I was making stupas for Buddhist temples in a 10 to 1 sand and epoxy mix.
These took a long time to ram as the mould had a very small aperture due to the finished products wall thickness and delicate detailing in a MDF mould.
I ended up having a helper hand mix in small ongoing batches as I rammed up.
Not a very sophisticated method but worked well on the 3 I made.
Hows the Bugatti progressing?
H.

Thanks. Yeah that should be possible but I havnt had a lot of luck in practice. You get funny joins in the sand and if it starts to go of in the slightest the new sand doesnt really stick. I guess if I had enough small batches coming in that it was essentially a continuous mixer id be good!:U

Ive got a chest freezer coming and the plan is to mix Part1&3 into the sand (this doesnt start the cure). Throw it in the freezer to get the temp down. Then mix in Part2 less aggressively. Since the sand is already wet and coated well, when I add Part 2 im hoping I can drop the mix speed.
Not sure what the next step is if that doesnt work. Probably making a small continuous mixer.

Yeah the project is going good. Ive decided to do the castings in the US. Which is a pretty big job when my workshop is on the other side of the world. Oh well, get to buy lots of tools!:U

[not-a-number]

So the answer was to mix the initial parts into the sand and then chill it down before adding the final part. If I chill it down to 10C I can get the work time to easily 20mins.