Question about ratio for mixing urethane

[joegreen]

I have some of this product https://specialtyresin.com/product/flex-it-70. It has a working time of 6 minutes and a fully cured time of 2 hours. It is supposed to be mixed in a 50/50 ratio. The issue I have is that between the mixing, vacuuming out the air bubbles and pouring it in the mold 6 minutes is not enough time for me to work with it before the mixture starts to get hot and cure. I was wondering if I mix in in a 25/75 ratio will that just increase the curing time or do you think that may also mess with the outcome of the product?

 

[AZjeff]

I worked with different resins for 15 years. Going to 25/75 is a HUGE change in ratio and yes you'll change the properties. I'd call the company, some will tell you how far off ratio you can go, some won't. You can gain a bit of timeby lowering the temperature of the A/B parts and even the mold. Also keep your vacuum chamber volume as small as possible. If you can't go smaller on the chamber you can take up volume with solid objects inside.

 

[joegreen]

I worked with different resins for 15 years. Going to 25/75 is a HUGE change in ratio and yes you'll change the properties. I'd call the company, some will tell you how far off ratio you can go, some won't. You can gain a bit of timeby lowering the temperature of the A/B parts and even the mold. Also keep your vacuum chamber volume as small as possible. If you can't go smaller on the chamber you can take up volume with solid objects inside.

thank you