I made a mold yesterday using the High Strength 3 product. I weighted 250 grams of part A and 25 grams of part B. I tried to be very careful in making sure my measurements were accurate. The mold came out too soft so it obviously didn't have enough hardener in it. Does anyone have any suggestions on how I can prevent this problem in the future?
Sorry for the long delay. I should have come back to this tread sooner.
1) Did you mix the base (side A) before measuring? (I didn't premix part A)
2) Did you shake the catalyst (side B) before mixing? I've taken to mixing both sides (separately) of everything I use before I measure and mix so that if anything has settled it's remixed. (No, I didn't shake Part B either).
3) Did you mix for an entire 3 minutes? (I believe I did but I didn't keep a timer or watch handy. I tried to make sure there were no streaks in the mixed product. )
4) What temperature was the area you had it in? Was it around 70 degrees? A cooler temperature slows down curing. (I did this inside my house so it had to have been over 75 degrees.)
5) How long has it been since you poured? Sometimes it takes a longer to cure if the mold has been in a cooler area. (I made one half of the mold but ran out of material. It took about 10 days for the next batch to arrive before I could make the other half.)
If you've done all these, then we'll go from there and figure out what we can do to fix the mold. (I don't think this is the right material for the parts I'm trying to make. I think I need something that is sturdier)
Then you might want to try the High Strength 1 which is a stiffer material. Or even one of the Plat series, I use Plat 25 and it is stiffer mold than the HS-3 ones I've made. But you do have to be a bit careful of the material you are making a mold of as there are a few things that will inhibit the Plat series.
I sometimes keep mixing until past the time I stop seeing streaks just to make it to the 3 minute mark, don't know if it makes much of a difference but I usually don't have a problem when I do that. Plus I wear a watch with a stop watch feature so it's easy for me to time it. And both sides A and B will settle in as little as 24 hours so giving each a little shake (side B) or stir (side A) does help. 75 degrees is still a good temperature so that should be fine.