Resin durability

[ERen89]

After some trial and error I have finally successfully made my first cast. Though i am noticing that due to its thickness, when i squeeze it feels like it will break, and I know if i pinched hard enough I will crack it. This is a shape i cast for a muzzle brake for a blaster i am making. Now is there a way to avoid this concern of flexibility/potential cracking?
I am pretty sure it is probably due to the type of resin I used, which is this Castin' Craft Liquid Plastic Casting Resin I found at Blicks.

http://www.ebay.com/itm/like/151548096356?lpid=82&chn=ps

Any resin suggestions?

 

[Contec]

Does the thing you are making need to be Clear? The resin you are using is made for encasing stuff and i believe not for making thin stuff.. If you buy resin that is made for fixing cars and boats and also use fiberglass, the part should hold it shape a little better.

 

[RogueTrooper]

Quality of the brand and ratio mixing can make and often break (pun intended) a resin piece.

I don't use the brand you have chosen, but the brand I use is only ever undermined by the mixing ratio.

 

[p00k1333]

Here's one result of a bad mix. A two part, 1 to 1 resin, and I messed up the mix by not having enough part A. The cast is about 3 weeks old and is like a piece of rubber. I've kept it just to see if it's properties will change over time.

LOL - not yet!

 

[NormanF]

First, the obligatory "then don't squeeze it".

With that out of the way, as others have mentioned that is not the best product for what you are doing. The biggest issue is that the amount of resin needed for that part will make mixing the correct ratio difficult unless you mix a large batch and waste most of it or get a very precise scale. For very small batches like this I use a digital reloading scale that measures down to ridiculously small amount. Most resins should give you the mixing ratio by volume and by weight. Here is the scale I use: http://www.amazon.com/Frankford-205205-Arsenal-Reloading-Scale/dp/B002BDOHNA