Jesmonite Strength Testing

Creative Resources Distribution has done some strength testing of Jesmonite in various configurations. Jesmonite is intended to replace polyester resin as a non toxic and non-flammable alternative for casting and laminating.

Note that Jesmonite can also be used to laminate on the inside of latex or silicone moulds - a Jesmonite Thixotrope additive is available to produce a gel coat for the initial layer.

Click the pictures to the left to see the bigger versions.

Jesmonite Test 1

A pattern was drawn on an A4 sheet of paper, cut out, and glued with paper glue to make a curved item. This method for construction was chosen in order to test the strength of the Jesmonite which was later stuck to it, rather than the strength of any other structure.

One layer of Jesmonite, mixed as directed, was painted onto the paper along with one layer of standard 30gsm fibreglass surface tissue. After about 20 minutes this was hard to the touch and allowed the next stage to be completed.

The next layer consisted of overlapping standard 600gsm fibreglass chopped strand mat laid up with more Jesmonite mixed as directed.

The outside of the item was also coated in Jesmonite, mixed slightly thicker than directed, and the item was trimmed around the edges.

After 24-48 hours, the Jesmonite is fully hardened. The item is strong enough to stand on and extremely impact resistant. Although not quite as strong as a fibreglass piece made with polyester resin, Jesmonite is a very suitable alternative where a non toxic and non flammable product is preferred.

Watch this YouTube video of the impact and strength tests on the item:



Jesmonite Test 2

For this test, Jesmonite was laid up onto a piece of A4 paper with one layer of 30gsm surface tissue and one layer of 600gsm fibreglass mat. The item was then trimmed down to a piece roughly 5cm x 25cm.

Various weights have been applied to the item while it is propped between two cups as shown:

1) A two litre bottle of water, which weighs 2Kg was placed in the middle of the item while the ends are suspended on the cups. As you can see the item has flexed a little.











2) Next a 4Kg kettle bell was placed on the item in the same fashion. There is a little more flex to the item.





3) An 8Kg Kettle bell is placed on the item. You can see there is a lot more flex to the item, but it did not crack or break. It also returned to it's normal shape after the weight was removed.

In conclusion, Jesmonite is a suitable material where a non toxic and non flammable product is preferred, for movie prop construction, costuming and model making.

Look at our pricing on Jesmonite or contact us for more information.