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  • 1 lb.


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HSIII mold rubber recreates minute details, is chemical resistant, very durable and easy to work with. HSIII is a high tear strength RTV rubber with exceptional flexibility and tear strength. Great for molds with deep undercuts. RTV mold rubber vulcanizes (cures) at room temperature in 24 hours. This kit contains enough catalyst and rubber base to mix 1 pound of mold making powder. You should get 30 to 50 parts per mold. Mold making instructions not included, recommended for advanced mold makers.

Product specifications:
Mix Ratio 10:1
Mixed Viscosity 150
Specific Gravity 1.16
Pot Life 2 hrs.
Demold Time 24 hrs.
Platinum/Tin Cure Tin
Hardness 10
Color Pink
Linear Shrink (%) .48
Tear Strength (ppi) 110
Elongation 575%
Tensile Strength (psi) 400
Temperature Range (F) -67-392

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Customer Product Reviews

Rated by: Bruce D in Michigan
HS3 is a great solution for many molding needs. I have used large amounts for many mold projects from copying cabinet knobs to even duplicating the body of inert hand grenades as gifts to friends who collect military items. It is very strong when cured and will even copy a medium threaded surface with ease. Yes it can be messy, but I overcame the messy pour issues by mounting a large plastic plumbing valve to a air tight container. But with the make shift spigot, it takes awhile to transfer to a mixing container but I found it worth while to work on preparing my items to be cast while the quite thick silicon transfers to the mixing container. (Up to 30 mins for about 6 to 8 ounces) I guess you need patience to do it my way, but I am always happy with the result. All told, a great product for molding fine details...
Rated by: M. in Ct
This product is fantastic! I used a few other mold making products that didn't work nearly as well, and the price is really reasonable!
Rated by: J B. in Port Allen, LA
Good, tough, stuff. This stuff is a lot harder than some other mold making material that I've worked with. Very tear resistant. Somewhat messy and difficult to work with because it's so thick (like molasses in January). Instructions give ratios by weight and volume.
Rated by: Graphi . in ,
Highly recommended product! Cures at "Room Temperature Vulcanization" = RTV Although this product says it is recommended for advanced mold makers... It is really quite easy and safe to use. Excellent Product at a realistic price!

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