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Polyester Resins - Products

J-Cast 70D Polyurethane Resin

Order Ref. No AAO 17698 (2kg pack)  AAO 17698 (10kg pack)

J-Cast 70D is is a two part quick curing polyurethane casting system curing at room temperature to a rigid tough material. It is ideal for the rapid production of small castings, models and prototypes, particularly from silicone rubber moulds.



Part A (Polyol)

Part B (MDI isocyanate







Specific Gravity/gcm-3 @25C



Viscosity / mPas@25C



Mix the resin component before use to keep in suspension the moisture scavenger. If a talc is to be added to the resin, mix primarily to both parts A and B before combining the hardener to the filled resin. Mix carefully to avoid air entrapment then apply quickly.

J-Cast 70D Part A

100 parts by weight

J-Cast 70D Part B

100 parts by weight

Pot life of 100g @ 25C

2 to 3 minutes

Demould @ 25C

20 to 40 minutes

(depends on the thickness of casting)

After Crosslinking

Shore Hardness/D [ASTM D2 240]


Tensile Strength/Mpa [ASTM D 638]


Elongation at break/% [ASTM D 638]


Compressive strength/% [ASTM D 695]


Flexural strength/MN/m2 [ASTM D 790]


Glass transition/C [ASTM D 3418]


We are now stocking the Reichhold Gelcoats and Resins which have several advantages over the older types that we have previously supplied. These gel-coats are very high quality, are easier to apply, have less porosity and better gloss retention.
There are considerably more resins available than shown on the following pages which are simply a representative selection including the more important resins which we will normally have available from stock. Resins and gelcoats marked* and any other resins not shown on the list are only available to special order.
All stock gelcoats and resins are pre-accelerated, except 420-100.
The recommended film thickness for all gelcoats is 0.55 - 0.85mm which will normally be achieved by using 700grm/M2 for brush gelcoats and 500grm/M2 for spray gelcoats. Due to the ease of application of the modern gelcoats care must be taken to avoid brushing out too thinly.
The following brief specifications may be sufficient for most users, if a full data sheet is required please do not hesitate to contact our sales department.
The following information regarding resins and gelcoats is based on results achieved through laboratory test in the Reichold technical departments.
The information is correct to the best of our knowledge and is supplied for the guidance of our customers, involving no responsibility on our part.


Wax Additives

A paraffin wax solution for adding to gelcoat resins used for coating the backs of mouldings, prevents the sticky surface caused by the air inhibition of the surface of the gel coat resin. Add 1 % to laminating resins and 2% to gelcoats.
Order ref.
AA 017990 1 kg    AB 017990 4kg

Polyester Colour Pastes and Gelcoats Colour Charts

Please note that each computer display is unique and therefore no two monitors will display colour ranges the same. The colour charts below should only be taken as a guide to the range of colours available and not as a true representation of actual colours.

The Llewellyn Ryland ‘Standard’ range is our normal stock range but we can supply pigments from the RAL and BS5252 ranges to order. Colour charts are available on request.