HARDEING & CURE.The attached manufacturers specification sheet states that at 25c temperature & using 1.25% of Superox 46709 or Interox HA2, Gel time is 18-30 minutes & cure time is 50-80 minutes.
Using our standard catalyst Butanox M-50 that is slightly less reactive than the 46709 & HA2, we advise using 2%, which is 22 cc’s per kilo of Resin.In lower temps the above gel & cure times would be longer, as also if the resin is cast in thinner layers, due to more rapid loss of gelation heat.We do not advise using this Resin in less than 25c or 77f, because the percentage of Cobalt Accelerator added at time of manufacture is far less than the proportion added to most other resins in order to avoid giving the resin the mauve tinge, apparent in most other Cobalt Accelerated resins.It is the chemical reaction of catalyst with the Cobalt that hardens the resin.
MOULDS.For casting paperweights or embedding specimens, round bottomed teacups or bowls are often used, also square or oblong mould made of plate glass, aluminium etc, these should have a slight lead upwards of the sides & ends to avoid a “mechanical” bond which would impede release.Plaster moulds are also used & Silicone Rubber Moulds, which will flex for release.
RELEASE AGENT.No release agent is needed with Silicone Rubber Moulds, but moulds made of Plaster, metal, glass china cups etc, require use of Release Agent.The Honey Wax Polish listed in our price list is suitable for this.The Liquid PVA Release Agent can also be used.
CASTING METHODSIdeally the ambient temperature should not be less than 25c & never less than 20c.This means air temperature as well as that of the resins & moulds.When pouring in layers, pour carefully to avoid resin surging up, which would leave a layer of resin on side of mould.If this happens the thin layer of surged up resin hardens on side of mould and the next pour adheres to this & results in a protruding lip of resin adhered to the next pour.Each subsequent layer should be poured the instant that the underlying layer goes tacky hard.Delay will make the division line more visible.Avoid incorporating air bubbles.The resin should be allowed to stand at least 24 hours in as warm a temperature as possible to allow any air bubbles to rise & dissipate from surface.
EMBEDDINGcoins, flowers & other objects.This is usually done in round-bottomed bowls or teacups.The round bottom will be the top of the finished casting so object to be embedded are placed upside down.Pour initial layer of resin, correctly catalysed & allow to harden.Place the object onto the surface & pour the successive layers.Each layer should be poured at the instant the underlying layer goes tacky hard.Delay will make the division line more visible in the finished casting.
TRANSLUCENT COLOUR PASTEScan be used, but in ratio of 1% or less by weight to the resin, unlike opaque colour pastes which are added @ 10%.The top layer poured, which will be the bottom of the finished casting, is normally pigmented to highlight the embedded objects.Metal Powders are often used.
CASTINGS THAT ARE TO BE MACHINED.These will chip unless the Flexible Additive resin is added in ratio of 10% by weight to the Clear Casting Resin.
UV LIGHT STABILISING ADDITIVE: NORPOL 1637is sometimes used @ 1% or 2% where flowers, especially heather are being embedded to prevent UV light fading their colours.
These additives in proportions stated do not impair CLARITY of the casting.The Flexible Additive Resin is also used where the finished casting is to be subject to wear or abrasion, such as doorknobs to avoid chipping of the castings.
GELATION HEAT & RISK OF CRACKING.Our notes on the previous formulation “34-50, which was much slower hardening, advised against pouring layers of much less than ½” thickness because of loss of gelation heat could impair the hardening and not much more than ½” thickness because the increased gelation heat could cause casting to crack.This new formulation Polylite 32032-00 is very much faster hardening than the 34-50 & manufacturers Spec. sheet states that it can be used for coating the tops of tables, which would be a very thin layer, say 1/8”.If poured in too deep a layer there is a risk of cracking due to the greater degree of gelation heat generated in the larger volume.In ambient temperature of 25c & using catalyst M50 in ratio 2% into a mould 4” x 2” surface area or if circular 3” diameter there should be no risk of cracking if poured to depth of 1 ½” per pour.If catalyst additive is reduced to 0.8% (4cc’s to lb of resin) it should be possible to pour a whole litre of resin (1 litre equals 2.2 lbs) in one pour, without the risk of cracking.In volume this approximates, 4” x 4” x 4”.One of our very skilled & experienced customers can make in one single pour castings measuring 12” x 12” x 15” depth.He does this by reducing the percentage of catalyst added, putting the casting in an oven made of plywood, insulated with REP Foam Sheets on the outside of the plywood and the oven heated with two 40 watt light bulbs, and he allows for seven days for hardening time.The catalyst is reduced to 0.2%.
TEMPERATURE.
The manufacturers specification sheet for the old formulation “34-50” specifies for ambient temperature to be 20c or 77f.
The specification sheet for this formulation 32032-00 specifies for ambient temperature to be 25c or 68f.
The resin will harden at lower temperature but will take longer to harden.The MINIMUM temperature is 16c or 60.8 f.
