Making Resin Gray.

[suwalski]

Hi guys,

I've always wondered about what kind of resin or additive is used to make the standard gray-and-gritty resin like we've all purchased at one point or another.

Is it just the same same old white/yellowish resin with the readily available aluminum powder?

I ask because the SmoothOn stuff I'm using is just a little on the soft side for some of the thinner parts I'm making, though I'll be damned if I'm going back to Alumilite.

Cheers.

[Johnnycrash]

What Smooth Cast ## are you using??

Adding aluminum or any dyes will NOT change it's strength to stronger/firmer. And in fact, they make the resin weaker. Although by an amount that is pretty much negligible.

To get resin that grey coour, a few drops of black dye are added to the white/tan resin. The tan resins will take the dyeing better than the white resin, due to the type of chemicals they add to the white to make it, well, white.

[suwalski]

I'm using SmoothCast 305. But do casters out there really just add dye? Why on earth would DLM, for example, do that? It would only add time and expense to the casting. My only guess would be colour uniformity; but otherwise, no real advantage...

[Johnnycrash]

I'm using SmoothCast 305.

Well, there's your problem. The slow set resin will always be weaker than the fast set. Again, it has to do with the chemicals that inhibat the cure. Get ye some 320. It's tan, and fast cure (10min demaold).

But do casters out there really just add dye? Why on earth would DLM, for example, do that? It would only add time and expense to the casting.

Yup, it's just that easy. Many casters like to dye their resin a custom colour, as it helps weed out recasters. If it's not Caster Colour 6097146811687, it's a recast. As for expense... The cost is next to nothing. A 4 oz bottle of dye (pigment) is about $5.00, and it only takes about 10 drops or less to tint a full gallon. So, it goes a VERY long way.

[Kylwell]

Because it takes so very little dye and really doesn't add much cost @ all and in many cases helps id the manufacturer.

[Kylwell]

damned dble post.

[Ziz]

I'm using SmoothCast 305.

Well, there's your problem. The slow set resin will always be weaker than the fast set. Again, it has to do with the chemicals that inhibat the cure. Get ye some 320. It's tan, and fast cure (10min demaold).

Smooth-On's site says that SC325/6/7 is designed for tinting and costs the same as the 300 and 320 lines. Not that the tinting won't work with 320, it'll probably just work better with 325. Here's the rainbow of tints.

[Blappy]

I use SC-305 and 300 primarily. If I mix 500ml of resin I will three or four drops of tint only. I usually do gray (black tint) for garage kits and what ever colour the customer asks when I am doing prototyping jobs.

I make mine gray for the sole purpose of the builder. I hate white castings because it is hard to see details and flaws that need fixing. This way you can get a lot of work done easily before having to prime the pieces.

I have also found that white resins take colour BETTER then tan due to the pure colour.

I have a bout a half dozen different resins around that I use depending on the job.