Got Resin?

[TER-OR]

Which resins have you used?
Which would you reccomend?
Which would you reccomend against?

[modelnutz]

I've used Smooth-on...and Industrial Polymer's.
CC-202 CC-200 real nice but tricky to work with...heating molds works well
SC-300 and 320 300 for small detail parts because it snap cures. Best stuff in the universe IMHO
320 is my standard casting material....real user friendly..very forgiving
Task 9 for high end industrial parts very tough when new...short shelf life tho
Used some Smooth-On low durometer stuff as well....not sure of the name. I'll follow up on Monday.

I'm sure that Im forgetting some ( lots) as I've been casting industrial parts at my day job for 'bout 5 years now and they let me play with materials quite a bit.

Modelnutz 8)
"gotta be a little crazy!"

[Sparky]

Don't forget the Clear resin:

Smooth-On's Crystal Clear 202 9 minuets of pour time, 90 minuets to 'full' cure.

I'll look at the one I use, it’s the longer pot life (pouring time) maybe the 200.

It took several months for the cockpit I cast to finally cure. You must pressure cast if you need crystal clear castings, and as stated in another thread by macfrank, heating the molds while/after the initial pressure casting time, is the only way to accelerate the curing. ( I also pre-heat the resin parts A and B but this will shorten the pot life I need a little more than 9 minuets to get my act together usually but not much more.)

I wear my respirator mask when mixing it although I've never noticed and odor it, same one I use when grinding resin or working in the atic.

There’s also EnviroTex Lite. Used to cover wood table tops with a thick clear coating. This is basically a 48 hour pot life 2 part clear cast resin. I foudn this locally at Ace Hardware and Menards (hardware) Our local hooby shop carrys a very small bottle set now too.

You don’t need to pressure cast it at all. BUT it has a noticeably low tensile strength. I put a small disk I made about ¼ inch think 2 inch in diameter in between the top of my white board and cube wall. Just to hold it in-place. It wasn’t a supper tight fit just the cushion of the fabric sub wall pushing the piece against the metal frame of the white board. A day later I took it out to show the guy that wanted to see it. The piece had a neat little mark where it had pressed against the frame. I left it out on the table, and a day later the mark disappeared. This piece is 2 years old. So it cannot be used in load bearing structures of heavy models.


Envirotex-Lite
http://www.eti-usa.com/consum/envtex/envlite.htm

Smooth-on's Liquid Plastics:
http://www.smooth-on.com/liqplas.htm

[macfrank]

Envirotex has a problem with RTV mold material. The molds must be baked or aged to cook off whatever compound inhibits the Envirotex.

It's otherwise a good, cheap clear resin. It is soft, though.


Frank

[TER-OR]

I've found that if put a very thin coat of petroleum jelly on it, the silicone molds have no problem with Envirotex Lite.

I've come to prefer SC321 from Smooth-on for at-home unpressured casting. It's a slow-curing resin, so make sure your mixing is very good.

[modelnutz]

Isn't Envirotex a form of E-Poxy? That would explaine the adverse reaction with fresh silicone....alcohol leaching from the silicone.
Alcohol thins epoxy

Modelnutz 8)

[Sparky]

Anyone tried smooth-on's new roto-cast resin

or is the 20 min pot life 310 just the same goo

[TER-OR]

Yes, Envirotex is an epoxy. It's great for high-use furniture tops, it's very hard and very durable. It can be used at home in silicon molds as I mentioned, but you'll need to take care and give it two days to cure - and don't expect a big thick peice to work, it's not designed for thick applications.

[Treadhead]

Has anybody used Alumilite? I'm curious about how good it is.

I've used Kwik-Cast from TAP plastics... the stuff smells like cheap wine but otherwise I have had good results. You have about a 3 minute working time before it starts to harden. Shrinkage is a bit of a problem though, but using microballoon fillers will reduce this. Aside from the horrid smell, it isn't bad stuff.

[Sparky]

Just about all the companies make a 3 minute version, Smoothon has the fast set kinds in most of their versions of resin. The color match (325,326,327), the offwhite amber (320,321,322) and white (300,305,310) resins. The fastest set crystal clear version is 9 minutes.

I find the fast set stuff difficult to use, I like to mix a big cup of resin and fill a lot of little molds, that then have to be stacked in a pressure pot.

[Antenociti]

UK stuff we use:

"Polyurethane Fast Cast" from www.tomps.com

or G26 biresin from Tiranti in London.

Both are good but we prefer the TOMPS one nowadays as it flows a little bit better and is a little bit cheaper, both resins are actually made in Germany

[Garrand]

I've used Alumilite. Captures detail well. I was still pretty inexperienced with casting at the time, so Ihad a lot of air bubbles (no mold release AT ALL), but its tough and pretty solid. After a while though, it seems the formula leeches moisture out of the atmosphere; I had a problem where during curing it would bubble. But this was with old bottles...

Damon.

[Spacephrawg]

Re: smoothon resin, I interned at a sculpture casting place. I forget which smoothon they used, but the bos was the North East distributor for Smoothon. For all you locals, its Skylight Studios of Woburn MA.

Anyhooo the boss claimed that the stuff secreted oils over the course of a decade's time and the only paint that (he said) didnt flake off was something called Japan Color. Also he claimed that the stuff shouldnt be thinned at all when aplied because of...something. THe paint I might add was kinda thick.

I asked a guy on a modeling email list I'm on and he claimed that he'd never had that problem.

It should be noted that Skylight's boss was not a model builder. He said he'd tried all sorts of model paints and that Japan Color was the only one that worked.

The whole uncertainty thing has kept me from messing with Smoothon's resins so far but I havnt checked out any others yet so I have no further info.

Also, about epoxies, according to more than one source, epoxies become brittle with time. Be warned.

[Darkov]

I have recently started using Smooth Cast 305 and I gotta say I love the stuff. If I need a little more working time I use Smooth Cast 310. Both of these have produced excellent results for me. I was previously using Alumilite Regular....too short a potlife and too many bubble (even under pressure casting).

[Sparky]

I've used Alumilite. Captures detail well. I was still pretty inexperienced with casting at the time, so Ihad a lot of air bubbles (no mold release AT ALL), but its tough and pretty solid. After a while though, it seems the formula leeches moisture out of the atmosphere; I had a problem where during curing it would bubble. But this was with old bottles...

Damon.

I think all resins have this issue. I had problems with my smoothon gallon jugs. There's a lot of volume in there and once you get down to half or 3/4 resin a lot of air resides in the container between pours.

Now I've added a dehumidifier to the basement and I have had a half gallon container sit for 6 months and cast just as good as the first cast.

If you are considering the extendit nitrogen gas cans they use to help extend the life of the resin, consider this. The gas is sprayed into the container and then you cap it. The gas shrinks. The container crushes inward. After you get to about 3/4 of a gallon your container is going to be collapsing a lot. With each use you are cycling form expanding the container to re collapsing it. Mine got cracks in the container. I was lucky and noticed them right after they formed. For a while I just left the container tilted so the fluid wouldn't spill. Then when I was mixing some rtv I put a finger dab over the crack. It sealed the breech. The end result is you can’t use the extendedit for very long. If you use 1/4 gallon every pour maybe you can use the extendit to preserve the resin parts between pours. Or just get a dehumidifier.

[Augustus]

Nevermind. Got my answer. Smooth-on all the way.

[Kun2112]

I was previously using Alumilite Regular....too short a potlife and too many bubble (even under pressure casting).

Glad to hear it's not just me with this problem. Now I need to see if I can get my LHS to carry some smooth-on (need to keep the local guys in business whenever possible)

[Dr. Snuts, M.D.]

I got my first order of resin this week. Its smooth-on 320 and I am amazed by the stuff. I have only handled a resin model once, maybe 15 years ago so this is my first real experience with the stuff. Its has about a 3 minute pot life and hardens real quick. I had some molds I previously made with smooth-on rubber. I had previously been trying to cast small parts on the cheap with liquid latex mold and fiberglass resin casts. This is an infinitely better way to go. much worth paying extra to get it done right the first time. I can't say enough good things about the stuff. I will still experiment with the other varieties they have though. They have a customer for life in me though.

[TER-OR]

My only word of warning about the 320 is that it seems somewhat sensitive to mix ratio and such.

I measure in two cups, transfer to a third to mix, then to a fourth to mix some more. I found the less-than-completely mixed resin would not set up right. But yeah, I found it very easy to work with in a home setting, without pressure pots. Granted, I mostly do small bits.

[Lt. Z0mBe]

I've used the last of the (coughcoughcoughcrapcough)Alumilite, and want to try some of the "Good" resins. I checked around, and can't find any little starter kits like with Alumilite. Does Smoothon and Envirotex (or other "good" brands) sell starter kits for learning with their brands?

Thanks in advance,

Kenny

[Sparky]

Yes smooth on has starter kits. Be sure and get the longer set life for your first resin. Faster set stuff is/might be good for making a kit, where you know exactly how much to mix and where its going to be poured and need to make a lot very quickly. You may still need slower set stuff rather than risk poorly mixed casts.

[Lt. Z0mBe]

Yes smooth on has starter kits. Be sure and get the longer set life for your first resin. Faster set stuff is/might be good for making a kit, where you know exactly how much to mix and where its going to be poured and need to make a lot very quickly. You may still need slower set stuff rather than risk poorly mixed casts.

Sparky,

thanks for your sagelike wisdom, as always.

Kenny

[Sparky]

Trial sizes are 1 pint each of part a and b (so a total pour able mix of 2 pints).

I suggest Smooth-Cast 322 - Trial Size
Click for more information $23.10
This is 20 min pot life 2-4 our demold with very little shrinkage 0.007 in/in. This doesn't include shrinkage due to pressure casting and air bubbles. . .

Smooth-Cast 321 has the same shrinkage factor but is 7-9 min pot life 30 min to demold. If you go to production this is what you may have to use.


If you want light able parts try the new Color match series, the old formula cured to a pine tree sap amber (ugly) the new stuff is milky white clear.
Smooth-Cast™ 327 10-20 minutes 2-4 hours
but shrinkage is a little higher 0.075 in/in costs the same:
Smooth-Cast 327 - Trial Size
Click for more information $23.10

<a href="http://www.smoothonsecure.com/store/ind ... 316b253809" target="_blank">hope the link works</a>

you can call in the order to bypass doing the internet transaction, be sure and tell them you want the cheapest shipping, on phone orders they default to their faster ups service.

[Lt. Z0mBe]

WOW! Thanks for that. I never thought to go straight to the manufacturer.



Do you use their silicone too?

Thanks!!

Kenny

[Sparky]

Yes I use the mold max 30, there are notes in the RTV thread. Others user their mold max 40. You can mix it with a chef mate scale from Target so don't worry about getting a super accurate scale or anything.

[Lt. Z0mBe]

Yes I use the mold max 30, there are notes in the RTV thread. Others user their mold max 40. You can mix it with a chef mate scale from Target so don't worry about getting a super accurate scale or anything.

Thanks!! Now to move on to the "real" resin.

Kenny

[Lt. Z0mBe]

Question about the RTV silicone. If I'm wanting to make a two-piece mold and I pour in the first half, and let it cure, will the second half bond to the cured first half?



Kenny

[Stu Pidasso]

YES. ABSOLUTELY. Unless you use mold release. It acts as a barrier between the two halves. RTV only sticks to itself, so you don't have to put mold release on the master.

[Lt. Z0mBe]

Thanks, Jimi!!

Kenny

[Lt. Z0mBe]

I have a question about the molds. I have RTV Silicone and I have latex mold-building compound. Can I make two-piece simple molds from latex too? Will it hold up to being demolded?

Thanks!

Kenny