Resin options?

[Thom]

I'm thinking about getting into the resin and I read in the latest FSM Techniques mag about the MicroMark starter kit. http://www.micromark.com/COMPLETE-RESIN ... ,8174.html

Other than buying everything piecemeal, is there a cheaper starter setup out there?

[Johnnycrash]

That is cheap. And it doesn't have any of other tools you would need to do it right. Great for the odd part and such.

[modelnutz]

The casting resin is Smooth-On's SC305 resin.

[Thom]

In another post about using resin, it was stated that some resin could turn liquid over time and ooze out of openings or hollow casting. It was suggested to shake the resin before mixing. My question is, wouldn't this create more air bubbles in the mix than the actual mixing would create?

And if the casting is solid all the way through, is this even a problem?

[USS Atlantis]

In another post about using resin, it was stated that some resin could turn liquid over time and ooze out of openings or hollow casting. It was suggested to shake the resin before mixing. My question is, wouldn't this create more air bubbles in the mix than the actual mixing would create?

And if the casting is solid all the way through, is this even a problem?

Shaking/stirring the resin before mixing insures an even distribution of ALL the materials - It's not just Part A and Part B - each part has multiple chemicals which can separate - mixing each part before combining helps to prevent "weep"

Letting the individual parts sit for a while after stirring and before combining them will help alleviate the bubble issue

Solid casts are actually more prone to the weeping issue than thinner ones, so even mixing is even more critical

The Suggested SC-305 has a 7 minute pot life, usually plenty of time for air bubbles that are introduced when combining the two parts to settle out

Vacuuming the mixed resin is also suggested

Moving to SC-310 which has a 20 minute pot life may also be indicated for larger molds/pours

[tetsujin]

I wouldn't bother with 1:1 by volume mold rubber. Just do yourself a favor, get a cheap postal scale and go straight to the stuff you mix by weight. 1:1 by volume (for instance, Smooth-On OOMOO) is extremely weak and prone to tearing. Something like Smooth-On Mold Max is just far, far better.

[Thom]

Thank you, you've been very helpful.

[chasd25]

If you want a "starter kit" this is a good deal:

http://www.smooth-on.com/Getting-Starte ... index.html

it does use the OOO-MO silicon, which doesn't have very good tear strength. But for the beginner, who is just making a few parts, its fine. Once you get the knack of things, buy a postal scale, get a good tin based silicone. I like the Circle K GI-1000, or douglas and sturgess 1621 (just as good, and a bit cheaper).

[dknight297]

hi, i know that i am new here (1st post) but i have been using moldmax 30 and smoothcast 321 for about 2 years now and i wont use anything else. nothing else seems to work as well for me.

[Joseph C. Brown]

...Vacuuming the mixed resin is also suggested

Did you mean "the mixed RTV" or did I just mis-interpret something?

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dknight297, good to see ya over here!

[USS Atlantis]

...Vacuuming the mixed resin is also suggested

Did you mean "the mixed RTV" or did I just mis-interpret something?

Duh - ya, thanks Joe

Vacuum the RTV - pressure cast the Resin

[USS Atlantis]

hi, i know that i am new here (1st post) but i have been using moldmax 30 and smoothcast 321 for about 2 years now and i wont use anything else. nothing else seems to work as well for me.

I use the SC-321 as well for my larger pours

I use the SC-300 for smaller parts

Only major differences between them - 321 is tan and has a 7 minute pot life; 300 is white and has a 3 minute pot life

The entire 300 and 320 series are remarkably similar, though there are some property differences between them when hard, thereby the color differentiation so you know which is which - but for the most part, where you can use a 320 series, you can also use a 300 series

[rokket2001]

After striking out scouring many sources for a complete and informative tutorial, I ended up compiling and editing the info, and then working in my own experience, into hopefully a helpful document that covers it all:


http://amp.rokket.biz/lib_resources

Hopefully this will help

[Squall67584]

After striking out scouring many sources for a complete and informative tutorial, I ended up compiling and editing the info, and then working in my own experience, into hopefully a helpful document that covers it all:


http://amp.rokket.biz/lib_resources

Hopefully this will help

Now that's a cool, well described, and easy to follow tutorial! I really like the pictures, especially the one showing the pour channel and air vents. Definitely saved that one!