Rebound 25 question

[Kyle138]

I am finally ready to mold my first sculpt and was planning on ordering some Rebound 25 from Smooth-on. My question is how much would I need for my particular sculpt? Would a couple of the small trial size kits do it? Thanks!

Here is a link to the sculpt progress on my facebook page and another picture of it.


https://www.facebook.com/media/set/?set=a.142474045815144.32382.100001576487999&l=6666309101&type=1

 

[Szyntax]

How big is your sculpt? :confused

 

[Kyle138]

Just added some pics. Its a helmet. Not sure of the size though.

 

[robn1]

Mold Making and Casting Materials by Smooth-On

 

[Bondo Fett]

One of the trial sized kits of Rebound was all I needed to get a mold from a full life cast (bust) of a persons head, so you might get by with just one kit. However, if the helmet sculpt is much larger than that I'd recommend two kits. Better to have too much than not enough, although if you run out you can just get more- silicon sticks to itself.
Additionally I would suggest you purchase Smooth-On's Thivex II additive. Just a few drops in your second and third coats will really improve the build of the material (no dripping 'cicles) as well as speed up the cure slightly. I've found it indispensable. The first coat goes on really thin to capture detail and the subsequent, thickened coats build up the rubber faster. Omit the thickener for your last coat so you get a nice smooth rubber surface.
Be sure to read Smoot-On's literature and check out their on-line tutorials, there's a lot of good info out there.
One more thing, and this is critical- if you use clay containing sulfur the sculpture absolutely must be sealed or the silicone will not cure and you will have an expensive mess on your hands. Rebound, being a platinum cure silicone is especially sensitive to this. A few thorough coats of spray acrylic sealer should do it. Make sure you coverage is total.
Good luck!

 

[TMBountyHunter]

Since I don't feel like creating a new thread for a Rebound 25 question


I'm doing a mold now, first detail coat went on fine but a little thin in places. I waited the recommended ~60min until it's tacky but doesn't goop off and started on the 2nd coat.

In one spot around a sharp edge as I'm brushing on the new coat I accidentally lifted the edge of the first coat (about 1 inch long along the edge, maybe 3/8 "deep"). I tried to sneak a bit of the new coat under it and then "glue" it back down and coat over it but now I'm worried that this might cause quite an imperfection in the final mold. Should I just start over?

 

[Auram]

If anything, I'd personally remove the section you just 'patched' and recover it, just like you would remove an even square or drywall before trying to fix a hole. having a known, clean edge to patch up should be ok