A strange question

[Havi]

Hi all,
It just occurred to me that perhaps someone here might be able to answer this -

remember the days when we used to buy eggs in a cardboard tray?
Suppose I want to copy this shape [or other 3 dimensional card board shape] and make a mold of this. How would I copy the shape so that the card board will not be damaged?
Or
How can I make a permanent mold which I could use repeatedly?
Of course, this mold will be the exact copy of the cardboard that kept the eggs - - -

Thanks in advance,

Havi

[twin vision glass]

Hi Havi,
Are you trying to make it as thin as a cardboard egg container OR can it be abit thicker AS you can paint or dip in wax to totally cover the containter . Then the sky is the limit. You have so many options that perhaps we should choose one. Take a rubber mold of the now wax positive. Then pour as many waxs as you desire. I also strongly suggest going to the www.smooth-on.com site and you can watch lots of videos to see exactly the best way to make mother molds as well. So try this site first and go with the painted or dipped egg carton . Let me know if any of this makes sense. Leslie

[Havi]

Thanks you Les,
You are the better of best.
Who in Israel could have imagined in his best dreams that there is such a place like the one you sent me to!
Absolutely NO IDEA.
So I am very grateful.
Nevertheless, I hate working with wax. I am aware of the benefits, but hate all the mess you have to go thru, including the bad smells while working with it. Still there are some other suggestions, which I shall to study - and decide what I am going to do, and how to do it.

Right now I am busy with some other staff, but soon I'll come back to this website and learn more.

Thank you so much,

Havi

[Morganica]

You can also use the first silicone you make (the negative) to create a second mold (the positive). The silicone positive allows you to directly make a refractory plaster mold without the use of wax. Apply the plaster directly to the silicone positive, and once the mold has set hard, VERY carefully remove the silicone. You'll be left with a clean, empty mold you can cast into. I do that to make molds for my sample tiles and production pieces--saves a lot of time.

You must make sure that the original object has no severe undercuts (or you won't be able to remove the positive mold without damaging the refractory. I'd also suggest using a softer silicone (look at the numbers in the Smooth-On product name; they correspond to the "Shore A hardness," which is a measure of how flexible and soft the silicone will be. The lower the number, the softer it is. I'd look for 25 or 30.). The softer silicone will allow you to gently pull the flexible mold around mild undercuts without damage.

Couple of caveats: A silicone mold won't damage or stick to the original, unless the material is textured or absorbent. Hard plastic usually only needs a light spray of release (if that). Cardboard or fabric will require first a sealer (such as clear lacquer or paste wax), and then a release. The Smooth-on site will have more information on which silicones to choose.

Also, when making a silicone positive out of a silicone negative, remember to use a good silicone release. Silicone isn't supposed to stick to anything, which makes it easy to remove...but it WILL stick to another silicone mold beautifully. I have one I keep around to remind me of that. My cousin, who has biceps the size of my head and works out like a fiend, cannot pull them apart.

[Havi]

Sealer!
That's the issue.

Thanks, Cynthia for your very interesting imput, as always. I certainly need a sealer, I am sure of that.


Do you think I could use a spray car paint???

I'll take care of this in a short while, after I come back from Zurich, which will be next Monday.
Thank you both, Les AND Cynthia

Havi

[Morganica]

It will depend in part on the texture. Anything instant-dry spray paint will probably work--the question is how much you'll need to spray to get it to really seal. The clear lacquer does the least damage.

[Mark Kemp]

I'd probably try acrylic varnish/sealer. It'll really soak into the cardboard and basically plasticize the whole thing. I've done this with paper and cardstock, to make things waterproof.

[Havi]

Thanks Mark
Only I worry that the cardboard will deform if it soaks the vanish....
Also, I am not sure I can get it in Israel, and where exactly


Yet I think along these line, as well as Les and Cunthia"s suggestions





Havi

[Havi]

Thanks Mark
Only I worry that the cardboard will deform if it soaks the varnish....
Also, I am not sure I can get it in Israel, and where exactly


Yet I think along these line, as well as Les and Cunthia"s suggestions





Havi

[Morganica]

Any paint store will sell it. You can avoid deformation if you apply in thin, successive layers, drying each layer thoroughly between applications.

[Mark Kemp]

I'm remembering now what I did. I used clear acrylic spray in a can, which was solvent based. It didn't distort card stock or paper at any rate. But yes, something water based might.

[Havi]

Thank you all!

I'll try later, and tell you the results, but it will take a while

many thanks, as always for you good , kind, help,
it helps!!!

Havi