I've been using the typical Plaster of Paris you find in the craft stores in small quantities. I found a 25 lb. bag in Home Depot for about $8 and thought I had found a better deal than the 8 lb jars I had been buying for about $5-$6 bucks in the craft stores. I had been reading in several pottery/casting/molding sites that pottery plaster (#1 plaster) is preferred over the weaker POP and gives much more detail. It also has a greater compressive strength. They said to buy it in bulk at pottery supply outlets. Well, I finally found one of those places today, called them thinking that I'd be paying more for this stuff than the usual POP, but to my surprise it was about $10.25 for 50 lbs which is much, much cheaper than buying that weaker POP at craft and home improvement stores and I'm getting a much better product. The outlet also suggested hydrocal (I believe that goes into the cement category?) which is workable like the plaster but has even a better compressive strength than the plaster and can be used much thinner. He didn't have it in stock but it was around $24 for 100 lbs--actually not a lot more cost than the pottery plaster.

I would highly recommend looking into finding a pottery supply store before you start paying a fortune in cheap plaster!

I'm probably going to try the pottery plaster out tonight and will let all of you know what I find out.

Gunnera is now FLIPPED!!!

LOL... I am soooooo happy that went off without a hitch. I begged my old room-mate and her husband to pop over to help me turn this thing over. Mark and I lifted the leaf mold while Juanita QUICKLY slipped a piece of plywood underneath. Then I placed a second sheet of plywood on top... like two pieces of bread with MOLD filling! lol Mark and I then held the three pieces and flipped it over and we didn't break anything. So here is it freshly flipped. The second picture is of most of the leaf removed. It has taken many many HOURS to remove that leaf!!! I still have tidbits of veins to pry out. Maybe tomorrow I can start making the silicone mold. We'll see.

The bottom pic is of the tools I have used for de-leafing the POP mold.

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BB... I sure wish my leaf had been as easy as yours was to remove. The gunnera leaf texture is rough ... rough as a cow's tongue!! LOL Farmgirl in me coming out there! My finger tips feel like they have been sanded! The leaf would peel off in fairly large pieces but would stop at a deeper vein, and of course the veins had to be cleaned out.

Well, I think I am beginning to see an end to this project. Making multiple copies in silicone will be a breeze after all this brain work and labour! lol

Marly

Congratualtions! Don't you feel like there should be a celebration or something? (Holding my cup up and toasting - with coffee!!) I know what you mean. Pumpkin leaves are the same way. I love the results, but I hate that they are so hard to remove from the POP!!! The elephant ear just lifted so nicely off. But then, all your work will pay off when you get that nice first gunnera leaf!!! I like the pumpkin leaves cause they have so much character! (all wrinkles and crinkles, kinda like my face!!!) Let me give a warning. A while ago I said I finally took a pop casting outside and hosed the leaf off of it. May not be a good idea. After I made the silicone mold, and then the cement leaf, I noticed that tiny teeeny air bubbles were probably exposed by the hose washing away thinner plaster. I think that not washing the POP with the hose may have produced better leaves. I don't know for sure. Good luck and once again, congratulations!! (I still haven't done a cement/'tufa cast, don't know what I am waiting for?? not ready to mix that much concrete! )BB

Is that POP all the way past the edge of your leaf or foam? If POP,How do you clean out all the outside curves and twists to have your leaf look as in the original shape? Am I making myself clear?
Thanks

BB... YES I was celebrating that I got this thing turned over!!! Mark and Juanita didn't see that though! lol My two cats just keep sitting on the plywood and staring at this monstrosity in my kitchen. They seem to be fascinated with it. Think the leaf has such an unusual fragrance and that attracts them too.

I was so worried that the POP was molding as it sat and sat and sat underneath all that wet POP and on top of the plastic sheets. But there wasn't a spec of mold anywhere thank goodness.

Thanks for that warning about the hosing off the POP. I appreciate that caution because I did remember your saying you had done that and I would have tried it if I could have gotten this thing outside. So I am glad I decided against it! If that thread is still going where you posted that suggestion... perhaps you could post your findings at the end of the thread. Would save others from having that happen.

Dian... I think I understand your question... perhaps a close-up of the tips of the leaf would help answer it.
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You can see that the leaf edges are clearly defined in the POP by the leaf itself... mostly. Sometimes I had to use that blade tool and trim a tiny bit of POP away but on the most part I didn't have to do that. When I cast the silicone mold... I will be TRIMMING the silicone right to the edge of the leaf. I found that really helped with my rhubarb leaf molds. Then when I cast the mortar mix on top, the more liquid mix will just drip off the edges. By doing that I have next to nothing to do as far as tidying the edges of the leaf stone. Hope that helps you with your question.

Marly

You know, your way sounds easier.
"When I cast the silicone mold... I will be TRIMMING the silicone right to the edge of the leaf"
I usually try to keep the pop just to the leaf edges, then when I do the Silicone, I put a bead right at the edge and smooth towards the center. If you did that on your leaf edges, the excess pop wouldn't even matter, and actually gives support to the edges. Cutting the silicone, duh, why did I not think of that??? BB

LOL BB... that is why we share in this forum. We bounce ideas off each other.

Here is another idea I think I will try. I am going to take a red colouring pencil and run it around the edge of the POP leaf. Then when I am applying the silicone it willl be easier to detect where the edge of the leaf is. I won't have to be wondering if I got the silicone right over the edge or not... and I wouldn't waste any silicone either.

Keep the ideas coming folks!

Marly

Well, BB, I did my POP mold the way you did yours. Had one heck of a time getting the leaf off the mold. My leaf is 23x23 and the first layer was 4# of POP. I then bought a bag of patching plaster 25# for $8 which was cheaper. Put the sticky dry wall tape in between layers. Now I need to save up for the silicone.
So when the time comes, the best release agent would be the vaseline or the murphys soap?

Thanks for taking the time to answwer all my questions
Dian

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Dian2, the leaf looks good. I usually use vaseline applied with a brush and spread really nice, no goopy gobs anywhere. Silicone comes right off. I think Marly uses Murphy Oil Soap? I haven't tried that. So can't compare for you. Good luck. Sometime I want to order Smooth On and try making a latex mold. Saving for that, maybe next year. BB

Just an update pic of my progress. The POP is now 100% de-leafed. I decided I was going to fill in the veins somewhat. I couldn't find it just now, but someone had asked about whether the POP would break as you tried to remove the veins or whether the silicone would be flexible enough to pull it out of the crete casting. I have not had any problems with my previous leaf castings in that regard but because this leaf is so huge, the POP did crack off a little along the veins! Bummer.

So what I did was take a hypo needle that comes with your inkjet refill kits and fill it with more runny POP. I didn't attach the needle. Then I just kept squirting the POP into the vein holes until they were 90% filled. I took a toothbrush and brushed it so that there would be a smooth dip where the veins are. I looked at the top of the real leaf in my photos and noted that the veins are not concave at all. Since I am trying to replicate the appearance of the top of a leaf, I decided to fill in the veins. I like the look of it very much! I think the next large leaf mold that I make in POP ... I will slice off the back of the veins so that I don't have to break the POP when I am de-leafing again. You never stop learning folks! Another benefit with this is that it will use slightly less silicone since I won't be filling the veins now. And that is a BIG plus for me!

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Marly

Not a bad idea, slicing off the veins. I sanded the edges of the veins a little on mine, cause they did create very tight veins. I'll try casting it this way, may try filling them in on next pop cast. Live and learn, is right! Very nice leaf. I am waiting to get a clear spot in the garage to set up a table, I don't want the cement casting on my kitchen table.I have had about enough of it in here!!BB

Great job guys and very informative! So glad all turned out well for you! Another way around the vein problem would be to let the leaf dry out. The veins will collapse as they loose moisture and be easy to remove. That we be for those with patience though LOL. Can't wait til the motar stage gals!
Leigh

Just wondering if you slice the veins off the back of the leaf, if that sugar content on a fresh cut would prevent the pop from setting up like it does with cement??

Well, now, Dian2, that is a VERY interesting question you raise there. Guess I will just have to go and get a rhubarb leaf from the garden, slice off the vein and give it a try. I don't think it will be a problem but I would want to make sure. I'll get back to you on this experiment. I will just put a little POP on one spot on the leaf rather than make an entire mold.

Marly

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I just applied the first layer of silicone. Peeeeuuuuuwwwww! lol Took a full FOUR tubes of silicone caulking! I applied it last night with the windows open and the ceiling fan going at full tilt. Yech! The deeper spots have all fully cured so I can apply the second layer today. Likely this afternoon with windows open again! Can't wait to demold this baby and put the POP in storage!!!!!!!!

Marly

Marly,

Four tubes? I think I woulda yakked.

In a different post someone suggested thinning the silicone with naphtha. I've tried that with good success. It makes the silicone easier to work.

Have you used naphtha? Or do you specifically not want to use it for a large project like this?

peak

I was reading on a site that deals with silicone (two part mix, can be poured on) and they said thinning with Naptha will weaken the finished mold. I would love to be able to brush or pour this stuff on. When it comes out of the tubes, it is hard to spread! Yeah, I used a lot of that on my leaf. $40 bucks worth. I had a window fan blowing out, and another window open with it blowing in. and I still nearly passed out with the fumes. Kinda like salt and vinegar potato chips with more bite!!!!! Nasty! I want to shape my silicone so that when I put in the cement, it will be a fountain or birdbath. Still working on the details, but found a childs small pool and am going to get some sand to put in there. ((((Hey, I did not know where to put this link( don't know if I should be linking to a commercial site). It cracked me up last night. It is a site selling sculptures and fountains. Check out "Farting Man" I can just hear those bubbles bubbling out of the water! )))))

Here is a link that might be useful: fountains

I only used the thinned silicone for the first layer and the mold has held up well. The thinned silicone dries quickly. Give it a go on a small leaf and see if you think it's worthwhile.

When I did my guerilla silicone molding I was surrounded by Lantana. About 100% humidity, no room to work, no air. Barf.

LOL Love the Farting Man! Just the thing for your formal garden :-)

peak

You know how it is such trouble getting the leaf off the POP? i have found the answer. You use duct tape. Rub the sticky side onto your leaf and pull it off. Works like nobody's business! Works of tufa too. I like to wait a day or two for the leaf to dry a bit, then the duct tape will even take out the veins.

Jo

I've removed the silicone mold now!!!! Fait accompli! Well, almost. I just have to trim the silicone to the edge of the leaf imprint and THEN I am done.

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Think I will make another mold while I have the POP mold out in the kitchen. After that I will place it under my bed for storage. I think it will fit. What a huge project this has been but I have learned a lot by doing it.

Marly

LOL interesting choice of terms... "fait accompli" means an irreversible accomplishment... but you are going to reverse the mold to use it!

LOL

OK

I'll

just

leave

now

peak

LOL Peak... you had BETTER skeedaddle outta here! lol Guess I should have put "c'est accompli". Took French in school for a long time but perhaps I needed to learn more! lol

Marly

No No No, you are NOT done, you are just beginning! You still have to cast that thing in concrete! I am putting that off, cause I don't want to do THAT on the kitchen table. Good luck! BB

Jo I love your duct tape idea, My friend Jodi and I have 4 big leaves to work on unleaving soon, I will try it out. Cindy

Lonowl, did you ever have success putting that silicone directly onto a leaf? I missed your post, if you reported your results! BB

Yep, Jo, plenty of uses for 'ol duct tape

peak

Woo Hoo Marly! I had stopped by another strangers house because I saw elephant ears? and begged another leaf!! This one was only 31 inches long, and I smeared it with vaseline and put concrete directly on it two days ago. Today was the unveiling!!!! I still say it is like opening up a present!!!! It was pretty good! And the best part was that the leaf was still good, so I mixed up some white cement, and smacked that on there, too! So, maybe I'll have "TWO, TWO, TWO LEAVES FROM ONE!!" Like the ole doublemint gum!! I put the 3 inch white cement ivy leaves there for comparison. I still haven't cast the silicone mold, but may get around to it by this weekend. I was kind panicking, I mixed up too much white concrete, and after I coated the leaf I ran around the yard getting as many leaves together as I could to use up the excess. I got about 10 small leaves done, too! Bonus! BB

Here is a link that might be useful: {{gwi:73636}}

Very nice, BB. Just beautiful! Vaseline must work nicely on those leaves to get 2 imprints.
I was really lucky the other day. Doing a garden for a botanist and she actually has an elephant ear plant! Imagine, right in upstate NY! I didn't think they would grow here. Casted one of many leaves I scored, today. I will be using vaseline on the next.

Jo

Butterfly Bush, your leaf is beautiful.!!!!
I tried a hosta leaf and it's a dud.
I laid my leaf on a sand bed to get the curve and used cement, sand and peat mixture. My edges are horrible. Globs of sand on the edges. Was I supposed to put plastic over the sand before I put the leaf down??
How do I get the edges so smooth and to follow the shape of the leaf??
Thanks, for Heelllppppp.!!!

Thanks guys! I mix only 1 part portland to 2 parts fine sand. The peat will cause you to lose detail and smoothness. Peat is great for 'tufa pots, where you want that roughness to be part of the character. For leaf detail, leave it out. I mix in enough water so that it is the thickness of Yoplait yogurt, thick but still smoothly moveable and I start right in the center with a big plop and use a gloved hand to gently push and pat it just to the edge of the leaf, but I don't let it run over. I add more concrete right on top of where I already put it, and gently push and pat till I get it all the way out to all the edges. If your mix is too thick it won't push easily to the edge, too thin and it will run right off the edge. Guess it is getting the right consistency. If you want to add a second layer next day, remember to scratch the top of the first coat, then brush with bonding agent, then you can mix up a mix with peat and perlite or vermiculite to make it not so heavy. You won't need to worry about the texture for the second coating. I wish you luck! BB

I put quikwall mixed with water directly from the bag onto the second try of that EE leaf, and it is even better than the first! It is beautiful, white, and picked up the details of the smallest swirls of the leaf! Unfortunately, it won't do a round 3, it fell apart as I took the leaf off. But still, two casts from one leaf! And although I can hardly wait to cast the 43 inch silicone mold I made, this 32 inch leaf is so easy to handle, and will make a nice water bird bath or water fall for my pond! I am beginning to fear the 43 inch size (weight of it) Maybe this weekend I'll give it a go. BB (still smiling)

ButterflyBush,
Did you use straight vaseline on your leaf or did you thin it down first?
Thanks

I took a 1/2 inch art brush and brushed it all over the leaf, straight from the jar, but you have to be sure not to leave it thick, it will show brush marks. I spread it very very thin. (The elephant ear is one of the best to use for casting as it is nice and strong, and casts well, removes easily.) Took a few minutes to do it well. I tried Pam type spray, but don't like using that as well. BB

Oh my gosh I am so tired after reading all this! Great job! How I wish (maybe not) we had Gunnera leaves in Texas....great info will come back later to print all this info!

Thanks so much for sharing...
Cindydj

BB, why do you like Vaseline better than Pam?

peak

I ain't Peak but I do like vasoline better. I just think it makes a thicker, better un-sticker. But that's just me. (not peak) I have an old brush that stays in the jar and it works so well - plus, I think vasoline is probably cheaper than Pam and can't be used in my skillet!

Um, yes, peak, what copperfish said.
Better un-sticker,
I have an old brush, too,
I prefer the smooth slick feel of it, if I go to using my hands in it,
It smells better,
Pam is fickle, bubbly, stinks and has no substance.
Copperfish, why do you insist you are no peak?

BB, I think Copperfish meant to say that she is not "BB" instead of "Peak".

BB, do you use that same brush for your vaseline on the POP molds as well?? I like the Murphy's Oil soap for the POP. I have tried using vaseline but I haven't been able to get the right amount to apply figured out. The silicone just slides all over it. I guess I have used too much then. The vaseline would be a lot cheaper I think so I might give it a try again.

Marly

Thinly, very thinly. On the POP mold, I wonder if you couldn't rub it on with a very soft cloth to just give it a sort of polished look without feeling greasy. I like the brush to get it in all the wrinkles. I think you must be using it too thickly. BB

Hi, Marly..... You have GOT to be so happy with such outstanding results! WOW! I am so impressed!
I know what a lot of work that was, and to have it turn out so beautifully.....
But, it doesn't surprise me for a minute! I knew you'd do a great job! Everything you make is great! You are so artistic and creative.
To have a mold that you can reuse for such a beautiful leaf...... What more could 'ya want!
Congrats! I'm proud of 'ya!
Mertie

Marly, this post has too much information to just drop off. I still have not cast my large silicone leaf in cement. I really want to. I may do it in the house after Christmas madness is all over, and I get the cabin fever doldrums. My Silicone mold is in storage! BB

I know I have come onto this thread late, after all problems have been solved. I do it the way wannadance does except I use quickwall applied direct to the leaf. It gets incrediable detail. and then I wax the leaf and make a smooth on mold off of the casting. I can shape that mold over sand any way that I want too.I can have a mold finished in just a few days as quickwall can be turned in 24 to 48 hours.After I turn the leaf I clean the edges up with a rasp and paint and seal.

Groovey

bump

bump

Marly, how's your mold holding up? How many have you cast from it?

Do you have a picture of the finished leaf? On MSN?

This is a great discussion. Thanks all for all your hints.

what's this for? Is it a stepping stone?

These leaves can be used for so much, as a stepping stone, as part of a water feature, sculpture in your garden, the uses are endless. It is exciting to cast a huge leaf like a gunnera.
Cindy

I am a newbe on molds from leaves for making hypertufa's. I am going to a class on making hypertufa stuff, but they never made the leaf hypertufa.

Please send me your recipe for making the leaf mold. Also any pictures that you may have would be greatly appreciated.

Have you ever used silk leaves to make the veins? My thoughts are, in a box I make a bed out of plactic with the center deaper for the middle of the leaf. Placing about 1 1/2" to 2"'s of hypertufa mixture on the top of this bed, I would place a silk leaf with strong veins on top to make the leaf impression. Does this sound like a wise move to make my leaf masterpiece?

I need your help soon because the class is 4/21/07.
Thank you very much.
You can also email me at srobinson41@yahoo.com.
Shirley

Where can I purchase a gunnera leaf mold? I really need to get one. Any help you can give me is appreciated. Please email me at rbem12@wildblue.net Thank you so much.