Shop Products
Houzz Logo Print
straw_dog

leaf veins

straw_dog
17 years ago

Hello,

jumping on the leaf bandwagon here.

I covered a leaf (Paulownia tomentosa) with plaster, the idea being to try and make a silicone mould. I really had to pick away at the vein ridges when removing the leaf from the plaster. The vein must be slightly fatter out from the surface. Should I cut back the edge of the vein 'groove' in my plaster mold? Or is that par for the leaf vein course? I'm guessing that the answer is yes (trim), but if the silicone is somewhat tolerant it would be nice to leave my leaf un-modified.

thanks,

Sean

Comments (23)

  • Dena6355
    17 years ago

    Sean,
    My two cents here. I have not made a POP leaf, and then made a silicone mold. I have made concrete/mortar leaves and made molds from that (latex).
    The mold is flexible and I have not had to change either the positive (leaf) or the negative (mold) to get the next to release well.
    If you modify the plaster leaf, the mold will come out with a much bigger vein, in your next project made from the mold.
    Dena

  • straw_dog
    Original Author
    17 years ago

    Thanks Dena,

    I suppose that if it doesn't work out I can always trim it later.

    Sean

  • Fleur
    17 years ago

    Dena,
    How difficult is it to work with the latex? How easily does the latex mold separate from the cast leaf? Can you recommend the product by name and let others know where to find it.

    Thanks. You're such a good source of information. Got a question? Dena's got the answer.

  • Dena6355
    17 years ago

    First off I have to say that in many of the things I do in life it is by the seat of the pants. I have tried a variety of latex mold materials. Latex products I have used are; Mold Makermaker (michaels craft store carries this, use the 40% off coupon to experiment with the product), Non-Skid Rug backing by fiber-lok (heck it was on a discontinued sale JoAnn's fabric/craft), latex rubber molding compound by fiberlay(pricey in my mind)and you must make sure you close the lid securely, and my newest FAVORITE is a product used by computer mother board solder workers, it is by Kester called Techform TC527 and is considered a peelable solder mask. The Kester product is also slightly pricey however goes on very thin and can be layered quickly, producing a fairly thin mold that seems VERY durable, my sister's father in-law told me about this, he knew someone who used it and gave him some extra for a project he was working on.Used alot as a mask in soldering components on computere mother boards(that is the part I have no desire to know any more about!).
    Latex or silicone molds are one of those things, kind of like any concrete product, "OH I couldn't do that". Just jump in try it it is easier than you think.
    To make a latex mold;
    I use a concrete already cast and cured leaf. I do not have to use any mold release for this. I paint on a thin coat of the product with a cheap chip brush, clean up the chip brush. Then let the first layer dry. You will see a difference in the color and opaqueness. Paint on another layer,repeat this process and brush clean up (water and soap) and do this until you have about 4 layers. For positives (leaves) that are 12" or larger I would recommend that after two layers of latex you add some stabilizers like strips of fabric or dry wall tape then add your additional layers of latex.
    Now this is very important!!!!! Once the mold is dry on your positive, sprinkle the back of the latex mold with baby powder/talc or cornstarch. Latex does not stick to much but WILLLLLLLLLLLLLLLLLLLLL stick to itself. Peel your mold off of your positive and sprinkle the inside with talc as well.
    When using as a mold (like a real leaf), mound up your damp sand, cover the sand with plastic, lay your latex mold veiny sideup, put on your mix, and get it to a dry stage where you can peel off your mold. Be sure to clean up your mold really well. Most of the latex molds I have made are very durable and can take a nylon scrubby to get off any residue. I have also used Pam on them but not really any more successfully.
    Sorry to go on and on, and trust me I read every thing that is posted here....................I learn so much here, and do NOT always have an answer. thank you to all the others out there trying and sharing new stuff.
    Happy casting,
    dena

  • Fleur
    17 years ago

    Dena,
    Thanks for ALL the information. Even with instructions on how to cast from the mold and tips re: latex sticking to itself. I was so excited to have it I printed it off to put in the car so I have the information when I get to the big city. You are truly a treasure here at the forum. (Probably elsewhere as well.)

  • straw_dog
    Original Author
    17 years ago

    Hi,

    I just peeled my brand new silicone rubber mould from the plaster leaf. Very cool! It has it's share of imperfections, but looks pretty good.

    I followed the Marly photo directions to make this mould. I now have a silicone version of the leaf. There's no wall or edge around my leaf (I think that I followed the directions faithfully). How are others using such a mould? Casting with sand to build up a containing barrier?

    cheers,

    Sean

  • Fleur
    17 years ago

    Nice going Sean. Now another question for Dena.

    Did you get a reasonably durable result with either the Michal's product or the carpet backing latex? I don't suppose your new favorite is readily available where I live but I can drive for a couple hours and get to a Michaels.

    How do you store you molds once you have them made. Do you roll them up? Keep them flat? Thanks.

  • Dena6355
    17 years ago

    SEan,
    When you have a chance please show a picture.
    Fluer,
    Kester leaf molds/skins are quite thin and very durable. MOLD MAKER (Michaels) makes a nice durable skin also, however may not remain as flexible in cooler weather. The rug backing I am experimenting with, and the small leaf I did with it did ok, however it appears to stretch and will more likely break than either of the other two mentioned.
    Now about Kester product, just yesterday I went to get a new container and the distributor that was less than 2 miles from me, has moved to a new place 60 miles. When I get some more I will post where I got it. I occasionally go to the area where they have moved, and I believe they will continue to do mail order. Seattle tool.
    Here are some pics of the process. I did not take a pic of the baby powder.
    Happy casting,
    Dena

    Here is a link that might be useful: behind the fence visiting leaf molds

  • Dena6355
    17 years ago

    Kester mask products can be purchased on line.
    Check out Seattle Tool link below.
    I am using Kester Techform solder mask TC527.
    The squeeze bottle goes quite a long way. I think I used a little over a bottle to make the molds shown above.
    Dena

    Here is a link that might be useful: Seattle tool

  • straw_dog
    Original Author
    17 years ago

    A pic. Sure thing.
    {{gwi:67837}}
    The silicone leaf's second layer was tinted orange, which just shows through,

    Sean

  • garden_chicken
    17 years ago

    How do y'all deal with those darned ruffled leaf edges? I've got some huge rhubarb leaves I'd like to mould, but the edges are very ruffley(?). I suppose patience has alot to do with it... I'm pretty short on that these days. :)

  • Dena6355
    17 years ago

    Sean,
    Did you end up taking away any of the plaster mold where the vein is? Or did you find the silicone so flexible that it pulled away?
    Brand name of the silicone you used? and what type of POP did you use?
    GC,
    Your set up will control how the ruffles of the leaves are. I use damp sand for the central mounding then use the damp sand, and shape it to the ruffles, or use crumpled rolled newspaper to support the ruffles. I use sand and a combination of paper more oftern only because as I am laying the mix on there are times the leaf shifts a bit, I can quickly reposition the paper. For me I am not as concerned with ALL the ruffles as I am with creating a few of the ruffles and the illusion of the leaf. I think few will notice that the ruffle got flattened and folded over when the mix was layed on. The leaf casting process already turns the leaf upside down, underside showing when released.
    Happy casting,
    Dena

  • straw_dog
    Original Author
    17 years ago

    Hi,

    details for Dena?

    the veins; right, I'd forgotten about that. They didn't present any problem. I left them as is, and the silicone peeled out pretty easily. So that was a non-issue so far. The materials were Lepage Poly  plaster of paris, and GE Silicone 1 window and door, int/ext 100% silicone rubber. That particular GE was mentioned specifically in the nofu post that I referred to, along with some others. I also added a small amount of glycerine and acrylic paint to the second layer of silicone. Technique was from information posted by Marly, Nofu, and Running_dog.

    I'll certainly be wanting to cut down on the small bubbles that I had in my pop. And I was pretty easy going when I blended it, but still ..

    But, I'm still wondering, how are others incorporating a mould like this into a piece? With all the veins it's a probably more than I need as a beginner, but the tutorial was too seductive, all spelled out as it was,

    cheers,

    Sean

  • Dena6355
    17 years ago

    Thank you Sean,

    I do not know how others use theres but here is my idea for them. They can be placed in sort of odd shaped molds with out the risk of the 'leaf' tearing. They can be used in the winter or at a time when a real leaf is not available, and when you want to make multiples of a very similar leaf pattern. They can be used as a 'texture pad' and pressed into wet mix.
    I have used them as a 'slap applique' as well. On the leaf ball I used them that way. I layed a long latex leaf skin veiny side up on my forearm and put mix on it. Then with a quick wrist and slap movement placed it onto the already formed ball (also did around a short column).
    It was difficult to peel the skin off too soon, with the mix not set up.
    My preference would be to use real leaves. But I have several molds to choose from if needed.
    Happy casting,
    dena

  • straw_dog
    Original Author
    17 years ago

    Thanks for the reply Dena. I jumped into that mould thing without any end-use in mind. I did want to try out some casting techniques so its win:win whatever I do with it. I came across this webpage, which I'm sure that you recognize; some good stuff. Posting the url for anybody else's reference,

    Sean

    Here is a link that might be useful: leaf casting faq

  • Dena6355
    17 years ago

    Sean,
    It has been a long time since reading the FAQ's.
    AND GOOD grief was I ever chatty about having found a place (here at GW, then at Garden Accoutrements) where there were others who were as excited as I was about what could be done. There were many who contributed to the FAQs!
    I have modified my directions a little bit, eliminating some things, and adding a couple things that work for me.
    At the very beginning the 'mold' that is being talked about is a REAL leaf, no artificial stuff back then. The 3 ft leaf I was going to try ended up being 5 ft by the time I got to it.
    There are so many memorable bits of shared information and friendships with people I have never met that have come from this forum. Happy casting,
    Dena

  • straw_dog
    Original Author
    17 years ago

    10-4 Dena, happy casting!

    Sean

  • straw_dog
    Original Author
    17 years ago

    Hi,

    just a quick follow-up re. a problem that I'm seeing doing this process. Specifically bad results with a different silicone.

    I used GE brand 'Silicone I' to make my mold and everything went fine. When I went to produce some more silicone molds from my master I thought that I'd go the extra mile, shell out another two dollars and get the GE 'Silicone II', their premium .. er caulk stuff. The masterful Nofu silicone thread specifically mentions that either silicone will be suitable. I bought a tube of brown GE 'Silicone II'.

    Anyway, to cut to the chase, the brown GE 'Silicone II' failed to set properly, remained gummy in places, and kind of mucked up my plaster master mold. I'm suspecting a bad reaction with the Murphy soap that I'm using as a release agent. As a second coat on top of a layer of 'Silicone I'
    it had been fine.

    The II really is different from the number I product. Lacking much of the awful aroma that number I gives, and feels softer to me.

    Anyway, caveat emptor, not sure why this is so, but that's what is going on over here, and I'm passing this on,

    SD

  • garden_chicken
    17 years ago

    straw dog, doesn't silicone behave badly like that if it has been improperly stored (i.e. frozen)? Maybe it met with some tragic circumstance in transit to the store where you bought it of at the store itself? Just a thought, maybe someone can confirm this. Errr... does the tube say 'Protect from freezing'? Seems to me when I've used silicone that I've (inadvertantly) left in the garage over winter it never really sets up... Dunno. I'm curious now.

  • straw_dog
    Original Author
    17 years ago

    GC,

    I used the start of the tube to finish a second coat on another mold (onto existing silicone layer); that set fine. Then I started another mold with the GEII silicone going onto the release treated plaster; that was where it didn't set up. I'm thinking that the Murphy soap interfered with or drastically retarded the cure.

    ?

  • dian2
    17 years ago

    Dena
    when you make your cement leaves to make a latex mold, are you making them flat? That way you can shape the latex mold any way you want , small bowl, deep bowl, flat, ect.
    you would also do it this way if you make latex molds with a real leaf?
    THanks
    dian
    Found this site that sells the kester product at a decent price

    Here is a link that might be useful: Kester TC 527 peelable mold

  • Dena6355
    17 years ago

    I have made molds from flat leaves and from already formed leaves. So far only the darmera is the one that creates a sort of less than flat mold, but even that could be flattened a bit more.
    The other forms as shown in the pic where they are hung up are basically flat even though they may have been formed on a concave/convex leaf.
    Hmmm Dian I would say you have been bitten for sure!!!!!!!!!
    Dena

  • dian2
    17 years ago

    yea I am bitten for sure and the rash is spreading. Just wish I had some talent.
    You can make these from a real leaf also? No lubricant needed no matter what u use?

    I can't see how you would make a flat leaf if your mold was made over a convex or concave object. That would leave you with more material to flatten than if it was already made from a flat leaf. Am I missing something here?
    PS I ordered a bottle :) since it only has a 6 month shelf life I went small.

Sponsored
EA Home Design
Average rating: 5 out of 5 stars69 Reviews
Loudoun County's Trusted Kitchen & Bath Designers | Best of Houzz