WetCanvas
Home Member Services Content Areas Tools Info Center WC Partners Shop Help
Channels:
Search for:
in:

Welcome to the WetCanvas forums. You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access our other FREE features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please visit our help center.

Go Back   WetCanvas > Explore Media > Sculpture
User Name
Password
Register Mark Forums Read

Salute to our Partners
WC! Sponsors

Our Sponsors
Reply
 
Thread Tools Display Modes
  #16   Report Bad Post  
Old 11-14-2005, 01:26 AM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion in 879 Easy Steps- Part I

Hi there Roger

Thankyou for your timely workshop ... just as I'm racking my brains and having nightmares over how to mold my first sculpture I come across your little gem ... well, actually they're not really nightmares, more like very excited dreams with a just a hint of scary adrenaline!! I particularly appreciated your information about how to protect an oil-based clay sculpture when making a mold.

Anyway, what intrigues me about this particular mold, Roger, is that it is a "single skin mold" around a 3d object. I've never seen that before but I'm really keen to try.

So I hope you will be able to answer these three questions for me:-

1. How did you actually attach the shim to the sculpture? I can see what looks like wire projecting from the shim into the dog, but I have no idea how you did it.

2. I notice that the shim does not touch the sculpture at all, and I am assuming that the dog became completely encased in silicon. So, when it came to cutting the seam from the chin to the base, were you using the track that the shim made as a guide?

3. How did you manage to cut the mold off without cutting into the sculpture?

Thanks once again Roger!
Jo :>

Last edited by Jeanned'Art : 11-14-2005 at 01:35 AM.
Reply With Quote
  #17   Report Bad Post  
Old 11-14-2005, 05:55 AM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion in 879 Easy Steps- Part I

Hi Noadi & Jo,

Noadi, sorry I didn't respond earlier to your last email but I wanted to let you know I used two stage pour and paintiing and coating the internal surface of molds for over two years before I managed to buy my first vacuum pump. When I did, I bought a refurbished pump and a friend fabricated a metal tank for me. I've also seen tutorials on other sites where they use pieces of sewer pipe to make the tank. I still use 2" thick kitchen worktop for the door and buy the seal from double glazing suppliers. Nice mermaid by the way - are going to mold it?

Jo, thanks for these questions. You are quite right in your observations I position the shim away from the surface and hold it in place with sewing pins strategically positioned either side of the shim following the proposed cut line. The main purpose of the shim is to act as aguide for the knife when cutting the silicon after curing.

The reason the shim is away from the surface is because the knife makes a neater cut. This means less fettling when cleaning the finished casting also if the shim touches or digs into the clay it can cause surface blemishes in the casting.

When cutting the mold off, I always cut deep into the original, it makes for a positve and clean cut on the inside surface of the mold and gives you a smoother joint line on the casting. The original very rarely emerges from this type of mold without significant damage so the the cut damage doesn't really matter.

Finally, I'm not sure if I stressed the point enough in the tutorial but it is normal to get surface damage on the original due to heat build up in the mother mold during curing. Making a thin casing in the way that I showed, significantly reduces the heat build up but you will still need to do a bit of cleaning up of your original before pouring the silicon. If your are at all concerned it is might be better to make a block mold first.

The silicon must be vacuumed to extract all the air. Before I got my own pump I used to take my mold to a friend who had a pump and chamber, to vac' the rubber before pouring.

Thanks again to both of you for your interest and good luck with your molding, I hope I've answered fully but let me know if I haven't.

Roger
__________________


website: www.landmarks.co.uk
Reply With Quote
  #18   Report Bad Post  
Old 11-14-2005, 05:30 PM
Noadi's Avatar
Noadi Noadi is offline
Senior Member
Maine
 
Join Date: Jun 2004
Posts: 463
 
Hails from United States
Re: Concept to Completion in 879 Easy Steps- Part I

My mermaid will hopefully be my first cast ever once I get my materials. I'm pretty excited to give it a try.
Reply With Quote
  #19   Report Bad Post  
Old 11-21-2005, 07:59 PM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion in 879 Easy Steps- Part I

Hi Roger,

Thanks so much for being so prompt with the information … our server has been down and so I didn’t get back as fast as I would have liked to.

I am very interested in what you have done. I think your shim trick is ingenious Roger and am really keen to follow it up.

What is your shim made of ... is it plastic? ...does it even matter?

Could you tell me what your procedure is for attaching the needles to the shim and inserting them in your sculpture? This is how I think you have done it. Please correct me if it is wrong. Because the needles are placed at different angles I am assuming that you would stick one of the needles on the shim with glue (a form of super glue perhaps) and then you position the needled shim into the sculpture. Once the shim is in its correct place relative to the sculpture, the other needles would be pushed into the sculpture using the shim as a guide. Then once in position, you would tack the needles onto the shim with a dab of glue. Am I right and if not, could you enlighten me please?

With regard to cutting into your original, I can see how that would make a much better seam as you would have more control over it.

I have been making figurative sculptures out of materials other than oil based clay but I had planned to do my next one in it, because I like the idea of recycling it into other projects. The figures are up to 10 inches/25 cm tall and so features can be pretty small. What are your thoughts Roger as to how those features might stand up to the heat generated from the jacket mold???

Thanks again Roger for sharing your information with budding novices like myself.
Jo :>
Reply With Quote
  #20   Report Bad Post  
Old 11-22-2005, 03:20 PM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion in 879 Easy Steps- Part I

Hi Jo,

Thanks for liking my moulding method.

Different sculptures will require different techniques with a basic shape like the dogs head this method is very suitable.

Taking your last point first, if you have very fine detail you need to decide if you can safely make a skin mould or if you should 'bite the bullet' and make a block mold. The shim preparation is usually the same either way sometimes the extra expense of the rubber is better than spoiling your hard won sculpture.

If you decide on a skin mould, make sure that your plaster back up is very thin and reinforced with fibrelass matting or tissue. The thinner it is the less heat build up and less damage. Also leave your master encased within the plaster back up as long as possible if you can put it in a fridge so much the better. I've damaged masters by taking them out whilst still warm and soft.

Mostly you should just have a few crease lines to clean up.

Regarding the shim itself, plastic sheet is the best but I have used waxed paper. I don't glue the pins to the plastic I just dig them into the master as deep as the gap will allow and set them alternate sides of the plastic. This seems to work fine for me but you could glue them if you wanted. The plastic is held firm by the main dowel running down from the chin.

One idea would be for you to test this out on a simple piece before using it on your more important work. I hope this explains it OK let me know if not

Good luck with your molding
Roger
Reply With Quote
  #21   Report Bad Post  
Old 11-26-2005, 12:47 AM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion in 879 Easy Steps- Part I

Hi there Roger,

Jo here again. Thanks for that information.

I understand what you mean by deciding whether you can safely do a skin mold on an oil based clay figurine with fine features. But Roger, you have some wonderful small figurine pieces at your web site (your Diana t'Huntress is really pretty fabulous) Were they made of oil based clay and if so, how did you mold them?

With regard to the shim, when you say "gap" do you mean the space between the shim and the sculpture?

You said that the plastic is held firm by the main dowel running down from the chin of the dog. Firstly, does the main dowel actually touch the chin of the dog? And secondly, how is the plastic held firm by the dowel? From the photos below, the dowel looks like it's embedded in the plastic.

Jo :>





Reply With Quote
  #22   Report Bad Post  
Old 11-27-2005, 07:16 AM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion - Diary of a Sculpt

Hello again Jo,

Thanks for the kind comments on my work.

Diana the Huntress was modelled in reuseable oil based clay/wax and was too complex with too many thin sections to make a skin mould straight off. So I put in shims in a similar way to the pointer but then I made a box around her with balsa wood and then an outer box around that in order to make a sort of two part wall of plaster around the figure as below. It is still a good idea to use registration points for the plaster to base etc.



Once this is done it is a fairly simple job to pour in vacuumed RTV and let it cure.

The main object of this for me, is to make a casting, from this rather cumbersome block mould, in workable polyurethane and then use that to make a skin mould for production purposes. If you only want a small number of castings, you don't need to bother with the skin mould.

I go to all this trouble with the plaster wall because it saves a huge amount of expensive RTV from being wasted and I am very mean with my materials

The gap is as you say is the word I am using for the space between the plastic and the clay/wax. I enjoy the differences between American-English and English-English or in my case Welsh-English

Below is an enlargement of the dowel, it is sharpened like a pencil at the top and you can see it actually goes into the chin and into the base at the bottom. The plastic is glued to the dowel and then I put masking tape around it to neaten up the join


Let me know if you need any more information, it's fun answering your questions and it's making me analyse my own methods and look for ways to improve, so thanks

When are you going to post some of your own work on the forum

Best wishes
Roger
__________________


website: www.landmarks.co.uk
Reply With Quote
  #23   Report Bad Post  
Old 11-30-2005, 03:52 AM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion - Diary of a Sculpt

Hi there Roger,

You're right, English does tend to vary among countries ... in my case I speak Ozzie English ... g'day mate!!!

The enlarged picture of your shim was so much better, and the info about the dowel and how you attached it has laid many speculations to rest. Many thanks for that.

With Diana, the Huntress, you have given me much to think about ... thank you ... and I would like to comment on it further down the track.

But I'm really at a cross roads now Roger, and I hope you may be able to advise me. I have only ever been involved in slip mold and press mold making, you see, and while I have done as much research as is possible to do I have only ever done one silicon mold ... it was a disaster, but that's ok ... I learnt a lot from my disaster and am now ready to go on.

The latest mold that I have been agonising over has been for this lady here. Any comments will be much appreciated.




She is 26 cm tall ... she is made out of water based clay with a single wire down the middle as a basic armature ... she has not been fired, but she has been dried slowly. I've sealed her with several coats of Krylon Crystal Clear acrylic ... it was done in matt to retain the clay look when she is cast.

Before I saw your tutorial, I was thinking of doing a stand up two-part-brush-on mold with a seam moving from the base up the left side of the body to her left elbow, across her head to the other elbow and then down the right side to the bottom of the base. I would have preferred to do a skin mold with her lying down but I was very concerned that she might break, given that she's just made of dried clay.

Anyway, then I saw your tutorial about how to reduce the seam lines and it started my mind whirling again. Wow, I thought!!! ... however, I eventually came to the sad conclusion that because my lady is hard, your method for inserting the shim is not suitable for this piece ... but I intend to make my next piece out of oil based clay, so it should be entirely suitable.

After many more nights of dreaming about molds and how to adapt yours, I have thought of two possible strategies :-

1. I've thought that maybe I could do a complete brush on mold, like a glove mold, to 6 mm (shore hardness 25) ... make a two piece support jacket out of hydrocal plaster reinforced with scrim ... then remove the jacket and cut a seam in the mold up the left side of her body ( the left side being the left side of the photo) to her elbow only. At the top of the cut in the elbow I would have laid a little piece of scrim in the silicon just to stop the cut from advancing any further.

2. I could do the glove mold ... then I'd lay on the sculpture a clay shim with keys, which would go from the base up the left side of her body ... I would brush on several layers of silicon to 6 mm. ... when cured, I would remove the clay shim, put vaseline on the silicon shim on the side where the keys are and then brush on the silicon layers to make the other silicon shim. Then I would make the two part hydrocal jacket mold as before. After the jacket mold has set, I would remove the silicon mold and cut through the seam using the silicon shims as guide.

Phew!! Think I've said enough ... so what do you think, Roger ... do you think either strategy would work? ... is one better than the other? ... or perhaps you have another possibility that I haven't thought of. Any information very much appreciated.

Jo:>
Reply With Quote
  #24   Report Bad Post  
Old 11-30-2005, 07:16 AM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion - Diary of a Sculpt

G'day Jo,

Nice figure, cheeky face.

Firstly, you can still fix a shim in a similar way to that shown in the Pointer mould. I've done this loads of times on hard originals.

If I was moulding this piece, given that it may break if laid on its' side, I would do the following:

1. Glue the sculpture down onto a wooden work base

2. Draw a cut line with a felt tip pen from the tip of her left elbow down her left side to the base (her left viewers right)

3. Using a modellers drill (or jewellers drill?) with a 'bit' roughly 1mm diameter carefully drill series of holes about 20mm spacing (less if you think you need more pins) along the cut line and about 13mm deep.

4. Proceed to fit a plastic shim as shown for the Pointer. I would be inclined to fix the pins in with a viscous superglue but watch out for dribbles on the surface of your sculpture. The dowel can be fitted into the work base but will need to glued to the the elbow (unless you would feel comfortable to drill/dig into the arm near the elbow and fix with a piece of epoxy putty or glue). I would taper the dowel away from the figure as it goes to the base.

After this, you have a choice: You can either "butter" the RTV on, as you proposed to do, this is the best way if you don't have access to a vacuum tank, or make a block mould as previously discussed.

Either way you will need to make a two part plaster back-up (as you have stated). Once the rubber is on and cured you won't need to worry so much about breakage. There is a small disadvantage I find, to making the back-up after the silicon is applied and that is, done this way, the RTV silicon always seems slightly too small for the plaster but it shouldn't make a noticeable difference to your casting

I think that should do the trick. Good luck with this, I shall be as nervous as you now, waiting to see how it comes out. Please let me know asap how you get on.

Any queries in the meantime just let me know

Best wishes
Roger
__________________


website: www.landmarks.co.uk
Reply With Quote
  #25   Report Bad Post  
Old 11-30-2005, 11:11 AM
Sassie2 Sassie2 is offline
New Member
California, USA
 
Join Date: Jun 2004
Posts: 40
 
Hails from United States
Thumbs up Re: Concept to Completion - Diary of a Sculpt

Thank you, Roger, for painstakingly posting such great tutoral....it is important for a self-taught artist like me to learn from true pros.

Jazzie
__________________
http://www.jazziestudio.com
Reply With Quote
  #26   Report Bad Post  
Old 12-01-2005, 07:43 AM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion - Diary of a Sculpt

Wow Roger!!!

This is really great ... I am really excited about the information that you have given me. I'm ready to make a few more mistakes and learn from them. I'll post pictures of my progress.

I've found myself a piece of hard clay, practised drilling a couple of holes and glued in needles with a good quality super glue called "zap a gap" ... seems pretty viscous ... anyway, it has done a pretty good job ... those needles have become amazingly strong.

Some questions to help me please:-

1. I plan to use the plastic from our milk bottles for the shim. It is approximately 1 1/2 mm thick. It's rigid but flexible ... do you think that would do the trick? Or do you think that I should glue two pieces together and make it 3 mm thick?

2. When you say to glue the sculpture onto a wood base, do you mean "glue" or can I stick it down with Klean Klay which is an oil based clay?

3. You said to draw the line on her left, that being the side she is looking toward ... did you suggest that side because it would preserve her face better, or because it would be easier to demold ... or maybe some other reason?

Thanks Roger for the comments about my sculpture ... Jo:>
Reply With Quote
  #27   Report Bad Post  
Old 12-01-2005, 02:45 PM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion - Diary of a Sculpt

Hi Jazzie & Jo,

Jazzie, thanks for the compliment of thinking me a "true pro". Sculpting and figurine manufacture is my main income but I am self taught just like you and most others. I wish I could paint Chinese girls like you can - I'm going to try but I think I'll stand a better chance if I sculpt one instead

Jo, nearly there! In reply to your questions

1. I wouldn't use plastic that thick. I buy plastic sheet from a model shop about .5 of a mm thickness. You could use heavy guage paper - card would be too thick - if you use paper put plenty of release agent on it or seal it with lacquer. Best to use plastic sheet if you have a model/craft shop handy

2. I usually like my work firmly attached to the base with wire and glue but as you are doing a "butter" on mould it's not so important. In your place I would be inclined to use a blob of general purpose silicon, like you get from a hardware store.

3. Purely For easier demoulding. The cut should not come anywhere near her face.

Good luck

Roger
__________________


website: www.landmarks.co.uk
Reply With Quote
  #28   Report Bad Post  
Old 12-04-2005, 06:31 AM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion - Diary of a Sculpt

Hi Roger,

Thank-you for telling me about the plastic ... unfortunately, I live out in the bush and don't often get to a hobby store ... but I have all sorts of "stuff" stashed around the place, so I went hunting for a piece of plastic 1/2 mm thick ... and found it!

Drilling into the sculpture was pretty hair-raising at first ... but I got the hang of it. Also, trying to work out how to thread the shim on the needles gave me a few adrenaline rushes ... Well, actually, I was pretty petrified most of the time!




When I reread your tutorial, Roger, I realized that you were using pins for the shim ... I thought I was supposed to use needles so I used needles. Will that be a problem, do you think?

Apart from using needles instead of pins, I think that I followed your suggestions pretty faithfully and am now ready to do the silicon detail coats prior to "buttering on". I would appreciate your comments on what I've done so far ... if perhaps there is something I could have done better, I would like to hear it for future reference.

Thanks ... Jo :>
Reply With Quote
  #29   Report Bad Post  
Old 12-04-2005, 07:04 AM
RogerA's Avatar
RogerA RogerA is offline
Member
South Wales
 
Join Date: Sep 2005
Posts: 72
 
Hails from Wales
Re: Concept to Completion - Diary of a Sculpt

Hi Jo,

It's looking good, exactly how I would have done it.

Pins, needles bits of piano wire are all OK but be careful at the end when you are cutting the gap/space, it often happens that you get needle stuck in your finger.

When you've finished moulding and you're ready to take the original out, bear in mind that it is likely to come out in pieces but you can make yourself as many reproductions as you like. For this design, you might get away with just cutting the space between the shim and the sculpture - leaving the mould without any outer joins - that way you will not have any leaks in when you're casting. The mould will peel off like a sock

Watch out for the point where the dowel meets the elbow and put plenty of silicon around it when you are detailing to hold it in place.

Otherwise good luck, I look forward with nervous anticipation to the "birth"

Roger
__________________


website: www.landmarks.co.uk
Reply With Quote
  #30   Report Bad Post  
Old 12-07-2005, 04:33 PM
Jeanned'Art's Avatar
Jeanned'Art Jeanned'Art is offline
New Member
 
Join Date: Nov 2005
Posts: 34
 
Hails from Australia
Re: Concept to Completion - Diary of a Sculpt

Hi Roger,

Ouch!! Well thanks for that tip ... I don't think that I'll be using needles in the future ... when I finally cut her out I think that I'll be more like this !!

Actually, a couple of the needles are placed at a bit of an angle out from the shim, so that when the silicon mold is completed, they will be embedded in the silicon ... which I daresay would be tricky to cut out. So I'm wondering Roger, if this happens to you, and if so, how you deal with it without damaging the silicon mold too much?

I will definitely keep in mind your suggestion that I might be able to get away with just cutting the space between the shim and the sculpture. I like the idea of not having any outer joins, particularly if it stops leakage into the mother mold.

I'm glad you told me about the spot where the dowel meets the elbow ... I wasn't brave enough to "dig into the elbow" before glueing ... I just put a dab of super glue on, pressed the dowel and elbow together for a short while and hoped for the best. Anyway just before I did the detail coat, I checked the area and found that the dowel had come away. A bigger dob of glue went on and after a really long time of holding them together ... it finally stuck!

I put the detail coat on the sculpture yesterday. Some of the tape came away from the dowel while I was putting on the silicon, so it will get embedded if I leave it there. For my next mold, I'll make sure that the tape is better stuck on, maybe with glue. For this mold, however, I am thinking that maybe I should cut that part of the tape off before I continue ... what do you think, Roger?

I did the detail coat in intense humid heat and I found that the silicon kept going off super fast ... it took three goes at it to fully cover her in one coat. So I've reluctantly put her away until the fierce heat lets up, which the reports say will be a few days yet.

Thank-you so much for all your advice, Roger ... I really am learning a lot ... from your suggestions and my mistakes.

Jo :>
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 09:42 AM.


© 2014 F+W All rights reserved.