Nifty
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Post by Nifty on May 10, 2023 13:25:13 GMT 1
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Post by Polarengineer on May 10, 2023 16:34:46 GMT 1
This is not the way it is done traditionally.
With my work with plaster, I first make a clay form of the pattern required, surround the clay form with a wooden box or fence then cover the clay form with plaster reinforced with hessian fibres. When the plaster is set, wash out the clay. This gives a negative of the pattern. Coat the inside of the negative pattern with a soap solution and pour in plaster and level the surface off as this face is glued to the picture frame later.providing the original clay form had no intricate shapes, it should then when set and dry be easy to tap out of the negative form.this is then glued to the picture frame.
For intricate shapes the reinforced mould is cast in sections, a method not easy to explain here.
When finished the frame can be gilded which is also an art in itself.
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Nifty
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Post by Nifty on May 10, 2023 17:17:57 GMT 1
I had a go at making a mould this afternoon to replicate parts of an old picture frame on an d print that I have had for fifty-ish years. This was on advice from a friend who I seldom get to see.
The plan was to make the mould with plasticine. I got the nearest equivalent that I could find. According to the pack that it came in, it is called Creative Kids. Knete-Set, Neon Zeataw mas plastycznych.
It in not exactly like the plasticine that I remember using as a kid. The problem that I face is that it sticks too we to the frame when I press it on to the area that I am trying to male a mould from. When I remove it it is too soft and pliable to hold the impression of what I am trying to recreate with plaster of Paris, or, if I can find one some other suitable material.
Like most things, doing it is easier if you go about it the correct way, and you know how. I am a bit pushed presently but will try and get a better explanation with some pics together asap.
edit. Problem might be lessened by pre coating with French chalk or soap as I think might have been suggested.
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Post by Polarengineer on May 11, 2023 14:39:48 GMT 1
for this you need to make a moulding of a section of the beading as follows, make a clay dam wall around the section to be copied, use artists clay mix up a 2 component silicone rubber such as www.formx.fr/moulage--tirage/tin-silicones/index.phppour the silicone in the dam to just cover the part you want to copy when set, leave in place and cover with plaster reinforced with hessian fibres about 2cm thick (allow for this with the height of the dam wall) when all has set, remove from the beading and use as a mould to cast copies. brush a thin soap solution into the mould before casting to ease the removal of the plaster copy. cut and shape the back and ends of the copied beading to fit where you need it to fit. simples |
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Nifty
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Post by Nifty on May 11, 2023 16:13:02 GMT 1
Thanks for that PE
Translation of description
PoYo™ Putty 40 is a mold making silicone (tin catalyst) that can be mixed and applied 'on the spot' - directly to almost any model. PoYo™ Putty will hold any vertical surface and capture even the smallest detail - perfect for making strong rubber molds that can be used in minutes.
PoYo™ Putty 40 has been used to make valuable antique molds and archaeological models and can be used to quickly make molds of sculptures, prototypes, candles, picture frames, coins, etc. You can cast wax, gypsum and a variety of resins in PoYo™ Putty 40
Use Less - Do More: Because PoYo™ Putty 40 is applied thinly, less material is used, saving you money. The molds are also lightweight, which makes them easier to handle. Pot life and cure time can be adjusted (faster or slower) by varying the amount of Part B catalyst.
User Friendly - PoYo™ Putty 40 can be measured and mixed by volume (no scales needed). It will bond to itself and other silicone rubbers giving the user many application options or to use as a silicone rubber repair material
In view Of the amount of stuff I would need the above may be the best bet to try first.
In light of the fact that the beaded edging that I want to repair/ replace runs parallel to and < abt. .5 mm to the picture side and seems to be on a bevelled edge that slopes down a mm or so to the outer edge of the frame there are problems, for me at least, with constructing any temporary edges to contain the modelling medium o make a mould from, I think that there are two possibilities to get around this. I need to experiment more to see the viability of them.
It would be ideal if I could remove a few inches of the broken beading from the frame and then make a cast for a strip of the feature that I want to replicate away from the picture and then go about repairing the damaged areas of the frame 10 in all the longest is 180 mm, the others 10- 30 mm.
The huge problem is removing a section of the beading without breaking it. I think it is made of plaster and is very fragile.
Perhaps an easier rout might be to mimic the desired shape. With a saw perhaps. I will take a look and see if I have anything that will fit the bill.
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Nifty
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Post by Nifty on May 12, 2023 12:15:15 GMT 1
I was thinking about what may be a suitable material to make a mould from.
I thought of trying chewing gum and experimented with a bit on about 30mm or so of the fine beaded edge that I wish to copy in plaster of Paris. It sees that it works better than the plasticine stuff. I need ideas how create this into a longer straighter piece 180 mm long. embed the chewing gum mould in a plastic drinking split along it length…….. maybe
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Post by Polarengineer on May 12, 2023 16:40:46 GMT 1
Satay sticks
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Nifty
Member
Posts: 5,023
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Post by Nifty on May 13, 2023 10:21:55 GMT 1
There is more than one way to skin a cat !
I just need a bit of time to see what resources are realisable, and, of course,
keep my eye on the ball before some other diversion crops up.
Fat chance.
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