Weathering Help please

Chalk is a sedimentary rock, but as it is soft it weathers horizontally and vertically. So you would use a knife and score it in both directions, but predominantly vertically.



What you want is to get a good paint and or plaster layer on the polystyrene to give the effect you need.

Paint it all white (matt acrylic), then when dry, lightly dribble black or brown ink thinned with plenty of water over the grooves that you previously cut out. This makes the grooves and cracks stand out. When that is dry, go back to your white mixed with perhaps a light grey or light beige and lightly brush it on again with a wide brush working from side to side.

Remember that at the base of any chalk cliff, you're going to have rock that has fallen down. Also, the grass at the top of a chalk cliff comes right up to the face, set in a thin layer of topsoil.

Another good photo of a chalk cutting.

Twinkle,

I'll pass on my method for chalk type cliffs.

1) Don't use polystyrene, use cavity wall insulation block, it's much easier to cut and shape and you get far less mess.

2) Cover it (the cliff face) with your filler of choice. I personally use a product called Hydrofibre which takes about 48 hours to dry out, which means plenty of time to get your rock face carved in!

3) Paint it with a layer of creamy grey emulsion, avoid pure white as the base colour, chalk is only gleaming white when it is freshly broken.

4) when all is dry, as Doug suggested weather using a nixture of very watery browns, greys and black to bring out the texture.

5) Add flocks/grasses etc on ledges, - where birds roost grass grows!

Hope this helps

Regards

John

supurb, thanks, will give it a go.

will put some pics up once i do it

Here's a photo I took of the cliff face between Seaton and Beer in Devon last summer. This one shows some interesting discolouration in some of the rock layers.



Around Beer itself the cliffs are whiter.

David

well tried to give it a bit of colour and its none not really a chalk wall but think its not to bad colour wise for my 1st attempt. any comments welcome, but please be gental as its my first go i ended up giving it a coat in well watered down black board paint

still needs work yet so not finished yet but what you think.

QUOTE (twinkle @ 23 Nov 2006, 23:48) <{POST_SNAPBACK}>still needs work yet so not finished yet but what you think.

Looks pretty good for a first attempt. A piece of advice, try to use bigger blocks, if possible, it makes joins less noticeable (another good reason for using a coat of your chosen filler). It also appears that you are using grass matting for the ground surface, to improve the look of the edge use a mixture of different green flocks to blend the edge in to the cliff face. A layer of brown/grey paint at the edge will also help.

Regards

John

QUOTE (BRITHO @ 24 Nov 2006, 16:16) <{POST_SNAPBACK}>Looks pretty good for a first attempt. A piece of advice, try to use bigger blocks, if possible, it makes joins less noticeable (another good reason for using a coat of your chosen filler). It also appears that you are using grass matting for the ground surface, to improve the look of the edge use a mixture of different green flocks to blend the edge in to the cliff face. A layer of brown/grey paint at the edge will also help.

Regards

John

thanks mate i was limited to what size i could use as the track was close to the edge, and i will give your method a go once i get my flocks (hopefully at the weekend)

thanks again

Yup,

Mike's on the right track there. I've noticed that greenery in chalk is small, and tends to follow vertical cracks where the water supply is regular. I think chalk cliffs are the hardest to do, why I stick to non -chalk, it's easier with natural products such as real bark!! (such as below, really easy to do!!