artificial hair

[jason.p]

Greetings to all from a newbie. It looks as if I could learn a lot from this forum, and hopefully pass on anything I have picked up along the way, so here's my first question. Has anyone out there had experience with artificial hair in lime render mixes. We've been using the usual Yak hair for some time but tried a batch of artificial, mainly because it is said to disperse into the mix much quicker than teasing the real stuff out "hair by hair". However, we found that it didn't disperse evenly throughout the mix. (This is using an ordinary cement mixer) and tended to end up all in one place.
It also seems to be very short at less than an inch, whereas we always cut our hair to an inch and a half to two inches. I suppose that if there's more pieces going in it would make up for the difference. In the end we didn't feel we had confidence in it and sent it back and replaced it with the tried and tested real stuff.
Perhaps we didn't get the best product available, so if anyone can suggest a better one I would be most grateful.

 

[Nemesis]

I am sure we have had posts about this in the past, and maybe a site search will bring them up?

I think Gervase has some experience of this stuff?

 

[Flyfisher]

What is the 'artificial hair' made of? If it's a nylon or other synthetic material, it's possible that it's a lot 'smoother' than real hair and, therefore, more easily pulled out of the plaster mix - even though it might itself be stronger than real hair.

As for clumping in the mix, could this be due to static charges? (a pure guess and, perhaps, a wet mixture would disperse any such charge anyway, or would it?)

 

[Gervase]

The artificial stuff is made from polyester with a slightly roughened surface. It works well enough, but I prefer the coarse yak hair. The thing is, the easier the hair is to tease out into the mix - as horse hair is compared with yak hair - the less effective it will be at reinforcing the plaster.
The clumping together, or 'dead mice' as plasterers call it, is usually down to not teasing the stuff out enough, but if you teased out the artificial stuff that shouldn't have happened.
The big advantage to polyester 'hair' (apart from salving the consciences of vegans :roll: ) is that you can knock up large batches of haired plaster and store them. Ordinary hair will dissolve in wet plaster after about six weeks.

 

[jason.p]

The clumping together, or 'dead mice' as plasterers call it, is usually down to not teasing the stuff out enough, but if you teased out the artificial stuff that shouldn't have happened.

Thanks for reply. As far as I understood, the only advantage of the polyester was that you could just throw a handful in while mixing and it should disperse evenly throughout the mix, thus saving time teasing it out. I'd assumed that this was due to the short length of the strands. If you've got to tease it out anyway, there seems to be little reason to use it in favour of hair.
I hadn't realised that it rotted so quickly in wet plaster. That certainly would be a consideration, although I think it unlikely that we would be using bulk mixes over that length of time.

 

[BMcD]

Were you using this stuff by any chance?

http://www.cem-fil.com/products/cf_product_sp4.html#01

It's about 1/2" long and for use in screeds and renders and is added when the mix is dry where in will disperse freely. Plastering hair should be at least 2 1/2" - 3" long or more

I've never used artificial hair for lime work as I've never seen the point in manufacturing a synthetic by product, when the original has worked fine for centuries.

When using a drum mixer you do tend to get clumping around the paddles

 

[jason.p]

Were you using this stuff by any chance?

http://www.cem-fil.com/products/cf_product_sp4.html#01

It's about 1/2" long and for use in screeds and renders and is added when the mix is dry where in will disperse freely. Plastering hair should be at least 2 1/2" - 3" long or more

I've never used artificial hair for lime work as I've never seen the point in manufacturing a synthetic by product, when the original has worked fine for centuries.

When using a drum mixer you do tend to get clumping around the paddles

I can't remember the package labelling, in fact I think our supplier probably had his own packs made up. The description fits, it looked like half inch pieces of the crinkly woven plastic as used for tarpaulins or bulk aggregate bags etc. I assumed it was a by-product of their manufacture.
I agree, I can't see the point of artificial (except perhaps for the rotting problem), and that's not just being pedantic!!, so long as the natural tried and tested material is still available.
Quite apart from that, we've got so much of the real stuff, we shouldn't have to re-order for quite some time
:roll: :roll:

 

[BMcD]

for me the issue about hair rotting is a bit of a non-issue because if you keep what's left of a haired mix and come to use it at a later date where upon the hair has dissolved, then add more hair. The hair should ideally be added just before use any way.
I do appreciate though that if you have a lot of plastering to do and you're on you're own then the idea of a haired mix is very appealing as the adding of hair is very tedious and time consuming
so in these circumstances artificial hair would be an advantage but Jason I don't think the strands you were using is artificial hair designed for lime plastering as it's too short. I could be wrong though

 

[jason.p]

Jason I don't think the strands you were using is artificial hair designed for lime plastering as it's too short. I could be wrong though

I wouldn't be at all surprised. It certainly wouldn't be the first time we've had the wrong product, and bad advice from the so called experts. That's why forums like this are so valuable. To be able to get advice from people who have actually got real hands-on experience is the only way.

 

[Gervase]

It certainly doesn't sound like the artificial hair I've encountered, which looks like, er, hair! Or rather lots of bits of rough old fishing line bundled together.

 

[Nemesis]

Our Premixed lime plaster/render can be supplied haired (synthetic or natural) or unhaired so that hair/fibre can be addred on site. Hair is usually included in the first two coats (scratch and float) to provide tensile strength.

Expertise on tap - give them a ring and ask what the artificial hair they supply looks like.

http://www.lime.org.uk/lime_products/Reinforcing_Hair.asp

http://www.lime.org.uk/lime_products/Pre-Mixed_Lime_Plaster.asp

 

[jason.p]

Thanks Nemesis. We do deal with Ty Mawr from time to time. It's worth a try to pick their brains.

 

[DaveBrigg]

Our plasterers used artificial hair, a bit like the fishing line strnds that were mentioned. I've not noticed any clumps, but there are patches where the strands stick through the top coat of the plaster, presumably from the coat beneath. The plasterer used a blow lamp to melt any that protruded, but must have missed some areas. The only solution has been to shave these parts of the ceiling with a knife blade held as flat to the plaster as possible.
A local horse livery yard heard about our repairs though, and has supplied bags and bags of the real stuff; the horses are clipped fairly regularly and it would otherwise be thrown away. Has anyone tried human hair? There must be shed loads swept up by barbers every day.

 

[jason.p]

A local horse livery yard heard about our repairs though, and has supplied bags and bags of the real stuff; the horses are clipped fairly regularly and it would otherwise be thrown away. Has anyone tried human hair? There must be shed loads swept up by barbers every day.

I don't think horse hair is as good as Yak, as it's not so "crinkly"
In the good old days I believe they used hair from dairy shorthorn cattle, but there aren't so many herds of those around now.
As for human hair, even if it was suitable I'm sure the European health and safety brigade would say it was unsafe to use. :roll: :roll:

 

[Gervase]

Human hair's no good (and I have tried it!) - it's too smooth. Horse hair is OK, but the coarse cattle hair is by far the best. Remember, the harder it is to tease out, the better it will bind your plaster.

 

[Cloudscape]

I know that cow hair was used locally to me. But there's another fibre sticking out of crumbled bits of plaster. It looks like fine wispy bits of straw. Is this likely?

When you're trying hard to stick to traditional materials, artificial hair would seem an odd choice to me. While it might be made of some inert material that should "last", it hasn't been tested for hundreds of years.

But artificial hair works for some people...

 

[Nemesis]

The other half could maybe do with one of those, although his eyes aren't as meltingly appealing.

Yes it could be straw.