Why would you need that? The current technology in scratch coat material far exceeds the, "hair " technology of years ago.
Try Structolite. I don't really want to see anymore bald animals.
Ron

US Gypsum told me they don't recommend any of their products for wood lathe......
So I'm looking at more traditional technology that has been proven to work for hundreds of years.

ron6519 is correct.

Horsehair plaster is an inferior technique that never worked well. Modern plaster techniques work much better.

You can always apply galvanized lath directly to the wood lath to provide a stong base for the plaster.

Or romve the wood lath and install lath rock as a base.

Better still may be to cover the entire wall with 1/4" drywall then skim coat over that.

But if you insist on using neandethal methods, try contacting a slaughterhouse or rendering firm in your area.

Goodness, such antagonistic answers!

I'm sorry I asked....

Here's a page with some plaster repair how-to. As a general rule, you don't need to use the "hair" in a repair. Using a traditional multi coat process will work well.

Diane

Here is a link that might be useful: Plaster repair tips

The only reason horse hair was added to plaster was to give it a bit more strength and to use as a filler

Horsehair didn't give it strength, per se, but prevented the scratch coat from cracking as it dried. Any spiderweb cracks in the brown coat would translate into the brittle white coat. I recall seeing somewhere a fiber additive for structolite/gypsolite; when I tried looking for it again, I can't find it!
Now, they add chopped fiberglass to concrete to minimize the cracked appearance that the surface can get from drying too fast.
Casey

A friend of mine who runs a plastering business recently married a friend of my wife, who owns and runs the horse-boarding facility where my wife keeps her horses. Hmmmm. Maybe he has an ulterior motive. :-) If Iceman starts inexplicably going bald, I'll know whats up.

The stuff you're looking for is called "concrete fiber". You should be able to get it at any concrete yard - I doubt it's available at HDepot/Lowes. It's a fiberglass based product.

If you really want to use natural hair, you'd need to screen and wash it yourself. Probably the best place to get hair in the proper, rather short lengths would be a dog groomer, though if you're in a rural area ANYONE with horses can give you all the horsehair you want. Just regular daily grooming makes PILES of the stuff..

I've had a few plaster contractors come out and give estimates on repairing our plaster, and one of them told me I have horse hair plaster. He also said that horse hair plaster contains,or can contain,"ASBESTOS". Is this true? I already started ripping one small wall down and now I'm a little terrified.

Just a piece of drywall as the base filler strip. Scrw it to the lath. Use the blue stuff made for plastering over.

For future reference, prepared bundles of horsehair (manes and tails) is available from Virginia Lime Works. Working it into a batch of lime/sand plaster takes a very long time, longer by far than mixing the mud; I think if it wasn't absolutely necessary to insure a good job, the old-timers would not have gone to the considerable trouble to add it.
Casey

Fiberglass works fine, you just need to be careful during mixing to not break it up to badly.

The fiber helps to hold the keys formed by forcing the base coat through the gaps in the lath together.

You should also use rough cut wood for lath, not planed.
Two coat over gypsum lath works much better.

If you have old wood that is badly out of plane, instead of trying to shim sister pieces ox 2x to the sides of the old wood sitting just proud of the lowest spot in the surface.

A laser protecting a vertical fan beam can be used to true up the new wood as it is screwed to the sides of the old studs.

Our house's main section is from 1874..the plaster undernieth the white top coat..(base coat) has hair of some type in it and seems lime based...And it almost looks like dirt is mixed in with it.It really crumbles away...and with out that hairy stuff would have failed long ago...(which pretty much has actually).
Really this plaster version sucks. The plaster used in our previous 1906 house was better..and the replacement plaster cieling in the kitchen which was done sometime in the 1950's-70 in that house was absolutely the BEST of the lot.
In this house they used hair cause the material they used NEEDED it ,it seems.

Using structolite...with a touch of cement...over wood lath that is vaccumed & dampened,( putting Plaster Weld a day before at exposed original plaster edges) has worked well for us. But..I usually pre drill & carefully renaill what I can, with very thin short Maze nails.. which is dangerous, as can shake things up. When you have a good dense consistancy of structolite and have applied it (working it upwards)..keying into spaces..After it sets a bit... gently go over it to compact it before scratching lines into it for second base coat.
Good Luck.Don't get discouraged...a neighbor here was talking about the "idiot" that put up a cedar shingle roof across the street at a party.When he was informend that the guy standing next to him(I) was that idot, he say's to me... "Are you crazy..does this look like a jungle man?"
3/4" thick Premium Cedar Tapersawn Pressure treated hand nailed with stainless steel nails, he calls it a jungle roof.

Use a finish nailer for re-attaching lathe.

1 inch long,#16, T-head nails works pretty well.

The single quick impact to drive the nail has far less of a chance to disturb the remaining plaster.

For small jobs I use a Paslode butane gun, for larger jobs I drag out the compressor.

We have had great luck using a 1/4" crown (pneumatic) stapler for putting up wood lath. If the staples rusted out it would be bad, but they grip the thin wood really well if the staple's oriented across the grain. Before we discovered this we were hand nailing with #4 sinkers, which work, but still could split some lath, and hand nailing is of course vastly slower.
We've re-attached two rooms worth of lath so far, and it's quite a grip.
Casey

Does anyone have any knowledge of whether or not horse-hair plaster does in fact contain asbestos?

"Does anyone have any knowledge of whether or not horse-hair plaster does in fact contain asbestos?"

Generally not.

Horse hair was cheaper.

We are considering buying a very old pre-1805 home in Virginia that (the realtor said) has horsehair plaster. I have done some old house repairs on a previous circa 1920 home, but never on anything this old or with horsehair plaster. Is this a job that my husband and I can do ourselves? I suspect that hiring would be very expensive and we already are looking at major and expensive repairs before we can close a deal -- new roof and electrical systems... Would love to do it ourselves if possible. Also, are there any books on the subject that I can consult? Thank you!

Call local plasterers (if you can find more than one!) and find out how much it costs. Don't assume that it is out of sight until you inquire.

We presently are bidding on a project involving some plaster work in a late 1700 building. Although I don't agree, the specs calls for horse hair. Older doesn't mean better. I have no idea where to buy an ample amount of horse hair.

As I stated years ago /\ up there somewhere, you can buy horsehair from Virginia Lime Works. Goat hair was also used, and has a finer texture and weight. http://www.wagmanprimus.com/product_detail.asp?pl_id=26&type=product_line&id=907
Casey

I understand Virginia Lime Works closed down last year, July of 2014

Then I suppose goat hair it must be!
http://store.limeworks.us/product_p/goathair.htm
Casey