Some folks seem to have a lot more trouble with this than others. Being the old dinosaur that I am I still lace these things with nails as we did years ago as well as making a shoe designed to stop expansion. (clips, barshoes etc) Here's a good vid from Ian McKinlay, one of the best crack specialists in the business.

How do you good folks deal with Quarter Cracks in your parts of the world?

George

Great information, Thank you.

I'll never be a farrier, but I find stuff like this fascinating. Thanks, George. 

I had the pleasure of first making the acquaintance of Ian McKinlay back in '99. I watched the Jockey Club Gold Cup at Belmont which was won by a horse named River Keen. The way it normally works is that trainers win races, horseshoers lose them. 'Nuther words they get the credit we get the blame.

This particular race was different. All of his connections were giving Blacksmith Ian McKinlay all the credit for the win. Dropped his name on national tv and everything. I thought that was really cool. Then when our paths finally crossed and I got to meet him, I congratulated him and told him how cool it was he got some well deserved recognition. He told me that race was a real nail biter. He was hoping the job he did on him held together and he stayed sound through the race. He did. Next day he was hopping lame but it didn't matter. He got a gold cup and had the rest of his life to heal up. Later on Ian went on to bigger fame for the job he did on Big Brown and others. Have a look at River Keen and what a good Quarter Crack man can do:

 

It's strange that the crack acualy closes when weight is applied. It seems counter intuitive but true.

 

great video

That repair is slick. In the olden days, I used to brand to a slight depth with my shaped fire poker at the top of the crack, if the crack didn't go all the way to the hairline. The "brand" would be parallel to the hairline. I used a wet rag above the hot iron so as not to cause a rodeo. That softened the horn. Then, I'd use my knife to deepen and clean out the area. I think that RTV (room temperature vulcanizing) material was available back then, but I used Bondo auto body solder. I knew it was non yielding, but it seemed to do the job. I used clips either side of the crack.

I use a round iron to burn a hole to the water mark to hoof holy stop the crack, and like George, I lace it if it has exposed sensitive structure. I have a H13 head stamp I heat and use to make a poker for the #3 race nailes. Usualy don't bother with clips, but do punch new holes in the shoes, typicaly in the toes. Honestly tho, I don't see many cracks that are not just superficial. When I do it's usualy I conjunction with a damaged coranary band. 

Here's one done with nails and wire. Another of many methods to achieve the same end result:

 

Butch Wheeler Used to patch all those bad footed horses leatherberry had back in the 80s.  George did you ever run in to butch much in the old days? He was from an old Maryland family of horseshoers. Butch’s old man,Kenny was in the union with Herb,Raymond Benton,F.a Bell and those old timers. 

No, never had the pleasure of making the gentleman's acquaintance. 

My dad and I never did much. We would run the side of the rasp perpendicular to the crack at the top so as to gouge the wall an 1/8  of an inch or so. It looks ugly but it stopped the back from advancing as to eventually grow out.