Using Bovi Bond

Bovi Bond is marketed as a simple, quick bonding method for applying wooden blocks commonly used by Hoof Trimmers. In the Northeastern part of the United States, the home turf of ST PIERRE HOOF CARE, the word "simple" doesn't apply during the winter! Cold weather adversely affects the bonding properties of the glue. It's been heard that some Hoof Trimmers have abandoned the use of the product until warmer weather returns. We at ST PIERRE HOOF CARE have found ways to continue using the product in cold weather (freezing temperatures) and are sharing our success with anyone else that may be interested. The following information is not limited to cold weather problem solving.

We encourage input from other users of this product so we can build a broader knowledge base that will benefit all hoof trimmers. send Email to: BoviBond@hoofcare.net

	PROBLEM: glue takes too much time to set up in cold weather.
	CAUSE: It is common knowledge that any epoxy based glue product takes longer to harden in cold weather. The problem with Bovi Bond is in the very nature of how it is applied to the wooden block and the hoof. When using other glue products, a much larger amount of glue is applied to the block and to the outer walls of the hoof. there seems to be a relationship between the mass of the glue and the heat of reaction which is understandable when you take into account that the heat must travel further to dissipate when the mass of glue is relatively thick. Because Bovi Bond is only applied between the block and the sole of the hoof, the result is a very thin layer of glue with much less heat of reaction. This is fine in the summer when every thing else is warm and a thin layer does not seem to be a problem. It is even recognized as a solution to a concern that some products produce too much heat of reaction. The next problem involves the amount of cold transferred from a relatively cold sole and ice cold block. Because the glue layer is thin, the cold from the sole and block are transferred almost instantaneously to the glue and results in a very slow chemical reaction. A third problem in this scenario is that using a heat gun to speed the reaction time of the glue is not a solution because the glue is trapped between the sole and block and can not be reached effectively.
	SOLUTION: The first and most obvious step is too find a way to keep the glue and blocks as warm as possible. one way to do this is to purchase an insulated cooler big enough to fit a freshly loaded Bovi-Bond gun with the tip installed. Just before leaving to go to work, fill 2-3 one quart plastic containers (empty one quart motor oil containers work best) with the hottest water available from your heating system. Place the containers, extra glue, tips, blocks and gun into the cooler. You may have to replace the water half way through the day. Most dairy farms have very hot water available to refill your containers. The ideal temperature range is between 65 & 95 degrees F. The next part of the solution is less obvious but very important and may make the difference between success and failure. Just before applying the glue to your block, take a heat gun at its highest setting and apply heat to the surface of the block that will be glued to the hoof. Hold the heat gun about an inch from the block and heat in a back and forth motion for about 15 - 20 seconds. this is an important step even if your blocks are relatively warm from being in the heated cooler. Apply the glue as quickly as possible and set your block in place. Our experience and success using this process indicates that the additional heat added to the block just before block application is enough to counteract the transfer of cold from the sole to the glue. Another "trick" is to store your extra blocks in a sealed container and keep them in the warmest room in your home. This lengthens the time before you might need to refresh your hot water bottles on the job site. Adding a thermometer to your cooler will also be useful as you learn how to achieve ideal conditions for using Bovi-Bond.

	PROBLEM: cutting tip off of new tube of glue sometimes causes leakage and ruins the tube.
	CAUSE: design constraints do not leave much room for error in cutting the tube as squarely as possible and at just the right height. The plastic tip is hard and stiff and adds to the difficulty of making a clean cut.
	SOLUTION: Use a pair of well sharpened quality hoof nippers instead of knives, scissors or pliers. Cut just above the line and not below it and you should not have any problems.

	PROBLEM: blocks don't seem to stay on as long as expected.
	CAUSE: ideally, a well prepared hoof would have a nice clean flat surface that corresponds with the surface area of the wooden block that is being applied. often times the hoof may have poor quality horn and/or significantly large areas of decay that must be pared away even though it is the better of the two claws. Sometimes while shaping the hoof and inner sole area, the trimmer will remove sole material that he might have left had he already been aware of a need to block the claw. The problem is compounded by the fact that the glue is relatively expensive (about $1.50 per squeeze) and we try not to use anymore than necessary. We end up with a block improperly anchored to the hoof, a teetering action starts to work the glue with detachment of the block resulting. also, insufficient support of the block may cause the block to fracture when uneven surfaces are encountered on the free stall or stanchion barn floor.
	SOLUTION: The most obvious solution is to apply a bit more glue. The convenience and speed of application of Bovi-Bond far outweighs the cost to a hoof trimmer that gets paid on a per cow basis and is sometimes under a time constraint to get a certain number of cows done before "chore time". Saving a little money on glue is not worth the inconvenience of having to return and do a problem hoof all over again because the block fell off 24 hours after application. However, the most benefit will be achieved by placing the "extra" glue strategically. For us at ST PIERRE HOOF CARE, "extra" means three squeezes instead of two. We all know that the first squeeze ends up mostly in the tip! Warm glue flows quickly. The trick is to work in tandem with gravity and what part of a sound hoof you have left to work with . If you have a layover table, gravity is a bit more of a problem especially when you have to work with what ever happens to be the top claw, where the inner sole area faces down hill. In these situations, we clean the surface of the outer wall about an inch and a half beyond the sole. We apply three shots of glue on the front two thirds of the block. The bottom of the block is first applied near the inner sole area and pressed flat until the glue flows out onto the outer wall. This glue is spread as quickly as possible over the area previously cleaned. It is usually too late to work the glue near the inner sole area but it doesn't hurt to try and do what you can. The overall goal of this process is to increase glued surface area as much as possible to make up for some of the missing or poor surface areas of the sole. We do the opposite procedure if it involves a block on the lower claw. The only difference is that the glue is spread around the inner sole concave area and onto the inner side wall. Upright tables offer a little different and somewhat easier situation where gravity is concerned. The hoof trimmer has a choice of using whichever side might benefit most from extra glue, but still needs to be prepared to redirect some of the glue "uphill" until it starts to set.
	SOLUTION UPDATE: MARCH 2002 Experience is the best teacher! From discussions with other trimmers and from our own experience we have learned more ways to improve success. 1. when applying the block to the sole, try leaving a thicker layer of glue by not pressing quite as hard as you have in the past. It does seem to make a difference . 2. after heating your block, make a pass over the sole with your heat gun. The super hot dry heat removes any surface moisture that may have condensed on the sole. While It seems unlikely that enough moisture may have accumulated to be problematic, we are convinced it has increased our success rate substantially.

	PROBLEM: wooden blocks in storage develop small stress cracks.
	CAUSE: drastic changes in humidity over short period of time.
	SOLUTION: store blocks in sealed containers and moderate temperature. if they are made from kiln dry lumber they should be at about 7-9% moisture content. Air dry lumber should be at 15-20% moisture. Green lumber is at about 25-26% moisture and most likely shouldn't be used. We at ST PIERRE HOOF CARE prefer air dry lumber as it most closely matches the environment of a properly managed free stall facility.