The Antler series Part 2
I love using deer antler for tip overlays on primitive bows. Not only does antler function well as a material for tip overlays, it also looks amazing. And given that primitive bow hunters both past and present have relished the opportunity to hunt deer, it seems fitting that a material from such a prestigious quary species should be used to enhance and embellish a primitive bow.
In this article I’d like to share my 4 most important principles to making beautiful, functional and efficient deer antler tip overlays.
For this project, you will need the following tools, materials and equipment:
- An unfinished bow stave without nocks already fitted.
- Suitable sized pieces of deer antler cut from the coronet end of an antler.
- A wood saw with small to medium sized teeth.
- A rasp/coarse file/belt sander.
- Titebond III wood glue.
- Spring clamp.
- Vice.
- Wet kitchen towel.
- Tile saw (optional).
- Chainsaw file.
- Sandpaper 80/100/120 grit.
Principle # 1 – Select the right type of antler.
For the purpose of making deer antler tip overlays, you will not want to use a piece of antler which is full of the pithy porous honeycomb like structure that you will typically find in antler from sections anywhere other than the coronet end of the antler. Antler from the coronet end is very nearly solid all the way through. Antler from anywhere else is effectively hollow from all the micro holes. Maximise the strength of your antler tip overlays by ensuring that your overlay material of choice is solid, or at least as close to solid as is possible.
Principle # 2 – Achieve the basic shape and profile of your tip overlays BEFORE you glue them on.
Don’t be tempted to simply saw your antler into blocks and then glue then on with a view to shaping them later. Shape then first before gluing!
I often see people take a tip overlay material such as antler and simply glue a chunk of it to the tips of their bows. Once the glue has set, they will then set about shaping the overlay.
The problem I see with this method is that the desirable character of antler is mainly at the surface level. It therefore cannot be optimised for inclusion in the final shape and appearance of the overlay unless these characters conform to the desirable shape and profile of the finished overlay.
If a chunk of antler has simply been glued on to a bow tip before shaping, the shape of the chunk of antler will likely be nothing like what is required of the finished overlay. As the functionality of the overlay will take precedence over its beauty, optimising shape and profile will rank more important than aesthetic appeal.
The absence of appropriate shape and profile will necessitate the removal of the surface material. This will result in the removal of much, if not all of the surface material along with all of the desirable characteristics and features of antler.
For example, if a chunk of antler with beautiful pearling is simply stuck on to a bow tip before shaping, the likelihood of that pearling remaining within the final shape and profile of the overlay after surface material has been removed is very low.
To put it another way, the amount of material which will need to be removed in order to obtain the final shape and profile of the overlay will have resulted in much of the antlers character being removed.
By shaping your overlay before gluing them on you will be able to optimise the inclusion of desirable features whilst prioritising the removal of unwanted material from areas which have undesirable feature. Examples of a desirable features might include the natural colours, shapes and pattern of pearling. Example of undesirable features might include the porous backside of the overlay or a plain spot which lacks any colour or features.
Once I have selected a good piece of antler I will select which part I want to use based on its appearance and its internal structure and integrity. The piece I choose to work with will then be ripped down the middle to create two equal albeit oversized slabs of antler.
It is important that the angle of your overlays taper is nice and low. I aim for around 10 degrees. This will allow for easy stringing of your bow. If you choose too steep an angle, you will find that when you come to string your bow, the string loop meets the transition to the overlay and comes to an abrupt halt rather than slipping smoothly over the overlay and into the string groove.
Now that the basic shape and profile is complete, there will be very little work to do to the top of the overlay after it has been glued on. Since there will be no need to take any more tools to the top of the overlay, the risk of damaging the back of the bow where the overlay transitions to wood is reduced significantly.
Principle # 3 – Create the strongest bond possible.
A bow is only as strong as its weakest point. Any joint is likely to be a weak point. With that in mind it is critical that all joints be made as strong as is possible.
Your bow string will sit directly on top of your tip overlays and receive the full force of your bows draw weight. Any torque will be felt by the tip overlays too. It is therefore imperative that the bond which you establish between your tip overlays and the back of your bow is made as strong as possible. We can maximise the strength of our tip overlay joint by ensuring three things have been attended to.
Firstly we must maximise the contact surface area between the components which are to be joined. In this instance we are talking about the roughly shaped overlay being jointed to the wooden tip of our primitive bow.
By making sure that your tip overlays are at least 1” long we are providing adequate surface area to create a large enough contact area to create a strong enough bond. Personally, I like to make my overlay a little longer than this and typically make my overlays between 1 ½” and 2” long. On static tips you could make your overlays even longer of course.
Let us assume we have made sure that our tip overlays have a contact surface area which is at least 1” X 3/8”” wide. Now we must optimise the contact between the two surfaces by making sure that the two faces to be joined together are as well fitted to one another as is reasonably possible.
By flattening the stave tips ready to receive the overlays we can begin to check how well the two surfaces match up. I like to take my time here and make sure that the two contact surfaces meet up perfectly before gluing. Don’t rush this part. Take the time to make sure that the two surfaces match up without any gaps.
Go careful when you start to flatten your bow tips. It is easy to get carried away and compromise the growth ring which forms the back of your bow. If this happens beneath your overlay, then it will not be an issue as the overlay will distribute the stresses back to the outer growth ring.
If, however, you accidently cut through the growth ring on the back of your bow ahead of your overlay then you will likely break the whole tip off your bow when you come to draw it. Always make sure that the transition from bow back to overlay occurs on the actual growth ring which makes up the back of your bow.
Wood absorbs glue much more readily when freshly exposed wood cells make up the surface layer to be glued. If you leave your prepared bow tips for any amount of time then, the freshly exposed surface layer of the wood will lose some of its ability to soak up the glue. Freshly exposed wood is hydrophilic. However, even after a short amount of time has lapsed, the exposed wood surface soon reverts back to being somewhat hydrophobic. So, get you bow tips and overlays matched up and glued up ASAP for the strongest possible bond.
The second thing to consider when trying to create the strongest possible bond is which adhesive to use. I’ve tried all kinds of adhesives over the years but always find myself coming back to Titebond. I’m currently using the MK III stuff and am happy to report that it really is a great adhesive for gluing most natural materials to wood.
If you are planning on using a stain on your finished bow then try and avoid getting glue anywhere other than the contact surface of you overlay area. Any glue that gets on the back of your bow will get soaked into the surface layers of the wood. This creates an impermeable layer which can prevent the absorption of stains at a later date. If this happens then you may need to intervene in order to avoid unsightly patches of unstained wood. You may have to scrap/sand away the upper layers of wood cells from affected areas in order to allow a stain to penetrate evenly across all parts of the bow.
I always like to glue up both contact surfaces. I also make a habit of leaving both glued surfaces to soak up some glue before positioning the two surfaces together for clamping. I believe this “sizing up” habit allows more time for the freshly exposed wood cells to suck up more glue. In fact, with wood that has been dried down to below 10% moisture content, it is often the case that more glue needs to be added after 5 minutes of sizing up. This is because much of the glue will now have been sucked up into the wood emphasising the need for an additional application of glue before placing the overlay in situ ready for clamping.
The third consideration to be made in order to create the strongest bond possible is the method of clamping used to press the glued surfaces together.
I find that if I apply significant compression to an overlay immediately after gluing up, all that happens is the overlay slips off the tip. To avoid this from happening, I only use slight pressure from a spring grip type clamp for the first 10 – 15 minutes of drying. This allows the glue to soak as deep as possible into the wood and start to grip the overlay into position. By doing this you will stop the overlay from simply slipping off the stave tip when the compression is increased to full pressure.
After 10-15 minutes I remove the spring clamp and insert the bow tip carrying the overlay into the jaws of my vice. From here I can crank up the pressure to make sure that the bond is really good and strong. The pressure which can be exerted from the vice will ensure that no gapes appear at the joint line.
Be sensible with the amount of pressure applied to the overlay/bow tip and use something reasonably soft as a packing material to protect the bow tip and the overlay from damage from the metal jaws of the vice. I use scraps of leather for this purpose.
I’ve never had an overlay come off when the join has been prepared, glued and clamped it the manner described above. The same can’t be said for the common practice of using superglue and a spring clamp!
Principle # 4 – Maximise strength, minimise mass, emphasis beauty.
After at least 6 hours of drying time, you should now be able to finalise the shape and profile of your tip overlays. Before you grab your tools and start working on the final appearance of you bow tips and overlays, take the time to ensure that the strength of your overlays will not be compromised by their final design.
The maintenance of strength needs to be given priority. A broken tip overlay is a significant repair at best, a broken bow at worst. Very fine bow tips are very popular these days but as tempting as it may be to reduce the width of your tip overlays to the bare minimum, antler is quite brittle and can snap under load if reduced too much.
An overstressed antler tip overlay will typically break at the string groove. To mitigate against this, I like to leave at least 5mm of material in the string groove. In order to achieve this, I find that an antler tip overlay needs to be at least 7/16th” wide and 3/8th”thick. I also like to leave the bottom overlay bluntly tipped because the bottom tip is always more likely to get knocked than the top tip.
Whilst you could leave your overlays much wider and thicker than this, by leaving excessive material at the tips you will be leaving unnecessary mass in the very tips of your bow. This additional mass will affect the performance of your bow albeit in a very subtle way. If maximising speed and minimising hand shock is important to you then aim to achieve a final shape and profile which reduces mass to a minimum whilst preserving strength.
Beauty is in the eye of the beholder. That said, long thin antler tip overlays are very easy on the eye. Especially if a suitable amount of antler colour and pearling has been retained during the shaping process. Play with a few different shapes and profiles and see what works for you.
Note that I will often leave both tip overlays oversized until after tillering is complete. Then I will refine the shape and profile to suit my overall bow design and appearance.
I like quite fine tips on willow leaf shaped limbs. These overlays are on a bow with some character. Since these particular limb tips are angled out due to the naturally curved out limbs, it was necessary to carry the string groove around the sides of the overlay to ensure that the string did not slip off the sides. This can happen on crooked limb tips which only have a groove cut across the face of the overlay.
So to recap, before you embark on your next antler tip overlay project, be sure to take the time to:
Select the right type of antler first. Then make the effort to achieve the basic shape and profile of your tip overlays BEFORE you glue them on. Work through the steps necessary to create the strongest bond possible. And finally finish your overlays in a way which is guaranteed to maximise strength, minimise mass, whilst emphasising the beauty of this magnificent natural material.
Until next time!