hey folks, thought i'd share the method i used to make an exact replica of my grip. i love my bob lee grip and i'm thinking of ordering a bow from a different bowyer but i want it to have the bob lee grip. so i made a replica of the bob lee grip so i can send it to the bowyer for him to copy.
it's really very simple and requires minimal tools and materials.
you need some modeling clay, a bondo kit (the car bog panel stuff), fibreglass resin and hardener, a small paint brush, some cooking spray, electrical tape and a couple of hours.
the pictures will do a better job of showing you how i did it.
hold the riser in a vice for easier working.
make a dam with the clay. this is to hold the bondo/fibreglas resin mixture which forms half of the mold you need to make. you want the floor of the dam to be at around the centerline of the riser. be carefull not to make the dam floor below the centerline or any contour of the riser that will lock the mold onto the riser and not allow you to pull the the mold off the riser once it's set, atleast without destroying the mold you just made. smooth the dam floor with a wet paint brush, an artist's brush is good for this. before you pour, spray the area with a light spray of cooking oil. this acts as a release agent for the bondo mix and stops it sticking to the riser allowing easy removal of the mold.
the bondo by itself is usually too thick for this type of molding so i thin it with fibreglass resin. place the required amount of bondo in a disposable container. now add fibreglass resin and mix it in to thin it down to a pourable viscosity. not like water, more like pancake mixture. mix the two together well and then add the right amount of hardener of both the bondo and the resin. mix well then pour it in the dam.
tip- be sure the dam walls are high enough so as not to have 'riser island' poking out above the level of the mold.
here's the dam ready for pouring-
let that cure and then take the clay off and the riser will pop out of the mold like this-
you now have half of the mold needed to make the cast of your grip.
now put the riser back in the mold ensuring it's fitted back in properly. now repeat the dam making procedure for the other half of the mold. using the mold you just made as the dam floor. this ensures the two halves of the mold fit together perfectly.
pour the other side and let cure-
now you have two half molds that fit together perfectly ready to cast the replica of the grip.
oil spray inside then fit the two halves together. tape them togther and put a clay bung on one end.
tip- consider the contours of your grip. when you pour the mix in the mold you don't want to trap air in there as this will leave unfilled 'holes' in the cast. bung off the end that will be best suited to your grip. you want to slowly pour the mix in and have the contours as such that the mix will displace the air in the mold and not trap it in there. basically, no overhangs.
let that cure then pull the molds off. you now have an exact replica of your favourite grip that can be sent to a bowyer with your next bow order for him to copy.
i forgot to take a pic of the finished product before i started tweaking the shelf and sight window. but you get the idea.
that's is another great thing about doing this. you can tweak things a little on the cast before you send it. simply remove material with sandpaper, file or grinder. add it with apoxie sculpt epoxy putty.
i'm changing the shelf and strike plate so that the arrow contact points are above the deepest part of the grip.