Step 1: Supplies
1. Bondo All-Purpose Fiberglass Resin
2. Liquid hardener
4. Pure silicon sealant and caulking gun
5. 5 0z plastic dixi cups
6. Plastic Knives
7. latex gloves
9. small square of cardboard
10. Masonry drill bit and hand held drill
(optional: colored sand)
All these items can be picked up at your local home repair store or Home Depot without hurting your wallet.
Step 2: Create the Hold
Create the holes for the mounting screws. I chose to use three 2.5 inch wood screws because these holds will not be moved often and will be mounted on a solid wood playground wall. The other option is to use the .5 or 3/4 inch t-bolt common to hand holds.
Step 3: Create the Mold
Use the gloves for all following steps to reduce the need to scrub your hands for hours to get them clean.
Place the finished clay hold onto a piece of cardboard that is at least two times larger than the bottom of the hold.
Using the 100% silicon sealant and caulking gun, cover the clay hold with at least a half an inch of sealant and make sure you get as much in the mounting screw holes as possible. This part may take practice to create a solid surface on the clay without trapping air between lines of sealant.
Let the silicone mold dry for 3-4 days. Be patient as this is the longest part of the process and starting to take the clay out early can be a mess if the silicone has not completely dried. Carefully remove the clay from the mold without damaging the silicone mold. Breaking the clay and using water are methods I have found to help clean the mold.
Step 4: Prep the Mold
Clean the inside of the silicone mold of any clay that may still be there.
Prepare it for the resin by pouring in just enough sand to cover the bottom of the mold. This will help remove the finished part after it has dried. I use colored silicone sand to give some color and texture to the holds.
Prop the mold so the top (where the bottom of the hold is) is level. Using your pail of sand to do this may be helpful.
Step 5: Mix the Resin
Make sure this is done in a well ventilated area as the fumes can be hazardous.
Fill a 5 oz dixie cup 2/3rds full of sand and the rest of the cup with resin. Mix the two thoroughly using a plastic utensil as it will have to be discarded after you're done.
Add the hardener 12 drops for every ounce of resin and mix completely. I figure just more than 2 ounces of resin for 1/3 of the 5 oz cups, so 30 drops has proven enough. All these ratios can be played with to find your preferred texture.
Pour the resin into the prepared mold and let harden. I have found that a medium sized hold will be hard enough to remove from the mold in 2 hours.
Once the resin has completely hardened, remove it from the silicone mold. If you had air bubbles or ridges form when you made the mold, these can be removed using sand paper or a rasp. The concrete on the side walk outside also works well.
Using a masonry bit, drill through the holes for the mounting screws as they will most likely not go through to the back side of the hold.
I suggest letting the hold set over night to achieve full strength before mounting on your climbing wall.
The silicone mold you have created can be reused several times. Just repeat steps 4 through 6 as many times as you want.
MOUNT AND ENJOY!