jimatbeyond wrote:
I have found that one coat on the rim and one coat on the tire doesn't result in complete adhesion.
I promise i am not intentionally trying to be frustrating, but i would honestly ask why? What is the mechanism for better adhesion? Likely we are working with some hydrocarbon that is in a fairly viscous solution with their chosen solvent. If you apply a layer, let it sit overnight you have now evaporated the solvent and just have the hydrocarbon/polymer adhesive that is now mostly solid. Applying another layer is essentially the same as applying a new layer on a fresh carbon rim as the adhesive is now dry.
Clearly it can be hard to get a thick layer due to most glues being fairly fluid, thus the reason people often layer. I would think a few layers 20 minutes apart would be ideal as you can start stacking layers but not allowing them to harden. If i was being extra cautious i would follow this protocol, anything else is dubious:
1. Completely sand and acetone/mineral spirits the rim
2. Apply very thick layer to rim
3. Apply layer to base tape on tubular
4. Apply another layer to the rim
5. Mount tire, adjust, inflate partially, readjust, inflate to 120+, roll tire with applied weight for a few minutes, let sit for 24 hours
The above process would require 1-1.25 tubes of mastik per wheel.