Monday, February 6, 2012

Current views after extensive sanding

These pictures are after extensive sanding -- literally to point of wearing through the skin on the finger tips. Now I am smart enough to tape my fingers.  When sanding, one can feel and hear the degree of smoothness of the surface quite well even with the fingers taped.  The resonance changes as the surface gets smoother.  As well the sandpaper moves faster with a smoother surface.  When sanding with the wet paper (320 and above in my case), I know when a surface area is done with that particular grit by how well the paper slides.  

Sandpaper -- I never use a coarser paper than 150 grit.  150 grit will take off a surface pretty quickly.  The progression - 150 (dry), 320 (wet), 600 (wet), 1000 (wet) and 2000 (wet).  I have only made it to 320 grit predominantly -- but to 600 grit in some places. As a note though, West System's specifies that a cured epoxy surface be roughed up with 80 grit paper before adding another layer of carbon fiber

For 150 grit, the 3M dry sandpaper (the purple stuff) is unbelievable.  You can buy 1 sheet of that or 10 of the regular paper.  It is literally that good.  The 3M product allows you to not have to change paper often which makes the sanding a bit more pleasurable.

The above picture shows a 4mm neoprene with a nylon layer on both sides.  I like the material in that it stretches and I cannot put a hole through it easily. Hopefully it will be comfortable.  This will be tacked in place with spray adhesive after the finish is complete.


  1. Ever heard of an electric sander?? Don't get buried in the finish yet until you've proven your design (my 2 cents). Looking great, btw.

  2. Three reasons:
    (1)Most sanders have a pretty flat sanding surface. That would work great on the flat surfaces of the carbon fiber for which there are not many on this design.
    (2)As one fine craftsman said, "The fingers are a great tool for sanding. They feel the imperfections."
    (3)One does not want to work down through the epoxy into the carbon fiber (at least not much). A power sander may do this.

    You are definitely right about the unproven design. I still need to build the wheels in order to test the design. The rims are back-ordered. Since I am using a transmission hub and I am using disc brakes on 700c wheels (disc brakes usually show up on mountain bike rims - 26", not 700c), I find that both wheels are not standard. I hope by this weekend I will have the rims and I will commence on building the wheels. Additionally, I have a final design and as well, I have ordered the parts I need in order to build the "pedals." So in another week or two, I should be fairly complete. During the meantime, I sand...