sanding limbs question

[Bob L.]

After the limbs are ready for final sanding with clear glass, how do you know how much to sand? what are you looking for, the shiny parts of the fiberglass? I was going to finish with 220 then 320 but what am I looking for. how many strokes does one apply on the back of the limbs, im afraid of sanding to much and loosing to much weight.
Thanks
Bob

[Badlands]

Bob.
I know it seems to be the conventional wisdom to rough up the glass before spaying it, but I have sprayed dozens of bows without sanding and they turn out just fine.
if all you are going to use is 220 or 320 you sure don't have to worry about taking any poundage off.
you might want to start out with some 150 and then smooth it over with something finer.
I think some guys do a wet sand too, but I don't have any experience with it.

Brad

[Bob L.]

Thanks Brad

[Pennsyltuckey pete]

Badlands,

You mentioned wet sanding so I will ask.  I have done a lot of automotive and aircraft paintwork and wet sand all the time.  No question I can get the best finish that way.  I have wanted to do it on some of the bows but always shy away because of the potential of the wood to absorb moisture and either stain or discolor.  Any thoughts?

pete

[Cupcake]

I sand all the way to 400 on the glass before finishing.  I may start with 150 if i have large scratches around tips and fades.

Like Pete, I worry about wet sanding the glass and have the wood absorb water.  Wet sanding is sure the best way to get a flawless finish.

[Apex Predator]

I normally spray a matte Fullerplast finish.  I only sand to 220.  I have never seen any scratches beneath my finish.

[No-sage]

Pete,

I only wet sand the finish.  I think it makes a world of difference in the finished pruduct.

I also always use water to raise the grain of the wood before I start sanding (all wood bows), and before switching to a finer grit.  Always let the bow dry in my hot box after wetting, or if winter, leave by the forced air register in my living room (just to make the wife happy).

I like a glass smooth finish, though it seems that I can always find at least one spot where I could have done better.  Leaves room for improvement on the next one... I guess.

[DCM]

I use mineral spirits for wet sanding glass bows.  Have heard notable comments sanding beyond 150 is pointless with modern catalyst finishes, even polyurethane, BowDoc in particular.  Don't wet sand all wood typically, but occasionally after a first coat to seal, again using mineral spirits.

[No-sage]

I dont go below 150 grit on wood.

I sand the finish down to 400.

[Badlands]

Pete,
Nope, I have no experience wet sanding and I, too, would be worried that the wood would absorb to much moisture that might later create a problem.
I also spray fullerplast and find that it is very forgiving when spraying it on glass. It seems to magnify evey little scratch when sprayed on wood, but even rough sanded glass limbs seem to come out looking good. I like a matte finish too, I use a lot of flap sanders when finishing bow handles and have found that the ones with the brillo pad foam stuff between layers of sand paper work really well for a final finish. They kind of burnish the wood and leave a really smooth, scratch free final finish.
I ussully give the limbs a once over with it too before spraying and it works well.
I suppose if you really wanted a glossy finish, a wet sand would be the best, but I'd let the whole thing dry out for a while before spraying.

[George Tsoukalas]

I wet sand my selfbows. I use a damp paper towel to dampen the wood. Let it dry and san with 220 grit. Repeat until the grain is no longer raised. Then I sand with 400 and 600 grit. Jawge

[No-sage]

George, wet sanding uses a wetting agent as a sanding lubricant.  Special wet/dry paper is used and it is kept constantly wet.  The sanding and lube creates a slurry on the surface of the work which is wiped off.

Kind of the way oil works on a sharpening stone.

What you described is not wet sanding.  It's raising the grain.

[George Tsoukalas]

No-sage, thanks. Jawge