rebuilding injectors

[Dasherhead]

In Vince's great writeup on rebuilding injectors he places sandpaper on glass and laps surfaces.  Is that water on top of the sandpaper?  Help me out here - I want to get this one right!  BTW - this is a great site for learning!   

[Vincent Waldon]

Welcome to the site!

It's a generic light oil... probably some 5W30 from my gasser days. 

As the instructions say... the "proper" tool is a precision microtome or a very fine green lapping block.  Sandpaper is kinda cheating,  so the trick is to do as little as needed after having a close look at how out-of-whack the surfaces are.

[cyrus #1]

I've had good luck using those peel and stick sanding discs.  They stick quite nicely to a sheet of glass.

About the only thing I do differently than Vince is the motion used for lapping.  I use a figure 8 motion and rotate the part 90° every couple seconds.  This method seems to virtually eliminate any chance of wearing the part unevenly. 

[Rabbit TD]

I've had good luck using those peel and stick sanding discs.  They stick quite nicely to a sheet of glass.

About the only thing I do differently than Vince is the motion used for lapping.  I use a figure 8 motion and rotate the part 90° every couple seconds.  This method seems to virtually eliminate any chance of wearing the part unevenly. 

The only thing there though is that can you get them in a 400-600 grit or finer and are they the wet or dry style and hold up to the oil very good?

[Smokey Eddy]

i ALWAYS use oil with wet dry for fine sanding like injector internals.
ALWAYS...

wet dry i would say is re-usable. The grit obviously goes down after exended use but used correctly and carefully it can last a very long time. escpecially tapped to a piece of glass.