pits in finish

[clockman]

i have tried the great advice given me and still have questions. could i have a buffer running to fast? i have sanded my pieces and tried to buff them and am getting pits in my pieces before i get all of my sand marks out. i am using a craftsman power tool motor rated at 9 amps and 3650 rpm. i also use 8" wheels and. i cant use 6" wheels on here because my shafts are not long enough to clear my motor. is the speed causing to much heat and that causing the pits?

[Gabourie]

Perhaps the pits might actually be pin holes in the material. What material is it you are trying to polish? I have found that sometimes when I polish various types of steel before platting, (stainless, cold rolled and hot rolled and pickled ) there are very fine pins holes all over the place. That is why I got the plating set up to help get rid of these.

the pits are an out gassing .. some of the mixtures in the metal are poor. and some times you get them out just to find a new set when buffing the part out .. i work them out with a sprial black combo trying not to remove to much metal

[allcarfan]

if the pits are indeed a form of outgassing, you could try heating the metal first so it will outgas.

Originally Posted by allcarfan

if the pits are indeed a form of outgassing, you could try heating the metal first so it will outgas.

nope you only do that in coating . if you were powder coating . and you heated the part then shot the powder on and cured it the powder will get in to the nocks and crannys so it will seal it . not with polishing the bubbles in the metal are there . when you buff you take metal away to form a smooth look . metal has texture and when you start to remove the texture you get a better reflection from the item . kind of like removing a mountain to let the sun flow in the window briter ..

i am glad i can help ... if you need any more just give me a call

[mpierich]

Hi, I'm new here myself but I can answer this one.

I just finished a Norton side cover which had these pores. It's due to less-than-perfect manufacturing of the metal.

No amount of grinding or polishing will remove them because you only expose new ones as you remove material. The best you can do is to make a glaze over the pits with rouge. It will look quite acceptable from a few feet away, but the dimples will remain.

Also, when polishing, the pores will suck the compound right off your wheel, so you need to overload it more than normal until the wheel begins to cut. When you clean between grits, use Fantastic or 409 a few times then Dawn detergent, to lift the grit out of the pores. Rinse well.

Good luck.

Originally Posted by clockman

i have tried the great advice given me and still have questions. could i have a buffer running to fast? i have sanded my pieces and tried to buff them and am getting pits in my pieces before i get all of my sand marks out. i am using a craftsman power tool motor rated at 9 amps and 3650 rpm. i also use 8" wheels and. i cant use 6" wheels on here because my shafts are not long enough to clear my motor. is the speed causing to much heat and that causing the pits?