Poll: Coarsest starting grit?

[mpierich]

I've been starting on sand-cast surfaces with 80-git (paper, drums, greasless, cartridge rolls) to save time. But I'm beginning to think that might be the source of some of my final finishing problems.

What do you guys start with? Is the extra time involved in starting with 120 or higher justified by the fewer large scratches you need to remove later?

Thanks.

[jrow]

Re: Poll: Coarsest starting grit?

I start with the finest/coarsest paper that will get the casting smooth. The last casting I did, I used 220 grit cartriges then went to 320 grit cartriges. I then switched to 320 greaseless to smooth out the ditits that the cartrige rolls make. I have on occasion had to go back to 180 or 150 grit but not that often. On real tight areas, like on intake manifolds I use a 3/16" daimeter 240 grit cartrige roll, greaseless, and a felt buff to finish.

John

[pickleboy]

Re: Poll: Coarsest starting grit?

i feel like the extra time spent is worth the few scratches that will haunt the finish if you start to low. i start all jobs at no less than 120. if needed to go to 80 ok but start with 120 and spot in the work so if coarser paper is needed you can isolate where its used. also the greaseless and expander wheel make the starting at a higher grit faster.

ps hows it been on your end mike. good for me just staying busy.

[mpierich]

Re: Poll: Coarsest starting grit?

I start with the finest/coarsest paper that will get the casting smooth...
John

Thanks John, that's helpful. Of course, any grit will get it smooth given enough time...I guess I was looking more for a cost/time ratio sorta. In other words, the 80 works a lot faster, but is it worth the extra step to get out the 80-grit scratches, etc...

[mpierich]

Re: Poll: Coarsest starting grit?

i feel like the extra time spent is worth the few scratches that will haunt the finish if you start to low. i start all jobs at no less than 120. if needed to go to 80 ok but start with 120 and spot in the work so if coarser paper is needed you can isolate where its used. also the greaseless and expander wheel make the starting at a higher grit faster.

ps hows it been on your end mike. good for me just staying busy.

Thanks Pickle, I'm starting to think the extra speed I get w/80g ain't worth it, as you say.

Things are real slow right now but that's a good thing - I do this part time and had no time to myself after work for months on end. Now I'm able to fix up my shop etc. during this slow time. I think I've pretty much broke even now on the equipment I bought so it's mostly gravy from here on out!

The work seems to come in waves...I should be surfin' heavily again when the weather turns cold and they start tearin' down the bikes for the winter...