Shared this with one of the regulars and he thought it a good tip, so...
When rough-sanding a rough piece, the coarseness of the 80-grit sometimes makes it tought seeing when I have sanded enough to get all the orangepeel out.
Now, when doing automotive painting, there comes a point where you need to block-sand the primer to ensure that it's flat. The way this is done is to spray a light coat of junk paint or primer over the surface in a contrasting color. So, during sanding, it's easy to tell where the low spots are 'cause the paint stays there until you have sanded enough to get everything flat.
It occurred to me that the same principle can be used with polishing, especially when first attacking a rough cast surface. Just spray a light coat of whatever color you see best (almost any color actually) before you start. The paint will hang out in the tiny dimples until you get the high spots ground down to the level of the low spots. When you don't see paint any more, you're done with that step.
Hope you find this handy.
When rough-sanding a rough piece, the coarseness of the 80-grit sometimes makes it tought seeing when I have sanded enough to get all the orangepeel out.
Now, when doing automotive painting, there comes a point where you need to block-sand the primer to ensure that it's flat. The way this is done is to spray a light coat of junk paint or primer over the surface in a contrasting color. So, during sanding, it's easy to tell where the low spots are 'cause the paint stays there until you have sanded enough to get everything flat.
It occurred to me that the same principle can be used with polishing, especially when first attacking a rough cast surface. Just spray a light coat of whatever color you see best (almost any color actually) before you start. The paint will hang out in the tiny dimples until you get the high spots ground down to the level of the low spots. When you don't see paint any more, you're done with that step.
Hope you find this handy.
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