Going up through grits before polishing polyurethane

[Tegmark]

While I wait for my eee ultra shine to arrive, I was wondering. Is it ok to sand 800, 1200, 2000grit? That seems like a large step up through the grits. But that is all there is available. Finally does sanding only with 2000 seem the better option? Might take a few pieces but at least there is no scratches from lower grits. Thanks

[LGS]

If you sand with earache grit until the scratches from the previous grit are gone, you shouldn't 't have scratches at 2000 grit. I have found 10 up and back passes will give a good result.

[Chesand]

If you sand with earache grit until the scratches from the previous grit are gone, you shouldn't 't have scratches at 2000 grit. I have found 10 up and back passes will give a good result.

I think you mean "each grit"

[RedShirtGuy]

LOL "earache" grit...

The idea of working up through the grits rather than going straight to the "finishing" grit (ie 2000) is that each grit smooths the timber right down to an even surface at each grit stage...and quickly. If you start straight away at 2000, all your doing is taking a crazily long time and only smoothing down the tops of the ridges...and while it might *feel* smooth, microscopically, the timber could look like any of these waves, but with a flat



What you really want, for an ultraflat and truly pure finishing surface is something microscopic, that looks like those waves, but with the absolute minimal "depth" in the drops, and working out the scratches from previous grits with each progressive grit does that. Technically, even 2000 leaves scratches...it's just that we usually can't see them with the naked eye and certainly can't feel them.

It took me a little while to understand sanding techniques for different finishes, but I guarantee that the little bit of elbow grease is worth it and stepping up/down through sandpaper grades gives you a finish you'd name your first born after

[Simplicity]

A little work now
For a life time of praise.
I think that's how it goes
You can find 1500 grit you can also get fairly easily 2500 and even 3000 grit and even higher.
Try auto paint stores.
Or one of the forum spooners
The sand paper man.
Mr redshirtguy is pretty much spot on with is description

[Robson Valley]

If and when the surface is flooded with polyurethane, there shouldn't be much left to do.
On raw wood, 320 is probably good enough to level the wood ridges.

If the poly gives you some raised grain, wait until the first coat is good and hard.
Then a gentle rub with very coarse steel wool (fine is useless) to cut off the raised
bit of wood. Coarse SW is not round, it's flat = cuts like a million chisels.

[FenceFurniture]

In the coarser grits I think there is great value in doing as many increments as possible, and it's no extra work or cost because each grit is used for less time than if you are skipping grits. This depends on the result I want and the timber being sanded, but typically on tight grained hardwood I'll go 80,100,120,150,180,240,320,400-500 and then I step it out a little (because after 4-600 it's really polishing). I'll go 800, 1500, 2500-3000.

The 80-100-120 part is pretty critical to observe because the scratches may not be visible during the sanding process but will become extremely obvious as soon as a finish is applied - and it's too late then......unless you want to start all over again.

[LGS]

Brett,
When I started Hard Burnishing, I used the same grits as you (minus the 320) for preparing the timber (dry sanding). However, I found that on timbers like Blackwood and some of the lighter timbers, such as Canadian Maple, that starting at 100 rather than 80 actually saved me some grief later in the sanding process. Once you get scratches from an 80 disc into the wood, they can be extremely difficult so sand out again. So now I use 100, 120, 150, 180, 240 and 400 grit. I get an excellent smooth finish ready for oiling and then subsequent sanding. I have also found that post oiling, the 400, 800 and 1200 are the grits that do most of the burnishing, 1500, 2000 and beyond still apply heat, but mostly help in "polishing' the wood.

Regards,

Rob

[Tegmark]

Brett,When I started Hard Burnishing, I used the same grits as you (minus the 320) for preparing the timber (dry sanding). However, I found that on timbers like Blackwood and some of the lighter timbers, such as Canadian Maple, that starting at 100 rather than 80 actually saved me some grief later in the sanding process. Once you get scratches from an 80 disc into the wood, they can be extremely difficult so sand out again. So now I use 100, 120, 150, 180, 240 and 400 grit. I get an excellent smooth finish ready for oiling and then subsequent sanding. I have also found that post oiling, the 400, 800 and 1200 are the grits that do most of the burnishing, 1500, 2000 and beyond still apply heat, but mostly help in "polishing' the wood.Regards,Rob

Hi, I'm not sure if sanding beyond 2000 with 2500, 3000 gives any benefit with eee ultra shine? They say 2000 gives up to 20-30,000 grit finish. Does that mean 3000grit would give any higher? Thanks.

[LGS]

Triple EEE will probably do all that you want. There probably isn't much purpose in going higher than 2K. But do remember that EEE is not a finish, it's a cutting compound

Regards,

Rob