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I just finished sanding a large red oak table top and stained it. Somehow I missed some sanding swirl marks - ugh! I know you are not supposed to sand after staining, but I really hate to leave the swirl marks. Have you guys had experience with sanding after staining? If I re-sand the entire top again, will it screw it up? I was planning to use a sanding sealer and spray poly after staining….
 

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It might be acceptable to skip grits when sanding but is never recommended. Which is probably what you did. You probably also did not stay on the smaller grit paper long enough.
The final grit of sanding should be determined by the label on the can of your finishing products and not by what someone on a woodworking site tells you.
 

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I just finished sanding a large red oak table top and stained it. Somehow I missed some sanding swirl marks - ugh! I know you are not supposed to sand after staining, but I really hate to leave the swirl marks. Have you guys had experience with sanding after staining? If I re-sand the entire top again, will it screw it up? I was planning to use a sanding sealer and spray poly after staining….
Sometimes if you sand immediately while the stain is still wet you can just sand the spot and stain. After allowing the stain to dry though you should sand the entire top to a uniform appearance and then stain. Stains contain hardening oils like linseed oil and if allowed to dry there is enough hardening oils there to seal the wood so if you sand just the spot it won't accept the stain.

On another occasion if it happens again try sanding the spot by hand with the grain and try staining the spot. Have some lacquer thinner and some rags handy in case it doesn't work. If it doesn't work wash as much stain off as you can and allow to dry. By washing it off it will make it easier to re-sand the top.
 

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You can usually sand the stain off, or at least down to an even distribution, since its going to imbed in the oak you'll never get all of it out without a total resurfacing.

But, doing that with an orbital sander will leave you with more swirls. They can be minimized by slowing down the speed, going slow, reducing pressure, and making sure you've got fresh, clean sandpaper. And, the quality of sander also makes a difference. Air sanders typically don't leave swirls, I'm not sure why.

IME the solution is never stain or dye anything after ROS sanding. Finish prepping the surface by either hand planing, card scraping, hand sanding, or a combinationand then you'll be good to go.
 

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So what ROS and paper are you using, grit?
 

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You can usually sand the stain off, or at least down to an even distribution, since its going to imbed in the oak you'll never get all of it out without a total resurfacing.

But, doing that with an orbital sander will leave you with more swirls. They can be minimized by slowing down the speed, going slow, reducing pressure, and making sure you've got fresh, clean sandpaper. And, the quality of sander also makes a difference. Air sanders typically don't leave swirls, I'm not sure why.

IME the solution is never stain or dye anything after ROS sanding. Finish prepping the surface by either hand planing, card scraping, hand sanding, or a combinationand then you'll be good to go.
You don't need to slow down the speed..

Air sanders do leave swirl marks..just have to look Hard enough...

When I was working at the furniture company I was looking about 12" from the project with my glasses. Brian Georgie the plant manager and part owner said " Do you need to look at it that close" I responded " If I can't see any problems, the customer cant" Brian liked that answer, and walked away...
 

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Discussion Starter · #7 ·
Great comments - thank you. I re-sanded RO 120 then RO 220, and hand sanded with a 320 sponge. I re-stained it and it looks much better. Guess I will do a better job of inspecting next time…
 

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It takes time to get use to it. Sander and sand paper options and usage.once you get the handle on it, it gets easy. Takes a good eye...

What sander are you using?
 

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I just finished sanding a large red oak table top and stained it. Somehow I missed some sanding swirl marks - ugh! I know you are not supposed to sand after staining, but I really hate to leave the swirl marks. Have you guys had experience with sanding after staining? If I re-sand the entire top again, will it screw it up? I was planning to use a sanding sealer and spray poly after staining….
I would suggest if you sand you do the entire top. I would also suggest sanding by hand, only in the direction of the grain. The problem with random orbit sanding is, especially with the finer grits, you do not see the swirls until the piece is stained or cleared. For that reason I always do my last two grits by hand, block sanding in the direction of the grain. Sanding does not need to be work, you are not looking for stock removal.
 

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Hand sanding was outlawed at the furniture company...once you get a good process, you move forward..
 

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I do the hand sanding with the grain. In the early days, I hand sanded everything because it was faster and better than using the old electric sander I had back then.

It is too late for the OP, but ...

When I first started out with woodworking, I was taught to wipe liquid (solvent or water) on the project with a rag to highlight the grain and scratches to make them visible before staining or finishing. The scratches were so much easier to see. An ultra-thin layer is all you need - just enough dampness to show the grain and scratches.

If you use water, it will raise the grain and you will have to sand it down.

I am not sure which solvent is most appropriate for this use. These days I use acetone because it evaporates very quickly, almost too quickly. I have also used mineral spirits which takes longer to evaporate. If anyone has any suggestions or recommendations for the best solvent or a better technique, I would like to know.

Note: I won't use solvents on food-safe projects like bowls or cutting boards.
 

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Great comments - thank you. I re-sanded RO 120 then RO 220, and hand sanded with a 320 sponge. I re-stained it and it looks much better. Guess I will do a better job of inspecting next time…
I would have went to 180 in between. Sanding is similar to sharpening in that higher grits are simply removing the marks left by coarser grits. But it’s all good. Hand sanding is the key.

Some other factors are :
1. Good dust collection inhibits dust collecting in the grit
2. Blow or wipe off the surface before going to the next grit, just in case there is any residue from the previous grit.
3) Use good quality paper.
4) Check it often. One little nib can wreak havoc in 1 second.
5) Change it often - even good sandpaper is not that expensive.

My understanding is air sanders don’t spin like a random orbital. I believe I learned this from Charles Neil.
 

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Here's the problem. If hes tryng to hit a certain color he cant get too high on grits. Even when go as high as 150 i flood the piece wit stain. .I use sheep's wool and just flood it..

I don't go higher than 150 unless it's getting straight clear. If I go higher at all.
 

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The number one problem with sanding marks from a RO sander is moving the sander to fast.
Even on TV they show guys going back and forth just as fast as hand sanding, that's wrong,
that leaves swirls. Like the instructions for the sander says, it has to go slow enough to cancel out the swirls.
Not the sander speed, the speed of moving it back and forth.
 

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Too fast too slow depends on the sander and the grit.

Too slow and too low a grit you ca end up with a pond..

There is a lot of this or that to sanding with someone else's sander and paper...
 

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Great comments - thank you. I re-sanded RO 120 then RO 220, and hand sanded with a 320 sponge. I re-stained it and it looks much better. Guess I will do a better job of inspecting next time…
When you are sanding a project if you would wipe the wood with a rag damp with water between grit changes it will raise the grain making your sanding more effective. If you seem to be plagued with swirl marks you might consider getting a different brand RO. Some of them are more prone to swirl marks than others.
 

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............I re-sanded RO 120 then RO 220, and hand sanded with a 320 sponge. I re-stained it and it looks much better. ...............
Most if not all of your problem is the skipping of grits. The sandpaper, not the breakfast stuff. If you went from 120 and then straight to 220, more than likely you never removed the 120 grit cuts unless you stayed with the 220 grit a v-e-r-y long time with a lot of sandpaper changes. To get quality results, each succeeding grit should remove all of the scratch marks from the previous grit before you can progress to the next grit.
Example: take a rough cut large tooth blade from a hand saw or bow saw and put moderate pressure on it and drag it across a surface of wood. It will leave relatively deep cuts. Now take a fine tooth hacksaw blade and drag it across the deeply scratched surface you just made. How many passes do you think it will take with the hacksaw blade to level it out?
That is what skipping grits is like. It could be done but will take a very long time. With most 220 grit sandpaper, you also will be using a lot of it. This process it neither time nor cost effective.
If you dont skip grits, you can go through the process relatively quickly and economically. Most woodworkers I know will skip just 1 grit at each point. It is better than skipping 2 or 3 grits but still not as cost and time effective as not skipping.
 

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Making sure your shop is clear of dust before you add seal is just as important as going down a grit..
 
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