# Sanding after final coat of Poly?



## Marco (Feb 21, 2009)

I believe somewhere in the search of the Forum I read where a few will sand after the final coat of poly with a super fine sand paper or steel wool, wipe off and then add a paste wax. I am looking at doing that.... stop me before I go down the wrong road.

I sprayed on 3 coats of water based satin poly with a HVLP spray gun, 220 after the 1st, steel wool after the 2nd..... 3rd coat is fairly smooth. 

Thanks


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## hawkeye10 (Jul 28, 2015)

I would try it and see what you think. You can't really hurt anything and if you don't like it spray it again.

What kind of steel wool do you use? I have some of the wool that is from China it breaks down into little short fibers or maybe I should say pieces. You can get some that is made in the US or Mexico I forget which. I know Woodcraft carries it.


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## Cherryville Chuck (Sep 28, 2010)

I’ve always heard you shouldn’t use steel wool between coats of water based. If any steel particles stick in the finish they will rust under the upper coats. One of the issues with sanding poly finishes is the heat generated if you go too fast. I’ve read that the best way is to use some water and a wet and dry paper in 400 or 600 grit but I haven’t tried it.


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## Stick486 (Jan 4, 2013)

I heard pumice..
ditto on the rust...


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## JOAT (Apr 9, 2010)

hawkeye10 said:


> I would try it and see what you think..


My thought exactly. Not tried it, but have heard that scotchbright pads work well.


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## DesertRatTom (Jul 3, 2012)

I make picture frames for paintings. I use sanding sealer, start with 150, repeat down to 220. It I didn't get it really smooth, I would repeat the 220 with sealer. Then after applying stain, dry the piece out, then go back to 220. Read that going to higher number paper actually works against the stain because the ultra fine paper producs particles that fill in tho pores in the wood and impede penetration. I no longr use regular paper sandpaper but use the new 2M soft or flex-back sanding media. I also use some rubber sanding blocks with a variety of round shapes--this gives me very nice results in a very short time. I also use the filler shown (Australian), which takes stain as if it were the original wood. Last step is water based, wipe on poly, which I apply with paper towels, sanding very lightly between coats (usually takes 3 coats to get the shiny surface I like best.

I would not use steel wool on poly. Oops, left out a step, After sanding, I very carefully wipe off every speck of sawdust, and I am particularly careful about cleaning off dust bfore applying each coat of poly. Clean, baby, clean!


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## hawkeye10 (Jul 28, 2015)

Plus one on the Timbermate. They say it never goes bad even after freezing.


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## Garyk (Dec 29, 2011)

Sand paper for auto paint goes up into the thousand grits. I have used that for sanding pens with a C/A glue finish. It works well. IF I can find it I also like the white version of scotchbrite pads instead of steel wool. Same results at the steel wool without the mess & metal bits. You can't "feel" the difference when you get past 220/300 but you can see it. Klingspor is a good source for sanding needs.


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## TwoSkies57 (Feb 23, 2009)

@Marco

You can use steel wool as a last step prior to waxing but you have to be very careful. The brand/type of steel wool you use as well as 'how' you use it makes a difference. Regardless of the brand, I would use nothing less than 0000 as a last step. It must be oil free!!!! I've had very good luck with this product from Rockler: 

Liberon Steel Wool-#0000 Steel Wool | Rockler Woodworking and Hardware

There are other long fiber steel wools out there, but I've no first hand experience with em. 

First and foremost, leave your project dry thoroughly. Give that poly a chance to completely set. 
Off the shelf steel wool's as mentioned have a tendency to break down in use. You'll run the chance of embedding small steel fibers into the project. Very light pressure is the key when using any steel wool. Too much pressure or spending too much time rubbing in one spot will rut on you in quick order and with poly's ghosting comes into play. Ghosting is what happens when you rub thru a top coat of poly into the 'layer' below often leaving a faint white ring around the area sanded thru. All wipe on products and aersol's for that matter are thinned out considerably in order to facilitate the application. So often several more applications are required to achieve the desired finish or a workable thickness. I'm happy with using steel wool to just knock down the nubs and fuzzies prior to moving on with the finish schedule. I don't use steel wool's on semi-gloss, gloss or mirror finishes. 

CherryvilleChuck mentioned wet sanding. This is my preferred method in conjunction with a automotive polish finish schedule when a top shelf finish is desired. Alot of work, alot of time and elbow grease required, but dang, the results speak for themselves. You could certainly use wet sanding to flatten out your surface prior to waxing and have a very nice finish! Works very well on satin finishes with up to 320-600 grit papers. Semi-gloss up to 1000 grit. The higher grits on serve to bring out the intended luster of the finish. Higher grits do not add to the sheen. 

Stick mentioned pumice. I've experimented a bit with pumice/rotten stone and a felt pad. Having some really nice results. I just havn't gotten a good schedule (sequence of applications) down yet. 

Just bout all finish schedules require two things. First, knowing what you want and second, knowing how to get there. 

Good luck with whichever method/means you go with!!!!


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## Gene Howe (Jul 10, 2007)

After the final coat, I use the Liberon 0000 wool to apply wax. If there are small nibs in the final coat, I fold a square of kraft paper...paper grocery bag stuff... to get rid of them. For bigger nibs, the white Scotch pads do it. Then, the Liberon and wax. 
For a really nice finish, you need a really good sanding job on the raw wood. I recommend viewing videos by Charles Neal on his "Trace Coat" method. It may seem like an extra step but, believe me, the results are phenomenal. Smooth as a baby's butt.


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## DaninVan (Jan 1, 2012)

Jim; I use the synthetic sanding pads for the fine stuff.
Also, adding wax before the poly has cured for a couple of days probably isn't a great idea. Any finish for that matter, Whatever the solvent was, it needs to escape ('solvent' in the chemistry sense).


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## Marco (Feb 21, 2009)

First off, thanks for the responses. I will try steel wool and paste on the backside of the Barn door and see how that looks after the poly is good and cured. I'll likely get some fine sand paper and use it with paste on the underside of the table and compare the 2 and go with the best for the sides that will show.

Secondly the different methods of finishing is endless which aids in confusion and difficulty choosing which method to use. I'll be the first to admit when I'm done sanding the finished project I am ready to move on to the next. Finishing, great finishing, takes knowledge, time, patience and a proven method. I found my problem. 

If I had Sticks money I would just send it out to be finished and move on to the next project. However it looks like I will be allowing the time and choosing a method that will work for me. One that has a low amount of harmful fumes as the shop is attached to the house.

One thing that stuck with me during my recent search on finishing was a guy stating that he was just an average craftsman/carpenter but having a great looking finish made his project great.


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## Cherryville Chuck (Sep 28, 2010)

I've read articles by some of the contributors of fine Woodworking saying that on a high dollar commission that they will often send the item out to a pro to be finished. It is that complex a task and the results from having it done right can be as important, or more important, than doing a stellar job of the build.

If you go with the water and et dry paper most hardware stores near me sell 400 and 600 grit silicon carbide wet dry paper. If your local store doesn't have any then go to an auto parts store that sells automotive paint and supplies. They will have it. Those papers are also useful to sharpen chisels and plane blades to a moderately sharp edge.


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## Marco (Feb 21, 2009)

Cherryville Chuck said:


> If you go with the water and et dry paper most hardware stores near me sell 400 and 600 grit silicon carbide wet dry paper. .


 I picked up a variety wet pack today 220-320-400-600 they sold singles but didn't have anything after 600 except 1500 so not knowing grabbed it as well.

I have to get the door and table finished and out of the shop so I can start the bench that goes with it. Simply not enough room in the shop. It was a logistic challenge to do those 2 at the same time.


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## CharleyL (Feb 28, 2009)

I've had good luck sanding the next to last coat of poly with 320 0r 350 paper on a flexible pad. Then cleaning the surface very well and then applying the final coat of poly. I don't use water based finishes. I've never been happy with the results. When applying poly I use gloss poly for all coats with a very light sanding, then use satin poly for the final coat if I don't want the shine. don't want the high gloss.

Charley


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## Marco (Feb 21, 2009)

DaninVan said:


> Jim; I use the synthetic sanding pads for the fine stuff.
> .


I saw those at the hardware store today while after the fine wet/dry paper. May end up using them at some point. Also asked about the white scotch pads but they didn't have any.


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## Marco (Feb 21, 2009)

CharleyL said:


> I've had good luck sanding the next to last coat of poly with 320 0r 350 paper on a flexible pad. Then cleaning the surface very well and then applying the final coat of poly. I don't use water based finishes. I've never been happy with the results. When applying poly I use gloss poly for all coats with a very light sanding, then use satin poly for the final coat if I don't want the shine. don't want the high gloss.
> 
> Charley


The last few projects I've been spraying water based poly with limited success as in no brush marks. Spraying because I had a HVLP gun that I hadn't used and a half gallon left of Minwax Clear Satin Water Based Oil-Modified Polyurethane I call it water based as clean up is with water.

After this project I need to pick a finishing method and stick with it as there have been some good ones mentioned and posted.


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## Cherryville Chuck (Sep 28, 2010)

CharleyL said:


> When applying poly I use gloss poly for all coats with a very light sanding, then use satin poly for the final coat if I don't want the shine. don't want the high gloss.
> 
> Charley


I've read of that method before Charley, maybe here on the Forum years ago. If I remember right the reason for using all gloss finish on the buildup coats was that it gave better looking depth of finish. Is that your results? It was also suggested that gloss finishes are harder than semigloss and satin but I don't know if that was true.


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## CharleyL (Feb 28, 2009)

Yes, the final result of using clear for the first layers and then using the satin or semi gloss for the top layer does produce a nicer finish with more depth. Sanding the next to last coat removes any bumps or imperfections that would show in the final layer without the worry of breaking through the stain layer, so I've found that my end result is way better this way. I don't have spray capability, so all of my staining and finishing is done by wiping with a lint free cloth. I don't use brushes, except sometimes if applying shellac.
This works for me. Others may have more or less success with it. Maybe someday I'll have the clean space needed for spray finishing, but now I clean the shop well before starting, and then do finishing only until the project finishing is done, before making sawdust again.

Charley


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## Marco (Feb 21, 2009)

*Table and Barn Door*

I ended up using 600 grit for very light smoothing on both the door and table followed by a paste wax for a little shine and protection. For my finishing abilities the door came out ok and the table came out good. I got the door hung but the small table will have to watch TV until the bench that goes with it is ready.

Thank God they are out of the shop!


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## harrysin (Jan 15, 2007)

I never use water based finishes. Most often I use rattle can high gloss lacquer and rub down between coats with 0000 wire wool, after which I thoroughly clean with a tack rag before spraying the final coat.
Now, with Danish oil I apply usually five coats, no rubbing down in between coats and 
then apply the sixth coat and leave it to fully harden over a few days. Then, using 0000 wire wool lubricated with wax polish, preferably Johnsons, which is no longer available in Australia, I give a good rub down, the more it's rubbed the higher the gloss.

As a matter of interest, Johnsons polish is now only available in America and the cost of freight is FAR more than the cost of the polish.


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## Garyk (Dec 29, 2011)

Cherryville Chuck said:


> I've read articles by some of the contributors of fine Woodworking saying that on a high dollar commission that they will often send the item out to a pro to be finished. It is that complex a task and the results from having it done right can be as important, or more important, than doing a stellar job of the build.
> 
> Google "French Polish" technique. Watched it done one time and it is what is used to get the deep mirror finish on $$$$ pianos. Been a long time so I don't remember the details other than he kept using steel wool between coats. I'm sure he used some kind of compounding agent.


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## HD74_al (Nov 28, 2012)

With poly it depends on the finish you are looking for. If you are looking for stain (mat) finish stop at 1200 grit wet & dry. Work you way all the way up to the final finish. If you want a high gloss then work your way up to 3000 grit wet & dry. Watch the edges as you can burn through real easy.


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