View Full Version : Advice on how to not screw up the final coat of poly

05-09-2005, 7:23 PM
I'm working on a counter/table project and am down to the third and final coat of oil-based, satin-finish poly (brand Olympic). I've sanded between the coats so far, but what do I do about the inevitable bubbles and dust that settles in the final coat? Surely, I can't leave it like that. FYI, the wood is unstained maple, and I used an oil-based wood conditioner before the first coat. I also use a nice Purdy angle sash brush meant for oil-based paints. I do not shake the can, nor do I try to overbrush.

Some have said I should thin the final coat, but others have said the major brands (Minwax, Olympic, and Varathane) suggest you use it at full strength. I read where one guy gets a thinner consistency by pouring the poly into a bucket and heating the bucket on a hot plate. I will try this in the future, but it's too late for this project, unless I go for coat #4.

Have read that I can lightly buff it with 0000 steel wool and then lightly rub the wood with rag slightly damp with mineral spirits...the guy said this would make the final coat very nice and shiny. This sounds intriguing...do you think it will work?

Any other suggestions on how to smooth out the final coat of poly without dulling it by sanding?

Doug Shepard
05-09-2005, 7:36 PM
Automotive rubbing compound. Works like a champ.

lou sansone
05-09-2005, 9:20 PM
there is nothing wrong with thinning poly. If you have air bubbles trapped from previous coats you will have to sand back to get them out. After the final coat you can let the finish harden for a couple of weeks and then try to rub it out as doug has suggested. Poly is hard to rub out compared to lacquer or shellac, but you can do it to some degree.


Keith Outten
05-09-2005, 10:30 PM

Awhile back I started a thread about using your ROS with Scotch 3M pads and paste wax to achive a hand rubbed finish that is so smooth you won't believe it and it only takes a few minutes. You can easilly obtain a satin or very high gloss finish whichever you prefer.

Paul Prescott
05-09-2005, 11:42 PM
Keith -

Tried to find that thread but couldn't. Could you point it out please? Thanks!

Keith Outten
05-10-2005, 4:11 AM

Here is the link to my thread on using your Random Orbital Sander for finishing projects.


Jim W. White
05-10-2005, 2:44 PM
I've used this on a couple of table tops recently and was very pleased with the results. Thanks Keith!

Per Swenson
05-12-2005, 5:34 PM
Hi Paul,

You do not need all the festool sanders but the Menzerna polish is
fabulous. You might want to give it a try. Here is the link on how we
did it with Behlens RHTT. I have had the same results with off the shelf polys.
Though not as durable. As has been mention here you must wait untill the top is fully cured. The longer the better. http://www.sawmillcreek.org/showthread.php?t=17615&highlight=shameless+festool
Hope this helps

05-16-2005, 5:10 PM
Just wanted to thank all who replied to my question.

I ended up taking a combination approach. I looked for the various 3M Scotch Brite rubbing pads that folks mentioned, and all the places I looked didn't carry them...but I did find some 3M "Synthetic Steel Wool" pads that were brown and supposed to be the equivalent of 000 steel wool. I took those with some Johnson paste wax and worked the dust nibs and bubbles out of the poly using a reasonable amount of pressure. I followed that up with some 0000 steel wool (the real stuff) rubbed in a bit more wax and worked over the same areas. Wiped it all off with a clean rag and was more than happy with the results.

Thanks again.

jack duren
05-16-2005, 6:08 PM
320 grit sandpaper and some #oooo steelwool usually does the trick on satin or semi-gloss. but beware of rubbing compound unless you want a glossier finish. for high gloss its excellent.

thinning poly for spraying or a penetrating first coat is ok. but after that unless your sprayer wont push it unthinned keep it to factory specs. if the manufacturer thought it worked better "thinned" they would do it themselves and enjoy the profits.....jack

Mark Katz
06-02-2005, 12:25 PM

Here is the link to my thread on using your Random Orbital Sander for finishing projects.



I tried your technique yesterday, and for the most part it worked great.

However, not having the precut H&L pads, I cut them from the 6x8 sheets as you did initially.

My experience was that the pads disintegrated very quickly and I barely could get the two sides of a 24" x 10" shelf done before changing pads. I was afraid the pad would disintegrate too much and the hook part of the sander backer would touch the surface and scratch it. There were shreds (and threads) of synthetic material everywhere.

You mentioned that the pads last a long time. Wonder if you are using genuine 3M pads. The stuff I have is from Rockler or Woodcraft, is not marked in any way, and I suspect it is imported.

Using a Bosch 3283DVS ROS which has a fair amount of vibration. Wonder if that's a factor.


Keith Outten
06-07-2005, 11:53 AM

I purchased my Scotch 3M H&L pads from Industrial Abrasives and they are made by 3M. I have never had a pad to disentegrate or even wear out quickly as they generally last a very long time. The 3M pads get thin, that is how you know it is time for a new pad. I don't recall seeing any of the 3M pads shreading either unless I hit a sharp edge. Just for some kind of metric I can normally finish 20 to 30 large plaques from one pad. I am using a 5" PC 333 ROS which should be comparable to your sander.

Mark Katz
06-07-2005, 2:24 PM
Thanks Keith.

I think I'll order some of the 3M pads before I try this again.