# I hate oil based polyurethane



## cain8885 (Aug 21, 2009)

More of a rant than anything I suppose, but I have developed a severe dislike of oil based poly. I posted on here before about building some new doors for my kitchen. Well I did, and am on to the finishing phase. Prior to finding this forum I just grabbed a can of poly and slung it on the cabinet carcases. Seemed fine. But boy, trying to get poly on 22 flat panel mission style doors and have it stay flat and dust nib free is going to drive me batty. 

Any ideas? I am thinning the poly with mineral spirits, I have shut the central heating off to stop dust being swirled around, etc etc.

My last big problem was that prior to applying my poly coat I wiped the surfaces down with mineral spirits. Apparently I didn't let it dry sufficiently and the next coat of poly would not coat certain areas leaving me with some nice pools and bumps. Meaning more sanding, yay.


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## Colt W. Knight (Nov 29, 2009)

Oil base Poly is the biggest PITA when it comes to finishing. I have stopped using it altogether. It has a long dry time, its messy, hard to clean up, clogs spray equipment, when I do spray it, it builds up on the hairs of my arms, sticky, you can't wet sand or buff it nearly as well as shellac or lacquer. I just plain don't like polyurethane.


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## cain8885 (Aug 21, 2009)

Here here, I wanted the poly so the color would match the carcasses. At this point I am wondering if I could just sand it flat(leaving the stain) seal coat it and go over it with a different clear. UGH.


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## cabinetman (Jul 5, 2007)

For the reasons given is why it's not a popular finish. If it's cured, scuff sand with 320x and you could use a waterbased polyurethane. Try a sample with whatever brands oil base is down and whichever WB you try.


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## cain8885 (Aug 21, 2009)

Waterbased poly over oil based poly? That works? I had imagined even once cured there would be issues( hence the seal coat). 

B


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## Colt W. Knight (Nov 29, 2009)

once its cured there should be no compatibillity issues.


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## TimPa (Jan 27, 2010)

i guess i've learned to live with it. i love using it on horizontal surfaces more then vertical (runs). i scuff between coats with 220, vacuum off, the tack off, then blow off with air to make sure. all while having a room air cleaner (homemade squirrel cage with 2 furnace type filters) running. i lay the poly on with 2" foam brush and don't touch it again. comes out smooth as glass. although i admit the long dry time leads to risk of dust falling on it.


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## cain8885 (Aug 21, 2009)

So you have the squirrel cage fan blowing out a window? Or simply circulating air in the room.

Brian


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## sanchez (Feb 18, 2010)

I feel your pain. I stained and oil poly'ed all the woodwork in my house when it was built in 2008. I did everything but the cabinets. That was my first ever try at finishing wood. 

That was a lot of work to get it done around my real job, and get it to end up looking reasonably good. Luckily I started with the baseboards, molding, and windowsills, then moved on to the french doors, 6 panel doors and staircase parts. It was real hard to get a good finish, especially in a house under construction.

Too bad it took me almost to the end to figure out thinning the poly worked great.


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## TimPa (Jan 27, 2010)

cain8885 said:


> So you have the squirrel cage fan blowing out a window? Or simply circulating air in the room.
> 
> Brian


it pulls air into the box, through two 14" x 20" stacked air furnace filters, and out the side toward the wall. motor is like 1/3 hp and fans are about 7" dia. works well. first filter is std mesh type and 2nd is filtrete.


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## Rick Mosher (Feb 26, 2009)

Build one of these racks. It doesn't have to be this large, when the doors or panels are stacked in the rack they protect each other from dust while they dry. Put a sheet of cardboard or plywood in the top and the wet panels under it. You will get very little dust with this system even using oil based poly.


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## cain8885 (Aug 21, 2009)

Thats a pretty nice looking system. I have an empty daylight basement so I have a 30' long bench built with all my doors on it. 

My luck has been improving as I have gone back to a previous system. So many people online said to try and use a nice brush. SO I used a nice brush and I loaded it with thinner before applying poly so the varnish wouldnt wick up into the brush. Well I think that was a problem as the thinner in the brush was thinning the finish random times as it pulled thinner out of the brush? Maybe maybe not but thats what it seems like. I went back to disposable foam brushes and things are looking much better.

I also convinced my wife that while the doors are being finished the central heating is off.

has reduced the dust dramatically.

B


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## jlord (Feb 1, 2010)

Try using Naptha instead of Mineral Spirits to thin your poly. The solvents will evaporate a little quicker & start the curing process sooner.


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## Chris Adkins (May 12, 2010)

I never brush on oil based poly only wipe on. The more you thin it the faster it will dry. 

The problem with water based is that it has a different look than oil based. The water based has a white look to it as opposed to the more yellow look of oil based. You can used a water based poly over the oil based as long as the oil based coat is completely dried. If you are ever concerned with covering one type of finish with another you can always use de-waxed shellac between the coats. de-waxed shellac is pretty much compatible with anything.

Good luck!


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## Dorm57 (Jun 1, 2010)

I too am having some difficulty with oil based poly. I just put together a small maple table, with bocote 'sock' feet on the bottoms of the legs. I'm using a Minwax poly, foam brush and ever so much patience. The finish is coming out streaky in places and fish eyes in others. I've taken a lot of care to make sure to wet the surfaces - not just spread the finish. And still have uneven spots with the finish coat.

I've applied 2 coats thus far and have just sanded the second coat w/400g sandpaper. I'm thinking of spraying from this point forward to get a more even coverage. 

If I do spray what do ones recommend ... should I thin the poly with some medium, or just leave as is from the can and spray away?


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## cain8885 (Aug 21, 2009)

Hey, mine ended up being ok after "a lot" of coats( dont ask). I would ask, are you thinning the poly when brushing? That is very helpful and I would recommend giving that a whirl. I had contemplated spraying as well, but couldn't bring myself to do it. It seemed it would make an absolutely HUGE mess and really easily muck up my hvlp rig.

B


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## Mr Mac (May 31, 2010)

Chris Adkins said:


> I never brush on oil based poly only wipe on. The more you thin it the faster it will dry.


I'm with Chris on this on. I love an oil based polyurethane finish but tend to wipe it on over brushing in most cases (unless it's a really big project).

Mac


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