# Polyurethane..why cannot we just get along



## handystanley (Jun 4, 2010)

It seems whenever I decide to use a polyurethane product…we just do NOT get along. My results are always substandard. This weekend I even read a previous article in Fine Woodworking by Lon Schleining (www.woodbender.com) on finishing. I applied a multiple coat of polyurethane using 300 grit sandpaper as he wrote…even had the artilce next to me as a reference …now I have scratch marks all over the door that I was refinishing….

To top off the frustration…this door is pocket door that needs to be installed before I can finish the trim work in my master bathroom…..

Frustrating….


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## gfadvm (Jan 13, 2011)

I never brush poly but prefer home made wipe on [Slower but goof proof] or spraying larger/intricate projects [like my chairs]. I use grey Scotch pads rather than sandpaper and dont bear down. The above have solved my poly problems. Hope this helps. I would wipe your doors and you probably wont need to sand/Scotch after the first coat unless in a dusty environ.


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## stevenhsieh (Jan 8, 2010)

I assume you are using a brand new sandpaper?

Rub two sandpapers together until smooth. Then use that to sand.


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## ajosephg (Aug 25, 2008)

I never have a problem using 220 grit for the final bare wood sanding. After each coat of gloss poly (Minwax oil based) using a good brush I sand with 300 grit wet dry automotive sandpaper with one of those rubber block thingies. Usually I get a finish I like after three or four coats. I've tried finer grits on after several coats but can't see any better results. The Minwax website has a lot good info on application, and they recommend 220 grit between coats. Besides the resulting super smooth finish, I'm told sanding is required to make sure the poly bonds well with the previous coat.

BTW - I change to semi-gloss or satin spray on (aerosol can) for the last several coats. That's kind of expensive but the results are great. Some day I hope to get a HVLP system.

Also - Go easy on the sanding or you'll go completely through the varnish down to bare wood.


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## wapakfred (Jul 29, 2011)

Like yoou, I've never had good success with anything "polyurethane". I've completely purged my shop of all products poly. For oil based varnish I now use alkyd/soya or alkyd Linseed oil formulas. For soya based P&L 38 is my favorite (when I can find it), but I've also used the Cabot 8000 series and like it really well. For a linseed oil formula the SW Fast Dry Oil Varnish is really great. If it wasn't for the amber color it has (linseed oil) I'd use it exclusively. As it is, it only gets occasional use in my shop. But they are all top notch products.


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## stnich (May 24, 2010)

I use Polyurathane products all the time and never have a problem. I use a foam brush to apply light coats on larger flat surfaces keeping a wet edge as I go. On mouldings and other detailed type surfaces I use a china bristle brush usually of the throw away variety. I sand with 320 grit paper and gray synthetic sanding pads in between coats. When I apply it I try to not go back into the poly to much that I've already applied so that in levels out naturally. I also use aresol spray cans of Poly with great success. Some of the things that I make are just to small to put a brush to. I combine the two finishes with no noticeable difference in the finishes.


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## richgreer (Dec 25, 2009)

I have pretty good luck with poly. Here's my approach. I only use wipe-on poly and I apply it with a disposable foam brush. Right after I cover an area of about 2 square feet or less, I wipe the poly off with a lint free paper towel. I wait 3-4 hours, sand lightly with clean 400 grit paper, and apply another coat. Each coat is quite thin and I consider 5 coats to be the minimum for any visible area. I'll get by with fewer coats on the underside or back of an item.

As an FYI, I like Minwax wipe on poly but I think the gloss is too glossy and the satin is too dull. I mix them 50/50 to get the finish I want.


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## Brett1972 (Nov 5, 2010)

I'll put in my $.02.

I used to get terrible results with oil based poly and I would get sooooo frustrated. Then I figured out, or was told, to thin it out. I do like many others have done, I make it into a wipe on poly, about 3 parts poly to 1 part mineral spirits, maybe even 2 poly to one spirits. I like to let each coat cure for at least 24 hours and sand lightly between each coat with 400 grit. I do AT LEAST 3 coats minmum. For my final coat and sheen (I like satin so I use satin sheen from the can) I dilute to 1 part poly to 3 parts mineral spirits. I wipe the whole piece down making sure to check the evenness of the application by making the piece look "wet". Using a good light source at a low angle to the piece is how I check for "wetness". I let this coat dry and I have always had good results. If I have noticed after that final coat that I have missed a spot, I very lightly sand and wipe the piece down again with the 1/4 ratio and check again when dry. The last coat is so thin that it is like wiping with just mineral spirits but there is just enough poly in it that it lays down a thin layer and gives it the final sheen that is indicated on the can.

Hopefully this gives you another method to try and I hope that you get the results that you are looking for.


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## stevenhsieh (Jan 8, 2010)

I love screwing up, because you get to learn newer things.

Apply another coat, you willl probably see the scratches gone.


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## helluvawreck (Jul 21, 2010)

Thanks for this thread - good info from it.


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## handystanley (Jun 4, 2010)

I have really appreciated the feedback that I have received so far. What I am planning on doing tonight is to try sanding out the scratches with 300 grit sand paper and then moving up to 400. I was thinking to sand until I see no more scratches on the door frame. Feedback welcome.

Question: Does anyone see an issue if I use my Makita palm sander instead of doing it by hand????

@cr1: Will consider using the General Finishes product the next time I need to use a polyurethane. The main issue is that no one in my county carries it. However, it will give me an excuse to go up one county to a wood store that I have not been to in a while.

@gfadvm: I originally used Old Masters wipe on Poly…followed the instructions and ended up having "ridges" which I did not discover until my third coat…that is when I started having my scratch problems…when family members wanted to "help me out"...ahem…

@StevenH: What is the purpose of sanding two pieces of sandpaper together? To dull the grit??

@josephg: thanks for the concern about sanding too much. I am also using a satin finish.

@brett: That is what I have been doing this week to a mirror frame that I am working on. Instead of applying Poly straight…I have been using 3 parts Poly to 1 part paint thinner / mineral spirits. It seems to be working better that way. I am applying the final coat tonight so we can get a mirror cut for the frame tomorrow.


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## stevenhsieh (Jan 8, 2010)

I asked you are you using a brand new sandpaper?

Most sandpaper brands 320 grit and 400 is too aggressive when new.

I never use a brand new sandper when sanding between coat.
Don't throw away your beat up sandpaper, they re perfect for this.
Yes sanding them together to dull them.

I bet 100 dollars that if you apply another coat, you will see the scratches gone.


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## bandit571 (Jan 20, 2011)

All I have ever used is Poly. I'll sand down to 150 grit on bare wood. Between coat #1 and #2 , 220 grit HAND sanding. Between #2 and #3, steel wool. After each sand ing/scruffing, I CLEAN the surface with a tack cloth. That is, one wipe, change to new areas of the tack cloth, wipe another section. Use a clean section of the TC each time. After coat #3 is on, I'll let it dry until it is just barely tacky to a finger tip. Then I grab an old T-shirt, and a big batch of elbow grease, and start rubbing things down, HARD. That was the way I was taught.


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## TimC (Sep 17, 2009)

I also used to have major problems with poly. I never thinned it. Poly straight out of the can dries quickly and that is usually where the brush marks come in. If you thin it and go extra light on the sanding between coats it should help a bunch. The poly will have time to fill any small voids. Good luck. If you can, snap a before and after pic to put into the thread so everyone can see the difference.


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## handystanley (Jun 4, 2010)

@ Steven H: Yeah…I have been using new sandpaper. I will try your suggestion tonight. BTW…your bet is tempting but my personal economy right now is stretched just like everyone else's…LOL!

@bandit571: Thanks….may try the elbow grease tonight.

@The Head Chuck: The best I can do in pictures is show everyone where I am right now and hopefully an improvement picture afterwards.

Boy…I got to get this door done so I can finish the bathroom and move on to getting the baseboard and window trim finished in the bedroom so the wife and I can move back in. We started a "remodel / repair" of both rooms a YEAR AGO last Memorial Day weekend and had a contractor totally screw it up. They say if you want it done right do it yourself. Well, I am certainly trying. LOL!


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## gfadvm (Jan 13, 2011)

Stan - If you're getting ridges with wipe on, you are probably applying too much at one time or it is not thinned enough to flatten out before it dries. Runs are a huge problem on vertical surfaces so I hope the door is lying flat rather than hung on its hinges. Good luck!


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## handystanley (Jun 4, 2010)

Hey everyone…interesting and similar discussion going on here: http://lumberjocks.com/topics/3306


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## ajosephg (Aug 25, 2008)

Hate to throw another wrench in the works. "If you're getting ridges with wipe on, you are probably applying too much at one time or it is not thinned enough to flatten out before it dries."

Ridges can also be caused by a surface that is too slick resulting in the surface tension of the varnish to dewet and ridge up. This can exacerbated by varnish that is to thin, or insufficient thickness. Wet sanding before application of secondary coats.


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## steve4182007 (Sep 7, 2011)

I work with poly all the time doing harwood flooring. sometimes you can get scratches in the poly if it is not totally dry. Make sure you give it a minimum 24 hours between coat especially on a humid day . we also use paint pads when we coat and have had good luck using them. 300 grit should be more than fine enough between coats and make sure to sand with the grain not against it. hope this helps STEVE


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## stratman (Sep 1, 2011)

Thanks. I learned some things. Being an old yacht restorer, I always use marine varnish . sometimes I'd use tung oil as a sealer and start the layers with it. I wouldn't have to sand in between coats if it isn't more than 24 hrs. drying time. I always worked with Teak or mahogany. sometimes with Brazilian or African exotics. Tung oil gives a beautiful honey look. with varnish 220 in between coats on exterior varnish. Interior varnish, I would go to 320 or sometimes. 400 grit for a mirror finish. on furniture, I always like hand rubbed tung oil. Dries hard and durable and always looks great. for the antique look, I would use a bees wax formula over the tung oil. Pretty old fashioned,but, nice.


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## richgreer (Dec 25, 2009)

Let me respond to the question, "Does anyone see an issue if I use my Makita palm sander instead of doing it by hand????"

This is one of the sanding situations where I prefer to hand sand. I want to sand just enough to get it smooth and not a single stroke more. With hand sanding I can actually feel the progress and I think it is easier to know when to stop. On large surfaces I will use a sanding block on occasion, but I usually prefer no sanding block. I want to feel the wood through the paper.


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## BillWhite (Jul 23, 2007)

Quit usin' polycrapithane.
Use a lacquer or a real varnish just like the masters did.
Now I feel better.
Bill


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## bandit571 (Jan 20, 2011)

Oh really? Take a look at my avatar then, that is three coats of Minwax Poly Gloss. Hmmmp.


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## rimfire7891 (Jun 15, 2010)

Poly definitely can be trying.
Have had good luck with Minwax quick drying poly. Use Wooster brush synthetic bristle. The first coat can be put on with cloth and wiped on so the is not too much on, no pooling, for porous woods it soaks in pretty fast anyway, maple not so fast. I don't sand between the first and second coats, just between the second and third or the third and forth. Try and get as much horizontal as possible to stop runs. The Minwax seems to have higher leveller content than most I have tried. Like to brush it out to a thin coat and "tip" the last brush strokes, i.e. hold the brush at 90 degrees to the surface and pull it along with only the tip touching. Sand before the last coat and rarely use more than 220 paper.Sand by hand for all except the initial sanding when you are blending and making the piece. Use 3M sanding pads that fit 5" 8 hole disc's Have two one about 1/4"thick and one about 1" thick, they are invaluable for hand sanding IMHO.
Poly definitely can be trying. Don't think you need to thin the Minwax fast dry product, it's pretty thin right out of the can. You can contaminate the product in the can with the brush if you use it right from the can. Better to pour a little into a brushing container and if you are a little short pour in bit more from the can and don't return the left over to the can. Throw it away, it is false economy because if you contaminate your canned finish, you could have trouble next time. The weather has an effect, not much where we live because it is pretty dry, high humidity doesn't help.
In my opinion it is stack up of a lot of little things that don't seem connected which are, and you get a big effect usually in the wrong direction. One by itself won't make much difference however together they do. Lallapalooza effect. 
Just a few thoughts. Generally had good luck with poly over the last few years, also had some real learning experiences too.

Thanks jb


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## bobasaurus (Sep 6, 2009)

I use the Minwax wipe-on poly quite a bit. Use a rag to apply (I cut up old bed sheets), let it dry 2-3 hours or more, buff with 0000 steel wool (very fine), remove steel wool lint with a clean cloth/shirt or magnet, then apply the next coat and repeat until shiny (~4-5 coats usually).


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## Carbide (Sep 14, 2011)

Thin the Minwax brand poly with some paint thinner and wipe it on. Sand between coats with a 320 sanding sponge. I use poly on everything I build.


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## LepelstatCrafts (Jan 16, 2011)

Here is what I have learned about poly. The first coat decides every following coat. If you put a thick first coat on, I tend to get a bad finish. I also have learned that you really need to sand the first coat almost completely off. I let the 1st coat of poly act like almost a filler. Use a high number grit sandpaper like 220 or so and then wipe the surface clean with Mineral Spirits. After that has evaporated, go ahead and apply a thin second coat and let dry. I tend not to sand the second or later coats at all. After the second coat is dry, I only ad a third if it needs it. By hand, I take a piece of copy paper and buff the surface. If after that, if needed, I will wax and buff the surface.

I have always followed this when I found out that it works, and I am happy with the performance of it.

Good Luck!


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## rusty2010 (May 26, 2011)

I also had terrible luck with polyurathane. I admit I never thought of thinning it. I'll try that on the next project. I finished hundreds if not thousands of pieces from furniture to interior trim. My personal choice has been Deft. I also use a conversion waterbourne varnish by Target Coatings. All of these products are sprayed on. So far so good, not a complaint yet from a customer,,Knock on wood.


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## jevarn71 (Sep 30, 2009)

+1 on the 0000 steel wool. On my last project I unraveled it and wrapped it around a sanding sponge. It lasted much longer wrapped on the sponge than just by itself. I use the Minwax Wipe-on Poly and apply with foam brushes.


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## handystanley (Jun 4, 2010)

Thanks everyone for the GREAT responses.

So the other evening I pulled the pocket door off the tracks to trim the "extension block" that I had mounted to the top of it (more door space than door…another story about a former contractor…did I say former?). Was about ready to haul it back into the house when my wife noticed the door was marred on the bedroom side of the door (if it was the bathroom side I would have understood due to the tile floor that it could have rubbed up against). Looking at closer…it was a gouge that did not go across the whole door. Stomped into the master bedroom, grabbed a light and looked into the pocket door cavity. Low and behold there was a drywall screw (did I say former contractor??) protruding through the drywall and pocket door frame near the floor. Drats!! Went over it with some 0000 steel wool and rehung the door.

Hopefully once I finish mounting all the trim I will take pictures and post them.


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## rusty2010 (May 26, 2011)

ouch


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## jeepturner (Oct 3, 2010)

Umm, yes! you did say former. I wanted to at least answer one question in this topic.

Thanks for the post, I always enjoy the responses from the experienced, and talented members of this site. 
On finishing I am usually just along for the ride.


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## pickpapa (Feb 12, 2011)

Those drywall screws can hurt a pocket doors feelings for sure. I was sent to this discussion to find all the great info already here. I'm in a re-finish quandry and have learned alot. It was said before, great thread here.
Chuck aka(pickpapa)


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## AttnToDetail (Sep 22, 2011)

Good thread. Just goes to show that in the world of finishing, everyone has got their own story.

Quick question / comment: When talking about Minwax Fast Drying Poly and Wipe on Poly - aren't these products just thinned out versions of the regular poly? This has just been my uinderstanding and was curious if I am correct?

I have been using both products on a recent project. First about 2 coats of the fast dry applied with a foam bruch and then about 4 coats of the wipe on with a rag. I use a cabinet scraper and light hand sanding between the first couple of coats and a light steel wool between the rest. I have been happy with the results but the later finishes are very thin which is why I need so many coats. It is very tedious work especially on a big project. It has certainly peaked my interest in spray systems.

Anyways, thats my 2 cents - have fun in the shop!


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## maljr1980 (Sep 4, 2011)

poly sucks.. i have worked in cabinet shops ever since i got out of school and all the shops use either a pre-cat lacquer with around a 20% sheen give or take, or a conversion varnish. or if you want to get really technical we use a baked on finish with UV lights. but for either of the options i mentioned you dont need fancy spray equipment either. you can shoot lacquer with a $20 harbor freight cup gun. and either of the finishes will stand up to the abuse as well as anything. i wouldnt use polyuerathane ever…period oh and another bonus the lacquer will dry in like 20 to 30 minutes for another coat, maybe wait an hour before you sand after the second coat, spray a final coat and done, wait 30 minutes and hang your door


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## rusty2010 (May 26, 2011)

maljr, what do you use on exterior doors and furniture.


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## BillWhite (Jul 23, 2007)

Not saying the a poly does not have its place. Just don't think that it is the "end all" product. 
Bill


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## b2rtch (Jan 20, 2010)

m


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## bandit571 (Jan 20, 2011)

Used Poly for DECADES. It has it's place. I do NOT thin poly, ever. I do go out and buy a few CHEAP "Chip" brushes before each project, maybe @ $.89 each. Use once, and toss. Yes, I do use 0000 steel wool between coats, AND a tack cloth. Wipe once with the cloth, find another clean spot on the cloth and wipe again, After the third coat is on, and just barely tacky to a fingertip, I will grab an old T-shirt and start to rub the surface down, HARD. I am trying to "Friction Finish" everything down nice.

Once knew a fellow that hated even the mere mention of "Poly". All he could talk about was P & L 38 varnish. Turned out, he was SELLING that varnish and Minwax was cutting into his sales. So, he went on a Grand Crusade against all things in a yellow can. One day, he decided to sell shellac, as well. Not just any shellac, mind you. It had to be made from the flakes he sold. Once again, another Crusade. "Got to be made fresh from my flakes, or it won't do any good for a finish." Really????


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