# Problems with Water Based Polyurethane Finish PLEASE HELP SAVE ME 70 $



## drinkabeerson (Apr 25, 2014)

Hi everybody this is my first post on reddit.... I made a desk for/study/computer etc.... The top of the desk was plywood/sanded from home depot for 35 $ but they gave it to me for 15 because of long wait lines and broken saws they had... so it wasn't the cheap cheap ones...It was smooth when i bought it and i got it for HALF price.......
ANYWAYS....
Spent the whole day applying polyurathane Varathane interior gloss ultrafast drying time....... on the whole thing even the back of the thick plywood top.... Didn't sand in between coats as it wasn't required on the can as instructions...
2x4s are very smooth like plastic very nice....(the legs and the base skeleton)
but! the top is very very rough.....it is almost like somone glued sand on the plywood that i bought which was smooth before...
Now i have one option... buy a peice of glass with the dimensions to just put on top 70 dollars...which raised the cost of my table to 110 
Any ideas? Should i sand it and apply another coat? would that help?
Please help I made the whole desk for only 36 dollars.....50x27 table top dimensions...
EDIT: this was done in a dust free environment... Also upon closer inspection the 2x4s are completely smooth and glossy EXCEPT on the parts when the grain is showing which is probably the result of branches Also the plywood top that is my problem has variations of roughness some parts are not AS rough as the other parts and the parts where it is rough is also because of the grain patterns..... Its either i drill it back out and make the whole thing with 2x4 which will simplify it to a park bench not suitable for writing... The 70 dollar glass or somehow sand and reapply? i just don't want to sand reapply and it happens again...or sand and not reapply and the issue still being there...


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## Steve Neul (Sep 2, 2011)

drinkabeerson said:


> Hi everybody this is my first post on reddit.... I made a desk for/study/computer etc.... The top of the desk was plywood/sanded from home depot for 35 $ but they gave it to me for 15 because of long wait lines and broken saws they had... so it wasn't the cheap cheap ones...It was smooth when i bought it and i got it for HALF price.......
> ANYWAYS....
> Spent the whole day applying polyurathane Varathane interior gloss ultrafast drying time....... on the whole thing even the back of the thick plywood top.... Didn't sand in between coats as it wasn't required on the can as instructions...
> 2x4s are very smooth like plastic very nice....(the legs and the base skeleton)
> ...


Anytime you use any film finish other than pour on epoxy you sand between coats. It's alright though. You can fix it by sanding it with 220 grit paper and putting another coat on. I don't know just how rough it is so you may have to sand it again and put an additional coat on that. If it still isn't smooth you can keep going but it isn't good to put a finish on that is too thick so keep it at a minimum.


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## Al B Thayer (Dec 10, 2011)

Drink
No mater how much sanding you do and how dust free the room is. Your going to have nubs. The wood is laying down flat after sanding then you pasted it with a water based product. That raises the grain and also makes the nubs stand on end. They just need sanded off and finish again like Steve said. 

You probably are experiencing a great deal more of this because you used a water based finished. Lot of pros can't make that stuff work so don't feel bad. It's not an easy finish to apply. 

I'm amazed the can didn't say sand between coats. 

Al

Nails only hold themselves.


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## cabinetman (Jul 5, 2007)

We have an introduction section where you can say a few words about yourself. If you fill out your profile in your "User Control Panel", you can list any hobbies, experience or other facts. You can also list your general geographical location which would be a help in answering some questions. In doing that your location will show under your username when you post. 

It would help if you could be more specific.

Which Varathane product? Waterbased, or oil base?

How did you apply it?

How long did you wait between applications?

Did you apply the finish with the sheet flat or vertical?












 








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## drinkabeerson (Apr 25, 2014)

cabinetman said:


> We have an introduction section where you can say a few words about yourself. If you fill out your profile in your "User Control Panel", you can list any hobbies, experience or other facts. You can also list your general geographical location which would be a help in answering some questions. In doing that your location will show under your username when you post.
> 
> It would help if you could be more specific.
> 
> ...


Thanks for the warm welcome will do very soon.....
I have no clue if I am replying correctly but 
to answer your questions...


Which Varathane product? Waterbased, or oil base?
WATERBASED

How did you apply it?
BRISTLE BRUSH, 3 COATS 

How long did you wait between applications?
1 hour for each 

Did you apply the finish with the sheet flat or vertical?
The sheet was flat...

The exact product was this ....

http://www.homedepot.com/p/Varathane-1-qt-Amber-Gloss-Interior-Polyurethane-2-Pack-266243/203326173


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## drinkabeerson (Apr 25, 2014)

Al B Thayer said:


> Drink
> No mater how much sanding you do and how dust free the room is. Your going to have nubs. The wood is laying down flat after sanding then you pasted it with a water based product. That raises the grain and also makes the nubs stand on end. They just need sanded off and finish again like Steve said.
> 
> You probably are experiencing a great deal more of this because you used a water based finished. Lot of pros can't make that stuff work so don't feel bad. It's not an easy finish to apply.
> ...


Thanks for the reply...Yup just checked doesnt mention sanding...Only mentions sanding if coat left to dry over 24 hours....


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## drinkabeerson (Apr 25, 2014)

Steve Neul said:


> Anytime you use any film finish other than pour on epoxy you sand between coats. It's alright though. You can fix it by sanding it with 220 grit paper and putting another coat on. I don't know just how rough it is so you may have to sand it again and put an additional coat on that. If it still isn't smooth you can keep going but it isn't good to put a finish on that is too thick so keep it at a minimum.


Hey Steve thanks for the reply....

Do you recommend an orbital Sander powered tool ? 
Also would it be okay to sand and not apply another coat? (I waited 8 days already to use it im so impatient!)
plus it is going to be in my bedroom so I dont want alot of fumes....


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## cabinetman (Jul 5, 2007)

An hour may not be enough dry time. I would recommend sanding between coats, but not the first or second. If you are brushing it flat you may be applying it too heavy. Letting it pool or puddle will be problematic. Waterbase poly works best when sprayed. You can use 320x sandpaper, and if you can find 'open coat' paper, it could be called 'Fre-Cut' or 'No-Fil'. I would use it with a wood block to keep it flat. Sand with the grain. You don't want to be aggressive enough to sand through the veneer.








 







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## drinkabeerson (Apr 25, 2014)

cabinetman said:


> An hour may not be enough dry time. I would recommend sanding between coats, but not the first or second. If you are brushing it flat you may be applying it too heavy. Letting it pool or puddle will be problematic. Waterbase poly works best when sprayed. You can use 320x sandpaper, and if you can find 'open coat' paper, it could be called 'Fre-Cut' or 'No-Fil'. I would use it with a wood block to keep it flat. Sand with the grain. You don't want to be aggressive enough to sand through the veneer.
> 
> 
> 
> ...


Thanks a ton sir!

So you recommend sanding it instead of paying the 70 for glass right?

I just want to be 100 percent before i use this desk because i am going to use a laptop which does get hot to also sometimes......

If so I just sand it down and apply a fourth coat of polyurethane? 

One more thing sir... Im actually considering a rebuild and using this desk for different application....
in the rebuild i would use linseed oil (boiled) because this desk will be in my bedroom which concerns be about the poly's toxicity 

Im so excited to be a member here (post photos and what you said) ....I need to make a bookshelf computer desk (currently working on) clothing drawers....
this is inspiring 
THANKS A TON AGAIN!


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## Steve Neul (Sep 2, 2011)

drinkabeerson said:


> Hey Steve thanks for the reply....
> 
> Do you recommend an orbital Sander powered tool ?
> Also would it be okay to sand and not apply another coat? (I waited 8 days already to use it im so impatient!)
> plus it is going to be in my bedroom so I dont want alot of fumes....


No, there is too much risk sanding through the finish with an electric sander. It's easy enough to sand through the finish doing it by hand. Have a little patience. Just sand enough to make the surface a uniform white and put another coat on. It's much better to put more coats on than to sand through the finish. Sanding though the finish is sometimes easier to strip the finish and start over than to fix.

A note about linseed oil. If you use linseed oil under a waterborne finish let the oil dry a week or use a coat of zinsser sealcoat as a barrier coat between the oil and the finish. Linseed oil often causes adhesion problems with waterborne finishes.


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## cabinetman (Jul 5, 2007)

Just FYI, once film finishes are cured they aren't toxic so-to-speak. Adding boiled linseed oil to the top would do nothing in providing a durable finish for a desktop.

If this was for me, I would consider going for the glass. It would end all your finishing problems and provide an indestructable (almost) surface. Really, think about it. You place the glass, and you're done. Ball point pens won't be scoring into a veneer finish. It would be easy to keep clean. 

If you do get glass, get the clear flexible plastic discs (about the diameter of a nickel), to put under the top. It will keep the top in place, and allow you to remove it if need be. If you just place glass on top of a film finish like you have, it's likely it will stick down after it sits a while. 








 







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## rrich (Jun 24, 2009)

From what I've read, the problem appears to be raising grain. All water based products do that. 

The solution from the point where you are is,

Allow the current water based polyurethane to cure completely, a week maybe.

Sand with the grain and a block of wood. Probably 220 grit would be best. You're not trying to remove the water based polyurethane but rather just smooth it. 

Then apply another coat of the water based polyurethane.


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## Manuka Jock (Jun 27, 2011)

Plywood is thirsty stuff .
It has needs that solid timber does not . 
Keep coating and hand sanding .

Got a photo ?


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## epicfail48 (Mar 27, 2014)

Im with the other guys, sanding between coats is a must. If you dont mind me sharing my method for poly, what ill do is put on a few heavy base coats, scuff sanding with 220 between coats just to build it up a bit. After that, ill let it cure for a week or so and then go through a rubbing out process, same as a lot of people do with a shellac or laquer. After i let it cure, ill wet sand it starting at 320 or so and move up to whatever the highest i happen to have is, usually 1000 or 2000, then go to automotive rubbing and polishing compound. Now, after this process the finish will feel great but look like crap. The reason for this is polyurethane is basically a plastic. Its durable but too soft to abrade well, unlike a hard and brittle finish like shellac, which is where the common mantra of "poly will never be smoother then it is off the brush" comes in, and its right. To solve this, i mix poly and mineral spirits in an equal-ish proportion, wipe a decent coat on the surface, give it a few minutes, and wipe it off. Take a few applications but these new coats will fill in the microscopic scratches the polishing left and make the surface look all shiny and crap. An added advantage of this method ive found are these thinned coats dry much, much faster than a thicker coat would, so theres less chance for dust to settle. Once all this is done, let the finish cure for another week or two, and the i like to finish up with a paste finishing wax, just to add to the shiny factor. Best of luck fixing your learning experience!


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## Fred Hargis (Apr 28, 2012)

I'll offer a dissenting opinion, sanding anything "poly" is a must because urethane resins don't adhere well, even to each other. So the sanding provides some mechanical "tooth". With other finishes the only reason to sand is to smooth the surface, the balance of them stick to each other just fine. That's why the label didn't suggest sanding, unless you waited over 24 hours (that's also when you need to sand because of the way waterborne coats link to each other). Now, the product you used is labeled polyurethane, but it's actually an acrylic finish with a small amount of urethane added so the can put that magic word on the label. I agree with the above that the roughness is probably raised grain, which isn't unusual for water borne finishes. Applying a couple of coats, then sand smooth, and the final coat should work just great for what you're doing. To reiterate Cabinetman's point, the finish isn't toxic either (none of them after they are fully cured). But BLO has a distinct smell that you may find disagreeable until it dissipates.


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## HowardAcheson (Nov 25, 2011)

>>>> Thanks for the reply...Yup just checked doesnt mention sanding...Only mentions sanding if coat left to dry over 24 hours....

Yup, that's the new regimen when using the newer oil based finishes. As long as the prior coat as been on less than 8 - 10 hours, it can be directly overcoated. Different finish manufacturers have different recommendations.

However, if you want a smooth surface, the first coat should be allowed to fully dry and then be sanded with 320 paper to smooth the surface. Also, is you have any application miscues, you should let the coat fully dry and then sand out the miscues.


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## Al B Thayer (Dec 10, 2011)

I'm going a different route on sanding between finishes. I'm doing such a large project right now that I've come up with a way to knock off the nibs. I sharpen a cabinet scraper and finish it off on a diamond stone. Then just leave it with the square edges. No burnish. It glides over the finish nicking the nibs in a flash. Then final coat. 

Al

Nails only hold themselves.


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## Steve Neul (Sep 2, 2011)

Al B Thayer said:


> I'm going a different route on sanding between finishes. I'm doing such a large project right now that I've come up with a way to knock off the nibs. I sharpen a cabinet scraper and finish it off on a diamond stone. Then just leave it with the square edges. No burnish. It glides over the finish nicking the nibs in a flash. Then final coat.
> 
> Al
> 
> Nails only hold themselves.


I've often wondered how that would work. I was afraid to try it in fear it would gouge the finish. I will give it a try sometime.


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## Al B Thayer (Dec 10, 2011)

Steve Neul said:


> I've often wondered how that would work. I was afraid to try it in fear it would gouge the finish. I will give it a try sometime.


Gota leave the burr off. I'm doing lots of 4X8 sheets and all I do it glide it across the flat spots. 

Al

Nails only hold themselves.


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