# can you use oil based over water based



## brown down (Mar 2, 2010)

can i switch from water based poly to oil. I just don't like the way it is laying when i spray it. I am using compressed air to spray. I tried water due to the fact it is easier to clean up, quite frankly the finish is not laying flat at all. splotchy and then flat. just wondering if i need to resand the entire piece or once the water based poly dries if it is ok if i us oil poly?


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## djg (Dec 24, 2009)

I don't know anything about spraying, but this is of interest to me also. Just a thought, is your air dry, or is it picking up condensation from your compressor tank causing the blotching? Your probably experienced with spraying in general so you might have already considered this.


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## brown down (Mar 2, 2010)

I have only ever done spraying. never used water based. I would have to think that it is due to the fact it is so dry and there are no humidifiers in the shop! it almost seems like the poly dries within seconds of it hitting the surface!!??? thats why i want to go back to my oil! I tried to do the switch because eventually we all will have to go to water based products! I just don't know what to do now??:wallbash:


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## cabinetman (Jul 5, 2007)

brown down said:


> I have only ever done spraying. never used water based. I would have to think that it is due to the fact it is so dry and there are no humidifiers in the shop! it almost seems like the poly dries within seconds of it hitting the surface!!??? thats why i want to go back to my oil! I tried to do the switch because eventually we all will have to go to water based products! I just don't know what to do now??:wallbash:


Which waterbased poly are you using? Did you thin it? How many coats did you apply?












 









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## Big Dave (Sep 16, 2006)

Yes you can use oil over water or vice versa but you will have to use a finish that is compatible with both to bridge between them. Zinsser Seal Coat is an excellent product that fits the bill.


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## bobd (Apr 1, 2010)

If the finish dries ok then you can separate just about anything with a coat of shellac. A two pound cut should be fiine or use one of the ready made variety in a can such as sealcoat. On the other hand if the water finish looks blotchy then I would remove the base finish before using oil. Bob


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## brown down (Mar 2, 2010)

thanks guys everything worked out just fine. never again will i use water based ANYTHING AGAIN!


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## cabinetman (Jul 5, 2007)

brown down said:


> thanks guys everything worked out just fine. never again will i use water based ANYTHING AGAIN!



Since you started off with WB, if you had answered some questions (mine), there might be a way of working through what you thought was in error. IOW, you would have had help with what you had.












 









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## Tom5151 (Nov 21, 2008)

Suprised to hear that you had so much trouble spraying WB. I have sprayed several projects with WB including a current kitchen cabinet build and have had really nice results. 

You mentioned that some places were flat and splotchy. I was just curious if you used any type of sealer and how many coats you applied. I found that it took me about 5 coats to get the finish I was looking for. 

Not discounting your struggles at all. They were obviuosly very real. I am just more curious than anything else so that perhaps i can avoid any obstacles in the future.

Thanks.


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## brown down (Mar 2, 2010)

cabinetman said:


> Which waterbased poly are you using? Did you thin it? How many coats did you apply?
> 
> 
> 
> ...


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## cabinetman (Jul 5, 2007)

brown down said:


> i apologize about that, this was a refinish of a piece for my best friend and i was a little mad about how it laid not to mention in straight panic mode due to the fact i am having cervical spine surgery in 3 weeks.. I was using minwax which i am done with, never again will they get a dime out of my pocket, this isn't the first time i have had serious issues with minwax. I had over 9 coats of the water based poly on there and no i did not thin the poly at all!!


Since the quake is over, it's really moot to discuss what went wrong. You gave up without having the problem dealt with. Since you had a start with WB, it might have been solved so you could get a good finish with the same material. The fix may have been very simple.

So, to answer your initial question, yes oil base polyurethane can go over waterbase polyurethane once dry and scuff sanded.












 









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## jack warner (Oct 15, 2010)

wb poly's dry faster than oil, so the trick is to put on a wet coat so that it will level b4 drying.atomization plays a bigger part when spraying wb material. i dont like wb finishes, and have much better results with oil. oil can be applied over water, but im against water over oil.


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## cowboy dan (Apr 11, 2010)

i used wb. i wiped the surface with a wet terry cloth 20 min after each coat. it looked like it would have taken 10 coats to do what 3 oilbased coats would do. i switched back to oil based mid project with no ill effects. it looks good and i have no coplaints of how the project looks but having to do 10 coats seems like alot more time.


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