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Would I be asking for trouble if I applied a water based poly over an oil based stain? If it matters, the stain is Minwax and the poly is Rustoleum.
 

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Would I be asking for trouble if I applied a water based poly over an oil based stain? If it matters, the stain is Minwax and the poly is Rustoleum.
If you allow the stain to cure, and apply the poly in thin applications you have no problems. Waterbased polyurethane works best by being sprayed in thin applications.






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Sometimes it's difficult to tell when a oil stain is dry enough for a water based polyurethane. A lot depends on the wood, the weather and how long you left it on before wiping it off. It might take overnight drying time or as much as three days. A short cut would be put a coat of a de-waxed shelac such as zinsser sealcoat as a barrier coat and then use the water based poly. The stain normally would only have to dry a few hours before the sealcoat could be applied.
 

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I recently finished a jewelry box and I put WB poly over some danish oil. The danish oil specifically said to wait 72 hours before applying a topcoat. The WB poly went on perfectly fine. I bet the time is quite a bit shorter for a standard OB stain.
 

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Sometimes it's difficult to tell when a oil stain is dry enough for a water based polyurethane. A lot depends on the wood, the weather and how long you left it on before wiping it off. It might take overnight drying time or as much as three days. A short cut would be put a coat of a de-waxed shelac such as zinsser sealcoat as a barrier coat and then use the water based poly. The stain normally would only have to dry a few hours before the sealcoat could be applied.
Applying a sealer like Seal Coat to "short cut" the dry time will prolong the cure time for the stain. It's possible the stain may never really dry. It's the same principle as capping a jar with stain in it. Personally, I don't like short cuts.





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Just let it dry over night and go for it. I use Minwax oil base and Polycrylic water base top coat all the time.
 

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Applying a sealer like Seal Coat to "short cut" the dry time will prolong the cure time for the stain. It's possible the stain may never really dry. It's the same principle as capping a jar with stain in it. Personally, I don't like short cuts.






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I don't agree. I think the stain will dry anyway. It's like if you put a light film in a jar and capped it the stain would still dry. I have to throw away stain all the time that has hardened in the can. I'm not suggesting putting sealcoat over wet stain but stain that is dry enough for a shellac finish but not a water based polyurethane.
 

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Would I be asking for trouble if I applied a water based poly over an oil based stain? If it matters, the stain is Minwax and the poly is Rustoleum.
I had a disastrous result using the products you have described. Minwax says that you should wait at least 24 hours before topcoating the oil stain with the clear finish, but a full day after I applied Varathane Ultimate Spar Water Based Polyurethane to the seat board of a bay window, I was horrified to see that the water based poly had not adhered to the stained wood beneath. It had surface blisters and easily peeled off. On the areas above, where I had not sanded to bare wood and left the original oil based poly intact and lightly sanded, the poly adhered just fine. Upon investigation on one manufacturer's website I saw that they recommend waiting at least 72 hours to permit the stain to fully cure. I could feel a waxy texture on the stain, which verifies the uncured state of the stain. The problem now, is that the poly that penetrated into the wood continues to leach a white residue, leaving deposits on the seat board surface. I tried sanding smooth again and brushing on an oil based poly to seal the stain. The spots disappeared temporarily, but then returned. I am considering sanding back and waiting a few days before applying an oil based poly. Frustrating, frustrating, frustrating.
 

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I had a disastrous result using the products you have described. Minwax says that you should wait at least 24 hours before topcoating the oil stain with the clear finish, but a full day after I applied Varathane Ultimate Spar Water Based Polyurethane to the seat board of a bay window, I was horrified to see that the water based poly had not adhered to the stained wood beneath. It had surface blisters and easily peeled off. On the areas above, where I had not sanded to bare wood and left the original oil based poly intact and lightly sanded, the poly adhered just fine. Upon investigation on one manufacturer's website I saw that they recommend waiting at least 72 hours to permit the stain to fully cure. I could feel a waxy texture on the stain, which verifies the uncured state of the stain. The problem now, is that the poly that penetrated into the wood continues to leach a white residue, leaving deposits on the seat board surface. I tried sanding smooth again and brushing on an oil based poly to seal the stain. The spots disappeared temporarily, but then returned. I am considering sanding back and waiting a few days before applying an oil based poly. Frustrating, frustrating, frustrating.
It's not just minwax, all waterborne finishes are incompatible with linseed oil which is contained in an oil based stain. It might take as much as a week for the linseed oil to fully cure to where it won't cause problems with a waterborne finish. This is why I recommended using sealcoat. The stain that isn't fully cured will have no affect on shellac, it will adhere to the stained wood and the waterborne finish will adhere to the sealcoat.
 

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Thanks for your advice. Now that I brushed oil based poly over the stain, I imagine I'll have to sand it back again before I can proceed. This is becoming a real concern. The surface is veneer, not solid. Ugh.
 

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Thanks for your advice. Now that I brushed oil based poly over the stain, I imagine I'll have to sand it back again before I can proceed. This is becoming a real concern. The surface is veneer, not solid. Ugh.
It's generally a bad idea to sand a finish off of wood because part of it soaks into the wood sealing it. When sanding a finish off you are likely to leave some varnish in the wood in spots and when you stain again those spots won't take the stain. Any refinish on wood should start with paint and varnish remover.
 

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Thanks again Steve. This is a job that I'm doing for an older gentleman who suffers from emphysema and can't be subjected to harsh odors. The strippers that I have would be risky. I don't want to use a slow working citrus stripper for fear that it will dry out before I can get back to it. Can anyone recommend a fast working, low VOC stripper that gets good results?
 

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Thanks again Steve. This is a job that I'm doing for an older gentleman who suffers from emphysema and can't be subjected to harsh odors. The strippers that I have would be risky. I don't want to use a slow working citrus stripper for fear that it will dry out before I can get back to it. Can anyone recommend a fast working, low VOC stripper that gets good results?
There just isn't one. The methylene chloride which makes stripper effective is what has such a strong odor. Stripping a finish is such a messy job it's something that should be done outdoors even if you use the citrus stripper.
 
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