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Forum topic by waldo posted 05-08-2011 03:24 AM 2122 views 0 times favorited 11 replies Add to Favorites Watch
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waldo

36 posts in 2113 days


05-08-2011 03:24 AM

I had this conference table to refinish, but after applying Cabot gloss poly I am left with these “puddles” so to speak. This table is made of 2 sheets of particleboard with a layer of cherry veneer. I took it down to the veneer before staining, I DID NOT use any chemical strippers, here is what I did:

Used 220 grit and mineral spirits to cut through the poly.
Used 150 grit up to 220 grit to sand through the stained veneer.
Used General Finishes water based stain and let dry for over 24 hours.
Applied General Finishes sanding sealer and let sit for another day.
Applied a coat of Cabot Poly, sanded in between with 500 grit and applied another coat of Poly and have these puddles if you will….

I am not sure what I did wrong in this process or what I have even done right up to this point, any help would be much appreciated..

-- One miscut away from firewood...


11 replies so far

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Grandpa

3256 posts in 2137 days


#1 posted 05-08-2011 04:28 AM

I am not sure what I am lokking for. Is it the white appearing spot in the center of the table? Is that also the white place I see in the close up photo? That is sometimes caused by moisture (water). I have used poly finishes that recommend not using over sanding sealer. Did you check that?

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waldo

36 posts in 2113 days


#2 posted 05-08-2011 04:48 AM

In the close up photo, do you see where the duller spots are towards the left side? It’s hard to explain, but the duller spots are actually shallower than the rest of the poly and it almost looks like puddling more than anything. The white place is the light reflecting in it. I checked the sanding sealer and also the stain and they all say that they’re ok to poly over. I am baffled…

-- One miscut away from firewood...

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DaleM

952 posts in 2845 days


#3 posted 05-08-2011 05:29 AM

I really can’t make out what you are trying to show in the picture, but if I understand you correctly, this only showed up on the final coat of poly. If that is correct, it sounds like something got on the finish in those spots before you applied the last coat. It sounds like “fish eye”, which is where a contaminant such as silicone or oil gets on a surface and the finish will not stick as well to that area and actually draws away to areas without the contaminant. You could look up fish eye and find some possible causes and solutions. I see the compressor under the bench. One possible cause is small amounts of oil spraying from the compressor hose if you blew the surface off with air before finishing. There are so many possible causes it’s just really hard to say. Based off of what I know, I would sand the table top, then wipe the entire surface down with mineral spirits especially around the affected areas, then apply another coat.

-- Dale Manning, Carthage, NY

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Grandpa

3256 posts in 2137 days


#4 posted 05-08-2011 05:31 AM

Okay, I see what you are talking about. I just wanted to be on the same page. So, it is like the finish soaked into the pores in a small area while all around that place it laid on the surface like we would expect. Was the poly mixed well by stirring? Just trying to brain storm. You would think there was some kind of reaction to something you used but it all looks right. I just haven’t had this problem.

You might ask Loren. He was using Cabot Poly finish on something the other day.

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Steven H

1117 posts in 2522 days


#5 posted 05-08-2011 05:43 AM

500 grit between coats of poly is WAY TOO HIGH
220 grit is industry standard 320 IS THE LIMIT!!!
Number 1 problem is adhesion problem. Poly have hard time sticking to its self.
Number 2 if you want a very smooth surface do that after your last coat.

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waldo

36 posts in 2113 days


#6 posted 05-08-2011 12:57 PM

It does seem as though the poly has fish eyed and from what I have found on the web it’s due to polishing etc, that has a silicone in it that absorbs into the grain and won’t allow the poly to adhere.

-- One miscut away from firewood...

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CharlieM1958

16241 posts in 3680 days


#7 posted 05-08-2011 03:44 PM

Hard to say from the photos, but to me it just looks like you do not have enough of a finish build up to fully fill the grain.

I would have used a clear grain filler like CrystaLac in the beginning, but since you’re past that point the best solution is to add several more coats of poly, the sand back from 220 through 400(wet) until you get a totally smooth surface. Once the finish is sanded totally level, it will be milky and ugly looking, but a final wiped-on coat of poly should dry as smooth as glass. Depending on what level of gloss you want, automotive polishing compound would be your next step.

-- Charlie M. "Woodworking - patience = firewood"

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Grandpa

3256 posts in 2137 days


#8 posted 05-09-2011 05:09 AM

I woke up in the night last night thinking about this. You are a bad influence. I was wonder if you got a contaminate on the surface from a compressor. This has been mentioned but I woke up with that on my mind. Something caused the problem so it either had to be contaminated from another source or possibly the adhesion problem someone talked about. I have always used 220 grit between coats. It wouldn’t seem that finer paper would cause this though. I guess it is possible. I have known people that used 0000 steel wool for this but I never liked it bacause I always end up with steel wool in my finish because I can’t get it all off.

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Steven H

1117 posts in 2522 days


#9 posted 05-09-2011 04:56 PM

We need more photos, Can you take photos at an angled? Like the first one but not too close.

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waldo

36 posts in 2113 days


#10 posted 05-09-2011 05:06 PM

Well, this is what I did this weekend:
Sanded the table completely down to bare wood, through all the grits.
wiped the table down with mineral spirits.
Sanded with 220.
Stained and then 2 coats of sanding sealer with sanding of 220 in between.
Then added poly and sanded with 220 in between.

The fish eyes aren’t nearly as bad, but noticable and it almost looks like the poly isn’t absorbing as it should. I am using a gloss polyurethane and I think I am going to go to a semi-gloss and just see if the dull areas will blend some. I didn’t use the air compressor to blow any debris or dust off of the table, I used a tack cloth. I am told by woodcraft that the fisheye is caused from years of funiture polish etc. on the table. I can’t sand the table down to bare wood any more or I fear I will get into the veneer and that would be tragic. Thanks everyone who is helping me out with this, this is definately something new that I have run into.

-- One miscut away from firewood...

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Earlextech

1159 posts in 2152 days


#11 posted 05-09-2011 05:51 PM

“I am told by woodcraft that the fisheye is caused from years of funiture polish etc. on the table.” This is wrong! If the wood had a finish on it how could silicone get through it.
It’s more likely that the contamination that caused the fish eye came from the tack cloth. Don’t use them. Use only clean dry cloth or with mineral spirits.

Also, I use the clean, dry air that comes from my HVLP system to blow off any dust, never the compressor.

-- Sam Hamory - The project is never finished until its "Finished"!

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