What's going on with this oil poly?
#11
This is the seventh "build" coat.  Cure time is 48 hours since application.  Still need two more coats to fully fill in the grain, I think.

All coats have been cut 50-60% with mineral spirits for wipe-on application. 

The surface looks like it has condensation on it.  At 24 hours after last application, it covered most of the surface.  At 48, it's about half, and as of this morning (60-ish hours), it's gone. 

Two pics attached.  One showing the droplets on the surface, one after wiping with my finger.  Droplets feel a little oily, but there isn't the heavy scent of mineral spirits present.  At least not like when it's freshly applied. 

If this is mineral spirits, why is it pooling like that?  If it isn't, what might it be?


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Semper fi,
Brad

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#12
(05-02-2022, 12:16 PM)®smpr_fi_mac® Wrote: This is the seventh "build" coat.  Cure time is 48 hours since application.  Still need two more coats to fully fill in the grain, I think.

All coats have been cut 50-60% with mineral spirits for wipe-on application. 

The surface looks like it has condensation on it.  At 24 hours after last application, it covered most of the surface.  At 48, it's about half, and as of this morning (60-ish hours), it's gone. 

Two pics attached.  One showing the droplets on the surface, one after wiping with my finger.  Droplets feel a little oily, but there isn't the heavy scent of mineral spirits present.  At least not like when it's freshly applied. 

If this is mineral spirits, why is it pooling like that?  If it isn't, what might it be?

Looks like the ms is coming out of the pores on red oak.   It normally happens with a oil based stain on red oak but I wouldn't think it would be doing it with that many coats on it.
 May be the pores are flooded with the ms.   Try waiting until it stops coming out before applying more.   Roly I don't think the pores are close to being filled yet with the poly thinned 50%
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#13
(05-03-2022, 08:29 AM)Roly Wrote: Looks like the ms is coming out of the pores on red oak.   It normally happens with a oil based stain on red oak but I wouldn't think it would be doing it with that many coats on it.
 May be the pores are flooded with the ms.   Try waiting until it stops coming out before applying more.   Roly          I don't think the pores are close to being filled yet with the poly thinned  50%

I think Roly has it right.  Thinning the finish so much just lets the pores suck up all the mineral spirits, and then they bleed it back out during drying.  Red oak is notorious for doing that.  I would let it dry for a couple of days until you can sand it w/o corning.  I'm not suggesting that you sand it again, only that it needs to be that dry.  Test on the bottom if you treated it the same way.  Anyway, when it's really dry I would put on a coat full strength using a brush, let it dry, hand sand it flat, then another coat full strength, sand that flat, and then wipe on your final coats thinned maybe 25 - 30%.  

Or switch to Arm-R-Seal or Waterlox and wipe it on straight from the can.  

John
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#14
(05-02-2022, 12:16 PM)®smpr_fi_mac® Wrote: This is the seventh "build" coat.  Cure time is 48 hours since application.  Still need two more coats to fully fill in the grain, I think.

All coats have been cut 50-60% with mineral spirits for wipe-on application. 

The surface looks like it has condensation on it.  At 24 hours after last application, it covered most of the surface.  At 48, it's about half, and as of this morning (60-ish hours), it's gone. 

Two pics attached.  One showing the droplets on the surface, one after wiping with my finger.  Droplets feel a little oily, but there isn't the heavy scent of mineral spirits present.  At least not like when it's freshly applied. 

If this is mineral spirits, why is it pooling like that?  If it isn't, what might it be?

Mineral spirits would evaporate long before 24 hours.  If you want to fill the grain why did you not begin with grain filler?
Bill Tindall
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#15
Thanks, folks. Appreciate it.

Bill, I didn't use filler because I stained the surface and was concerned with the filler not taking the stain like the rest of the wood. The base has many coats of thinned poly applied, but I wasn't concerned with filling the pores with the poly. I didn't want the top to be a different color from the base.

This is my first table build AND first time use red oak like this; it's been quite a learning process.
Semper fi,
Brad

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#16
(05-03-2022, 11:15 AM)®smpr_fi_mac® Wrote: Thanks, folks.  Appreciate it.

Bill, I didn't use filler because I stained the surface and was concerned with the filler not taking the stain like the rest of the wood.  The base has many coats of thinned poly applied, but I wasn't concerned with filling the pores with the poly.  I didn't want the top to be a different color from the base.

This is my first table build AND first time use red oak like this; it's been quite a learning process.

Tis true filler will not stain like wood once applied.  But that is not the way to do it.  Oil based filler is colored with artist oil pigment.  For oak and walnut I use Burnt Umber.  I remain flummoxed by what sweats out and doesn't evaporate straight away.  A mix of mineral oil and whatever oil may be in the stain or varnish could have this property.
Bill Tindall
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#17
Update:  I think y'all were right, and that it was mineral spirits seeping to the top.  I let it cure for a week and hit it with 600 grit.  Cleaned that of with mineral spirits then put down a 60% cut coat.

Even when wiping really thin and moving the cloth slowly, in a straight line with the grain, I'm *still* getting these tiny bubbles.  They don't come out as the finish sits. 

I assume I'll be able to knock them down with the final 0000 steel wool rub down.  I hope. 

What do you say?


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Semper fi,
Brad

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#18
I have to think that after the first coat or 2 cures, you could smooth it and apply more without the bubbles. If there are still bubbles, it's in the finish instead of MS seeping out of the wood. The finish will have sealed the wood surface (once it's cured) and you shouldn't have anything seeping out. So, if the finish what do you do. Well, one thing would be to thin it even more. But it may be the media you are using to wipe it on (I use those blue paper shop towels you see at Wal mart and such in the automotive section) and I guess it  it could be something else I haven't thought of.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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#19
You can rub out the final finish with rottenstone.

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#20
I'd forget the thinning and shoot straight poly. Poly will fill pores
Steve

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