Polyurethaning tips and troubles for trim
07-21-2005, 02:30 PM
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Burning Brakes
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Polyurethaning tips and troubles for trim
Greetings All:
And Adam, thanks for this much needed forum. Filled up a full page in one day. I'm impressed!
Tip: (and I wish I knew who to credit, if it is you, please stand forward and claim it.)
I had to stain and two coat polyurethane twelve red oak doors. They were done on a sawhorse in my den, with a healthy double thickness canvas tarp on the carpeted floor, and happily it has stopped every drip of stain or polyurethane of making its' way through to the rug. Usually, you need to allow 12 hours or so before you can flip the door over to do the other side and not mark the barely cured polyurethane. And at about 90 pounds per door, flipping was usually a two person job, especially in my state, weakened by radiation for cancer. Flipping of doors was to be minimized.
A smart A-CL member told me to drive 3.5" wood screws into the top and bottom four corners of the doors, and rest the screws on the sawhorses. Good tip! This way, after staining, you could put two coats of poly (after you let the first coat dry thuroughly) on one side of the door before flipping, cutting the number of flips in half. If you stayed on top of this, a door could be completely double coated in 18-24 hours or so.
My doors, because they were so heavy stayed indoors, in air conditioning, and under a lightly blowing ceiling fan, and I encountered no finish problems with the poly. Patience was required. Note the contrast with the "troubles" below.
Troubles:
I had a SHITLOAD of trim and door casing that needed the same treatment as the doors. But because the base/casing was so light and portable, I decided to use the aid of Mother Nature, where the temperatures were in the high 80s and low 90s to accellerate the drying of the polyurethane to accellerate the job.
Bad, bad idea.
Moisture and sap still reside in the oak, and the elevated temperatures used drove them to escape to the surface. Trapped by a still wet coat of poly, bubbles formed, some up to 1/8" in diameter. These could be corrected by wet brushing again the just poly coated piece after about 10 minutes of sitting in direct sunlight at 90F. Still, that is double work, and I had somewhere around 800 feet of this stuff to do. This phenemenon is called "outgassing", and I could have defeated it by staining all of the trim, setting it in the sun until it got nice and hot, and then applying the poly.
After late night applications of poly and when the weather threatened to rain overnight, I left the trim on the sawhorses. No bubbleing was encountered whatsoever.
On a different matter, usually you steel wool the poly after the first coat. Steel wool is rather messy and leaves "remenants". Try a Scoth Brite 3M pad instead. Works just as well.
Also, apply poly slowly. Air bubbles are your enemy.
And Adam, thanks for this much needed forum. Filled up a full page in one day. I'm impressed!
Tip: (and I wish I knew who to credit, if it is you, please stand forward and claim it.)
I had to stain and two coat polyurethane twelve red oak doors. They were done on a sawhorse in my den, with a healthy double thickness canvas tarp on the carpeted floor, and happily it has stopped every drip of stain or polyurethane of making its' way through to the rug. Usually, you need to allow 12 hours or so before you can flip the door over to do the other side and not mark the barely cured polyurethane. And at about 90 pounds per door, flipping was usually a two person job, especially in my state, weakened by radiation for cancer. Flipping of doors was to be minimized.
A smart A-CL member told me to drive 3.5" wood screws into the top and bottom four corners of the doors, and rest the screws on the sawhorses. Good tip! This way, after staining, you could put two coats of poly (after you let the first coat dry thuroughly) on one side of the door before flipping, cutting the number of flips in half. If you stayed on top of this, a door could be completely double coated in 18-24 hours or so.
My doors, because they were so heavy stayed indoors, in air conditioning, and under a lightly blowing ceiling fan, and I encountered no finish problems with the poly. Patience was required. Note the contrast with the "troubles" below.
Troubles:
I had a SHITLOAD of trim and door casing that needed the same treatment as the doors. But because the base/casing was so light and portable, I decided to use the aid of Mother Nature, where the temperatures were in the high 80s and low 90s to accellerate the drying of the polyurethane to accellerate the job.
Bad, bad idea.
Moisture and sap still reside in the oak, and the elevated temperatures used drove them to escape to the surface. Trapped by a still wet coat of poly, bubbles formed, some up to 1/8" in diameter. These could be corrected by wet brushing again the just poly coated piece after about 10 minutes of sitting in direct sunlight at 90F. Still, that is double work, and I had somewhere around 800 feet of this stuff to do. This phenemenon is called "outgassing", and I could have defeated it by staining all of the trim, setting it in the sun until it got nice and hot, and then applying the poly.
After late night applications of poly and when the weather threatened to rain overnight, I left the trim on the sawhorses. No bubbleing was encountered whatsoever.
On a different matter, usually you steel wool the poly after the first coat. Steel wool is rather messy and leaves "remenants". Try a Scoth Brite 3M pad instead. Works just as well.
Also, apply poly slowly. Air bubbles are your enemy.
07-21-2005, 02:34 PM
#2
Administrator Alumnus
I stained a cabinet after we moved in, got about 1/4 of the way and had my dad come over and finish the rest. The process isn't as easy as it sounds; certainly not like painting a wall. If you're not careful, you can make something look like complete shit.
07-21-2005, 02:55 PM
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Burning Brakes
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Nah, staining isn't hard...
Just be consistent.
The best tip I can give is that in stain, considerable solids (the pigment) will settle to the bottom of the can. Stirring before use is imperative. Better yet, take it to ACE and have them shake it for two minutes or so. The solids will stay in solution for a long time.
Use a rag and latex gloves. Stain is hard to remove from your skin. Just saturate a cotton rag in the stain and start out. Wipe all surfaces until it is essentially dry. Rewet the rag with stain, and restart again about 2/3-3/4 from where you though you were getting light on the stain.
And wood is not necessairly supposed to be lock step uniform in color. That is more determined by the grain of the wood than anything else. My trim/doors are anywhere from a very light honey (bordering on blonde) to a bold, dark amber, and everything looks quite fine at 80% done.
To save on stain rags and debris desposal, when done staining, I just threw the stain rag right into the can of stain and sealed it up. Fish out with gloves or a screwderiver the next day, wait for the drips to stop, and you are ready for another fun day of staining.
USE a RAG, not a BRUSH! You wull be done in one quarter of the time!
The best tip I can give is that in stain, considerable solids (the pigment) will settle to the bottom of the can. Stirring before use is imperative. Better yet, take it to ACE and have them shake it for two minutes or so. The solids will stay in solution for a long time.
Use a rag and latex gloves. Stain is hard to remove from your skin. Just saturate a cotton rag in the stain and start out. Wipe all surfaces until it is essentially dry. Rewet the rag with stain, and restart again about 2/3-3/4 from where you though you were getting light on the stain.
And wood is not necessairly supposed to be lock step uniform in color. That is more determined by the grain of the wood than anything else. My trim/doors are anywhere from a very light honey (bordering on blonde) to a bold, dark amber, and everything looks quite fine at 80% done.
To save on stain rags and debris desposal, when done staining, I just threw the stain rag right into the can of stain and sealed it up. Fish out with gloves or a screwderiver the next day, wait for the drips to stop, and you are ready for another fun day of staining.
USE a RAG, not a BRUSH! You wull be done in one quarter of the time!
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