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Wiping Polyurethane


Roy Boomershine

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Below is a method of whipping on finish that I have use a number of times and it does work well. These direction are written by Jim Kull a well known and respected finisher. The will give you a nice finish.

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First, you can use any full strength oil based clear finish. Polyurethane varnish or non-poly varnish is fine.

If you are making your own wipe-on the mix is scientific - thin. I suggest 50/50 with mineral spirits because it is easier to type than any other ratio and easy to remember. Some finish formulators have jumped on the bandwagon and you can now get "wipe on" finish pre-mixed. If you use a pre-mixed, thinning is generally not neccessary. But making your own is cheaper and you know what's in it.

The number of coats in a given day is not important. Important is to apply a wet coat with an applicator and merely get it on. Think of a 16 year old kid working as a busboy at Denny's you have sent over to wipe off a table. Sort of swirl the the material on like you would if you were applying a paste wax. Don't attempt straight strokes. The applicator should be wet but not soaked. The applicator can be a paper towel, half a T-shirt sleeve or that one sock left after a load of washing. Then leave it alone. The surface should not be glossy or wet looking. If you have missed a spot, ignore it - you will get it on the next coat. If you try and fix a missed spot you will leave a mark in the finish.

Timing for a second coat involves the pinkie test. Touch the surface with your pinkie. If nothing comes off you are ready for another coat. If was tacky 5 minutes ago but not now, apply your next coat just as you applied the previous coat. Remember, you are wet wiping not flooding. After applying the second coat, let it fully dry for 48 hours. Using 320 paper and a sanding block ligthtly sand the surface flat. Now, begin applying more coats. Do not sand between coats unless you have allowed more than 24 hours to elapse since the prior coat. The number of coats is not critical - there is no critical or right number to apply. For those who need a rule, four more coats on non-critical surfaces or six more coats on surfaces that will get abraded seems to work.

After your last coat has dried at least over night you will have boogers in the surface. You should not have marks in the surface because you ignored application flaws. You may have dust, lint and, if you live in Texas, bug legs. Use a utility knife blade at this point. Hold it between your thumb and forefinger, near the vertical, and gently scrape the surface. Gentle is the important word - no harder than you would scrape your face. If you start scraping aggressively you will leave small cut marks in the surface. After you have scraped to the baby butt stage gently abrade the surface with 320 dry paper or a gray ScotchBrite. Clean off the surface. Now, leave the area for two hours and change your clothes. Apply your last coat with a bit more care than the previous coats and walk away.

An anal person is going to have a tough time with this process. Missed spots have to be ignored. Wet wipe, don't flood. Scraping to babies butt smooth means scraping no harder than scraping a babies butt. Ignoring any of these will leave marks that are tough to get out. Getting these marks out requires some agressive sanding to flatten out the surface and starting over.

Jim Kull

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Finally, It works better to use a gloss varnish for all coats except the last. The flatteners in semi-gloss and satin tend to rapidly fall out of suspension when the finish is highly thinned. If you want a non-gloss finish, use it only on the final coat or two and be sure to stir the material frequently or you will end up with cloudy streaks.

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The method described by Richard or Jim Kull is excellent.

Just wipe in on and leave it alone for a while and it will look great. I used the wipe on method on the chess board I posted a while back. I put on a couple of coats before I did the light sanding. Then a couple more coats. I didn't do the scraping but it sounds like a great idea.

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Scraping with a utility works great if you have dust nibs and you can do that on most finishes.


John Moody said:

The method described by Richard or Jim Kull is excellent.

Just wipe in on and leave it alone for a while and it will look great. I used the wipe on method on the chess board I posted a while back. I put on a couple of coats before I did the light sanding. Then a couple more coats. I didn't do the scraping but it sounds like a great idea.

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Don't hold back Larry, put it out there. We are all ears.



Larry Jenkins said:

Roy..

All the advice presented so far is excellent. I have one tip that works very well for me. My wife gives me her old nylon ankle socks after she's worn them for a while and washed them for me. These make excellent pads for wiping on the diluted poly. They seem to provide a nice wiping action and distiribution of the mixture. Three suggestions for the wiping process:


Don't overload the nylon pad with too much mixture;

Overlap stroke by about half, and

don't go over the previous "wipes."


Now, if anyone wants to know how to "finish the finish" my way, just ask.


Larry

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Along with all the good advice, I'll throw in my 2 cents.

I use Waterlox as it is a wipe on finish and holds up beautifully without much build up as with most poly's and varnishes.

The technique I use is to wipe it on just enough to change the color of the wood but not enough to leave a residue.

Try wiping a peice of plywood with a water damp rag. You can see the wood suck up the water and change color to darker.

Stop your done. Enough to allow it to suck it up, but not enough to pool on the surface.

Let it dry.

By the way, I use 3m scotchbrite pad on a block to scuff up surface and remove nibs. Then wipe with a tack rag and use a air line to blow off.

Then go for round 2

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I got going on it pretty much following what Richard had posted. I got the first 2 coats on and today I'll knock that off a little and then start building up some more coats. In a way I'm liking doing it this way, it goes on a lot faster and I'm not watching for runs in it all the time. But at the same time I'm not sure I'm going to like the way it builds up, I think I'm going to like the thicker coat better. Guess we'll have to wait to the end and see how it looks. So far so good.

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Roy, I actually put on a thicker coat the the article I posted suggest. Just don't get to carried away. Remember the thicker the coat the longer the dry times. The longer the dry times the more chance of getting air borne dust in your finish. With a 50/50 mix of poly and mineral spirits I find the thicker coats levels out just fine. Also if you're using a satin finish keep it mixed well and often. If the flatterers start settling out you can get a streaked finish.

If you go more than 24 hr. between coats of poly you MUST sand between coats to promote adhesion.



Roy Boomershine said:

I got going on it pretty much following what Richard had posted. I got the first 2 coats on and today I'll knock that off a little and then start building up some more coats. In a way I'm liking doing it this way, it goes on a lot faster and I'm not watching for runs in it all the time. But at the same time I'm not sure I'm going to like the way it builds up, I think I'm going to like the thicker coat better. Guess we'll have to wait to the end and see how it looks. So far so good.

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For Roy.


I'm making a couple dish washer fronts using a gel stain with wipe on poly (matching existing) for a kitchen I did back in 1989 because they have bought a new dish washer and the old front won't fit the new washer.


Here a couple pictures on how I apply the finish. The first three pictures you can see I just slop it on and left a very wet coat, that is not to say a real thick coat but very wet coat. The last picture is after the very wet coat has dried.

Hope this helps. Typically I put on 6-9 coats depending on use. I don't use much poly anymore because I spry most my finishes but when I do use poly this is how I do it.

ning-img-0469medium-51864-5.jpg?width=72


ning-img-0468medium-51864-63.jpg?width=7


ning-img-0467medium-51864-78.jpg?width=7


ning-driedpoly-51864-55.jpg?width=721

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First couple of coats I use nothing. After the third coat I let it dry a two or three hours and very lightly sand with 400 grit wet/or dry sand paper until if feels smooth, does take much sanding. After that I'll use the 400 grit every couple of coats until finished. Oh, I don't use brand new sandpaper. I use some that's been broke in a little. I have also been known to let the last coat dry a few days and very lightly sand the finish with mineral spirits and 1000 grit paper. It feel real nice after that. This is a satin finish.

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Don't go away, we want to keep up with the house here. How will I keep up and see if I finish the bathroom before you finish the house?



Larry Jenkins said:

John Moody..

I have a real uneasy feeling about this whole thing after the conflict we had on this site before. Maybe it's just my old age starting to allow me to be more vocal about things than I should be, and maybe my skin is getting a lttle thinner as I get older.


So, I think I'll just go away for a while before I piss everyone off.. Progress on the model house will be over on the other site.


You are the only one who gives a rip about the old guy, and I really appreciate that a lot.


Larry

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I'll give you an "ATTABOY" Larry!!!


Man, it was hard finding your Blog and getting to it But it was worth it.


I'll have a talk with John about this.


Seems it was a little hard to jump over there to your blog.


for anyone else, click on this to go over there


http://www.theamericanwoodworker.com/profiles/blogs/finishing-the-a...

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Naw Larry, No poke or fun at you. I should have copied the blog and set it over here in the finishing forum.


It was well written and contained a TON of good stuff!!! (Bet Roy doesn't know about rottenstone!!! )


Heck, even I have to be reminded every once in awhile with all the "Quick and Easy" methods out there.


That's why we need guys like you Larry, to teach and remind us about the "Right" way to do it instead of the "Quick" way!!!!!!

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Well I have seen the blog, and I thought it was done very well, actually I saw it when it was on here the first time and I read it with great interest and Larry received a ton of attaboys at that time. So this blog is nothing new to me, I had the privilege of reading it way before you all did!Grin.gif So far I haven't seen anyone getting peeved here. I hope folks jest settle down and keep it fun.

Now I am working on getting that blog thing worked out, Larry's blog should have popped up along with the new blogs on the main page. For some reason it didn't. I hope yall give this guy a little time to work it out, I am on it.


Larry Jenkins said:

John Moody..

I have a real uneasy feeling about this whole thing after the conflict we had on this site before. Maybe it's just my old age starting to allow me to be more vocal about things than I should be, and maybe my skin is getting a lttle thinner as I get older.


So, I think I'll just go away for a while before I piss everyone off.. Progress on the model house will be over on the other site.


You are the only one who gives a rip about the old guy, and I really appreciate that a lot.


Larry

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I fixed the blog feature!!! Now when you go to the home page and look at the "Blog Posts" below the Featured Video you will see blogs displayed by date added. It was set to blogs with the most comments. I had it set to recently added but somehow it got switched around. Thanks for bringing this to my attention guys! And Larry, ATTABOY!!Smile.gif

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