DIY Wipe-On Poly?

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Mike Camp

New User
Mike
I was thinking about taking my first stab at making my own wipe-on poly by thinning some Minwax satin I have on the shelf 50:50 with MS. Was wondering what concentrations other people prefer or use here.
 

Mt. Gomer

New User
Travis
That's the exact mix I used on my recent Bunk Bed project. Worked great for me though you may need several to many coats depending on the finish you're looking for. It does go on very easy with a MS soaked rag and dries quickly so it won't take too long to build up the finish. I think I stopped after 3 coats on the beds as I was really looking just to seal it up so finger prints, markers, etc could be washed off a bit easier...
 

Howard Acheson

New User
Howard
50/50 is the recommended starting point. Further, let me say that the application of a thinned wiping varnish is very different from brushing on a finish. It's a totally different technique.

Here is something that should help. A friend of mine who was an early advocate, put it together years ago and it has worked well for many.

QUOTE

There are a number of suggested application regimens that are totally subjective. The number of coats in a given day, the % of cut on various coats, which coat to sand after, when to use the blade and a whole host of other practices are all minor differences between finishers. There are some things that I consider sacred when applying a wipe-on finish.

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 necessary. 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 rub/swirl the the material on like you would if you were applying a paste wax. Don't attempt any straight strokes. The applicator should be wet but not soaked. The applicator can be a non-embossed paper towel shop towel, half a T-shirt sleeve or that one sock left after a load of washing. Once applied,leave it alone. The surface should not be glossy or wet looking and, if applied correctly, there should be no "brush stroke" type marks. 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 lightly 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 aggressive sanding to flatten out the surface and starting over.

Jim Kull

END QUOTE

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.

Lastly, let me strongly suggest you prepare some scrap wood from your project and test and learn the technique. When finishing, never let your project be you learning curve. Experienced and professional finishers will always test their finishing schedule completely before committing to the project.
 

ehpoole

Administrator
Ethan
I have not thinned my own Wipe-on Polyurethane as of yet, but I have used Minwax's own pre-thinned Wipe-On Polyurethane with great success (even just using disposable blue shop towels - Scott's brand) -- just refold and/or replace the paper towel regularly to prevent it from falling apart). For hand application, it is a really nice option on vertical surfaces and for areas where you don't want excessive buildup in crevices since the thinned coat does not flood the surface like a brushed on coat does.

Due to my health and snail's pace, I don't do enough finishing to save much by making my own Wipe-On, but I would expect your 50-50 ratio to be a good starting point. Just keep in mind that Wipe-on Poly requires more coats than brush on.
 

Bas

Recovering tool addict
Bas
Corporate Member
Is it okay to spray the thinned poly with hvlp turbine system?
Possible? Yes. But it's likely to be messy. Get a spray can of oil-based poly to see why. Unlike shellac (or lacquer), the overspray doesn't dry immediately, which means you get a nice gooey mess. If you spray outside, that's less of an issue, but you'll probably end up with a lot of muck in your finish since there's this nature thing outdoors (bugs, pollen, leaves etc.)

If you want to spray, go water based. Minwax polycrylic is actually a pretty decent finish, and sprays really well.
 

Bill Clemmons

Bill
Corporate Member
I was thinking about taking my first stab at making my own wipe-on poly by thinning some Minwax satin I have on the shelf 50:50 with MS. Was wondering what concentrations other people prefer or use here.

You might take it one step further and do a three way mix w/ equal parts varnish (or poly), mineral spirits, and boiled linseed oil (BLO). I've used this mixture for years the way Howard's friend Jim Kull described. It works great. The BLO seems to add some nice coloring / aging to the wood. BLO has a reputation for slow drying, but when you apply it this way it's not a problem.

Is it okay to spray the thinned poly with hvlp turbine system?
Qui, when I spray I usually thin about 25% w/ MS or paint thinner. Try to keep it as thick as your gun will spray w/o causing problems.

Bill
 

Howard Acheson

New User
Howard
Any finish can be sprayed if you have the right equipment and have the air pressure, needle and cap properly set up. Each set of equipment is different.

But, let me say that spraying oil based finishes is problematic. Oil based finishes are very slow drying and the over spray is in the form of liquid droplets. They will get all over everything in the area drying to a crust that is impossible to remove from tools, wood and surrounding surfaces. Spraying is best done if you have an efficient spray booth or spray outdoors.
 

Bill Clemmons

Bill
Corporate Member
Any finish can be sprayed if you have the right equipment and have the air pressure, needle and cap properly set up. Each set of equipment is different.

But, let me say that spraying oil based finishes is problematic. Oil based finishes are very slow drying and the over spray is in the form of liquid droplets. They will get all over everything in the area drying to a crust that is impossible to remove from tools, wood and surrounding surfaces. Spraying is best done if you have an efficient spray booth or spray outdoors.

I absolutely agree w/ Howard. If you're going to spray, it needs to be in a dedicated area where dust and other elements can be controlled. My experience in spraying in an open shop is that no matter how calm you think the air is, there is always enough movement to stir up dust. And as Howard pointed out, the overspray is a mess.

Qui, I think you saw my finish room when you were here for the sharpening workshop. If you want to spray something, or just experiment w/ spraying, you're more than welcome to come down some day and try it out. It's ventilated and overspray doesn't matter a bit. I think I'm trying to see how many layers I can build up on the floor. :rotflm:

Bill
 

BillGriz

New User
Bill
Thanks for the post Howard. I'm gonna give this a try.
Just happens that I finished a bowl tonight that I just turned. The one thing I never seem to get right is the finish. I did learn one thing this afternoon..actually by accident.. and that was I get a much better finish applying with a cloth then with a brush. Unfortunately I learned that on the last two coats. When I stood there looking at the finished product, I decided to get on this forum and see what I could learn about finishing. It was a shame to mess up such a beautiful piece of wood!!!
Hopefuly with your help, I won't do it again.
Thanks!
Bill
 
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