Last week, we looked at brushing and (not-) spraying varnish.  Today we look the third alternative, ragging (or wipe-on). Again, here, we’re talking about oil-based varnishes (including poly).  The following is paraphrased from Steve Mickley’s post on this subject    As long as it’s active: http://www.askhlm.com/Articles/ArticleViewPage/tabid/75/ArticleId/5/Wipe-on-Varnish.aspx

The Product

Wiping varnishes are simply varnishes thinned more than one meant for brushing.  They are often sold under misleading names such as "Tung Oil Finish"*   But you can easily make your own and control the amount of thinning by taking a regular varnish and thinning.  Start with 50:50 mineral spirits:varnish and adjust to your preferences.

Characteristics

Wiping varnish is probably one of the most fool-proof ways to apply finish.    Work with a low angle light behind the work so you can inspect for problems as you go.

 

Since the varnish is more thinned, you get thinner layers, meaning:

• ·         Dries faster

• ·         Less chance of brush marks, runs, drips, and dust settling

• ·         Needs more coats to achieve the same “dry film thickness”,  usually about three times as many

• ·         Great for projects with lots of connections like chairs and projects with spindles or pegs.

• ·        You can apply a wiping varnish as a final coat after you’ve built some base coats brushed on, yielding a nice, smooth finish.
•       For Satin and Semi-gloss sheens, stir frequently because the flatteners will fall out of suspension faster because it is less viscous.

The process

First day:

• ·         Wipe on a light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on second light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on a third light coat

• ·         Let dry overnight

Second day:  (sand, then same as first day)

• ·         Sand lightly with P400 sandpaper and Scotch-Brite, wipe off dust with rag dampened in mineral spirits

• ·         Wipe on a light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on second light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on a third light coat

• ·         Let dry overnight

 

Third day: (same as second day)

• ·         Sand lightly with P400 sandpaper and Scotch-Brite, wipe off dust with rag dampened in mineral spirits

• ·         Wipe on a light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on second light coat

• ·         Wait for it to try until no longer tacky, 3-4 hours in good conditions

• ·         Wipe on a third light coat

• ·         Let dry overnight

 

At this point you will have nine coats of finish, with the following characteristics.

• ·         About the same elapsed time (3 days)

• ·         About the same time spent (since each coat goes faster and you don’t have a brush to clean)

• ·         About the same dry film thickness as three brushed on coats

• ·         No brush strokes

Gel Varnishes as a wiping varnish

Gel varnishes are varnished thickened with a thixotropic agent.  Gelled at rest, and liquefied when energy applied.   Gel varnishes are generally a lower build and flatter sheen finish.   Wipe on and wipe off quickly before it starts to set.  Like gel stains, they don’t penetrate into the wood surface very far. Usually 3-5 coats are needed.   One con with using gel varnishes is if there is a lot of detail and concave surfaces.   It can be difficult to get the excess out of these areas and you may need to use a brush to remove the excess.

Fixing Goofs

If you have drips, runs, embedded bristles or dust, air bubbles or brush marks, the cure is to sand and re-coat.   In severe cases, you may be ahead to strip and start over.

* Common brands of finish that are wiping varnish: (Ref: Bob Flexner)

• Formby’s Tung Oil Finish

• Zar Wipe-on Tung Oil

• Val-Oil

• Hope’s Tung Oil Varnish

• Gillespie Tung Oil

• Waterlox

• General Finishes’ Sealacell

• General Finishes’ Arm R Seal

• Daly’s ProFin

• Jasco Tung Oil

 

 

I use Watco as a thinner. Start with 50/50 and step up the poly in 25% stages. That is, I add approximately 25% more poly to the mix. Usually, two coats per stage. Final coats are 25/75. + or -. All ratios are approximate. It ain't rocket science. 

 

9 hours ago, Gene Howe said:

I use Watco as a thinner. Start with 50/50 and step up the poly in 25% stages. That is, I add approximately 25% more poly to the mix. Usually, two coats per stage. Final coats are 25/75. + or -. All ratios are approximate. It ain't rocket science. 

 

Next week's subject

 

Thanks for this post!

I use Minwax Wipe On Poly and have always brushed it on being very careful of runs.  I slather the first coat and let it keep soaking in and wipe off the excess.  The following coats are brushed on thin and left to dry.  Builds faster that way.

I haven't tried Steve's suggestion to use the blue shop towels for applicators. Though I haven't had any issues with the old T shirts, it makes sense that the towels might be consistently more uniform.To me, wipe on finishing is the only way to go.

I have used the blue shop towels and not to impressed.  After a few minutes they start to deteriorate and if you don't change out quick enough will start to leave bits and pieces behind.

Cal

T shirts for me, too. Although the Brawny brand shop towels from Costco are pretty tough. 

Excellent topic!

I love General Finishes Gel Finish Topcoat, I just started using it lately. One of the many benefits of the Gel Finish, is it does stay where you want it, and there is no seeping or bleeding out because of the viscosity (thick) it stays where you want it. Some wipe on finishes tend to bleed out later and you have to go back and clean it up, the Gel does not. The disadvantage, there is a slight learning curve to use it, I found out the hard way, but I was able to clean up my mistake quickly and re-apply the finish in the area I fubared. Love it!