I've used some wipe on poly to create non-gloss finishes on some interior furniture - oak that wasn't mirror sanded in the first place.  And thus got a nice non-gloss finish, with wood grain still evident. This finish might be slightly more imperious to water damage than simply finishing with paste wax - which I did put over the finish on this piece anyway.  And often as not I finish interior furniture with paste wax only. For high gloss finishes I go to laquer or similar. 

I can't imagine trying to create a nice finish with wiped on varnish, even if thinned.   And I think to get a streak free finish you'd need to basically wipe off all varnish on each coat, and would have a terrible time achieving a gloss. And of course would have to have a lint free wipe.

Most importantly, I don't think you'd ever achieve the buildup that is necessary to protect your boat out in the environment.  Every coat of varnish past about the 3rd coat is actually just to pretect the previous coat of varnish from oxidation, contaminates and U/V. Maintaining the plasticity of the base coats, and thus micro cracks, leading to larger cracks, leading to eventual failure of the finish. 

Athough you'll gradually develop a deep honey color (nothing wrong with that in my book), you can probably maintain a varnish surface for 20 years without ever going back down to bare wood if (depending on use, sun/salt exposure and storage conditions/tempertaure variations) you lightly sand off the old U/V and weather damaged 2-3 top coats fo varnish, and add back 3-4 coats of new varnish.

Finally, varnishing per some of the various methods people use isn't all that tedious. I've tried many methods, and personally get best success (dependent upon brand) with about 10% thinner and a foam brush, working quickly to keep a wet edge, no "tipping" other than keeping final strokes very light across the top of the surface, calling a surface "done' (no more brush strokes) before feeling any "drag" or "virbration" of the foam brush (which happens if the surface is starting to dry just a bit after a minute or two).

If you try wiping, lets us know how it works out.

   When I discussed all the variables as to when y(in my experience) you need light sanding and new top coats of varnish, I neglected to mention that I was getting to saying those variables determined time between sanding and topcoating.  Could range from about 2 yrs to 8 years, depending upon on those variables.

Can't help myself from adding one more thought.  My best success with PAINT has been with a good sprayer, but almost equally good and my preferred hand-applied method is a roller (still working to a wet edge) immediately folowed by foam brush tipping.

   As a professional woodworker for over 40 years, I have to say that yes, of course you can do a wipe on, high gloss varnish finish.  The various wipe-on polys and varnishes are simply diluted versions of the regular ones, and there's no reason you can't do the same by diluting marine varnish to the point where it becomes a wipe-on finish. But it will take more coats to achieve the same build necessary to get the uv blocking which is the important reason for the many coats. I buy boxes of rags from my hardware store or finish supplier, which are similar to t-shirt rags, and never have a problem with lint. I find that a minimum of 6 coats are necessary for a true gloss finish on furniture, but I would go far beyond that on a boat, perhaps 15 coats. But that depends on the varnish you're using and how much it's diluted. I'd try starting with 50% thinner and see how it works. Most oil-based finishes can be diluted with paint thinner, and you can also use naphtha, which accomplishes the same thing but evaporates faster. The up side to a diluted varnish is that it will set up faster, allowing more coats per day. And it you apply the next coat within 24 hours, you will still achieve a chemical bond without sanding. I usually sand between every second or third coats. Experimentation is the key here.  And don't over-think it. Any mistakes can be corrected. 

   +1 on no need to sand if reapplying varnish after the previous coat is dry to touch (and within 24 hours). I think a chemical bond is the best bond.

As a perfectionist with a love-hate relationship with boat varnishing that tends strongly toward hate (and a Kaholo paddleboard in the early stages of a build), I eagerly anticipate the results of any experiments this thread might inspire. I might even run a few experiments myself. I put about 15 coats of varnish on my wood duckling (which was as painful as it sounds) - I had a real knack for sanding too aggressively and removing most/all of what I put down.

The difference between chemical and mechanical bonds is only for epoxy and other products that link molecules to form inert polymers. All solvent-based varnish bonds are mechanical bonds. It's because of the difference between curing and drying. Linking products cure, solvent-based products dry. Curing is the process of all active bonding sites being used up, drying is the process of all the solvent evaporating.

For linking products, if the old coat hasn't completely cured, there are still active sites on the polymers that can link up with the new molecules in the next coat. That's the basis for a "chemical" bond - there is an active chemical reaction which links the molecules of the new coat to the molecules of the old coat. Once the previous coat completely cures, it's inert and won't chemically react with the new coat. In that case, the new coat simply adheres, the so-called "mechanical" bond.

Solvent-based finishes have a solid material dissolved in a volatile liquid (petroleum solution, alcohol, etc.) When they're applied, the solvent evaporates and leaves a layer of the solid material behind. If the layer is too thick, it will skin over and the solvent below the layer will take much longer to evaporate. That's why many thin layers of varnish give better results than one thick one. That's also why you need to wait until the varnish is completely dried before adding a new layer.

When the new layer goes on, the solvent softens the top of the old layer which then mixes with the new layer. There is no chemical reaction, just a mechanical process of the previous coat softening, mixing with the new and then both hardening.

With epoxies, sanding the previously-applied cured coat creates more surface area for the new layer to adhere to. For varnishes, it provides a finer structure that dissolves faster in the new layer's solvent (like table salt melting faster in water than large-grained sidewalk salt).

So attempting to get a "chemical" bond with varnish may actually result in an inferior finish. Waiting for it to completely dry is the best course for solvent-based materials.

Laszlo

 Herbieridersagain 

I plan to try wipe finish but that will awhile brfore I gat to that point. As Sherpiro,Peter says " And don't over-think it. Any mistakes can be corrected. ".

Lazslo

your explaination was great, From this, it is evident you know the subject. On other forums  contributors claim aurthority by blustering, titles, tenure on the forum or being a moderator, You posses authority by your explainations of your knowledge.

jimqr,

Thanks for the kind words, but it isn't just me. I find that all the posters on this forum (except for the ones trying to stick us with spam) are exceptionally polite and knowledgeable. The wealth of experience is almost scary, whether it's hspira, markn and Dan Thaler (all prize-winning kayak builders) sharing their expertise about stripper building, Silver Salt (also a prize winner) and his sailboats, the guys upthread who are longtime boatbuilders and pro carpenters and all the others that I can't remember at the moment. It's a great group and I feel lucky to have access to them all and to have learned so much from them.

Laszlo

   If you're looking to add color don't forget a water based dye. I used General Finishes water based dye on my Peapod with great results. 

Dean