Glen-L.com

Well in this boat building odessy I am now to the varnish stage, I have laid down 4 coats of 207 special all over the 19ft runabout, and now 3 coats of Interlux Perfection Varnish by roller and tipped with a brush down to the waterline. I now need to get the brush strokes out, I have heard that I should wet sand with 1000 or 1500 grit, then polish with 3M Marine Finesse II to remove the haze left by the sanding. Can anyone confirm if this is the way to go?

Personally I am not a fan of wet sanding varnish although this is a general practice for many wooden and vintage runabouts thats all wood. I think your issue of brush marks is more about the application . If indeed you have visable brush marks, your brush may not have been proper or you applied the varnish in weather that did not allow for the varnish to flow or even in some cases large areas that created lap marks from the skin tacking up because of the temperature or even air flowing across the finish. [yea I know a long winded sentence]


I use a broad brush here as others may read this and also consider the same thing when there are indeed a fix other than having to sand out varnish. Its also important in the build up stage that you sand properly these layers and you may have an issue that is what we call telegraphing up through the varnish coats. Do you have any pictures of your actual job?

I don't know about two part finishes.

But if we're talking about traditional varnish, I'll go with Oyster on this one. I prefer not to sand and buff the final coat. I believe that it damages the varnish and shortens its life. It may look great in the short term, but I understand that it will degrade much more quickly.

The "Brightwork Companion" by Rebecca Wittman is a great book on this.

She recommends at least six coats on bare wood. Be patient as each coat gets smoother than the one before it.

Getting the right balance of brushing thinners is key to getting the varnish to flow out on the later coats.

_________________
Bruce.

~~ Do what you love, and love what you do. ~~
~~ To me - only my boat is not yet perfect. Everybody else's is to be admired for I know the path they have walked (Dave Lott, 2010) ~~
Dow's Monaco Project

Just a clarification. Perfection "Varnish" is a 2-part polyurethane, UV inhibited, clearcoat.

So, methods for traditional varnish may not completely apply.

Bill

_________________
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

One big issue with clear wood finishes and the excitement to get it looking slick begins in the initial coats. While epoxy does a better job on filling the grains, this material still needs to be slick which requires serious sanding and BLOCKING on large surfaces. When building with varnishes, in many cases after several hot coats without sanding, a great way to build up without a lot of work, will need to have a lot of the material actually sanded off too being carefull not to break through the sealer materials. You just have to frin and bear it, the tiresome job of sanding hours and hours to get a surface in most cases that takes 15 minutes, figurebly[sp] speaking for the finish work to be applied.

Good point Bill, most true polys after the surface has been compromised will not last and also can discolor if left exposed to the UV for an extended period of time.

oops. mea cupla.

all my comments were for traditional spar varnish. I've edited.

_________________
Bruce.

~~ Do what you love, and love what you do. ~~
~~ To me - only my boat is not yet perfect. Everybody else's is to be admired for I know the path they have walked (Dave Lott, 2010) ~~
Dow's Monaco Project

I ran the system 3 2part LPU ran 1000 - 1500 then Finesse IT. this works great both on autos and boats with the 2 part finishes. If you find (on a small area first) you can not level your brush strokes and start with a heavier grit, i would recommend adding another coat or two of paint before finishing as your surface will be very thin.
-Billy

_________________
(insert witty phrase here)
Billy's Belle Isle website

Thanks for the inputs, the special coating applications were all sanded before the next coat. When I applied each coat of Perfection in a 70-75 degree day (our Labor day in Indiana this year) dry sanding with 320 grit before each coat, tack clothing, then a wipe down with the N2333 thinner. I thinned the first coat but was not happy with the gloss factor, the second and third coats were not thinned. All Perfection coats were applied with a short nap foam roller, then tipped with a 3" red badger brush.

From the inputs so far it sounds like I may need to experiment with thinning more to get the material to flow out the brush marks.

Lt1Mike

As I remember, your application method is right off the can and your conditions look right.

Bill

_________________
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

I used the Perfection 2-part on my first build 3 years ago and love the stuff. But I have a patience issue and the two part helped. Three years later and I am showing no need for touch-up or recoat.

I achieved a smooth and glossy finish without sanding and polishing. With proper thinning it should flow well but you are right, it might take some experimenting.

That being said, if you are trying to achieve a glass smooth finish like you see on show-boats, you will need to sand and buff. That product is more like a paint than a varnish. It's like seeing a good paint job on a car - it looks good. But then color-sand and buff it and it looks like a totally different paint job.

Good Luck,

KB

_________________
"I'm not trying to get it perfect. I'm trying to get it finished!"
Squirt Build: http://www.tubbytug.com/SquirtHome.html

So I have a question: Would there be anything wrong with wetsanding and then brushing on one more coat?

In my mind, I'm thinking that early failure would be due to the varnish being too thin. That's because wetsanding removes material. But if one were planning on wetsanding, why could he not apply extra material knowing he's going to remove some of it. So instead of applying 2 or 3 coats and waking away, he could apply 4, 5 or 6 coats and then wetsand back to the same thickness that the 3 coats would have given. Then brush on one final coat. I'm just thinkin here.

_________________
Isn't it amazing!! The person that never has the fortitude to pursue his own dreams, will be the first to try and discourage you from pursuing yours.

I wouldn't see any problem with doing that. I plan on doing it on the Squirt deck in the next month.

Whenever I painted cars that I knew I would be wet sanding, I sprayed on extra coats and then sanded back down and polished. I think it would work with rolling too. I hope it does anyway. That's my plan.

KB

_________________
"I'm not trying to get it perfect. I'm trying to get it finished!"
Squirt Build: http://www.tubbytug.com/SquirtHome.html

Just an update, over the weekend I sanded away all of the brush marks from the previous 4 coats, so that nothing could "telegraph" through. I then applied two more coats over the two days with a light 320 grit sanding before the second coat. Both coats were thinned 5%. The thinning really made a difference in the material flow, now no new brush strokes!