Varnish without sanding between coats

[dmksails]

A while back I read an account of how someone was applying varnish without sanding between goats. If I remember correctly they started with varnish thinned by 80 or 90% for the first coat, then increased the concentration by 10% for each additional coat.

I've tried to locate the original conversation. Has anyone used this technigue to success?

I've ready to refinish my bow pulpit and would like to give this a try.

[coopec43]

This thread in the Wooden Boat Forum is along those lines.

Multiple coats of varnish per day?

Clive

[contrail]

Back when I had a boat with wood to varnish, my regular practice was to sand every two coats. The coat without sanding was applied immediately after the previous coat was no lonber tacky. I never used thinners, even with the first coat, but did keep the varnish in the refrigerator. This was in a tropical climate. The cold varnish went on as if the climate was much cooler.

[Rex Delay]

Just finished my 6th coat of Epifanes Varnish Alternative on my cockpit table. No sanding, same as with Cetol. It has a very nice finish. If I was fanatical I would sand the last coat with 4-600 grit and do one more for a glass like finish but this is fine the way it is.

[ayates]

My typical process is no sanding between coats, up until right before the last coat. Then I sand with 220 and do the final coat.





Allan.

[Cheechako]

Me too, typically only sanded when there was some debris to smooth out. Especially the first few coasts on bare wood.
Coat 1: sand after, the grain raises up and you need to.
Coat 2 and higher: only if it needs smoothed. On these layers I'm trying to get some build up.
Before the final coat I will sand so the final comes out nice and smooth.

[CaptRory]

Awlgrip 3131 requires no sanding between coat provided you don't wait more than 24 hours, per the manufacturer. Epiphanes requires sanding between coats, but not surprised if someone got away without it. With Awlgrip in good weather I could apply three coats a day to my cap rail, bowsprit, eyebrows. No need to sand during build up coats. Three coats a day for three days, then let it cure for three for sanding smooth. Another three coats and cure and sand, then the final very careful finish coat, thinned to flow. Thin the first two for sealing, and then thin to the weather to make it flow without drips. I find it lasts better that Epiphanes too. After initial applications, sand and apply maintenance coat at least once a year in Florida and it will stay beautiful.

[Ken Z]

I always sand between coats, sanding smooths and gives a better bite for new varnish. It depends on the quality of varnish, for the quality of the job. I hace seen varnish peel when not sanded in the tropics, don t know the brand of varnish. It only needs light sanding.

[bharney]

instead of sanding, I rub the surface down with acetone to clean and soften it, then apply varnish before it hardens up.

[Cpt Mark]

I was taught decades ago to use thinner at 90%, then 80% etc with light sanding in between. Results were good but truthfully I find that full strength, high quality oil base varnish works best with a light sand in-between each coat. 22 grit, just enough to turn the varnished surface white, then tack cloth and apply. Takes a bit of time but if your base is done correctly then the refinish top coats are not a huge deal. When I took it down to bare wood, it's 12-15 coats (usually 15) and then regular maintenance coats as needed.

[NCboatrx]

CaptRory is wrong when he says that Epifanes needs sanding between coats. Here is the link to the Epifanes website https://www.epifanes.com/page/wood-finish-gloss
I have personally used this particular finish many times in the tropics with excellent results.

[LooseGoose]

Originally Posted by dmksails

A while back I read an account of how someone was applying varnish without sanding between goats. If I remember correctly they started with varnish thinned by 80 or 90% for the first coat, then increased the concentration by 10% for each additional coat.

I've tried to locate the original conversation. Has anyone used this technigue to success?

I've ready to refinish my bow pulpit and would like to give this a try.

After preparing the wood for finishing, I apply a 50% thinned sealer coat of Eptphanes clear gloss varnish, then a 25% then 10% thinned coats with light scuffing between with a scothbright green pad. Then I use #Epiphanes gloss Wood Finish for 7 build coats with no sanding, topped with 2 coats of the clear gloss varnish......with just maintenance coats , I've had the finish system last 20 years before having to re strip.

https://1drv.ms/a/s!AsNFZsAKNwRLnnyA5BRF0mqkAXVh

Is a photo album of a large project using these steps.

[Hardhead]

Has anyone tried sanding to bare wood, then applying an alcohol thinned epoxy, then a few coats of varnish?

I've heard tales that the epoxy makes the finish last much longer. I've tried this on a few small cockpit teak pieces, but it's only been a year in the weather until now. Looks good so far - but I was wondering if anyone else has more experience, or a longer test of the epoxy/varnish combo?

As the thread alludes, the less labor the better, so long as it meets personal approval..

[LooseGoose]

Originally Posted by dmksails

A while back I read an account of how someone was applying varnish without sanding between goats. If I remember correctly they started with varnish thinned by 80 or 90% for the first coat, then increased the concentration by 10% for each additional coat.

I've tried to locate the original conversation. Has anyone used this technigue to success?

I've ready to refinish my bow pulpit and would like to give this a try.

Here's the Eptphanes product for you

https://www.epifanes.com/page/wood-finish-gloss

[Tillsbury]

If you imagine the surface of the wood as a series of mountains and valleys (in small scale), the first coats of whatever you put on will sink into the valleys, partly filling them up. The mountain tops will still be proud of the surface, and (when dry) the fibres of the wood are stiff and sticking out of the top. Over time, these mountain tops are broken off and water can penetrate down through and under whatever finish you've applied.

Sanding after the first coat or two will knock off the tops of these mountains (since they're now brittle being soaked in the finish you're using).

It's critical for good waterproofing that you sand at some point during the process, to make this happen. You don't need to sand between every coat. You can usually use anything from fine (320-400 grit) sandpaper, to fine (grade 0000) steel wool, or scotchbrite or similar sanding pad. They'll all do the same job.

I will usually apply a coat or two -- somewhat thinned to get better penetration and dry quicker --- then do this sanding. You don't then need to sand between every coat, particularly if you're applying them before the previous one has fully cured. I would then sand again before the very end. This sanding is mainly to remove any dust particles or other junk that has settled on the surface during drying and stuck on, which would make the final result imperfect.

The very last coat is the equivalent of a car lacquer -- it should be applied to the best surface you can make, with as little dust around as possible, and well thinned. That will give you the neatest finish.

Disclaimer: I distribute wood finishing products...