# Cetol Marine Finish Woes



## Dave_E (Aug 7, 2013)

Hi All,

I'm refinishing all the woodwork on the outside of the boat. Standard practices, sand down (removed all old finish), clean and wipe down with spirits, let dry, ready to apply finish.

I have a new can of Sikens Cetol Marine, applying it per instructins on the can. With a brush, I'm getting tiny bubbles. I can "brush" most of them out, but after 24 hours, the ones that remained are little "bumps" in the finish. So I lightly sand between coats, knock off the bumps, re-apply... same thing.

I'm using disposable brushes, should I be using a "good" brush? Should I apply the finish thicker? I know this is not a fine woodworking project, but since I am a woodworker (guitar builder), this is driving me nuts.

Dave


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## Alex W (Nov 1, 2012)

I use foam brushes with Cetol and don't have that problem. They work very nicely.


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## christian.hess (Sep 18, 2013)

Im a fan of a very very good brush and use appropriately or disposable foam brushes

bubbles can be from unsettled varnish in the can...let it sit for a while or try softer brush strokes

if its too thick from the cold it can be this too and you have to spread it more


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## Dave_E (Aug 7, 2013)

Alex W said:


> I use foam brushes with Cetol and don't have that problem. They work very nicely.


Thanks Alex, I'll give it a try.


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## doug1957 (Dec 13, 2011)

Agree on the foam brushes. We usually finish with a coat of gloss. Seems to last longer.


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## CapnChuck (Apr 4, 2013)

We've been using Cetol for many years and we have lots and lots of teak. We mostly use foam brushes but also use the disposable type. The problem with the disposable type is the bristles falling out. Never had bubbles. Says your in Washington State. Don't try to apply Cetol if the wood is damp or wet and you need to follow the directions for minimum temperatures for application. Chuck


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## Dave_E (Aug 7, 2013)

CapnChuck said:


> We've been using Cetol for many years and we have lots and lots of teak. We mostly use foam brushes but also use the disposable type. The problem with the disposable type is the bristles falling out. Never had bubbles. Says your in Washington State. Don't try to apply Cetol if the wood is damp or wet and you need to follow the directions for minimum temperatures for application. Chuck


Hey Chuck,

The wood is all in the garage, heated to 60-65 deg F. I hope it's the cheap brushes! And the hair falling out thing... 

Dave


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## weinie (Jun 21, 2008)

Never used cetol myself, but are you shaking the can rather than stirring?


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## Dave_E (Aug 7, 2013)

weinie said:


> Never used cetol myself, but are you shaking the can rather than stirring?


No, but darn good thinking! Never shake varnish or shelac of any kind.


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## Minnewaska (Feb 21, 2010)

When you say you removed the old finish, was that fully down to the grain? Zero remaining impregnation? That's a ton of work and does need to be wiped with solvent anyway. I ask because many products are just not compatible with each other.

Some less nefarious possibilities are letting the product stand for 10 or 15 mins before applying. Warm up the room to at least 70 degs, which will improve flow. Use something other than Cetol (I'm just not a fan of the product).


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## lancelot9898 (Dec 30, 2008)

I've never had problems with the cetol and I'm using foam brushes and second the comment about the gloss giving a more durable finish than just the natural alone. I thought it would be the other way around. The other thing that I do is to use a damp rag to wipe down after roughing up the surface instead of using a solvent. In either case make sure the surface has enough time to completely dry.


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## Ajax_MD (Nov 24, 2009)

Interesting problem.

I've been shaking my Cetol can to mix it, and using cheap, disposable, bristle brushes. There are bubbles in the can, but they never translated over to the wood.

Stir to mix, and use a foam brush and see what happens. I went the extra mile and used the recommended Interlux thinner, instead of just acetone or generic paint thinner. That may or may not be your problem.


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## Minnewaska (Feb 21, 2010)

Is the solvent you cleaned the wood with compatible? Just a WAG.


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## RichH (Jul 10, 2000)

Bubbles can appear during the application of any coating on (POROUS) wood and whether brushed, sprayed, etc. 

The usual 'cause/culprit' is SUNLIGHT and the heating of the wood surface which causes that portion of the coating that has partially penetrated to "OFF-GAS" ... and form bubbles. Once you laydown first coating which totally SEALS the natural porosity of the wood, rarely will you experience bubbles and no matter how much the sun heats the material. Its that FIRST thin coat that becomes WARMED/HOT before the coating fully sets/cures that is what causes bubbles. 

The prevention: don t apply that first coat on a hot day or a day with lots of SUNLIGHT that will 'heat soak' the material under where the coating will be applied. First coats or thinned down 'spit coats' are best applied in the SHADE, and several 'spit coats' to ensure total sealing of the porosity. Once you fully SEAL the surface, then its time to lay on FULL THICK, wet coats. 

Bubbles shouldnt be a problem but can cause a lot of needless extra work - resanding, filling the craters left by broken/sanded bubbles, etc. Better to put a shade over your work for the first few thinned down 'spit coats' and prevent this from happening. Even in the shade, you have to FEEL the surface temperture when applying first or spit coats .... and if that surface feel warm or HOT .... wait until a cooler time. 

;-)


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## christian.hess (Sep 18, 2013)

his issue is for sure not extra heat

all temps have different applying techniques down here we thin it out more especially the first coats...if too thick basically you runover the brush strokes and get hat orange peel look from physically moving the varnish too much

use ony the thinners recomended by the manufacturer and dont abuse the percentages they say

lastly its the wood prep that counts the most
what was the last grit used to finish the wood?

I have a purdy varnish brush that is damn good and almost 20 years old...the brush is very important unless using disposable foam brushes which are great


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## christian.hess (Sep 18, 2013)

Minnewaska said:


> Is the solvent you cleaned the wood with compatible? Just a WAG.


this is an awesome point...I actually stopped doing the wipe with solvent or whatever to clean before the first coat...preffering actually to simply air dry and wipe with a clean new towel...

I noticed no cons to this method and never had any orange peel or incompatabilty issues from cleaning with so so solvents, acetones etc...

down here in intense tropic heat I have even washed down with water the sand finally with a very fine grit paper after sundrying

the first coat goes sun up and last before 11am or so...it will cure anddry throughout the rest of the day and then sand next morning

anywhoo


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## RichH (Jul 10, 2000)

I think christian.hess makes a VERY important point re: solvents and especially STRIPPERS (paint removers). If you dont remove the traces of these 'soaked-in' chemicals, either by allowing 'dry out completely' or following the recommendations for their subsequent extraction and removal, you always are at risk for - especially strippers - that are 'down deep' in the wood porosity to begin to attack your 'new' coating. When using chemical strippers, I feel, you should allow sufficient time (sometimes weeks if necessary) for these to completely remove themselves (effervescence, etc.) into the atmosphere and before apply 'new' coatings. 

I have the tee shirt and sore hands/finger from applying 'new' over bare wood that I chemically 'stripped' when I 'rushed' ... and more than just a few times. 

;-)


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## Seaduction (Oct 24, 2011)

What you're seeing is dust, not air bubbles.
Read this section from Epifanes thoroughly; its a great reference and applies to Cetol as well as Epifanes. They recommend a bristle brush however I have used the foam ones with great success.
http://www.epifanes.com/qanda.htm


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## Minnewaska (Feb 21, 2010)

Yup, could be dust too. When I did varnish work at home, I emptied every single thing out of the room and damp ragged every surface. All walls, ceiling, everything. If you have forced air heating, you're screwed! Block it off. Even convection through a window will stirs the air in the room and spread dust. It's a brutal game!


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## Boredop (Feb 21, 2013)

I have used xylene as the preparation wash with great success, flashes off quickly and leaves no residue. I would recommend an activated charcoal respirator though as the fumes can be rather potent.


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## DearPrudence (Apr 8, 2013)

Having just completed my exterior teak re-finishing project this winter, I will say that when I saw bubbles, I would use a 3M Scotch Brite pad between coats of Cetol. It slowed me down some, but, the results were (are) worth it.

Jeff


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## rbyham (Dec 25, 2012)

I too think wood prep is key. It is very easy to stop just short of the final sanding surface needed. Any "soft" teak layer will create a less than perfect application of any varnish. My guage for having reached the right level of sanding is when a tack cloth run over the surface does not catch at all... My recommendation would be to work with a short section and take it to complete smooth 400 grit. If that works you have your answer...


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## heelangle (Dec 30, 2009)

I have been using the Cetol Marine for 4 years now. Holds up much better than Spar Varnish, although not much chance for sun damage here in the Pacific NW.
In Hawaii my 5 coats of Spar Varnish used to last 6 months.
I have found the Cetol Marine a durable finish that holds up well and is scratch resistant. My last 4 coats lasted over 3 years. The only thing I don't love is the color. Seems they add some sort of iron compound to decrease sun damage to the finish, and it works!
If you are going to use it, don't shake it, or any varnish product. Only stir it and get all the thick stuff up from the bottom of the can. Shaking will cause bubbles. Also, I cannot believe all the people using sponge brushes. OK, so you are in Tahiti and can't find a Lowes, that is a good excuse. Otherwise, buy a good china bristle brush and go slowly for a really nice finish.
I don't like the Cetol Gloss finish. Way too shiny and way to slippery!
Teak forever.


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## CapnChuck (Apr 4, 2013)

Our boat spends most of its life in south Florida and the Bahamas. We have found, over the years, that the base coat last a very short time without the gloss. It might not be a problem in northern climates. We try and spend as little time as needed in northern climates. Chuck


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## Seaduction (Oct 24, 2011)

CapnChuck said:


> Our boat spends most of its life in south Florida and the Bahamas. We have found, over the years, that the base coat last a very short time without the gloss. It might not be a problem in northern climates. We try and spend as little time as needed in northern climates. Chuck


Right on! Cetol now recommends 2 or 3 coats of Cetol (light, natural or regular) followed by 2 coats of gloss.


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## NewBaySailor (Dec 16, 2007)

It's been a year, but I'd like to add my voice to the mix - I have used cetol for almost 5 years and find that the Jenn foam brushes work best - they're available on E-bay. I have not had a problem with air bubbles in the finish, using a light touch, not over-working it on the wood, and keeping a wet edge. Also, I'd add that I use about 2 coats of cetol marine, and then follow up with one coat of cetol gloss, which seems to help maintain the finish longer. I let each coat dry, sand lightly or use a green 3m scrub pad, and then apply next coat. B.


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## lennyv (May 11, 2012)

Try wiping the wood with acetone before applying the cetol. It will remove moisture from the wood. Also let the cetol breathe a few moments in the shade after stirring. I use cetol with a foam brush and put it on as thin as possible. A few thin coats are better than 1 thick coat. Good luck


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## JimsCAL (May 23, 2007)

Redid all the outside teak on my Cal 33 this spring. Took off the varnish with Citristrip, then heat gun on the tough spots, then sanding. Used Cetol Natural Teak and had no problems. I followed the recommendation on the can for the "two rag" cleaning using paint thinner. I like the look of the Natural Teak. Matches to color of varnished teak very well.


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## FloridaBoy (May 4, 2014)

Gentlemen, Please forgive me for bringing up this old thread but it was so helpful. I've been Cetol'ing the outside teak. Not much to it, companionway boards, a few hand rails, some trim. Didn't start with much knowledge but I've got a poop load now. Most of this stuff I brought home and am doing in the house where the light is good and you can SEE EVERY DUST PARTICLE! For days I thought they were bubbles but it was dust as so clearly stated by Seaduction, in this thread. When I read that I went in and looked closely and sure 'nuff, thats what it was. I've been sanding and swearing and doubled up on my dose of Prozac, couldn't figure it out. Now I turned the ceiling fan off and got me a tack rag and move real slowly and I've got three nice coats of clear on with no DUST! Looks almost perfect. Of course, as usual, by the time I figure it out, I'm almost done. Oh, well....I appreciate all I read here by you geniuses. Here some links to pics....kevin


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## Minnewaska (Feb 21, 2010)

FB, looks good from here!! Congrats.

As I said above, I'm not a big fan of Cetol. I truly hope your experience is better. Does it require a primary thinned coat to penetrate the wood?


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## FloridaBoy (May 4, 2014)

No Minnewaska, I don't have the can with me but I believe it says not to thin. So, when did I start following directions??? At 45 bucks a can, I'm reading the label. The label says thick coat but I found that a thin coat was much better. Did not sag like when I started with the thick coat. Every experienced sailor at my marina had tried about 5 different methods over the years, I just picked Cetol to be my first. Several guys are now using Ace Hardware Spar Varnish, some Captains and some those 2 part varnishes. So, who knows. I'm committed now, so , I'll let you know as the years go by. One thing, varnishing bright work is TOUGH! Taping and stirring and crouching. And waiting for 24 hrs is a *****! Dad gum, I don't wanna do this again next year. Think I'll sew some hatch covers and rail covers this month! LOL Kevin


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## svHyLyte (Nov 13, 2008)

FloridaBoy said:


> ...Dad gum, I don't wanna do this again next year. Think I'll sew some hatch covers and rail covers this month! LOL Kevin


Kevin--

We have been using Cetol here in southwest Florida for about the last 7 years. As long as one keeps up with the clear coat, refinishing is unnecessary. A light buffing with a 3M Scratch pad and a single clear coat at roughly 6 - 9 month intervals is all that's necessary (covers will help however). Invariably, some of the bright work will be damaged. For that I have a couple of my wife's discarded finger nail polish bottles (with brush applicators). One of "Natural Teak" base coat and one of Clear coat. With these I can make quick repairs of scratches/divots in the finish when they occur. (We use the "5 Foot Rule"--if it looks good from 5 feet away, it's good enough.) Eventually one does have to remove the old finish and start over. I have found that the best way to remove old Cetol is with a cabinet scraper and, when necessary, a modest application of heat (while I have a heat gun, I also have an old hair dryer that, on high, puts out enough heat to soften the old finish for removal without the danger of singing the underlying wood. A good sanding with 180, followed by 320, followed by a good wipe down with lint free cloths and 90% alcohol from the pharmacy seem to be all that's necessary in re: preparation. I use a single coat of "Natural Teak" followed by three coats of Clear seems to get us back in business pretty quickly. Tip: Use a high quality natural bristle brush to apply the finish. While costly, the results are notably better than can be achieved with a disposable brush or foam brush. Cleaning the brush thoroughly with brush cleaner after use and storing it wrapped in wax paper in a zip-lock bag will preserve the brush for many years.

FWIW...


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## FloridaBoy (May 4, 2014)

Hey HyLyte, I did most of that. Used stripper from Home Depot, then 2 part teak cleaner, like that stuff, looks like fresh sawn wood. Sand a little, 3 coats per directions and 2 coats of gloss. But if you are doing well with 1 and 3 then I might try that next time. Used a china boar bristle brush and I clean them well. I cleaned the Natural Teak brush with acetone but when I used acetone for the gloss brush, it got all sticky and wads of stuff built up on the brush. I didn't want to buy the 29 dollar a quart Special thinner 216 recommended. The ingredients were 75 percent xylene and 25 benzene something or other, so I got some xylene for 8 bucks a quart at HD and that worked great. And I wrap my brushes like you say. I should of sanded more but I didn't want to take off too much wood. All in all it looks great. It was so shabby since I bought the boat a year and a half ago, it looks sweet now. Gotta word the next three days, gonna rain anyway here in Cocoa,Fl. Ought to have it finished next week. Appreciate the guidance from everyone. I'll post a pic when it's done. Kevin


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## FloridaBoy (May 4, 2014)

Guess I'm gonna have to do those 70 feet of toe rail next! Kevin


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## Minnewaska (Feb 21, 2010)

FloridaBoy said:


> Guess I'm gonna have to do those 70 feet of toe rail next! Kevin


After years of battling the toe rail, I finally stripped it back to bare and let it grey. I think it's the absolute toughest to keep the brightwork in good shape. It's not because it gets kicked, it's because it's nearly impossible to seal the edges against the deck and keep water from getting behind the finish. Same if you have hardware attached. Getting water under any brightwork is a certain blister and repair.

All my brightwork is now in the cockpit, where it remains relatively covered.


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