cetol application

[jimmd]

i'm not starting a new thread about the relative merits of various finishes. i do have a question after reading the instructions on the cetol can where it reads to wipe the wood with interlux special thinner 216. is this anything other than their own brand of paint thinner? would it be just as well to clean off with regular thinner. the wood had been previously finished and has been stripped and sanded.
thanks

[TrueBlue]

Acetone has always worked very well for me.

What's important is using a solvent that evaporates quickly, but has the ability to remove the natural teak oils from the wood surfaces after sanding. This preps the surface for a better bond with the initial sealer coat of Cetol - which should be cut 25% with thinner.

It's also important to coat the wood immediately after a wipedown. I don't believe regular thinners and other turpentine products can do this as effectively as either acetone or thinner 216.

[brak]

When I used cetol, I use alcohol to wipe down the wood. It dries faster, removes the dirt just fine. That said, I always have to deal with OLD teak so teak oil is not an issue, and in fact I'd rather not remove what little may be left in it.

ymmv

[hphoen]

I use acetone, too. Just don't spill it and let it sit on the gelcoat. It turns gelcoat to rubber.

[ronbo1]

Another vote for acetone.
For a smooth finish don't be afraid to brush out the Cetol with a good quality brush to prevent ridges and puddling.

[Valiente]

Depending on how warm the day is, you can do three coats in a day with a light sanding (240 grit or so) between coats. I usually do three coats and in fresh water, that holds for a couple of years.

Use the green painter's tape. The blue stuff can stick too well, and it's nasty to get out of the tight spots.

[KeelHaulin]

MSDS for Thinner #216 says 75-100% Xylene, 10-20% Ethyl Benzene. So I'd use straight xylene to wipe down; it's possible that acetone is incompatible with Cetol. Use good nitrile gloves when using xylene; it's not good for your liver...

I agree with TrueBlue; you should thin ~25% for first coat; I found that thinning both the base and clear helped brevent getting it on too thick. If you don't apply thin coats it may either wrinkle or remain wet beneath the skin. I talked with a Sikkens rep and they said to use mineral spirits for the thinner.

[LarryandSusanMacDonald]

Between Cruises I have spent a good deal of my time at Hartge Yacht Yard in Maryland applying varnish and Cetol. Most of what has been said above is correct - as there is no one 'best' way. Most of it works.
My comments:

1. I would avoid the acetone - it can do a number on the gelcoat.
2. Always, always carry a rag with you to wipe up spills and spatter - cetol will permanently stain porous (older) gelcoat.
3. If you time it right, in spite of manufacturer's recommendations, you can put two or sometimes even three coats on in a day without sanding in between. The previous coat needs to be dry to the touch, but not yet hard. Depending on sun, temperature and breeze, that's somewhere between 45 minutes and four hours. (Not much help, huh?) Lots of sun, temp over 85 and a fresh breeze and it will dry so quickly and start to cure that you can't really apply a coat without sanding. Partly sunny, temp around 70 or 75, and light breeze help. You have to go more by feel - if it's hard; sand, if it's sticky; wait. If it isn't sticky but you can scrap it with your fingernail, go for it - it hasn't cured yet and will give you a chemical bond. We do this frequently with good results that last and it saves our customers a lot of money - at $60.00 an hour it costs a lot to spend time sanding. If you're doing the work yourself it cuts into the rum time.
4. Keep everything clean - vacuum up the sanding dust and wipe down the entire area - unless you like the 'non-skid' feel of your brightwork.
5. Don't skip the taping. If it's the 3m brand - the blue is thinner and will conform better and (despite what was said in a previous post) will pull off easier. If you can't get the work done in one weekend, pull the tape and retape. It's easier than trying to scrape up baked on tape. The green tape is good if you know you're going to have to sand - it will stand up better to the rubbing without breaking through.
6. It's best (most efficient use of time) to try to do an area small enough that you can get all three coats done in the alloted time. If you have tons of brightwork on your boat and you try to sand it all, tape it all and apply three coats - it can take days. (this is why boaters hire people like me to refinish their boat.)
7. If your cetol is in pretty good shape, you can clean it (soap and water and a scrub brush), tape it, lightly sand it, wipe it down with an alcohol soaked clean rag that you turn frequently (so as not to put the dust back down), tack rag it, and give it a coat. Let it set up and pull the tape, clean up and tip back a cold one.
8. If your cetol is in bad shape - resulting from years of neglect or too many coats to the point where it looks like turd-brown paint, well, sorry, you need to scrape and sand to get down to bare wood and start over.
9. Always tape before sanding. I've seen many who do not and it is impossible to sand next to the gelcoat without scratching it. (Don't kid yourself, you're not that good.)
10. When applying cetol - especially the final coat - apply as you would varnish - brushing back into the wet area on each stroke and 'tip it out.' (Light final stroke with only the tip of the brush touching.)

Good luck with your refinishing. I hope this helps.

[maru657]

I also vote for Acetone. My boat has a fair amount of teak and it's worked well for me. Maybe a better question is, What's best for removing old varnish, paint, etc?