Stripping old varnish

irati · #1 (**permalink**) 01-12-2012

Hi everyone!

How can you tell which type of varnish was used to protect the exterior teak of a boat?

I've had the boat for about 2 years, and the varnish on the exterior wood needs to be stripped and re-aplied again.

The current varnish is falling off in such a way that, if you pick it with your finger tips and pull it, you end up with a long strip in your hands (could be 1 feet long or even more). It feels more "plasticky" than "brittle", as the bits that peel off are quite flexible. Does it mean it is a 2 component varnish, epoxy+varnish, plain old 1 component, or ...?

Unfortunately some of it is still well stuck. What is the best way to remove it? I've read "The brightwork companion" by Rebecca Wittman, but I couldn't find the answer there (re. identifying old varnish types).

FYI I have no previous experience with varnishes.

Many thanks!

pschoonveld · #2 (**permalink**) 01-12-2012

It sounds like Cetol, particularly if it has a heavy color in it. Great stuff, but everything other than the natural color looks really plasticky.

You can cook it off with a heat gun or strip it with any of the typical chemicals. The soy-based ones are particularly easy.

Capnblu · #3 (**permalink**) 01-12-2012

The best way is a razor blade, watch out for that learning curve...

MarkSF · #4 (**permalink**) 01-13-2012

I used some 3m environmentally-friendly stripper on mine, and it worked fine.

svHyLyte · #5 (**permalink**) 01-13-2012

Quote:

Originally Posted by pschoonveld

It sounds like Cetol, particularly if it has a heavy color in it. Great stuff, but everything other than the natural color looks really plasticky.

You can cook it off with a heat gun or strip it with any of the typical chemicals. The soy-based ones are particularly easy.

I agree that it sounds like Cetol although I think a good furniture scraper is the fastest way to remove the stuff (that and a shop-vac to collect the debris) and not create a heck of a mess. The (relatively) new Cetol "Natural Teak" is an excellent, long lasting, finish.

irati · #6 (**permalink**) 01-13-2012

Many thanks, I wanted to be sure I could remove it with a heat gun before commiting to buying one. I'll try a good scrapper first, as with the one I have now I managed to scrape some teak off together with the varnish, despite doing it as carefully as possible.

I remember reading somewhere in the forum that some finishes had some "plastic" components on them (I can't remember what finish it was), so would burn with a heatgun and make a big mess. I'll try it first in a not-so-visible area and see how it works.

Thanks again!

sailprudence · #7 (**permalink**) 02-19-2012

You have probably already taken care of this varnish but I'd like to say that I second the idea of using a card or cabinet scraper and have just recently posted a video showing how. Maybe it can help someone else.
How to use a card scraper to remove varnish - YouTube

MY36 · #8 (**permalink**) 02-19-2012

It sounds like regular varnish to me, but I've never worked with Cetol.

A heat gun and scrapper is the only way to go. Scrapping is so much easier when used with a heat gun.

Good luck. Varnishing is a lot of work, but it can get fun when you see what
amazing results it can give.

PorFin · #9 (**permalink**) 02-20-2012

There are a few things to keep from getting frustrated mid-course:

1. Heat Gun. Ease your way into this cautiously -- take your time and figure out the right heat setting, distance from the wood, angle of attack, etc, so you don't accidentally char the teak.

2. Card Scraper. Before you start, take the time to practice sharpening the scraper. Getting a good uniform burr on the edge is not as easy as it looks on YouTube. Again, start slowly until you get a feel for which angle of attack is most efficient, how many times you can turn a new burr, and when to resharpen.

3. Sand Paper. Yes, it's more work and messier/dustier, but you're going to be doing it at some point anyway so lay on your supplies now.

Have fun -- it can become hypnotically enjoyable

bljones · #10 (**permalink**) 02-20-2012

I agree with Porfin- if you take the approach that it is done when it is done, and immerse yourself in the varnishing sub-specialties (scraper maintenance, sand paper selection, sanding.scraping technique, finish selection, etc.,) it can become very zen.

The difference between varnishing and cetoling is like the difference between smoking a pipe and smoking marlboros. One is a rewarding process with more preparation, the other is a quick hit.