Expertise needed on stripping/refinishing teak

[angus99]

I’ve started the dreaded job of removing decades of varnish from the rails of our boat.

First issue: I’m using a heat gun, which is getting most of the old fnish off. However, on the aft rail—which I assume was most-often in the sun—I’m only able to get the upper layers off with the heat gun. There’s a base layer that heat and paint strippers, by themselves, won’t touch. The only thing that’s had any effect is copious amounts of stripper, followed by wiping it down to remove flammability, followed by a heat gun. Even then, I still don’t get down to bare wood, but am left with a gummy layer (first photo). So, I’m guessing my only option is sanding it off. (80-grit, followed by 150 and 220)

Second issue: Even where the heat gun is working well, there are still other places where some of the original finish is visible after sanding with 80 grit. (Second photo).

I’m going to go back with Cetol Natural Teak followed by Cetol Gloss—I do not want to use varnish. Cetol tech support says their finish will only stick to bare wood. They recommend against penetrating epoxy or any other barrier coat.

For those using Cetol, is it really necessary to strip down to perfectly bare wood? If so, it looks like I’ll need to use 60-grit to get all the finish off and remove a fair amount of wood in the process.

If any of you faced similar issues, I’d appreciate knowing how you handled them.

 

[alormaria]

I've only used Cetol and yes you have to go down to the wood to start fresh.

Wood scrapers are your friend.

 

[Comodave]

I am stripping off the Cetol on my teak. It didn’t last 2 seasons in Michigan where the boat is inside for 6 months out of the year. I did take it down to bare wood before I started. Did it exactly per the directions. I am going with paint. Tired of messing with finishing teak. We really like the look of the white painted rails so we are stripping the toe rails this winter.

 

[STB]

The folks who initially redid the brightwork on my last boat used a tool like this:
-- https://www.thehardwarecity.com/products/3010-1in.-Single-Edge-Paint-Scraper/T005129

I've used one with much better efficiency that flat scrapers, heat guns, or chemicals ever since.

Your mileage may vary.

 

[Maerin]

It may help to get as much old material removed as you can, do a quick sand with 80 grit, then use a strong stripper to loosen the finish that remains. I used a carbide scraper, it works well with the heat gun, but you must be careful with gouging. You'll discover that one direction works better than the other, depending on the grain structure. It's not a fun job, and there's just no easy fix to replace plain old elbow grease.

 

[Choices]

I stripped an entire GB 36 with a heat gun and scrapper in a weekend. Was removing Cetol which came off easy.

I see no reason to go back with Cetol, unless you just want to do it again in 18 months.

There are much better high performance teak finishing products on the market.

I am at year four with Awlwood, still looks great, same as when applied. It is very labor intensive to apply, and unforgiving, but in my opinion worth it.

I use a heat gun and small red devil stripper. When working it will get so hot it is best to have several to keep moving. I end up with lots of third degree burns.

For some areas I have a piece of sheet metal roughly 4" sqr. that I use as a scrapper. It gets the wood very level, and you can really bear down on it and even shave the wood versus sanding.

A heat gun can burn the wood quickly. A small sqr palm sander works wonders also for final clean up. Tape everything to keep from scrapping and scuffing gelcoat and stainless.

I would suggest more heat to get the last remnants off. What I have found is that the more you sand the darker the teak gets.
It is labor intensive to apply.

 

[BruceK]

It sounds like you have some 2 pack varnish or similar at the bottom of the old finish, fortunately only in one section. I wonder if hard sanding and leaving it a day or so before getting back at it might help. There is no alternative to getting all the old finish off.
Wood finish choice is nearly as controversial as anchors. I have some Cetol areas, it works and lasts well enough and application is easy, but for rails etc I use Deks Olje 1 & 2 to produce a finish inferior to Cetol or varnish but way easier to maintain and recoat. In 10 years I`ve not had to go back to bare wood.
Where I felt I had to reduce the amount of material I was removing I have used a teak color stain to revive the teak color without hard sanding.

 

[OldDan1943]

I am stripping off the Cetol on my teak. It didn’t last 2 seasons in Michigan where the boat is inside for 6 months out of the year. I did take it down to bare wood before I started. Did it exactly per the directions. I am going with paint. Tired of messing with finishing teak. We really like the look of the white painted rails so we are stripping the toe rails this winter.

Why not let it go gray?

 

[angus99]

I see no reason to go back with Cetol, unless you just want to do it again in 18 months.

Thanks for the ideas. Not sure what you mean by 18 months. My experience with Cetol is that it needs scuffing and a recoat every 12 to 18 months, not a total redo.

 

[angus99]

It sounds like you have some 2 pack varnish or similar at the bottom of the old finish, fortunately only in one section. I wonder if hard sanding and leaving it a day or so before getting back at it might help. There is no alternative to getting all the old finish off.
Wood finish choice is nearly as controversial as anchors. I have some Cetol areas, it works and lasts well enough and application is easy, but for rails etc I use Deks Olje 1 & 2 to produce a finish inferior to Cetol or varnish but way easier to maintain and recoat. In 10 years I`ve not had to go back to bare wood.
Where I felt I had to reduce the amount of material I was removing I have used a teak color stain to revive the teak color without hard sanding.

Thanks, Bruce and all. You may be right about some two-part Finish underneath. since my original post, I found a local guy who specializes in refinishing boats. Going to try to have him look it over.

 

[hmason]

My caprails were finished with Allwood by the Grand Banks yard. I was told to wait 6 months and then to wax them regularly with an automobile wax; not a cleaner wax. I use Mother's pure carnuba wax. I can do the job in 15 minutes. The shine is unbelievable. We are in the Florida sunshine year round so we'll see how long it lasts. January will be one year. Still looks new.

 

[Oldersalt]

I suggest going with Cetol Gloss for ALL coats--6 coats is best. Gloss has the most UV inhibitor and holds up the best to Sun. After a year, or more if you are lucky, give it 2 or 3 more coats. Looks good, holds up well, and is easy to recoat.
Enjoy....
Oldersalt

 

[Comodave]

Why not let it go gray?

We like the look of white rails. Besides now I will have a bit of work every 6 years of so instead of every year...

 

[Datenight]

Hi Angus,

I'll second the scraper with a file to keep it sharp. It's amazing how quickly it will work esp. if you soften the finish with stripper first. Are you waiting for the stripper to work before scraping? Not sure what you mean by wiping it down to remove flamability.

Spread the stripper, let it work for 5-10 min then scrape. Sharpen often. Attached photo is a store bought and home made scraper. Both take standard 1" Red Devil blades. I scraped the edges of that 14 X 21 room in about 20 minutes using stripper and a sharp blade

Rob

 

[angus99]

Hi Angus,

I'll second the scraper with a file to keep it sharp. It's amazing how quickly it will work esp. if you soften the finish with stripper first. Are you waiting for the stripper to work before scraping? Not sure what you mean by wiping it down to remove flamability.

Spread the stripper, let it work for 5-10 min then scrape. Sharpen often. Attached photo is a store bought and home made scraper. Both take standard 1" Red Devil blades. I scraped the edges of that 14 X 21 room in about 20 minutes using stripper and a sharp blade

Rob

Thanks, Rob. I was using a chisel-like scraper—very sharp but I push vs pulling it. I’m going to try some different stripper and a scraper similar to yours tomorrow and see how it goes.

One problem might be the number of coats I’m removing. This stuff is thick!

 

[Datenight]

One problem might be the number of coats I’m removing. This stuff is thick![/QUOTE]

Hope it went well today. I did the soles of two boats two weeks ago. One had at least 12 coats of finish. Since they were teak and holly plywood I did not want to remove the finish by sanding. I used the scraper but it took at least two applications stripper and scraping. Many spots took three applications and a few four.

I did follow up with sanding with 150#, 220# between coats. Total of seven coats.

The boats were 35' and 40' sailboats. Did the entire sole stem to stern. Both took about 5 hours of scraping.

Rob

 

[Westiculo]

My experience: scrape as much off as you can, then let it go one winter uncovered in Boston. The rest will jump right off. Sand off the gray, and you're good to go.

 

[wkearney99]

Card scrapers are fantastic for prepping wood surfaces. They're basically just sheets of metal with J-shaped hook edge. It's the hook that does the work, unlike a chisel. You're dragging the hook across the surface, not knifing through the wood like a chisel.

They're available in a number of different shapes. It's easier to create the hook on flat edged ones, but curved ones can be used as well. I've used card scrapers on various wood projects and the finish is often superior to what you'd get from sandpaper. You do get a hand and forearm workout though!

 

[Bacchus]

Card scrapers are fantastic for prepping wood surfaces. They're basically just sheets of metal with J-shaped hook edge. It's the hook that does the work, unlike a chisel. You're dragging the hook across the surface, not knifing through the wood like a chisel.

They're available in a number of different shapes. It's easier to create the hook on flat edged ones, but curved ones can be used as well. I've used card scrapers on various wood projects and the finish is often superior to what you'd get from sandpaper. You do get a hand and forearm workout though!

+1 for card scrapers. Be sure to get the burnishing tool to put the correct edge on. It takes a little practice to firm the edge but it's not all that difficult.
You will be surprised at the smoothness of the cleaned surface... beats sanding

 

[rslifkin]

Thanks for the ideas. Not sure what you mean by 18 months. My experience with Cetol is that it needs scuffing and a recoat every 12 to 18 months, not a total redo.

This has been my experience as well. As long as you scuff and re-coat before the coating starts to fail, you get a pretty good number of seasons before it's time to strip it back to bare wood and start fresh.

 

[wkearney99]

+1 for card scrapers. Be sure to get the burnishing tool to put the correct edge on. It takes a little practice to firm the edge but it's not all that difficult.
You will be surprised at the smoothness of the cleaned surface... beats sanding

There's some epiphany moments with card scrapers. One is the initial reaction to how smooth a surface can be made. The other is finally grasping how the edge works and making new ones on your own. It's the drag of the VERY SMALL J-shaped hook that does the work, not just the scraping of a flat edge. But like any edge, it requires being kept sharp. So a good burnishing tool is key.

It helps to have a vise handy to hold the card when burnishing a new hook, but it's not mandatory. I've gotten reasonably good at making one holding the card firmly against a vertical surface and running the tool along it. A smooth-jawed vise, or one with two strips of rubber inner tube helps to keep the card from getting chewed up while hold it.

 

[angus99]

This is great advice, y’all. I just finished removing the thick varnish from the sundeck rails. Tedious, but not the worst job I ever did. I’ll try card scrapers when I begin work on the next set of rails running from sundeck to bow.

 

[angus99]

Another question

Using a heat gun, I scraped off the thick layers of varnish from the top rail around our sundeck.

In a couple of test areas, I then used two applications paint stripper, a pull scraper and shave hooks—followed by 80- and 120-grit sandpaper—to get down to what feels like smooth bare wood, which is what’s required for Cetol. It feels and looks great, but I’m sure there is still varnish deep in the wood grain.

Has anyone applied Cetol over previously varnished wood and how has it held up, assuming—like me—you didn’t grind half your rails away to get to ”pure” bare wood?

Thanks again for all the replies thus far.

 

[angus99]

Ignore post 23. I was able to reach Interlux tech support who says there are no issues with any varnish remaining embedded in the open pores of the wood. It’s still considered “bare wood” that Cetol will adhere to.

 

[angus99]

One more question

The railing I’m working on sits on stanchions, each of which is screwed, via a metal flange, to the underside of the rail. I can see tiny gaps between the flanges and the wood. Does anyone go to the trouble of unscrewing the rail and caulking between it and the metal flange? Seems like it would let moisture in as is.

After a week of stripping this to bare wood, I’m NOT looking for more work, but neither do I want to sabotage the finished product.

 

[SteveK]

I will be doing this next summer, so following along with your results.
RE post 25, I will be unscrewing and bedding the stanchions, mostly as some screws are now loose but for same reason you mention, that little area does not get the TLC like the rest of the teak.

 

[PMF1984]

A piece of wood should not touch something else without proper bedding. Water will sit in there and rot out the contact area, wick up the screws and rot out the screw holes.

 

[OldDan1943]

A piece of wood should not touch something else without proper bedding.

Yea, that's what she said.

 

[Island fish lifter]

How did the painted railings turn out? I may consider doing the same. Thanks!

 

[Comodave]

How did the painted railings turn out? I may consider doing the same. Thanks!

We really like them, it brightened up the sundeck and really updated the boat. The one part poly paint should last 5 + years and then a scuff sanding and add one more coat and good to go. Way less work that varnish and we think it looks better. Sorry for the sideways photos. We also removed all the hardware and cleaned off the varnish that the PO slathered all over so the hardware looks much better also.