Author Topic: Teak deck removal  (Read 3663 times)

Yngmar

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Teak deck removal
« on: October 21 2020, 22:19 »
I've started the big task of removing the 20 year old teak deck from our Bavaria 40 Ocean.

After initial success in removing the entire piece from the anchor locker lid in one chunk, the rest of the deck is proving more difficult. Seems doable with an oscillating multi-tool though, although progress is slow and my knees already ache. Oh well, this was always going to take a while, no matter which method!  :-\

The good news is, underneath is virtually new non-slip gelcoat in a moulded pattern that has been protected from the sun so far. Getting the old adhesive/caulking out of it is difficult, suggestions welcome. I've tried so far various chemicals, which did little (apparently I'd need a PU sealant digesting product, which I can't find in Italy, solvents do nothing).

Wooden tools to avoid damaging the gelcoat and stiff nylon brushes seemed to work best, although it sure is a lot of scrubbing that way. I've ordered some nylon brushes to fit a drill and will try those when they get here.

A pressure washer I borrowed showed some promise, but 130 bar isn't quite enough, it works but progress is glacial and it's using a lot of water. There's 150 bar ones available, but I'm not sure that's enough either, and at some point the pressure will just take the gelcoat off as well, although so far that hasn't been a problem.

For photos you can follow this Mastodon thread here, which I'll keep updating with progress: https://social.tchncs.de/web/statuses/105068670817241655

Any suggestions welcome, especially for products I can get in Italy :)
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Salty

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Re: Teak deck removal
« Reply #1 on: October 22 2020, 03:58 »
Hi Yngmar, I’m not sure if the following thoughts and suggestions would be of any help at all, but its possible that there may be a tool hire shop nearby from which you could rent a more powerful pressure washer. Also in regard to the fresh water usage which presumably you have to pay for,  perhaps you could use sea water instead through the pressure washer, though if you did I’d be inclined to run fresh water through the machine after every use. A rotating patio cleaner tool used with the pressure washer might do a better job of cleaning the deck once the sheathing has been removed.
After reading about the difficulties in removing worn out wooden deck sheathing, my yachting colleagues and I are of the opinion that no matter how nice wooden decks appear when in good condition, they are otherwise a nit of a disaster waiting to happen. We are all glad that our boats didn't have anything more than the cockpit area sheathed. If you are successful in being able to remove the sheathing and get back to a nice clean gel coated deck, would it be worth considering not replacing the timber decking ?

elias

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Re: Teak deck removal
« Reply #2 on: October 22 2020, 04:38 »
Hi !
Recently I used Acetone to clean the black rubber on my boat that was getting soft , I hope it helps !

sy_Anniina

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Re: Teak deck removal
« Reply #3 on: October 22 2020, 07:09 »
No personal experience on removing the PU stuff, but have seen soda (sodium bicarbonate) blasting remove paint and leaving gelcoat unharmed.

The downside: blasting may mean hiring contractor to do that.

BR,

Tommi
s/y Anniina

SYJetzt

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Re: Teak deck removal
« Reply #4 on: October 22 2020, 12:14 »
I don´t have experience with removing the caulking.
But as i used  hydrocloric acid to clean up my holdig tank from urinal cake, i spoilt some drips on my teakdeck by mistake.
As i discovered the mess some minutes later, there was a bleach on the wooden surface and the caulking was pretty affected.
Maybe you could give this a try.

IslandAlchemy

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Re: Teak deck removal
« Reply #5 on: October 22 2020, 15:01 »
Give cellulose thinners a try

Laysula

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Re: Teak deck removal
« Reply #6 on: October 23 2020, 18:29 »
Is that teak faced ply that you are removing? I'm just doing mine at the moment (teak faced ply) and i have done it with a hammer and chisel. However, the surface below is smooth so has cleaned up with a scraper and then a orbital sander with 60 grit. The hardest bit was the caulking around the outside which needed a lot of sanding with sandpaper around my thumb, In some places the adhesive has pulled up the gel coat, these bits I have filled with marine epoxy filler. Finish is unimportant as long as its flat as I am replacing with plastic teak.
The most frustrating thing though was some of the nuts holding the guard rail around the foot of the mast and the guard over the dorade vent are above the bulkheads and glassed in place.

Mirror45184

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Re: Teak deck removal
« Reply #7 on: October 24 2020, 02:07 »
Try a soft rubber pad or block and "scrub" it off. Might work, will tend to just ball it up and possible get it off that way.....
Good luck and a lot of beer to help with the job may the part of the answer.
Challenge the neighbors with the problem and invite them to experiment and demonstrate!
Cheers
Mark Hutton
SV SYnergy
B40 Cruiser 2009

Jam

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Re: Teak deck removal
« Reply #8 on: October 24 2020, 10:10 »
Hi
Have a friend that removed his glued down deck, also a Bavaria, completely and all glue.  Have spoke to him, he used a pressure washer but said that if it is too powerful it will damage the deck gelcoat. That was his experience and said he would recommend not using industrial pressure wash with high pressure. He spent a long time with a plastic scraper removing bits, cleaning with jet wash and scrubbing.  Also used CT 1 multisolve which helped but said the weather, rain, saltwater across the deck eventually loosed the bits left over.  It took him weeks/months and lots of patients I am afraid but I was amazed when he showed me the finished result. I am confident it can be removed......if I attempt my own boat.  Good luck with yours.
John

Yngmar

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Re: Teak deck removal
« Reply #9 on: October 24 2020, 11:47 »
Thanks for the tips, keep 'em coming.

I've tried acetone, it does soften it, but evaporates in seconds and the caulk then re-hardens. Maybe I'll try again when it's colder and stick to chiseling away the teak for now.

Hydrochloric acid reacts a little bit with something (might've just been dust), but doesn't have any apparent effect on the adhesive.

Rubber block. Err, gotta see where I can find something like that. Sounds like it might be worth a try.

DCM may work, but I can't find a source in Italy, probably because it's horribly toxic.

The gelcoat underneath is in good condition, apart from the mystery deck holes, of which I've found several more previously undiscovered ones. I'm gonna have to buy more fast-cure epoxy to fill them as I go so the water stays out of the boat.

If I can get the moulded non-slip gelcoat cleaned up, there is no reason to attach or paint anything else onto it. Certainly not teak! :o

Jam, pressure washer and stiff brushes are the best I've come up with so far too. It's rather slow though, but luckily the glue is pretty non-skid itself so I have no problem going sailing for a year in the med and let the UV kill it off - based on how the Sikaflex I foolishly used in my early days of ownership is chalking off, the deck adhesive might just crumble off on its own in the sun :D

Beer always helps! Helpful neighbours have already offered me advice and random chemicals to try, none of which did much - including concentrated industrial strength PVC cleaner for lorry canvas.
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Markus

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Re: Teak deck removal
« Reply #10 on: October 25 2020, 18:25 »
A bit of an obvious question, but have you tried contacting Sika to get their view? I have received excellent advice from their tech support so worth a try.

SYJetzt

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Re: Teak deck removal
« Reply #11 on: October 28 2020, 14:26 »
The use of DCM is forbidden in the private field due to REACH (EU-Regulation) because of its toxicity. I suspect, you would not get the stuff in Italy.  :(

Markus

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Re: Teak deck removal
« Reply #12 on: October 30 2020, 12:48 »
I have a lot of interest in this thread as the deck of my Ocean 40 needs same treatment in the not-too-distant future...   :)

I was thinking would it be possible to lift of complete sections of the deck (like a side-deck) starting from one edge by heating the glue with heat gun and putting wooden wedges between deck and wood. Then you would work your way forward with heat gun and lifting the deck more as you go. According to Sika the glue takes 140 °C for 1 h so probably 150...200 °C would be sufficient to get it loose enough...

Regarding removing the glue from the gelcoat, maybe a nylon wheel brush (without any abrasives) could work: https://benchmarkabrasives.com/products/3-x-1-4-mandrel-nylon-wire-flap-brush

Yngmar

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Re: Teak deck removal
« Reply #13 on: October 30 2020, 21:31 »
Thanks SYJetzt, that explains why I couldn't find any to buy.

Have meanwhile been chiseling away, with a day or two off in between to allow my hands to rest - the oscillating multitool is very much a meat tenderizer. The foredeck is done and I'm halfway down the starboard side.

The teak comes off best where the underlying ply is rotten from water getting in and sitting there, and in some areas the glue had poor adhesion. Where the teak and underlying ply are still in good shape, they come off in 5cm pieces and progress is slow. Once the multitool has cut the glue, I'm using a claw hammer to lever the wood off the deck, it's got a nice wide and smooth surface that doesn't damage the gelcoat. Taking the wood off is not difficult, just a fair bit of manual labour to get through.

What remains (see new photos at the bottom of my Mastodon thread) is some black adhesive. I've tried sanding, but that takes off too much gelcoat. What worked better was an angle grinder with a fine scotchbrite pad, at low speed. This removes the black adhesive from the surface without taking much gelcoat with it.

Then there remains some adhesive in the grooves of the patterned gelcoat. This is difficult to remove. I've just got a 150 bar pressure washer (120 bar one I'd borrowed wasn't enough) and had another try with that. It's about as much pressure as the deck can handle without chipping off and it only gets it out in some areas where the glue is weaker. In others it doesn't. So I might do like Jam says and let the sun do the work - PU adhesives are luckily quite vulnerable to UV >:D

This just leaves a lot of detail work with removing the caulking along the edges of the deck, epoxy-filling the holes and finally repairing and re-patterning the damaged gelcoat from blade slips, deck holes, chipped non-skid and pressure washer void-finding. I'll be busy for a while.

Heat will not work according to my research, as the PU adhesive can absorb more heat than the cured gelcoat can take.

I haven't found a non-abrasive Nylon drill or grinder brush of sufficient strength with fine enough bristles to get into the grooves yet. Markus, the ones you've linked to are abrasive (thus the grit specifications).
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Markus

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Re: Teak deck removal
« Reply #14 on: October 31 2020, 10:24 »
Thanks SYJetzt, that explains why I couldn't find any to buy.
I haven't found a non-abrasive Nylon drill or grinder brush of sufficient strength with fine enough bristles to get into the grooves yet. Markus, the ones you've linked to are abrasive (thus the grit specifications).

Yes, you are right, I just took the first link with google and did not check. Maybe the grooves could be cleaned with dremel with a tiny nylon brush... https://www.amazon.co.uk/Dremel-403-02-Nylon-Bristle-Brushes/dp/B015PK3BC8


Yngmar

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Re: Teak deck removal
« Reply #15 on: June 11 2021, 10:53 »
Forgot to update this in a while. We had some aggro from the marina about it, which was very silly of them as people come to winter liveaboard marinas for doing boat work, and we really weren't making any mess compared to the "professionals" removing teak decks on other boats in the same marina, which they said nothing about.

Anyways, some more photos in this Mastodon thread: https://social.tchncs.de/web/statuses/105068670817241655

I've got the teak off except for the aft deck and lazarette lockers, which I decided to leave for another winter due to the marina being difficult. That section of the deck is still okay though, the forward deck was not (melting caulking and secret leaks under the deck). In terms of timing, it took me about two weeks to do half of the deck, but see below - the removal of the teak is only part of the job. My back however suffered and you have to take breaks from the oscillating multi-tool or the vibration will damage your hands.

Tools of choice were an oscillating multitool (if you can find or make a longer blade knife, do it). This was jammed under the teak edge to separate the glue from the deck and then the teak was levered off with a claw hammer. Some parts were rotting and came off easy, others had poor adhesion from new, but most were solid and came off in 5 cm wide strips (one blade length). Sometimes it was possible to pull off a plank or two intact, separating it from the teak ply underneath, which made it much easier to then remove the ply.

After that, a bunch of black PU adhesive was left. I removed the bulk of it with an angle grinder and a fine scotch-brite pad, which made quick work of it without doing much harm to the non-skid square gelcoat underneath. Then there was quite a lot of detail cleanup needed along the edges and the gaps between the non-skid sections. For this I took an hold wood chisel, ground the edges on both sides round to much the gelcoat corners and then scraped away by hand.

I kept things clean by chucking the wood into a big builders bucket and vacuuming up the black dust from grinding the glue off. I found a few more of the mystery deck holes hiding underneath, some of which had been leaking (see this thread). I filled those in and also removed a few useless fittings while I'm at it. Luckily there are very few things bolted through the teak part of the deck, so this was not adding much work.

Then came a lot of gelcoat repairs! A lot lot lot, which are still ongoing. The holes in the patterned part were filled with thickened epoxy, ground down with a rotary tool and filled with gelcoat. The pattern is easily repaired with a small triangle diamond file (kit from Lidl), by following the existing pattern and extending it through the new gelcoat.

Also a ton of cracks along both edges where the teak had been. I suspect these were from the original mould release and just never fixed at the yard as they knew it would all be covered up with a teak deck. And the pressure washer found a lot of voids in the corners (normal from the layup process), which I also had to fill in. There was a single osmosis blister on the deck where water had been trapped under the teak and seeped into a gelcoat crack. Not a big one, so repaired with some epoxy injection and filled with more gelcoat. The areas where I've already filled, faired and polished the gelcoat look great but it's a lot of crawling around which is hard on my knees and back. I'm definitely too old to ever buy another boat with a teak deck!  ;D

Then there is the remaining black PU adhesive in the grooves of the non-skid pattern. This is impervious to chemicals. Pressure washing with high pressure/focused beam chips off the gel coat before removing the glue. It can be physically scraped out with a knife blade, but there are more grooves than stars in the universe. Various brushes did help only a little, but being rubbish PU stuff, the UV seems to be making short work of it and every time I pressure wash the deck (at regular low/medium pressure), more "white patches" appear where the glue comes off. So I expect after summer there will only be a few shaded areas where it needs removing by hand and then probably a good scrubbing with a fine brush to get it out of the deeper grooves.

Overall it's doable, but despite the initial good speed at which the wood came off, it's a ton of work with most of it being in the little details and I wouldn't recommend a teak deck to any sensible sailor  :kewl
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Yngmar

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Re: Teak deck removal
« Reply #16 on: June 11 2021, 14:42 »
Some macro shots of the non-skid under the teak. The clean area is from the coach roof which never had any teak on it. The other one with remaining glue and a "white patch" nearby.


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Jeffatoms

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Re: Teak deck removal
« Reply #17 on: June 14 2021, 04:11 »
Thank you, Yngmar, for not only starting this thread, but simply going for it on task.  We too have this task on our list to-do on our 1998 Ocean 38.  All of our teak slats are still in place but in many places the decking has separated from the under-decking and has popped up.  We are in the process of installing a 3 x 2 meter waterjet table at work and I am considering tracing out the original deck for a shop made replacement, though I would use composite decking which I have yet to locate an appropriate option.  I can peek under and I see my non-skid looks save-able. 

I am also considering remolding the non-skid if it is damaged.  There is a great video on youtube called Boatworks Today where the guy shows how to pattern a flexible and reusable non-skid mold from the good non-skid you have.

The Boatworks Today guy has a video of how to trace the decks too.  I hope to find industrial sheets of fake teak composite that are tough and UV stable....still looking.

Stockie

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Re: Teak deck removal
« Reply #18 on: June 29 2021, 11:11 »
Another option, used for removing glue residue under decals.
They are called Caramel Wheels, looks like Caramel, a plastic
Rubbery disc with a spindle attached to use in a drill, maybe they
Do industrial strength ones that mount in an angle grinder.
Work well on sticky adhesives on gel coat, sort of melts it off with friction
And makes the glue ball up and spin off, without any damage to the substrate!

Cheers Richard

Yngmar

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Re: Teak deck removal
« Reply #19 on: July 10 2022, 17:48 »
Update, 13 months later. Doing nothing seems to be working! I pressure wash and scrub the deck occasionally, but that's normal boat cleaning. I would guess another year and it should be gone completely.

For once, the UV works for me instead of handing out skin cancer, embrittling plastics and gnawing away the sail and canvas stitches :)

I'd say about half the old glue is gone. All the center dimples have gone away and the grooves are filled about half way instead of all the way to the top now.

I filled all the gelcoat damage, but haven't managed to sand it down as my back is still a bit grumpy about this, but there's no more holes and I think I'll leave the detail work to a future owner :kewl

Still have to do the aft deck as well, and that's on me :(



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Petef

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Re: Teak deck removal
« Reply #20 on: July 11 2022, 23:14 »
It might be worth a try (again) with Acetone given the state of your deck now.

I say this as I have been removing some of the loose planks on my deck. Where the deck meets the gel coat of the deck on the raised areas of the cabin, I had been left with some small black glue/caulking on the gel coat. However, Using metal tools cause the gel coat to be scratched and is not very effective at removal.

The following has been an effective way to remove the above.

I put a little Acetone in a small bottle with pointed nozzle on the lid (actually from my wife's hair colour kit). This allows you to place small amounts of acetone where you want it.

I used a wood ice lolly stick (bought as a pack from a craft shop). I cut one diagonally so that it has a point and the rounded end.

Lastly a kitchen sponge with a scrubbing pad attached.

Using the lolly stick I scraped at the black bits dry. This roughed up the black bits, but they were still stuck to the gel coat. I then poured a little acetone over the black bits and again rubbed with the pointy bit of the lolly stick. This started the black stuff to melt and come away from the gel coat, however, the the acetone started to evaporate (temp in high twenties), so added a little more acetone and and scraped with the lolly stick (used both ends) ended up with a mush of the black stuff which could be moved out the way. Any black remaining was again given a dose of acetone ant the sponge scrubbing pad used to remove the stubborn black.

As you now have very little of the glue left on your gel coat this might work for you. Do a small bit at a time (2-5 cm long). The bottle of acetone only puts a small amount out each time so you aren't using litres of the stuff. Ruffing up the black fisrt seems to allow the the acetone to penetrate better, and additional small amounts keeps it wet. So maybe worth a try.

Jeffatoms

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Re: Teak deck removal
« Reply #21 on: July 14 2022, 15:12 »
This is so timely!  We too are removing our deck. The entire starboard side simply lifted up but the stern decking is putting up a good fight.  We too have found that UV is our friend on this project.  We found that a rotary Scotchbrite scrubbing head attached to a cordless drill does the trick of removing the black bits without damaging the non-skid pattern of the gel coat.  Next I will try a little acetone or possibly a weaker fingernail polish remover to help out.

Yngmar

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Re: Teak deck removal
« Reply #22 on: July 14 2022, 16:15 »
This is so timely!  We too are removing our deck. The entire starboard side simply lifted up but the stern decking is putting up a good fight.  We too have found that UV is our friend on this project.  We found that a rotary Scotchbrite scrubbing head attached to a cordless drill does the trick of removing the black bits without damaging the non-skid pattern of the gel coat.  Next I will try a little acetone or possibly a weaker fingernail polish remover to help out.

Photos please, Jeff :)

Especially of that Scotchbrite scrubbing head, if it indeed got the black bits out of the non-skid grooves?
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Petef

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Re: Teak deck removal
« Reply #23 on: July 14 2022, 22:19 »
further to my post above, It's a bit wearing doing this manually; so i thought how can a mechanise this? The answer cut the ice lolly sticks into two, carve a semi circle out of both halves, the use them in a multi tool!

You still need to remove as much material as you can mechanically 9 (OR BY TIME AND SUN LOL).

Then use the multitool with with the wood sticks and acetone to remove the black stuff.

See pics
1 & 2 are showing the ice lolly sticks attached to the multi tool.
3 the effect of using the above with acetone

Only warning is that if the sticks dry out for lomg yjey can generate heat that could affect the gel coat. Also as the stuff is wet it can splash the the surrounding areas. So maybe cover those or wash off with acetone.

This was very effective for me. 

keef

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Re: Teak deck removal
« Reply #24 on: August 16 2022, 14:56 »
When I replaced the teak faced ply on my 1994 Bav 350 many years ago I used a powered router with the depth set very carefully to create small sections which were easy to remove with a wood chisel and mallet. I then carefully removed as much of the adhesive as possible with the same wood chisel. I removed the residual adhesive with methylated spirit. However, the gelcoat surface was smooth in my case.