Sanding down teak

[DavidJ]

I’ve just replaced my teak steps (no skill, just bought them from the original Sealine supplier and stuck ‘em on)
You can see the contrast with the ladder locker and bathing platform which are still in good condition and good thickness.
Can I just mechanically sand down the old teak to something approaching good looking condition?

 

[Daydream believer]

I would get some decent brick cleaner & give the old teak a really good clean. flood it with cleaner & work in with a 3 inch paint brush. Then scrub with a "not too stiff" brush although in your case a hand held deck type scrubber may be needed first time. Wash off with water. Do it a couple of times. The colour can be restored very easily & one does not have to spend cash on marine teak cleaners.
I clean my teak twice a year & the acid in the cleaner prevents green mould etc.
When I had my joinery works we had to be very carefull with teak, as the dust gave some joiners some bad skin issues. The dust is seriously dodgy & not good for the eyes either.

 

[Hurricane]

I've done this all before.
The 2 part Wessex cleaner and the old TCM method of cleaning will bring the colour back (look back on very old threads).
But that doesn't do anything for the unevenness of the teak so sanding is a solution.
And the Wessex chemical treatment also helps to erode the teak.
The unevenness is usually a result of the old teal wasting away forming ruts in the grain
The caulking doesn't erode leaving it protruding above the level of the teak.

If you use an orbital sander, it takes ages to sand the caulking down to the level of the teak before you can actually sand the teak itself.
Also sanding the caulking can tear the caulking.
Remember this stuff doesn't start very thick (around 6mm) and I expect it is already down to 4mm.
So the caulking won't have much of a grove left.
The solution is to get a VERY sharp wide wood chisel and run it down the length of the caulking thus cutting the black down to the level of the teak.
With a sharp chisel, it comes off like strips of black spaghetti.
Quite therapeutic.

After that, you can then "go at the whole area" with an orbital sander.
This all takes a long time and you will start to see how thin the teak is.
The groves start to disappear completely.

As you know, we had teak fitted to our boat since new.
I like to keep the teak looking like new by cleaning it regularly.
In doing so, and coupled with the weather, I was only able to get about 10 years out of it.
If I were to buy a new boat again, I wouldn't have teak fitted.
It is really difficult to keep it looking like new.
But I like the teak look so synthetic teak would be my solution (and is).

 

[Fire99]

In a word... Yes. I have sanded down both my foredeck and rear deck so far and the difference is night n day.. I wouldn't sand if I didn't have to but if there are ridges or graining you can get a fingernail into, I certainly would. Then once the teak is smooth like the new pieces, I'd maintain them all together (cleaning etc) to keep a uniform look. If there is plenty of thickness in the old teak, you can easily get the old to look as good as the two new pieces.

 

[DavidJ]

Many thanks @Daydream believer @Hurricane and @Fire99

Agree with @Hurricane about synthetic, your past pics look amazing and will look the same in a decades time. I’ve only got a bathing platform with teak on and I should really bite the bullet and do the same. By the way I used your recommendation for Arno MP20 sealant with good result.
Good tip on chiselling before sanding. I think it’s gone too far for chemical treatment to bring it to where I want it. I love @Fire99 result and that’s the way I will go.
Is there anything to be gained in chemical cleaning before chiselling and sanding?
Thanks chaps
David

 

[DavidJ]

For those wondering what the tcm method was:

TCM Teak thread reproduced.

You'll see new looking decks at (some) shows that are actually selling secondhand boats. There are even one or two forumites boats with secondhand but sparkling new decks. Here's how. My own background is having swankyish boats in the south of france, having built annd maintained 3 teak patios outside houses one of them 200 square metres, employed know all and notso know all cleaners and skippers, spent hundreds on all sorts of jetwashers, brushes, gizmos, and chemicals.

1. First decide if you want you teak to look like teak - or teak covered with something else. I can tell if it's oiled, or if it's got semco onnit, and so can everyone else. It looks a bit yellowish, uniform and non-natural, and it's clear that you trying to short-circuit the actual cleaning. Ultimately, it's a bodge, cos you either can';t or can't be bothered with cleaning. There's also fake teak, which if you talk to sealine they can tell you is actually twice the price of real teak. But we humans are very good at identifying tactile materials even from a good distance away. Teak should look like teak, imho.

2. First off, the chemicals. You need two-part cleaner which can be obtained from wessex chemicals. You get this in 5-litre plasrtic containers, about 20 quid per container. Mark the containers "part 1" and "Part22 very clear cos the coloured dye can go off after year and yer can't tell which is which.

3. Now , the kit: NO BRUSHES, NO JETWASHERS. You need the mildest possible way of swooshing around the boat, and on new teak this means a sponge. But a sponge on a stick, so a vileda floor mop thing that squeezes out is excellent. For outside teak tho, esp teak which is a bit nackered, the floor mop is not quite spongified enough. The Surehold range (pretty sure that's the right name?) sure summink anyway haven't got it in from of me - you get a long stick and put attachements onnit , red handle - is the one to get, and get the flat attachment to which you can stick on a pad that looks like a panscrub. You want the very mildest one, white one that is soft enuf to wash your face with - only just not a sponge, not as severe as a loofah. Plonk this on the flat face of the attachment.

Key thing is that you need this to take a short amoujnt of time - so hands and knees is a bit rubbish cos you will never do it more than once - an effective AND quick clean is what we want.

3. Cleaning even a colossal floor takes minutes, not hours. get everything out of the area, tables chairs etc so no water goes on anything cept the teak. Screw-down tables need to be out as well. Hoover dusty inside areas if neccesary, then wet the area with hose NOT blasting, just dribble about.

4. Now use a mild dilution of part 1 in a bucket and bosh it on the teak. 5 to one is the most severe you shd use ever on mossy grreenish teak, but try 10 to 1 to start if it's just greyish. The teak will go uniformly dark, the colour of mahogany. Agitate the stuff over the teak, across the grain. That floor mop to sloosh it around, always acros the grain, or the soft spongy pad. As it goes dark, there's a tendency to not bother rubbing everywhere, but you do need to "apply" it to the wood with the sponge/mop thing, not just rinse over.

5. Pretty much as soon as the stuff is is on, it's done the business. So once it is all uniformly wet and dark, rinse the area, and tons of brown crap will come off. You need it all off. I use a rubber window wiping blade on a stick to swoosh it all out. You can use a bit of rag to get the edge bits up against a wal where to mop didn't agitate - you get toknow after doin g it the first few times. Again, don't blast with water, low pressure and lots of it.

6. Now the part two, the red stuff. Again , mild solution. 10 to one on wet teak after part 1. This isworrying to put on cos it bleaches back the colour, and the bucket seems to make a mark. Argh! Don't worry - it will all come off, as the bleachiness goes all over. Provided you stay at a mild dilution, you can't put "too much" on - it retuirns to it';s natural colour, so it won't go white or anything like that. On big patios or on the pontoon (yep, you have to clean the pontoon too soon, see below) i use a garden watering can and a rose to sploosh it on. The teak is clean now, and just needs this part two (which is dilute oxalic acid) to be rinsed off. If you missed an area with p1, it'll be silvery grey after p2, so yerd have to start again.
Again, rinse and wipe with a blade to speed up the drying process, and get the dirt off without tons and tons of water.
Walking on the teak whilst it's drying meanns you lose the "utterly fab clean new-boat" feeling, but the footmarks do evaporate so it's ok, ish. The rubber blade v significantly reduces drying time. The teak looks brand new when it dries. Is it clean tho? Get a white tissue and wet it, wipe over tyhe teak, and the tissue will remain clean. It's clean enough to eat food from.

7. Soon the teak will get filthy again. Why's that? Well it's cos of the rain, or the air or (mostly) cos you did it. In the south of france, big boats are "no shoes" - you step aboard in bare feet, not deck shoes, not socks, but Bare Feet, even if you charter the boat and pay a zillion pounds a week. All those swanky boats , look at the pics v closely and none are wearing shoes. Ok, on some they ARE wearing shoes, but they are either deck pumps (that always stay on the clean deck) or boneheads.

8. To keep the deck clean, i'm afraid that you need to try a bit harder than you are doing. You have a deck that is utterly clean and visibly so, like white carpet. But the pontoon is filthy. It's like having muddy garden path and muddy driveway, and white carpet indoors. You need to instigate a regime to limit the dirt arriving on board, or do more cleaning, and more cleaning means more wearing away the teak dunnit, so you have to be nice but then again, look after thhe boat, difficult i know, but anyway.
Clean the pontoon where you step aboard for a start, using 2-part teak cleaner again, and this time a stiff brush cos it will be filthy. If the quayside of you normal berth is concrete, clean and paint it with garage floor paint. put a mat down on the quayside for changing shoes. The mat will fly away in high wind so make sure you have spare mats and take it away in a gale. I lose about one mat per year, mebbe two. If you can't be shoes-off on board the boat cos in the uk it's cold, have one pair of shoes for schlepping over to the car park etc. and dedicated shoes on board that are only for on board, never ashore.

9. Knackered ridgy teak. Teak is inherently quite weak, really. To keep it from disintgrating, you need to never clean it and never wash it, and never step on and keep it covered. UNfortuntately, this aint possible on a boat. But a winter cover (over the whiole boat or at least over the teak) makes it last longer. If you have bare teak indoors perhaps in a wheelhouse, and also outdoors on the deck, you'll see how the indoor stuff stay flat and not-ridgy for much longer. The rain does this - its a moderate jetwash that happens lots of times per year. So, if you had a cover, or individual covers for bitos of the deck, your teak won't go ridgy anywhere near as quickly. I haven't got this, cos it's a bit anal and i can't be bothered. If you have a professional skipper, he could get it done, but there will be protests: this is cos it's work. But the name of the game is to have the teak under cover , accessible with air to stop it going mouldy a bit, but never with rain landing on it. Le Grand Blue is abramoviches ugly ship with loads of boats incl a big 70 foot powerboat - now replaced with a sunseekker predator, but the first powerboat they had on there (Sirius) had individual covers for the teak held on with poppers - and the teak is lovely, even after a several years.

10. Sanding the teak. Yeah, well, you need a machine to do this, and make it flat. Easy to decsribe, hard to do and makes a right mess. Once the teak is flat, you can make it smooth with finer and finer sanding, tho it will be slippery if you go on too long. It will need sanding eventually.

11 Finally about the semco and other protective coverings: at the cost of it looking like real natural teak, these stop dirt from entering the grain. So, it's sort-of protecting the teak for the next owner of the boat. I spose you could use the semco over winter, that would be okay. Would a top-class superyacht or classic racer use semco. No they blimmin well wouldn't, they'd be chucked out of st tropez and the skipper doomed to everlasting ridicule, the lazy git. Teak means teak.

 

[tico]

Looks like i'm not the only one that copied, pasted and saved it for future reference!
Love the bit about Wessex chemicals being £20 for 5 litres!
It's gone up a bit since.

 

[Elessar]

Many thanks @Daydream believer @Hurricane and @Fire99

Agree with @Hurricane about synthetic, your past pics look amazing and will look the same in a decades time. I’ve only got a bathing platform with teak on and I should really bite the bullet and do the same. By the way I used your recommendation for Arno MP20 sealant with good result.
Good tip on chiselling before sanding. I think it’s gone too far for chemical treatment to bring it to where I want it. I love @Fire99 result and that’s the way I will go.
Is there anything to be gained in chemical cleaning before chiselling and sanding?
Thanks chaps
David

I hard sanded mine when I got the boat. Had to replace the bathing platform and steps as it was too far gone.

Sealine use solid 6mm teak unlike the ply used eg by fairline of the era.
So you can sand hard but you will find in places the caulking will go as the caulking rebate is only 3mm. You’ll need to use a router to make the caulking rebate deeper and put new caulk in if it does. It happened to me in 2 or 3 places.

Straight edge needed. Screw it down through a caulk line and make that good when done. The consequence of it slipping is significant so weighting it down risky.

The border planks were loose in places on both my S37 and my T46. Lazy install by sealine as the deck moulding was round in the corner but the plank square so it didn’t push down fully and bed firmly in places. They should have sanded the bottom corner of the plank off. If these are bad you can lift and rebed or make a new one if it splits.

 

[DavidJ]

I hard sanded mine when I got the boat. Had to replace the bathing platform and steps as it was too far gone.

Sealine use solid 6mm teak unlike the ply used by eg by fairline of the era.
So you can sand hard but you will find in places the caulking will go as the caulking rebate is only 3mm. You’ll need to use a router to make the caulking rebate deeper and put new caulk in If it does. It happened to me in 2 or 3 places.

Straight edge needed. Screw it down through a caulk line and make that good when done. The consequence of it slipping is significant so weighting it down risky.

The border planks were loose in places on both my S37 and my T46. Lazy install by sealine as the deck moulding was round in the corner but the plank square so it didn’t push down fully and bed firmly in places. They should have sanded the bottom corner of the plank off. If these are bad you can lift and rebed or make a new one if it splits.

The caulking rebate is interesting as a little of my caulking has come away and there is hardly any depth of gap. That explains it.
So it’s not teak strips then!
The thought of using my router on the decking is a bit frightening I must admit.
I only have bathing platform and step teak on my S37 so the border planks don’t apply to me, thankfully.
Thanks for invaluable input.

 

[Hurricane]

For those wondering what the tcm method was:

TCM Teak thread reproduced.

You'll see new looking decks at (some) shows that are actually selling secondhand boats. There are even one or two forumites boats with secondhand but sparkling new decks. Here's how. My own background is having swankyish boats in the south of france, having built annd maintained 3 teak patios outside houses one of them 200 square metres, employed know all and notso know all cleaners and skippers, spent hundreds on all sorts of jetwashers, brushes, gizmos, and chemicals.

1. First decide if you want you teak to look like teak - or teak covered with something else. I can tell if it's oiled, or if it's got semco onnit, and so can everyone else. It looks a bit yellowish, uniform and non-natural, and it's clear that you trying to short-circuit the actual cleaning. Ultimately, it's a bodge, cos you either can';t or can't be bothered with cleaning. There's also fake teak, which if you talk to sealine they can tell you is actually twice the price of real teak. But we humans are very good at identifying tactile materials even from a good distance away. Teak should look like teak, imho.

2. First off, the chemicals. You need two-part cleaner which can be obtained from wessex chemicals. You get this in 5-litre plasrtic containers, about 20 quid per container. Mark the containers "part 1" and "Part22 very clear cos the coloured dye can go off after year and yer can't tell which is which.

3. Now , the kit: NO BRUSHES, NO JETWASHERS. You need the mildest possible way of swooshing around the boat, and on new teak this means a sponge. But a sponge on a stick, so a vileda floor mop thing that squeezes out is excellent. For outside teak tho, esp teak which is a bit nackered, the floor mop is not quite spongified enough. The Surehold range (pretty sure that's the right name?) sure summink anyway haven't got it in from of me - you get a long stick and put attachements onnit , red handle - is the one to get, and get the flat attachment to which you can stick on a pad that looks like a panscrub. You want the very mildest one, white one that is soft enuf to wash your face with - only just not a sponge, not as severe as a loofah. Plonk this on the flat face of the attachment.

Key thing is that you need this to take a short amoujnt of time - so hands and knees is a bit rubbish cos you will never do it more than once - an effective AND quick clean is what we want.

3. Cleaning even a colossal floor takes minutes, not hours. get everything out of the area, tables chairs etc so no water goes on anything cept the teak. Screw-down tables need to be out as well. Hoover dusty inside areas if neccesary, then wet the area with hose NOT blasting, just dribble about.

4. Now use a mild dilution of part 1 in a bucket and bosh it on the teak. 5 to one is the most severe you shd use ever on mossy grreenish teak, but try 10 to 1 to start if it's just greyish. The teak will go uniformly dark, the colour of mahogany. Agitate the stuff over the teak, across the grain. That floor mop to sloosh it around, always acros the grain, or the soft spongy pad. As it goes dark, there's a tendency to not bother rubbing everywhere, but you do need to "apply" it to the wood with the sponge/mop thing, not just rinse over.

5. Pretty much as soon as the stuff is is on, it's done the business. So once it is all uniformly wet and dark, rinse the area, and tons of brown crap will come off. You need it all off. I use a rubber window wiping blade on a stick to swoosh it all out. You can use a bit of rag to get the edge bits up against a wal where to mop didn't agitate - you get toknow after doin g it the first few times. Again, don't blast with water, low pressure and lots of it.

6. Now the part two, the red stuff. Again , mild solution. 10 to one on wet teak after part 1. This isworrying to put on cos it bleaches back the colour, and the bucket seems to make a mark. Argh! Don't worry - it will all come off, as the bleachiness goes all over. Provided you stay at a mild dilution, you can't put "too much" on - it retuirns to it';s natural colour, so it won't go white or anything like that. On big patios or on the pontoon (yep, you have to clean the pontoon too soon, see below) i use a garden watering can and a rose to sploosh it on. The teak is clean now, and just needs this part two (which is dilute oxalic acid) to be rinsed off. If you missed an area with p1, it'll be silvery grey after p2, so yerd have to start again.
Again, rinse and wipe with a blade to speed up the drying process, and get the dirt off without tons and tons of water.
Walking on the teak whilst it's drying meanns you lose the "utterly fab clean new-boat" feeling, but the footmarks do evaporate so it's ok, ish. The rubber blade v significantly reduces drying time. The teak looks brand new when it dries. Is it clean tho? Get a white tissue and wet it, wipe over tyhe teak, and the tissue will remain clean. It's clean enough to eat food from.

7. Soon the teak will get filthy again. Why's that? Well it's cos of the rain, or the air or (mostly) cos you did it. In the south of france, big boats are "no shoes" - you step aboard in bare feet, not deck shoes, not socks, but Bare Feet, even if you charter the boat and pay a zillion pounds a week. All those swanky boats , look at the pics v closely and none are wearing shoes. Ok, on some they ARE wearing shoes, but they are either deck pumps (that always stay on the clean deck) or boneheads.

8. To keep the deck clean, i'm afraid that you need to try a bit harder than you are doing. You have a deck that is utterly clean and visibly so, like white carpet. But the pontoon is filthy. It's like having muddy garden path and muddy driveway, and white carpet indoors. You need to instigate a regime to limit the dirt arriving on board, or do more cleaning, and more cleaning means more wearing away the teak dunnit, so you have to be nice but then again, look after thhe boat, difficult i know, but anyway.
Clean the pontoon where you step aboard for a start, using 2-part teak cleaner again, and this time a stiff brush cos it will be filthy. If the quayside of you normal berth is concrete, clean and paint it with garage floor paint. put a mat down on the quayside for changing shoes. The mat will fly away in high wind so make sure you have spare mats and take it away in a gale. I lose about one mat per year, mebbe two. If you can't be shoes-off on board the boat cos in the uk it's cold, have one pair of shoes for schlepping over to the car park etc. and dedicated shoes on board that are only for on board, never ashore.

9. Knackered ridgy teak. Teak is inherently quite weak, really. To keep it from disintgrating, you need to never clean it and never wash it, and never step on and keep it covered. UNfortuntately, this aint possible on a boat. But a winter cover (over the whiole boat or at least over the teak) makes it last longer. If you have bare teak indoors perhaps in a wheelhouse, and also outdoors on the deck, you'll see how the indoor stuff stay flat and not-ridgy for much longer. The rain does this - its a moderate jetwash that happens lots of times per year. So, if you had a cover, or individual covers for bitos of the deck, your teak won't go ridgy anywhere near as quickly. I haven't got this, cos it's a bit anal and i can't be bothered. If you have a professional skipper, he could get it done, but there will be protests: this is cos it's work. But the name of the game is to have the teak under cover , accessible with air to stop it going mouldy a bit, but never with rain landing on it. Le Grand Blue is abramoviches ugly ship with loads of boats incl a big 70 foot powerboat - now replaced with a sunseekker predator, but the first powerboat they had on there (Sirius) had individual covers for the teak held on with poppers - and the teak is lovely, even after a several years.

10. Sanding the teak. Yeah, well, you need a machine to do this, and make it flat. Easy to decsribe, hard to do and makes a right mess. Once the teak is flat, you can make it smooth with finer and finer sanding, tho it will be slippery if you go on too long. It will need sanding eventually.

11 Finally about the semco and other protective coverings: at the cost of it looking like real natural teak, these stop dirt from entering the grain. So, it's sort-of protecting the teak for the next owner of the boat. I spose you could use the semco over winter, that would be okay. Would a top-class superyacht or classic racer use semco. No they blimmin well wouldn't, they'd be chucked out of st tropez and the skipper doomed to everlasting ridicule, the lazy git. Teak means teak.

Or read the article in this month's (January) issue of MBY
Just a plug for you MBY guys!!

 

[Elessar]

The caulking rebate is interesting as a little of my caulking has come away and there is hardly any depth of gap. That explains it.
So it’s not teak strips then!
The thought of using my router on the decking is a bit frightening I must admit.
I only have bathing platform and step teak on my S37 so the border planks don’t apply to me, thankfully.
Thanks for invaluable input.

They are real strips. Bonded onto 1mm (ish) thick GRP at Wattson’s factory to make a big area and stuck onto the boat by sealine.

Plank profile like this so then can be butted together when installing.

 

[DavidJ]

They are real strips. Bonded onto 1mm (ish) thick GRP at Wattson’s factory to make a big area and stuck onto the boat by sealine.

Plank profile like this so then can be butted together when installing.

View attachment 147040

Ah! I get it
Do the synthetics have a similar rebate?

 

[Elessar]

Ah! I get it
Do the synthetics have a similar rebate?

No the “caulk” is mostly pre welded in and the butt tightly together. Take a look at Hurricane’s excellent post on making his deck. You front weld “caulk” in in certain places.

 

[Moonstruck]

I've done this all before.
The 2 part Wessex cleaner and the old TCM method of cleaning will bring the colour back (look back on very old threads).
But that doesn't do anything for the unevenness of the teak so sanding is a solution.
And the Wessex chemical treatment also helps to erode the teak.
The unevenness is usually a result of the old teal wasting away forming ruts in the grain
The caulking doesn't erode leaving it protruding above the level of the teak.

If you use an orbital sander, it takes ages to sand the caulking down to the level of the teak before you can actually sand the teak itself.
Also sanding the caulking can tear the caulking.
Remember this stuff doesn't start very thick (around 6mm) and I expect it is already down to 4mm.
So the caulking won't have much of a grove left.
The solution is to get a VERY sharp wide wood chisel and run it down the length of the caulking thus cutting the black down to the level of the teak.
With a sharp chisel, it comes off like strips of black spaghetti.
Quite therapeutic.

After that, you can then "go at the whole area" with an orbital sander.
This all takes a long time and you will start to see how thin the teak is.
The groves start to disappear completely.

As you know, we had teak fitted to our boat since new.
I like to keep the teak looking like new by cleaning it regularly.
In doing so, and coupled with the weather, I was only able to get about 10 years out of it.
If I were to buy a new boat again, I wouldn't have teak fitted.
It is really difficult to keep it looking like new.
But I like the teak look so synthetic teak would be my solution (and is).

If you Google a “Mozart vinyl trimming knife” this worked perfectly for me when trimming down protruding caulking. It has a “U” shaped blade so works perfectly. Originally designed for trimming protruding vinyl welds on commercially installed vinyl floors.

 

[DavidJ]

If you Google a “Mozart vinyl trimming knife” this worked perfectly for me when trimming down protruding caulking. It has a “U” shaped blade so works perfectly. Originally designed for trimming protruding vinyl welds on commercially installed vinyl floors.

Hmmmm
eBay £60 with a handle and £7 for a spare blade.
Is the handle really necessary?

 

[Hurricane]

Hmmmm
eBay £60 with a handle and £7 for a spare blade.
Is the handle really necessary?

I know the tool he is referring to but, IMO, a large flat chisel would be better.
Over time, the teak erodes but about 1mm close to the caulking, it doesn't erode as much.
Using a large flat (and very sharp) wood chisel removes that small 1mm "corner)" as well making the deck smooth, ready for sanding.
I suggest that a wood chisel at least 1" (25mm) wide.