Tips for applying new Sikaflex on teak decks

[Caladh]

Tranona - in some parts on the deck the caulking is effectively "free" in the groove and just pulls out. There is def no existing tape.

 

[SV Kittiwake]

I've just recaulked the teak decks on our Tayana, it's nowhere near as big a job as people seem to make out.

I found the tool that worked best for removing the caulking was a cheap painters tool (that funny looking scraper thing), as it separated the old caulking from the wood rather than cutting it away as a Stanley knife or Fein blade would. Then there's way less sanding to do inside the seams. I found that a Fein (ours is actually a Bosch copy) with the grout removing blade worked really well for cleaning up the seam sides and widening / deepening the seam if needed.

The hardest bits were getting the masking tape up without getting sealant everywhere (leave big tabs for grabbing once covered in caulking and don't mask in long stretches) and cleaning up the inside of the grooves well.

In terms of masking tape, you'll use a lot and I didn't see much point using the blue stuff at €5 a roll, the €1 stuff from the Chinese shop worked fine as it wasn't down for long and it's not like you're using it to create a perfect painted edge.

You'll definitely need access to a hoover, probably the most essential tool for the job, and some knee pads.

I know it's too late for you, but we used marineflex which is significantly cheaper than sika or TDS (£4 per tube vs £18-22) and it seems really good so far.

 

[Tranona]

Tranona - in some parts on the deck the caulking is effectively "free" in the groove and just pulls out. There is def no existing tape.

Sounds like it has lost adhesion to the adjacent planks. Assuming the deck is glued down it seems reasonable to clean up, prime and fill.

 

[Tradewinds]

Sounds like it has lost adhesion to the adjacent planks. Assuming the deck is glued down it seems reasonable to clean up, prime and fill.

In the past I've posted a link to Teak Decking Systems advice re (acid) cleaners. Obviously TDS are trying to promote their own range of products (caulk, adhesives & cleaners) but their advice might be worth considering by owners of teak-decked boats

Acids may have the effect of softening the caulking in the seams of our panels and the resulting softening will lead to seam failure over a period of time. Once a crack opens between the seam and the wood, it allows cleaning solutions to collect in the cracks where it cannot be easily rinsed out, and seam failure accelerates.

The "cleaning" action of acids appears to be very effective, because the acid actually removes some of the material being cleaned—in our case, the wood and the caulking. Over time, enough material may be removed to compromise the integrity of the wood where it meets the caulking seam, causing a crack, which, as described above, accelerates the failure of the adhesion of the caulk to wood.

Interestingly, regarding onward maintenance of teak decks they make this point.

Even with care, in time the surface of the wood will become uneven. When this happens, the deck should be lightly sanded with a sanding machine to smooth the surface. This will actually increase the life of the deck by exposing less wood to the elements and preventing the grain from trapping dirt or air-borne corrosives.

Sounds a little counter-intuitive but I can see some logic to this.

 

[Chris_Robb]

Thge use of bond tape depends on the method of construction, thickness of teak and type of caulking used. The purpose is to only allow bonding to the edges of adjacent planks to accommodate movement of the planks if they are not firmly attached to the substrate. Thick, wide planks screwed to the substrate clearly have the potential to move more than thin narrow ones glued down with no fastenings.

So there is no universal "must use tape" rule, although with some caulking it is essential to clean and prime the seams to ensure the caulk adheres fully.

If there is no sign of tape when the old caulking is removed, nor signs of caulking breaking away from the sides in otherwise sound seams then it is reasonable not to use tape in the replacement.

Tranona

Useful bit of info as I was slightly puzzled by the use of the tape. I was just going to follow the instructions come what may. My decks are epoxied in position - no screws, so they should not move.

I found this thread very useful and bought the tools I need to do the job. In my case its only the odd seam, but it seems to be worth getting on top of it to prevent water ingress and subsequent further un bonding of the siki.

As for using the cheaper varieties - I think I will stick with TDS or Siko.

 

[Chris_Robb]

In the past I've posted a link to Teak Decking Systems advice re (acid) cleaners. Obviously TDS are trying to promote their own range of products (caulk, adhesives & cleaners) but their advice might be worth considering by owners of teak-decked boats



Interestingly, regarding onward maintenance of teak decks they make this point.



Sounds a little counter-intuitive but I can see some logic to this.

As regards the use of Teak cleaners, they certainly remove some deck, and I wont let anything with out a neutral Ph near my decks. No brush of any form, just a soft cloth and very weak detergent. I usually sponge over a solution of MMC (moss and mold cleaner), which is Ph neutral. Although in Greece we dont get green algae over the decks, you do get a small =hardly noticeable Mildew in the wood grain. The MMC gets rid of this over time, and leaves the deck quite a light colour.

As for sanding, I have a couple of high wear areas - I might just try a light sanding - though as you say, it seems counter intuitive!

 

[wazza]

I used TDS caulking on my after deck, it was the best decision I made. I used a caulking that was haft the price of TDC on the coachroof and I had to tape everywhere, took hours. With TDS I could lightly sand after without taping.. brilliant?

 

[One A.]

I used TDS caulking on my after deck, it was the best decision I made. I used a caulking that was haft the price of TDC on the coachroof and I had to tape everywhere, took hours. With TDS I could lightly sand after without taping.. brilliant��

+1

 

[Ric]

Although my teak is right as rain, the Sikaflex between the panels is tired in some places, and non-existent in others.

I´ve bought the relevant Sikaflex to fill the gaps, but before starting I was wondering if anyone had any helpful tips /advice.

Electric tape to protect the teak and a confident squeeze to get the continuous line are my 2 main thoughts...

Thanks

Justin

Well my advice is best to just rip it all out an replace with Flexiteek.

You will spend hour taking out the old sikalfex, then adding primer, laying the new sikaflex, then sanding it down. And in a few years you will have melting sikalfex, black smudges on your clothes, and will have to do it again. Just bite the bullet and buy Flexiteek - totally excellent product with no downsides.

 

[wazza]

Well my advice is best to just rip it all out an replace with Flexiteek.

You will spend hour taking out the old sikalfex, then adding primer, laying the new sikaflex, then sanding it down. And in a few years you will have melting sikalfex, black smudges on your clothes, and will have to do it again. Just bite the bullet and buy Flexiteek - totally excellent product with no downsides.

Apart from the fact of an extreme high expense to do the job. I’ve even looked at doing this myself but the materials cost a lot too, not to mention the time involved..