Project Teak Clean

Making Anika's decks look like new again

24th March 2019 by Martin

We get lots of compliments on Anika’s deck and people often ask how we did it, so here goes.

Although teak wood is incredibly hard wearing, you do have to treat it with some consideration. The enemy of any teak deck is a brush. Heavy brushing along the grain will eventually just rub the the teak away. It’s fair to say Anika has a lot of teak on her deck. I’d much rather put effort into looking after the teak than face the bill for replacing it all one day.

The broker had the teak cleaned just before we completed the purchase of Anika, although it looked good it gradually went a very dull shade of grey over the winter. There were also a few patches that were starting to go a bit green where water had collected a little. Our “boat coach” James offered to help us clean and protects the teak and showed us how to use the 3 step clean, renovate and teak seal cleaning products.


Here’s a list of everything we used for this project

  • Two part teak cleaner and renovator
  • Semco “Natural” teak sealer (large tins are better value than quart sized)
  • Plastic buckets
  • Foam kitchen sponges
  • Foam brushes
  • Stir sticks
  • Cloth rags
  • Blue roll
  • Rubber gloves
  • Knee pads (optional)
  • Rubbish bags
  • Lot’s of fresh water

Step 1 - Clean

After soaking the deck with fresh water from the hose, the cleaning product we used was the Onward Trading Company concentrated Part One Teak Cleaner. It was diluted in a bucket with clean water. We applied it using kitchen washing-up sponges, working small areas at a time.

It’s wicked stuff. I thought it would be a good idea to wear my rubber gardening gloves to protect my hands. After about an hour or so I realised my hands felt wet. I took my gloves off and found that I had a couple of nasty looking chemical burns on one hand. You know things must be serious when you have a hole in your finger but it doesn’t hurt one bit. And for the next week using my iPhone was a bit tricky as I didn’t have any finger prints! Note to self: gardening gloves do not offer adequate protection against hazardous chemicals, wear kitchen Marigolds instead.

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After cleaning each section, that section of the deck was thoroughly rinsed down with water from the hose. You could clearly see the dirt and muck washing right off, and the colour of the teak starting to appear. In hindsight it would have been a good idea to thoroughly rinse the sides of the hull too as the chemicals did leave some streaks down the side that I had to later polish out.

Step 2 - Renovate

Once a large section was cleaned and rinsed we moved onto Onward Trading Company concentrated Part Two Teak Renovator. This was also diluted with water in a bucket, and also applied to small areas at a time using a kitchen sponge. You can immediately see the teak’s deep reddish colour turning a more fresher lighter colour. As each section was treated they were again given a good rinse off using the hose pipe.

Step 3 - “Semco” Teak Sealer

This was by far the most rewarding step of the whole process as you can really see golden colour of the teak as you go. Semco comes in a variety of colours, we chose the Natural colour. The trick with Semco is to give it a good stir before you start and to keep stirring it as you use it. If you don’t, the coloured pigments fall to the bottom of the tin and you will get a very uneven finish across your deck.

Working in small sections, we used foam brushes to apply the watery Semco to the teak straight from the tin. To ensure an even coverage you then take a cloth rag and gently wipe over the surface of the freshly applied Semco. Move to the next section, give the tin a good stir and repeat. Depending on temperature the Semco will take a few hours to dry sufficiently to be able to put on a second coat. Semco recommend two coats for the first application. For the second coat you just repeat the whole process with the foam brushes, cloth rags and frequent stirring. Be careful to mop up drips on the hull, your top sides or any metal work before it dries as it can be stubborn to completely remove. The whole 3 step process took us the best part of a weekend.

I estimate we used 3 and a bit of the quart sized tins for our 40ft deck. Semco does come in larger tin sizes and these work out much more cost effective than the quart sized tins. Don’t worry if you have some left in the tin it will keep for a good few months until you need it again.

Once the Semco is fully dried you will notice water just beads up on the surface and does not soak in. If you do walk on it too soon you can feel the soles of your shoes slightly sticking to the surface and you run the risk of trailing Semco shoe prints everywhere.

Ongoing Maintenance

Unfortunately Semco does need to be re-applied roughly every 6 months. In high wear areas you can see the grey starting to appear and water just does bead up like it does when fresh. You do not need to go through the whole 3 step process and it only needs one coat of Semco to continue to protect the teak. We usually spend a weekend at the start and at the end of each season doing the teak. The most important factor is that the teak deck is completely dry when you apply these top up maintenance coats. So don’t leave it too late in the season as finding a completely dry weekend gets harder as you get closer to winter.

Overall we are really pleased with how the Semco looks and protects the wood. It’s a little extra work to maintain but we think the end result is worth it.