Blotchy teak

[robp]

A couple of years ago a yard valeted my boat after some warranty work. I believe that the cleaners may have used a jetwash at close quarters, or a steam cleaner. Since then, the teak (which now looks very grainy), seems to hold more dirt and where verdigree (spelling)? has formed over winter, there are now greeny grey blotches which don't come out.

Anyone know how to retrieve this?

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[tillergirl]

Well, the classic teak (or any wood cleaner) is oxalic acid. It's the active ingredient in most teak cleaners but you can get it from the chemist and mix it up with water. My recipe says 25 grams to 500 cc's of water.

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[Ohdrat]

Re: Oxalic acid

isn't that the substance in Onions... try rubbing with a cut onion???

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[Forbsie]

Re: Oxalic acid

Doesn't look like it, but you could try.....

"Plant foods with high concentrations of oxalic acid (over 200 ppm) include (but are not limited to): lamb's-quarter, buckwheat, star fruit, black pepper, purslane, poppy seeds, rhubarb, tea, spinach, plantains, cocoa and chocolate, ginger, almonds, cashews, garden sorrel, mustard greens, bell peppers, sweet potatoes, soybeans, tomatillos, beets and beet greens, oats, pumpkin, cabbage, green beans, mango, eggplant, tomatoes, lentils, and parsnips."



<hr width=100% size=1><A target="_blank" HREF=http://www.arweb.co.uk/argallery/forbsie?&page=1>My Project</A>

 

[billmacfarlane]

Rob , I'm using products from a company called Semco. It's in 3 parts , a cleaner ( contains caustic soda ) , a restorer and a sealer which I think is silicon based. You're welcome to try it if you can catch me on my boat,

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[tillergirl]

Re: Oxalic acid

Yesssssssss. I think the point of buying it from the chemist is that you don't get any other natural dyes with the oxalic! I think the idea of scrubbing the deck with an onion would probably work but I wonder if Robp would let me come and watch - for some reason perhaps the total lack of humour about the news today - the idea of watching someone scrub a plastic boat with a fake teak deck (yes I know it's real wood) with an onion or two sounds highly entertaining! I bet the yard will be pleased with the left overs for breckie!

By the way, I hope he won't use French Onions!
<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by tillergirl on 17/03/2003 23:58 (server time).</FONT></P>

 

[robp]

Re: Oxalic acid

Right then, next time we're having a barbie, I'll get everyone to lob a few of Forbsie's ingredients around the place. Come to think of it, there won't be much change there then!

I think it's in the hull warranty that only French ingredients can be used on board. Just as I was hoping we'd be thrown out of the EU too!!

Oi Tillergirl, my Teak looks as good as the real thing - well it did anyway...

I did try Oxalic Acid, in the convenient and cutely expensive form of Teak Brightener. It didn't get it out.

Thanks for the suggestions, I think its all in the scrubbing!.

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[robp]

Thanks Bill, I've been thinking of trying that stuff but thought the cleaner part of it was the same as Teak Brightener? I've tried that. Maybe I'll take you up on it, xcept that I've tried catching you on your boat before!! I've got a new Genoa now though.....

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[ianwright]

Re: Oxalic acid

If the teak is grainy, and if the yard used a pressure washer it bloody well will be, the second thing you should do is to sand the teak smooth. The first thing is to sue the yard.
NEVER use a pressure washer or anything harsher than a sponge to clean teak. Not a stiff brush, not a soft brush, not, please not, a bronze bristle brush (Ideal for teak decks!) , not even a hose pipe jet. A sponge.
Once you have sanded the deck smooth (finish with 240 grit) then an oxalic acid treatment will help bleach out any imperfections. After that wash with sea water as often as you can.
Use the entire sea,,,,,,,,,,,,,,,,,

IanW

<hr width=100% size=1>Vertue 203, Patience

 

[robp]

Re: Oxalic acid

Thanks Ian. Yes, sanding is my next job. Reckon to lose about 0.5MM! Orbital OK?

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[tillergirl]

Re: Oxalic acid

Yes, I know your teak looks good - I'm sorry it's the thought of you scrubbing the deck with a load of onions that made me behave badly. The other postings about the high pressure washer and the need to sand are dead right. The advantage of oxalic acid made up yourself is that you can strengthen the mix a little and its a lot cheaper than the commercial teak cleaners so repeated applications aren't going to hurt financially.

Interesting about the warranty - I thought it was illegal in the EU to restrict competition in this way.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by tillergirl on 18/03/2003 18:27 (server time).</FONT></P>

 

[robp]

Re: Only for everyone else but the French! nm

~

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[ianwright]

Re: Oxalic acid

Yes a RO is fine as far as it will reach, in any case fininsh the job with a hand sanding (240) with the grain. A pain I know, but worth it.

IanW.

<hr width=100% size=1>Vertue 203, Patience

 

[robp]

Re: Oxalic acid

Thanks for your advice.
Rob

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[billmacfarlane]

I#ve just finished my teak and it doesn't look at all bad though I didn't have any heavy staining or blotching. The stuff I used was called Semco. The teak cleaner is very effective and contains caustic soda and works VERY well. I'm not sure what's in the brightener. Have a look at Out Of The Blue. Catch me with your new jenny ??? In your dreams matey !!!!

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[Barry777]

Rob

I've got some of this stuff too - it's very good. Demonstration possible. I'm on J52

Barry

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[pvb]

There is another way...

Agree that some sanding to minimise surface imperfections is a priority. But, after that, there's a much easier way of caring for teak decks. It will keep the green stuff at bay, and it involves almost no work. Hallberg-Rassy recommend a product called Boracol, which is generally sold as a timber preservative. It’s highly effective in killing green algae, mould spores and termites. Unfortunately, in the UK it’s only licensed for professional use. However, the two active ingredients - disodium octaborate (a fungicide) and benzalkonium chloride (an algaecide) - are available in various amateur products. Easiest to find and use is Polycell 3-in-1 Mould Killer (about £5 a litre from bigger B&Q stores). It’s a colourless liquid. I’ve used it for a couple of years now, and I’m very pleased with the results. In comparison with neighbouring boats, my deck looks pristine.

To apply it, first clean the deck thoroughly and allow at least 24 hours to dry. Choose a day when rain isn’t expected for 24 hours and apply the liquid liberally with a soft paintbrush. I use about 2 litres on my 35-footer. You should wear protective gloves and safety glasses. Wash splashes off skin immediately. Reapply every 4-5 months.

I use the same liquid on the inside and outside of my canvas sprayhood, again with good results.

Most mould and mildew products are basically bleach. This Polycell product contains no bleach, but has the powerful fungicidal ingredients which get rid of the mould. It also has a medium-term residual effect, so a treatment every 4-6 months should keep your deck and sprayhood looking good.


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[robp]

Re: There is another way...

Crumbs, I had to do a double take at the year on this one! Thanks though for this pvb, it's interesting. Presumably you have to hose it off after it's done it's magic?

Rob

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[pvb]

No, don\'t hose it off...

You don't hose the Polycell 3-in-1 off, just leave it to dry. It really is quick and easy. Trouble is, it's such a simple solution, most people can't believe it would work, so they spend hours rubbing away with oxalic acid, etc.

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[robp]

Re: No, don\'t hose it off...

Even better! I'll try it.

Thanks
Rob

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